WO2012088318A1 - Blends of polynorbornenyl polymers comprising hole transporting side groups and polynorbornenyl polymers comprising electron transporting side groups, as host materials for oleds - Google Patents

Abstract

The various inventions and/or their embodiments disclosed herein relate to the inventions described herein relate to compositions comprising a blend of a. at least one first norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted arylamine hole transporting side group, and b. at least one additional norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group. The blend compositions are useful as host materials for luminescent guests, which are capable of carrying holes, electrons, and excitons into contact with the luminescent guests, for making the emissive layers of electronic devices such as organic light emitting diodes (OLEDs).

Description

Blends of Polynorbomenyl Polymers Comprising Hole Transporting Side Groups and Polynorbomenyl Polymers Comprising Electron Transporting Side Groups, As

Host Materials for OLEDs

STATEMENT OF GOVERNMENT LICENSE RIGHTS

[0001] The inventors received partial funding support through the STC Program of the National Science Foundation under Agreement Number DMR- 020967 and the Office of Naval Research through a MURI program, Contract Award Number 68A- 1060806. The U.S. Government has certain rights in the invention.

TECHNICAL FIELD OF THE INVENTION

[0002] The inventions disclosed and described herein relate to compositions comprising blends of two or more polynorbomenyl polymers, wherein at least one of the polynorbomenyl polymers comprises side chain links to hole transporting groups, and at least one of the polynorbomenyl polymers comprises side chain links to electron transporting groups. The polymer blend compositions are useful as hole and/or electron transporting hosts for luminescent guest emitters, for use in the emission layers of organic light emitting diodes "OLEDs."

BACKGROUND OF THE INVENTION

[0003] Considerable research has been directed toward the synthesis of organic light-emitting diodes (OLEDs), in view their potential applications in full- color flat panel displays and solid state lighting. Such OLEDs often contain a light emissive layer comprising a luminescent material as a guest, dispersed and/or dissolved in a mixture of host/carrier materials capable of transporting holes, electrons, and/or excitons into contact with the luminescent guest. The luminescent guest is excited by the electrons, holes, and/or excitons formed on the host, and then emits light. The light emissive layer is typically disposed between an anode and cathode.

[0004] Single layer OLED devices are known, but typically exhibit very low efficiencies and lifetimes, for a variety of reasons. Efficiency has been dramatically improved in some cases by employing additional layers of materials in the OLED

4840-6681-1406.1 devices, such as an additional layer comprising a material whose properties are optimized for transporting holes into contact with the emission layer, and/or an additional electron transport layer comprising a material whose properties are optimized for carrying electrons into contact with the emission layer. Upon application of voltage/current across the OLED devices, holes and electrons are transported through the intermediate layers and into the emissive layer, where they combine to form excitons in the host material, and/or stimulate the formation of excited states of the luminescent guest material.

[0005] High-performance phosphorescent OLEDs with good short term luminescence and efficiency have been reported, at least for green and red/orange emitters, see further discussions below However most of the best prior art devices employ small molecule components that are fabricated by expensive multilayer vacuum thermal evaporation processes. For example, materials comprising small molecule carbazoles have been utilized as hole transporting and/or electron blocking materials in OLED applications, and as hosts for guest emitters in OLED emissive layers. Examples of known small molecule carbazole-based hole-transporting materials are shown below. Solution processable polymeric carbazoles such as polyvinylcarbazole ("PVK") are also known for use as the hole transporting layers,

[0006] A recent article by Duan et al (J.Mater. Chem. 2010, 20, 6392-6407) reviewed the status of "Solution Processable Small Molecules for Organic Light Emitting Diodes, hereby incorporated by reference herein, described a number of the

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4840-6681-1406.1 characteristics and structures of known hole transporing small molecules, as shown below;

[0007] Duan et al described major advances in the area of OLEDs based on solution processable small molecules, but concluded that "There is a long way to go for solution processed OLEDs based on small molecules to fully demonstrate their potentials for ubiquitous and low cost displays and lightings." However Duan et al also noted that the state of the art is even more difficult for solution processed

4840-6681-1406.1 polymers, which typically have difficulty self ordering in the solid state as easily as small molecules do.

[0008] Polynorbornenyl polymers and copolymers having linked side chains comprising carbazole groups have been reported, see for example Zaami et al, Macromol. Chem. Phys. 2004, 205, 523-529, and Liaw et al, (Journal of Polymer Science: Part A: Polymer Chemistry, Vol. 45, 3022-3031 (2007), and US Patent Publication 2005/0182220. Use of such carbazole-linked polymers in OLED applications gives significant potential to employ low cost solution and/or ink-jet printing processes for making the OLEDs, which can be very important for potential large area and/or low cost applications, but the fabrication of efficient multi-layer OLED devices wherein all the layers are deposited by solution processes still suffer serious limitations and remain a big challenge.

[0009] Recently, WO 2009/026235 and WO 2009/080799, hereby incorporated by reference herein, reported norbornenyl homopolymers, copolymers, and corresponding norbornene monomers comprising one, two or three linked carbazole groups. Norbornenyl homopolymers comprising tris carbazole groups, such as CZ-I-25 whose structure is shown below, were used in the hole-transporting layers in OLEDs to give external quantum efficiencies as high as about 18.5%. CZ- I-25 was also used as a host (for green emitters) in OLED emissive layers to give external quantum efficiencies as hi h as about 5-6%.

[00010] Correspondingly, small-molecule oxadiazoles (PBD and OXD-7), triazoles (TAZ), benzimidazoles (TPBI), and pyridines such as those shown below are well known materials for use in making electron transporting layers for OLED devices

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4840-6681-1406.1

B3PyPB

[0001 1 ] Furthermore, solution processable polymeric or copolymeric norbornenyl- linked oxadiazoles have also been reported for use as both electron transporting materials and as host materials for guest emitters in OLEDs. See for example WO 2009/080797, hereby incorporated herein by reference. When polynorbornenyl-oxadiazoles such as YZ-I-293 (structure show below) were blended with the vinylic carbazole polymer PVK, and used as a host for small molecule green emitters, moderately bright devices showing external quantum efficiencies in the

4840-6681-1406.1 [00012] Recently, some of the Applicants filed PCT Patent Application PCT/EP2010/058728, hereby incorporated by reference herein, which disclosed certain ambipolar polymers and copolymers that comprised both oxadiazole and carbazole groups, and described their uses in OLED emissive layers. One such class of ambipolar homopolymers had monomer subunits that comprised both oxadiazole and carbazole subunits, whose structure is shown below;

wherein at least one of the R¹, R² and R^J groups comprise an optionally substituted carbazole group having the structure

[00013] PCT Patent Application PCT/EP2010/058728 also disclosed a different class of ambipolar norbomenyl copolymers that have at least some subunits having each of the structures shown below:

wherein

4840-6681-1406.1 a. L¹ and L² are independently selected Ci-C₂₀ organic linking groups, b. R^c comprises at least one carbazole group, and

c. R^ox comprises at least one 2-phenyl-5-phenyl- 1 ,3,4-oxadiazole group.

[00014] Yang, Meerholz et al (Adv. Mater. 2006, 18, 948-954) disclosed that an OLED employing an emissive layer comprising a blend of the polymeric carbazole PVK with the PBD small molecule oxadiazole and Ir(mppy)3 guest emitter gave current efficiencies up to 67 cd/A and EQE of 18.8% at 100 cd/m², and 56 cd/A and EQE of 15.7% at 1000 cd/m².

[00015] Very recently, in a June 2010 public presentation at a LOPE- C meeting in Frankfurt (but without providing significant details), ruger et al reported an OLED with an emissive layer that used a blend of vinylic homopolymers comprising carbazole hole carriers and benzimidazole electron carriers (structures shown below), which yielded green OLEDs with current efficiencies up to about 40 cd/A, and luminance up to about 10,000 cd/m².

[00016] Nevertheless, devices based on mixtures of hole carrying and electron carrying materials in their emission layers, whether based on mixtures of small molecules, and/or polymers may undergo phase separations, undesirable partial crystallizations, and/or otherwise degrade upon extended OLED device heating, decreasing OLED device efficiency and/or lifetimes over time.

[00017] Accordingly, there remains a need in the art for improved host materials that can very efficiently function as guest materials that transport holes, electrons, and/or excitons into contact with phosphorescent guests in emission layers, without undergoing undesirable phase separations, crystallization, or thermal or chemical degradation that can cause OLED performance to decline rapidly.

[00018] It is to that end that the various embodiments of the inventions described herein relate, in that the various embodiments of the blend

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4840-6681-1406.1 compositions comprising blends of norbornenyl polymers comprising hole transporting side groups, and norbornenyl polymers comprising electron transporting side groups described and claimed herein can serve as hosts materials in OLEDs that provide performance that is among the best yet known, and is unexpectedly superior to the results known for comparable solution processable materials. Moreover Applicants methods and unique polynorbornenyl materials provide a unique and ready method for stabilizing the polymer blends against undesirable phase separations.

SUMMARY OF THE INVENTION

[00019] The various inventions and/or their embodiments disclosed herein relate to polymer blend compositions comprising a blend of

a) at least one first norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted arylamine hole transporting side group, and

b) at least one additional norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group.

[00020] As will be further elaborated below, the optionally substituted arylamine hole transporting side groups include for example monocarbazole, biscarbazole, triscarbazole or triarylamine side groups. The optionally substituted electron transporting side groups include for example oxadiazole, phenyl-pyridine, triazole or benzimidazole side groups.

[00021 ] These polymer blend compositions are useful for making organic electronic devices, and are particularly useful as hole and/or electron transporting hosts for luminescent guest emitters, wherein the resulting compositions are typically useful for making the emission layers of organic light emitting diodes, "OLEDs."

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4840-6681-1406.1 [00022] Further detailed description of preferred embodiments of the various monomer precursors, polymers, polymer blends, compositions, and OLED devices will be provided in the Detailed Description section below.

BRIEF DESCRIPTION OF THE FIGURES

[00023] Figure 1 shows absorption and fluorescent emission spectra of the polynorbornenyl-oxadiazole homopolymer XH-I-98a, see Example 3.

[00024] Figure 2 shows absorption and fluorescent emission spectra of the polynorbornenyl-triscarbazole homopolymer XH-I-98b, see Example 4.

[00025] Figure 3 shows absorption and fluorescent emission spectra of the random copolymer XH-I-41 comprising 1 : 1 bis oxadiazole/triscarbazole groups, see Example 5.

[00026] Figure 4 shows absorption and fluorescent emission spectra of the random copolymer XH-I-53c comprising 3:2 bis oxadiazole/triscarbazole groups, see Example 6.

[00027] Figure 5 shows absorption and fluorescent emission spectra of the diblock copolymer XH-I-68a comprising 1 : 1 bis oxadiazole/triscarbazole groups, see Example 7.

[00028] Figure 6 shows solution absorption and fluorescent emission spectra in CH2CI2 of a 1 : 1 blend of the polynorbornenyl-bisoxadiazole homopolymer XH-I-98a with the polynorbornenyl-triscarbazole homopolymer XH- I-98b, see Example 8.

[00029] Figure 7a a schematic device configuration for an OLED device described in Example 9, which employs a 1 : 1 blend of the homopolymer XH- I-98a with the homopolymer XH-I-98b, and 6% Ir(ppy)3 in its emissive layer. Figure 7b shows the current density versus voltage characteristics of the OLED, and Figure 7c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00030] Figure 8a a schematic device configuration for an OLED device described in Example 10, which employs a 1 : 1 blend of the homopolymer

XH-I-98a with the homopolymer XH-I-98b, and 12% Ir(ppy)3 in its emissive layer.

Figure 8b shows the current density versus voltage characteristics of the OLED, and

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4840-6681-1406.1 Figure 8c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00031 ] Figure 9a a schematic device configuration for an OLED device described in Example 1 1 , which employs a 1.5: 1 blend of the homopolymer XH-I-98a with the homopolymer XH-I-98b and 6% Ir(ppy>3 in its emissive layer. Figure 9b shows the current density versus voltage characteristics of the OLED, and Figure 9c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00032] Figure 10a a schematic device configuration for an OLED device described in Example 12, which employs a 1 : 1.5 blend of the homopolymer XH-I-98a with the homopolymer XH-I-98b and 6% Ir(pppy)3 in its emissive layer. Figure 10b shows the current density versus voltage characteristics of the OLED, and Figure 10c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00033] Figure 11a a schematic device configuration for an OLED device described in Example 13, which employs a 1 : 1.5 blend of the homopolymer XH-I-98a with the homopolymer XH-I-98b and 6% FIrpic in its emissive layer. Figure lib shows the current density versus voltage characteristics of the OLED, and Figure 11c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00034] Figure 12a a schematic device configuration for an OLED device described in Example 14, which employs a 1 : 1.5 blend of the homopolymer XH-I-98a with the homopolymer XH-I-98b and 12% FIrpic in its emissive layer. Figure 12b shows the current density versus voltage characteristics of the OLED, and Figure 12c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00035] Figure 13a a schematic device configuration for an OLED device described in Comparative Example 15, which employs a random norbornenyl copolymer XH-I-41 comprising 1 : 1 bisoxadiazole and triscarbazole side chains in its emissive layer. Figure 13b shows the current density versus voltage characteristics of the OLED, and Figure 13c shows the luminescence and external quantum efficiency of the OLED versus voltage.

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4840-6681-1406.1 [00036] Figure 14a a schematic device configuration for an OLED device described in Comparative Example 16, which employs a random norbornenyl copolymer XH-I-53c comprising 3:2 bisoxadiazole and triscarbazole side chains in its emissive layer. Figure 14b shows the current density versus voltage characteristics of the OLED, and Figure 14c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00037] Figure 15a a schematic device configuration for an OLED device described in Comparative Example 17, which employs a diblock norbornenyl copolymer XH-I-68a comprising 1 : 1 bisoxadiazole and triscarbazole side chains in its emissive layer. Figure 15b shows the current density versus voltage characteristics of the OLED, and Figure 15c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00038] Figure 16a a schematic device configuration for an OLED device described in Comparative Example 18, which employs a random styrenyl copolymer YZ-IV-25 comprising 1 : 1 bisoxadiazole and triscarbazole side chains in its emissive layer. Figure 16b shows the current density versus voltage characteristics of the OLED, and Figure 16c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00039] Figure 17a a schematic device configuration for an OLED device described in Comparative Example 19, which employs an ambipolar styrenyl homopolymer YZ-iV- 13 comprising both oxadiazole and carbazole groups in its emissive layer. Figure 17b shows the current density versus voltage characteristics of the OLED, and Figure 17c shows the luminescence and external quantum efficiency of the OLED versus voltage.

[00040] Figure 18a a schematic device configuration for an OLED device described in Comparative Example 20, which employs an ambipolar styrenyl homopolymer YZ-IV-21 comprising one oxadiazole and two carbazole groups in its emissive layer. Figure 18b shows the current density versus voltage characteristics of the OLED, and Figure 18c shows the luminescence and external quantum efficiency of the OLED versus voltage.

DETAILED DESCRIPTION OF THE INVENTION

1 1

-1406.1 [00041 ] The various inventions and/or their embodiments disclosed herein relate to and include norbomenyl polymers, copolymers, polymer blends, and blend compositions that are useful as host materials for luminescent guests, which are capable of carrying holes, electrons, and excitons into contact with the luminescent guests, for making the emissive layers of electronic devices such as organic light emitting diodes (OLEDs).

The Norbomenyl Monomers and Polymers

[00042] The inventions described and claimed herein relate to polymer blend compositions comprising at least two different types of polymers or copolymers,

a) at least one first norbomenyl polymer or copolymer comprising one or more norbomenyl subunits in the polymer backbone linked to at least one optionally substituted arylamine hole transporting side group, and

b) at least one additional norbomenyl polymer or copolymer comprising one or more norbomenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group.

[00043] In many embodiments of the invention, the first norbornenyl- polymer or copolymer is a homopolymer consisting essentially of norbomenyl subunits in the polymer backbone, wherein each norbomenyl subunit is linked to at least one optionally substituted arylamine hole transporting side group.

[00044] Similarly, in many embodiments of the invention, the additional norbomenyl polymer or copolymer is a homopolymer consisting essentially of norbomenyl subunits in the polymer backbone wherein each norbomenyl subunit is linked to at least one optionally substituted electron transporting side group. Such homopolymers can be conceptually envisioned as having the generic structures shown below.

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4840-6681-1406.1 (Norbomenyl Subunit)- (Norbomenyl Subunit)_n

Linking Group Linking Group

One or More Hole Transporting Groups One or More Electron Transporting Groups

[00045] In some preferred embodiments of the polymer blend compositions of the invention,

a. the first norbomenyl polymer or copolymer is a homopolymer

comprising norbomenyl subunits in the polymer backbone linked to at least one optionally substituted mbnocarbazole, biscarbazole, or triscarbazole side group, and

b. the additional norbomenyl polymer or copolymer is a homopolymer comprising norbomenyl subunits in the polymer backbone linked to at least one optionally substituted oxadiazole side group.

[00046] In many embodiments, the at least one first norbomenyl polymer or copolymer of the blend compositions typically comprises one or more, or at least a plurality of norbomenyl subunits in the polymer backbone having the structure

wherein

a) L¹ is the organic linking group, and

b) R^c comprises at least one optionally substituted arylamine hole

transporting side group.

[00047] In many embodiments, the at least one additional norbomenyl polymer or copolymer of the blend compositions typically comprises one or more, or at least a plurality of norbomenyl subunits in the polymer backbone having the structure

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4840-6681-1406.1

wherein

a) L² is an organic linking group, and

b) R^ox comprises at least one optionally substituted electron transporting side group.

[00048] The nature of the linking groups will now be further described below.

[00049] The organic linking groups, including L¹ and L², are typically independently selected normal, branched, or cyclic divalent organic groups that can be selected from organic groups that are thermally, chemically, and electrochemically stable under the conditions of operation of organic electronic devices such as OLEDs, and include for example but not limited to alkylenes, cycloalkyls, ethers, carboxylate esters, arylenes, arylene oxides, heteroarylenes, hetereroarylene oxides, and the like, and combinations thereof.

[00050] In many embodiments, the organic linking groups, including L¹ and/or L², comprise from C1-C20 carbon atoms, or C1-C12 carbon atoms, or Q-C6 carbon atoms. The organic linking groups can be optionally substituted with substituent groups such as but not limited to one or more fluorides, alkyl groups ether groups, aryls, heteroaryls, and the like.

[00051 ] In many embodiments, the L¹ and/or L² organic linking groups can be independently selected from the structures

^-0-(CH₂)_z-^ or \— (CH₂)₂— O— | wherein z and z' are independently selected integers 0, 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or 12. [00052] The optionally substituted arylamine hole transporting side groups such as the R° groups recited above, as noted by Duan et al,"should have electron donating moieties to form stable radical cations," so as to be able to transport holes (formed by removal of an electron to leave behind a reasonably stable radical cation). Duan et al noted that "molecules with phenylamine groups have gained much research attention due to their high hole drift mobilities..." Applicants concur with that accessment, but view such groups somewhat more broadly, as including one or more arylamine hole transporting side groups having the general structure of a tertiary amine shown below; wherein at least R_a, and possibly Rb and Rc as well are optionally substitute aryl or heteroaryl groups, and R_a, Rb and Rc may or may not be joined together to form cyclic structures. Rb and Rc are not hydrogen, and can be many organic groups, including alkyls of various forms, so the arylamine hole transporting side groups having the general structure of a tertiary organic amine group.

[00053] The arylamine hole transporting side groups may be optionally substituted with one or more halides, cyano groups, alkyls, alkoxides, aryls, heteroaryls, and the like.

[00054] In many embodiments the arylamine hole transporting side groups and all the optional substituents comprise from C1-C30 carbon atoms, or C|- C20 carbon atoms, or C|-C|₂ carbon atoms.

[00055] The optionally substituted arylamine hole transporting side groups, including the Rc groups, include for example monocarbazole, biscarbazole, triscarbazole or triarylamine side groups, or groups combining one or more such groups, and/or other aryl or heteroaryl groups conjugated thereto, any of which can be attached to the linking groups anywhere in their structures.

[00056] Exemplary monocarbazole groups can have structures including the following non-inclusive examples;

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4840-6681-1406.1

wherein R¹ and R can be independently selected from a linear or branched C|-Cn alkyl group or H, and R³ can be a linear or branched C1-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H. It is worth noting that the structure on the right above could also be considered a triarylamine group.

[00057] Monocarbazoles can also have structures such as the following:

wherein R^land R² can be independently selected from a linear or branched C1 -C12 alkyl group or H, and R³ can be a linear or branched Q-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H. It is worth noting that this structure could also be considered to comprise a triarylamine, or a pyridine group.

[00058] Typical biscarbazole groups can have structures including the following non-inclusive examples;

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4840-6681-1406.1

wherein R^l, R², R⁴, R⁵, R⁶, R⁷ can be independently selected from a linear or branched C1-C12 alkyl group or H, and R³ can be a linear or branched C1-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H. It is worth noting that these compound above could also be considered to comprise triarylamine groups.

[00059] Biscarbazole groups can have structures that incorporate heterocycles such as pyridine groups, such as the following

wherein R'and R² can be independently selected from a linear or branched C1-C12 alkyl group or H, and R³ can be a linear or branched Q-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H. It is worth noting that this structure could also be considered to comprise a triarylamine, or a pyridine group.

[00060] Typical triscarbazole groups can have structures including the following non-inclusive examples;

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4840-6681-1406.1

wherein R¹, R², R⁴ and R⁵ is a linear or branched C1 -C12 alkyl group or H.

[00061 ] Typical triarylamine groups can have structures including the following non

wherein R¹, R², R⁴and R⁵ can be a linear or branched C1-C12 alkyl group or H.

[00062] As already noted, the polymer blend compositions described and claimed herein also comprise at least one additional norbomenyl polymer or copolymer comprising one or more norbomenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group. As noted by Duan et al, "electron transporting materials should have electron accepting moieties to form stable radical anions." Duan et al noted that many of the known electron transporting small molecules suitable for use in OLEDs comprised oxadizole derivatives, pyridine derivatives such as phenanthrolines, triazole derivatives, imidazole, and benzimidazole derivatives, or combinations thereof.

[00063] Accordingly, in many embodiments of the inventions described and claimed herein, the optionally substituted electron transporting side groups include for example, but are not limited to oxadiazole derivatives, pyridine derivatives such as phenanthrolines, triazole derivatives, imidazole and

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4840-6681-1406.1 benzimidazole derivatives, or combinations thereof, as side groups, such as for example the R^ox groups initially described above.

[00064] Suitable oxadiazole derivatives for use as optionally substituted electron transporting side groups or R^ox groups include 5-phenyl- 1 ,3,4- oxadiazole groups or 2,5-diphenyl-l ,3,4-oxadiazole groups, as shown below:

wherein each optional R and R^c group can be an independently selected from hydrogen, fluoride, one or more linear or branched C|.₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

[00065] Similar "bridged" oxadiazole derivatives suitable at R° include

wherein each optional R^b and R^c group can be an independently selected from hydrogen, fluoride, one or more linear or branched Ci.₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

[00066] Very similar triazole derivatives can be formed by replacement of the oxygen atom of the oxadiazole rings with an optionally substitu

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4840-6681-1406.1 wherein the R^c group can independently selected from hydrogen, fluoride, one or more linear or branched Ci_-2o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and the other Ra, Rb, and x values cap be as previously described above.

[00067] Accordingly, in many embodiments of the polymer blends, the additional norbornenyl polymer or copolymer comprises a plurality of oxadiazolyl or triazole subunits having the structure

wherein

a. L² is an organic linking group, and

b. R^ox comprises at least one optionally substituted oxadiazole or

triazole derivative comprising the structure.

wherein Z is:

and Y is a C6-C20 aryl or heteroaryl group, and each optional R^a, R and R^c group is independently selected from hydrogen, fluoride, one or more linear or branched C1.20

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4840-6681-1406.1 alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

[00068] Similarly, in many embodiments of the polymer blends, the additional norbornenyl polymer or copolymer comprises subunits wherein the R^o group can be an optionally substituted benzimidazole group comprising the structure

wherein each optional R^a, R^b, and R^c group is independently selected from hydrogen, fluoride, one or more linear or branched C|.₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

[00069] The R^ox groups can also comprise optionally substituted dimeric or trimeric benzimidazole groups, such as for example the following:

wherein each optional R^a and R group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_-20 alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

[00070] Suitable optionally substituted electron transporting side groups and/or R^ox groups can also include optionally substituted pyridine derivatives. In many embodiments, such optionally substituted pyridine groups can

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4840-6681-1406.1 have other aryl or heteroaryl rings fused thereto, such as for example phenanthroline groups having the structures shown below;

wherein each optional R^a or R^b, group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_-2o alkyl, fluoroalkyl, alkoxy,

fluoroalkoxy, aryl, or heteroaryl groups, and each x is an independently selected integer 0, 1 , or 2.

[00071 ] Other pyridine derivatives that are known to be capable of serving as electron transporting materials include quinoline derivatives that can inclu

2-phenylquinolines 2-phenylpyrido[3,2-flquinoxalines

Preparation of the Necessary Monomers, Polymers, and Copolymers

[00072] A variety of norbornenyl monomers linked to arylamine hole transporting side groups such as triarylamines and carbazoles, and norbornenyl monomers linked to electron transporting side groups such oxadiazole, pyridine, triazole, or benzimidazole side groups are known in the art, and many of them could readily be made and used by one of ordinary skill to make polymers or copolymers that are useful as hole-carrying materials, and can be used for making polymer

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4840-6681-1406.1 blends or compositions within the scope of the inventions disclosed and claimed herein.

[00073] For example, WO 2009/026235 and WO 2009/080799, hereby incorporated by reference herein for their synthetic teachings regarding relevant norbornenyl monomers and homopolymers, copolymers, and corresponding norbornene monomers comprising one, two or three linked carbazoles, describes a variety of suitable norbornenyl-carbazolyl monomers and homopolymers. Example 1 hereinbelow provides a specific example of the synthesis of a novel norbornenyl- triscarbazolyl monomer (structure shown below), which is useful for synthesizing a corresponding norbornenyl-triscarbazolyl homopolymer (XH-I-98b, polymerization described in Example 4) that is useful for making and illustrating non-limiting exam les of the polymer blends disclosed and claimed herein.

XH-l-98b

[00074] Alternatively, norbornenyl monomers linked to two types of hole carrying biscarbazole groups can be made by the reaction sequences shown below;

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-1406.1

[00075] Either of the above monomers can be homopolymerized or copolymerized by one of ordinary skill in the art using the typical ROMP polymerization methods described herein.

[00076] Similarly, numerous norbornenyl-linked oxadiazolyl monomers and corresponding polymers are known in the art as electron-transporting materials, and could be used by one of ordinary skill in the art for making the polymer blends of the invention. For example, WO 2009/080797, hereby

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4840-6681-1406.1 incorporated by reference herein for its synthetic teachings regarding relevant norbornenyl monomers and polymers, reported norbornenyl homopolymers, copolymers, and corresponding norbornene monomers comprising two linked oxadiazole groups, discloses a variety of suitable norbomenyl-oxadiazolyl monomers and homopolymers. Example 2 hereinbelow provides a specific example of the synthesis of a norbomenyl-oxadiazolyl monomer (structure shown below) useful for synthesizing a corresponding norbomenyl-oxadiazolyl homopolymer g non-

[00077] Many similar norbornenyl monomers comprising arylamine hole carrying groups can readily be made by those of ordinary skill in the art by similar well known methods. For example, a variety of norbornenyl monomers linked to hole transporting triaryl amine side groups could be made via the method illustrated below, or by obvious sequences of well known organic reactions:

25

4840-6681-1406.1

[00078] Similarly, : a variety of norbornenyl monomers linked to electron transporting benzimidazole side groups can be made via the method illustrated below, or by obvious alternative sequences of organic reactions well k

[00079] Similarly, a norbornenyl monomer linked to trimeric electron transporting side groups comprising both triarylamine and carbazole groups, such as that shown below can be made via the method illustrated below, or by obvious alternative sequences of organic reactions well known to those of ordinary skill in the art:

26

4840-6681-1406.1

[00080] Similarly, a variety of norbomenyl monomers linked to electron transporting triazole side groups could be made via the method illustrated below, or by obvious sequences of well known organic reactions:

[00081 ] Additionally, various methods could be employed to bond phenanthrohne side groups to norbomenyl monomers, such as the following;

27

4840-6681-1406.1

[00082] Homopolymers derived from any of the above-described norbornenyl monomers can be readily made by ring opening methathesis polymerizations (ROMP) that are well known in the art, which are typically catalyzed by metal complex catalysts well known in the art, including the various "Grubbs" catalysts mentioned below. Random norbornenyl copolymers can also be made by polymerizing mixtures of such norbornenyl monomers (see Examples 5 and 6 below). However, one paricularly attractive feature of norbornenyl polymer chemistry (as compared to largely used free-radical polymerized vinyl monomers such as acrylates, styrenes) is that ROMP polymerizations can be conducted in a highly controlled way employing "living" catalysts such as the Grubbs family of catalysts. Such "living" chain-growth polymerizations enable unique control over molecular structure and composition, chain-length and end groups. More particularly, it is possible to prepare well-defined di-, tri- and multiblock copolymers, as well as gradient compositional copolymers. See for example, Furstner, A. Angew. Chem., Int. Ed. 2000, 39, 3013; T. M. Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res. 2001 , 34, 18; each of which is respectively incorporated herein by reference for their teachings regarding methods and catalysts for ROMP polymerizations.

[00083] Example 7 and the drawing below illustrates the synthesis of such a norbornenyl diblock copolymer, XH-I-68a, via sequential ROMP polymerization of one of the norbornenyl monomers shown above, followed by addition of the second norbornenyl monomer shown above.

28

4840-6681-1406.1

[00084] As further described below, such norbornenyl diblock copolymers can be used as "phase compatibilizers" to prevent, modify / control, and stabilize the norbornenyl polymer blend compositions of the invention against undesirable phase separations.

Polymer Blend Compositions Comprising Blends of Norbornenyl-Hole Transporting and Norbornenyl-Electron Transporting Homopolymers

[00085] In many aspects, the inventions described herein relate to a composition comprising a blend of

a. at least one first norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted arylamine hole transporting side group, and

b. at least one additional norbornenyl polymer or copolymer comprising_i one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group.

[00086] The linking groups, optionally substituted arylamine hole transporting side groups, and/or optionally substituted electron transporting side groups (of the first norbornenyl polymer or copolymer or additional norbornenyl polymer or copolymer) can be any of the groups and/or combinations thereof described above.

[00087] The blend compositions comprise at least two components, including at least one first norbornenyl hole transporting polymer or copolymer and

29

4840-6681-1406.1 at least one additional norbornenyl electron transporting polymer or copolymer as described above, but may and often do comprise other components. The blend compositions may be physical blends of the separate components, or blends of the materials in liquid solution dissolved or suspended in an optional solvent, or be in the form of solid phase mixtures or solid solutions (preferably amorphous solid phases or solid solutions). Alternatively, solid phases formed from such polymer or copolymer blends may be partially phase separated or partially crystallized, but the two or more component materials or phases are preferably still in intimate contact on the nanometer and/or micrometer scales.

[00088] In many embodiments, the blend compositions are a single amorphous solid phase, preferably with a glass transition temperature of at least 120°C. In many other embodiments, the blend compositions comprise a mixture of at least two or more amorphous solid phases, preferably wherein each amorphous solid phase preferably has a glass temperature of at least 120°C.

[00089] In many embodiments, the blend compositions suitable for making OLED emissive layers comprise a luminescent guest emitter. Many such guest emitters are known to those of ordinary skill in the "OLED" art, and many of those known guest emitters can be used in the blend compositions described herein, and can be selected from non-polymeric small molecules, organic oligomers, and polymers or copolymers comprising emitter chromophores. In many embodiments the guest emitter is at least somewhat soluble in common organic solvents, so as to make for easy preparation and application of the blend compositions by solution processes. It is preferred that the guest emitter remains highly dispersed in the host polymer blend after deposition of the emission layer.

[00090] In many embodiments the guest emitter is a metal complex wherein the metal is Re, Ru, Os, Rh, Ir, Pd, Pt, Cu or Au. Metal complexes comprising 3d row transition elements such as Re, Os, Ir, Pt, or Au are often employed because they can accept energy from both singlet and triplet excitons from the host, and aid the conversion of the singlets to triplets, and then phosphoresce from their triplet states. Various complexes of Ir and Pt are particularly well known as highly efficient triplet guest emitters. Several such Ir complexes that are highly efficient emitters of green or blue light are described below..

30

4840-6681-1406.1 [000 1 ] The blend compositions of the invention can contain variable proportions of the first norbornenyl hole transporting polymer or copolymer as compared to the additional norbornenyl electron transporting polymer or copolymer. Applicants have unexpectedly discovered that, especially in the case of blends of the first norbornenyl hole transporting polymer and additional norbornenyl electron transporting polymer or copolymer, that the proportions of the polymers can be varied over a wide range enabling to tune, optimize and stabilize the efficiency of the resulting OLED devices. See for example Examples 10-12 and corresponding Figures 8-10 below. The tunability is further increased by the high control over the molecular weight within a wide range: The number average degree of polymerization can be varied from about 3 to about 300. It is not required to use high molecular weights; low/moderate degrees of polymerization, from about 3 to 50, more preferably from about 3 to 30, are advantageous, both for ease of solubility in common solvents and solid phase blend mixing.

[00092] While the specific effects of such variations in the ratios of the polymers in the blends will of course vary with the specific identity of the polymers, devices and other components of the devices, and without wishing to be bound by theories, it is believed that such variations in the ratios of the hole- transporting and electron transporting polymers or copolymers can help to beneficially optimize the balance of holes and electrons supplied to the luminescent emitters in the emission layers of the OLEDs during operation. Preferably the weight ratio of the hole-transporting and electron transporting polymers or copolymers can be varied from about 1 :5 to about 5: 1 , or from about 3: 1 to about 1 :3, or from about 2: 1 to about 1 :2, or from about 1.5: 1 to about 1 : 1.5.

[00093] As already noted above, in some embodiments the blend compositions are a single amorphous solid phase, while in other embodiments, the blend compositions comprise a mixture of at least two or more amorphous solid phases. The phase morphology of the blend compositions, especially when they are being employed to form emissive layers of OLED devices, can have an important effect on OLED performance, so it is highly desirable that the phase morphology of the blend compositions be controllable and stable.

31

-1406.1 [00094] In that regard, the norbomenyl polymers and copolymers utilized in the present inventions provide a unique and unexpected opportunity for potentially modifying or stabilizing the phase morphology of the blend compositions, because of the ease of making norbomenyl block copolymers that can serve as phase stabilizers.

[00095] Accordingly, in some embodiments of the blend compositions of the invention, the blend compositions may comprise a block norbomenyl copolymer comprising at least a first block comprising one or more polymerized norbomenyl subunits, in the block copolymer backbone, that are linked to side groups comprising at least one optionally substituted hole transporting group; and a second block comprising one or more polymerized norbomenyl subunits, in the block copolymer backbone, linked to side groups comprising at least one optionally substituted electron transporting group. In such embodiments, it can be preferable that the norbomenyl subunits of the first norbomenyl- polymer and the first block of the block copolymer are the same, and that the subunits of the additional norbomenyl polymer and the second block of the block copolymer are the same.

[00096] In many embodiments of the blend compositions that do comprise such block norbomenyl copolymers, the first block of the block norbomenyl copolymer comprises a plurality of, or consists essentially of, norbomenyl subunits having the structure

wherein

a) L¹ is an organic linking group,

b) R^c comprises any of the Rc groups discussed above with respect to the first norbomenyl hole transporting polymers or copolymers.

[00097] In many embodiments of the blend compositions that do comprise such block norbomenyl copolymers, the block norbomenyl copolymer also comprises a block that comprises a plurality of, or consists essentially of norbomenyl subunits having the structure

32

4840-6681-1406.1

wherein

a) L is an organic linking group, and

b) R^ox can be any of the R^o groups disclosed above in connection with the norbomenyl electron transporting polymers and copolymers.

[00098] In many embodiments, the block norbomenyl copolymers can be present at a concentration of from about 0.1 to about 20 wt% of the composition, or from about 0.1 to about 10 wt% of the composition.

[00099] While not wishing to be bound by theories, it is thought that the phase stabilization that can be achieved by adding such norbornyl block copolymers to the blend compositions of the inventions may result from the ability of the two different copolymer blocks, one having norbomenyl hole transporting subunits, and another block having norbomenyl electron transporting subunits, to be physically, chemically, and thermodynamically compatible with the similar norbomenyl hole transporting subunits, and norbomenyl electron transporting subunits in the primary polymers or copolymers of the blend, so that they compatibilize the two primary norbomenyl polymers or copolymers against phase separation, so that the overall polymer blend can be stabilized as a single phase.

[000100] Alternatively, in embodiments wherein the two or more primary norbomenyl copolymers do desirably undergo at least some degree of phase segregation, the block copolymers may self-orient themselves at the interfaces of the separate phases, so as to stabilize, or alter or "tune" the degree of phase separation. Accordingly, unique and unexpected advantages can derive from the use of norbomenyl polymers, copolymers, and block copolymers, which allow the easy preparation of highly compatible norbomenyl polymers, copolymers, and block copolymers.

OLEDs Comprising the Polymers and Copolymer Blends

33

4840-6681-1406.1 [000101 ] Some aspects of the present inventions relate to novel organic electronic devices, especially organic light emitting diodes (OLED) devices that comprise the various homopolymers and copolymers described herein as components of host blend compositions for making the emission layers of OLEDs. As further described below, many of the various compounds, homopolymers, copolymers are often readily soluble in common organic solvents or mixtures thereof and can be mixed with guest phosphorescent emitters, and the polymer blend solutions coated or wet-printed by various printing technologies onto appropriate substrates to form a smooth, defect-free emission layer of an OLED device.

[000102] In many embodiments, the OLED devices comprise an anode layer, a hole transporting layer, an emission layer, an electron transporting layer, and a cathode layer. Such devices are illustrated in the diagram below:

^■ Cathode Layer

Electron Transporting Layer

Emission Layer

Hole Transporting Layer

- Anode Layer

- Glass

OLED Device

[000103] Accordingly, in many embodiments of the OLED devices disclosed herein, the OLEDs comprise the following layers:

a. an anode layer,

b. a hole transporting layer,

c. an emissive layer,

d. an electron transporting layer, and

e. a cathode layer.

[000104] In many embodiments of the OLED devices disclosed herein, the emissive layer comprises at least some of the blend compositions, especially when the norbornenyl hole transporting and norbornenyl electron transporting components are homopolymers, to form unexpectedly good hosts for guest emitters.

34

4840-6681-1406.1 [000105] Indium tin oxide (ITO) is a well known example of a suitable transparent semiconducting material for making the anode layers, and is often applied by vacuum deposition in a layer over an inert and transparent substrate such as glass. Suitable ITO coated glass plates are available from Colorado Concept Coatings LLC, with a sheet resistivity of ~15 or 20 Ω/sq, which were used as the substrate for the OLEDs fabrications described herein. The ITO coated substrates were patterned with kapton tape and etched in acid vapor (1 :3 by volume, H 0₃: HC1) for 5 min at 60 °C. The substrates were cleaned in an ultrasonic bath of detergent water, rinsed with deionized water, and then cleaned in sequential ultrasonic baths of deionized water, acetone, and isopropanol. Each ultrasonic bath lasted for 20 minutes. Nitrogen was used to dry the substrates after each of the last three baths.

[000106] Many materials are potentially useful as hole transporting layers, including monomeric or polymeric carbazole compounds, such as for example polyvinyl carbazole (PVK, commercially available) which can be dissolved in a solvent such as toluene or chlorobenzene, and spun-coated onto the ITO substrates. PEDOT: PSS A14083, commercially available from Heraeus of Hanau Germany, is an aqueous dispersion of Poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), structure shown below. PEDOT: PSS is typically spin coated (60s(S⁾,1500 rpm, acceleration 10,000) onto ITO coated glass substrates, in a N₂ filled wet glove box, to form a hole-transporting layer with a thickness of about 40 nm. After spin-coating, a rectangular strip of the layer is removed at the edge of the substrate to expose ITO and ensure electrical contact to the anode; then the coated substrate is baked for 10 min at 140 °C on a hot plate. The PEDOT: PSS coated substrate is removed from the hot plate only until its temperature is down to 40 °C.

35

4840-6681-1406.1 PDOT: PSS

[000107] Poly-TPD-F (structure shown below, see Zhang, et al,.

Synthesis 2002, 1201 and Domercq, et al., Chem. Mater. 2003, 15, 1491 , both of which are incorporated herein by reference in their entirety) is especially useful as a hole transporting layer, because it is photo cross-linkable and can be used to produce photo-patterned hole transporting layers that are largely unaffected by solution processes for depositing the emissive layers comprising the norbornenyl polymer blend compositions.

Poly-TPD-F

[000108] For the Poly-TPD-F hole-transport layer, 10 mg of Poly-TPD- F was typically dissolved in 1 ml of chloroform (purity of 99.8%; which was distilled and degassed over night). 35 nm thick films are then spin coated (60s@1500 rpm, acceleration 10,000) onto the indium tin oxide (ITO) coated glass substrates, (pre-treated with an 0₂ plasma for 3 minutes prior to the deposition of the hole-transport material). Spin coating is carried out in a N₂ filled wet glove box. After spin-coating, a rectangular strip of the layer is removed at the edge of the substrate to expose ITO and ensure electrical contact to the anode; then, the sample is transferred to the wet glove box ante-chamber and subjected to vacuum for 15 minutes; then the sample is transferred back into the wet glove-box were it is baked for 15 min at 75 °C on a hot plate, after which the hot plate is turned off. The sample is removed from the hot plate only after its temperature is down to 40 °C. Finally the sample is exposed to 0.7 mW/cm² of UV illumination for 1 minute to crosslink the TPD-F hole-transport layer.

[000109] The polymer blends described and claimed herein are typically employed as host materials for forming the emissive layers of OLEDs, by dissolving the individual polymers or blends thereof in common organic solvents

36

4840-6681-1406.1 such as toluene, chlorobenzene, and the like, and likewise containing soluble polymeric or non-polymeric guest emitters, which are most typically complexes of Iridium, Platinum, and other 3d row transition metals, see for example US 2006/0127696, or WO 2009/026235, the teachings of both of which are hereby incorporated by reference herein . Well-known blue emitters commonly used as guest emitters in OLED devices include FIrpic (Y. Kawamura et al. Appl. Phys. Lett. 2005, 86, 071 104/1), FIr₆ (T. Sajoto et al. Inorg. Chem. 2005, 44, 7992-8003) and Ir(ppz)₃ (C. H. Yang et al. Angew. Chem. Int. Ed. 2007, 46, 2418-2421). Commonly used green emitters include Ir(ppy)3 (Y. Kawamura et al. Appl. Phys. Lett. 2005, 86, 071 104/1 ), lr(pppy)₃ (US 2006/127696), and Ir(mppy)₃ (H. Wu et al. Adv. Mater. 200

Ir(PPy)3, Ir(ppy)3 FIrpic

[0001 10] Many organic materials are suitable as electron transporting and/or hole blocking materials, such as a variety of substituted phenanthrolines, such as bathocuproine (BCP = 2,9-dimethyl-4,7-diphenyl- l , 10-phenanthroline) and BPhen (4,7-diphenyl-l , 10-phenanthroline), quinolates such as Alq3 and BAlq, imidazoles such as TPBI (2,2',2"-(l ,3,5-phenylene)tris(l -phenyl-l H- benzimidazole), or various phenyl-pyridyls, such as "B3PyPB" (3,5,3",5"-tetra-3- pyridyl-[l , l ';3',l "]terphenyl)„ which can be readily applied to the devices via vacuum/therma

37

4840-6681-1406.1

B3PyPB TPBI

[0001 1 1] Many materials can be suitable as cathode layers, one example being a combination of lithium fluoride (LiF) as an electron injecting material coated with a vacuum deposited layer of Aluminum.

Electroluminescent Properties of the PLED Devices

[0001 12] Examples 9, 10, 1 1 , and 12 below illustrate the unexpectedly good performance of OLEDs comprising the norbornenyl polymer blend compositions of the invention when used with green phosphorescent emitters, in terms of a combination of reasonable turn-on voltages, very good brightness, and excellent External Quantum Efficiencies (EQE) and luminous efficiencies. It is notable that efficiencies were clearly significantly dependent on the ratios of the norbornenyl-carbazolyl homopolymer and the norbornenyl-oxadiazolyl

homopolymer.

[0001 13] Examples 13 and 14 illustrate the suitability of the norbornenyl polymer blend compositions of the invention for use with blue emitters, such as Firpic, though a different hole transport material was used(PEDOT:PSS vs TPD-F in Examples 9-12), and luminous efficiencies were significantly lower in the blue OLEDs actually made and tested.

[0001 14] . Comparative device Examples 15-20 illustrate the significantly poorer results obtained from comparative tests of OLEDs comprising

38

4840-6681-1406.1 other structural types of polymers containing the same types of carbazole and oxadiazole groups.

[0001 15] Comparative Exampled 15 and 16 describe OLED devices employing an emissive layer comprising random norbornenyl copolymers (XH-I-41 or XH-I-53c) comprising norbornenyl-bisoxadizole subunits and norbornenyl- triscarbazole subunits, and the results of testing of that OLED. The EQEs obtained from the comparative devices are clearly significantly inferior to the OLED devices of the invention, see for example Example 12.

[0001 16] Comparative Example 17 describes an OLED device employing an emissive layer comprising a diblock norbornenyl copolymer (XH-I- 68a)comprising norbornenyl-bisoxadizole subunits and norbornenyl-triscarbazole subunits, and the results of testing of that OLED. The EQEs obtained from the comparative device are clearly significantly inferior to the OLED devices of the invention, see for example Example 12.

[0001 17] Comparative Example 18 describes an OLED device employing an emissive layer comprising a random styrenic copolymer (YZ-IV-25) comprising norbornenyl-bisoxadizole subunits and norbornenyl-triscarbazole subunits, and the results of testing of that OLED. The EQEs obtained from the comparative device are clearly significantly inferior to the OLED devices of the invention, see for example Example 12.

[0001 18] Comparative Examples 19 and 20 describe OLED devices employing an emissive layer comprising random styrenic hompoiymers comprising norbornenyl subunits in the polymer backbones that contained both oxadizole and carbazole groups within the same sidechains, and the results of testing of that OLED. The EQEs obtained from the comparative devices are clearly significantly inferior to the OLED devices of the invention, see for example Example 12.

[0001 19] The details of the complex physical interactions that combine to produce the results illustrated by the examples and comparative examples included herein are not yet well understood. Nevertheless, the OLED device Examples and Comparative Examples cited immediately above empirically support an assertion that the norbornenyl polymer blend compositions summarized above, described in detail below, and/or claimed herein can be utilized to prepare OLEDs

39

4840-6681-1406.1 with unexpectedly good electrical and emissive properties, as compared to the known prior art or obvious variations thereof.

EXAMPLES

[000120] The various inventions described above are further illustrated by the following specific examples, which are not intended to be construed in any way as imposing limitations upon the scope of the invention disclosures or claims attached herewith. On the contrary, it is to be clearly understood that resort may be had to various other embodiments, modifications, and equivalents thereof which, after reading the description herein, may suggest themselves to one of ordinary skill in the art without departing from the scope of the inventions described herein.

[000121 ] General - All experiments with air- and moisture-sensitive intermediates and compounds were carried out under an inert atmosphere using standard Schlenk techniques. NMR spectra were recorded on either a 400 MHz Varian Mercury spectrometer or a 400 MHz Bruker AMX 400 and referenced to residual proton, solvent. UV-vis absorption spectra were recorded on a Varian Cary 5E UV-vis-NIR spectrophotometer, while solution and thin-film PL spectra were recorded on a Fluorolog III ISA spectrofluorometer. Lifetime measurements were taken using a PTI model C-72 fluorescence laser spectrophotometer with a PTI GL- 3300 nitrogen laser. Cyclic voltammograms were obtained on a computer controlled BAS 100B electrochemical analyzer, and measurements were carried out under a nitrogen flow in deoxygenated DMF solutions of tetra-«-butylammonium hexafluorophosphate (0.1 M). Glassy carbon was used as the working electrode, a Pt wire as the counter electrode, and an Ag wire anodized with AgCl as the pseudo- reference electrode. Potentials were referenced to the ferrocenium/ferrocene (FeCp₂ ^{+ 0}) couple by using ferrocene as an internal standard. Gel-permeation chromatography (GPC) analyses were carried out using a Waters 1525 binary pump coupled to a Waters 2414 refractive index detector with methylene chloride as an eluent on American Polymer Standards 10 μιη particle size, linear mixed bed packing columns. The flow rate used for all measurements was 1 ml/min, and the GPCs were calibrated using poly(styrene) standards. Differential scanning calorimetry (DSC) data were collected using a Seiko model DSC 220C. Thermal

40

4840-6681-1406.1 gravimetric analysis (TGA) data were collected using a Seiko model TG/DTA 320. Inductively coupled plasma-mass spectrometry (ICP-MS) for platinum and ruthenium was provided by Bodycote Testing Group. Ή-NMR and ^{l 3}C-NMR spectra (300 MHz Ή NMR, 75 MHz ^l3C NMR) were obtained using a Varian Mercury Vx 300 spectrometer. All spectra are referenced to residual proton solvent. Abbreviations used include singlet (s), doublet (d), doublet of doublets (dd), triplet (t), triplet of doublets (td) and unresolved multiplet (m). Mass spectral analyses were provided by the Georgia Tech Mass Spectrometry Facility. The onset of thermal degradation for the polymers was measured by thermal gravimetric analysis (TGA) using a Shimadzu TGA-50. UV/vis absorption measurements were taken on a Shimadzu UV-2401 PC recording spectrophotometer. Emission measurements were acquired using a Shimadzu RF-5301 PC spectrofluorophotometer. Lifetime measurements were taken using a PTI model C-72 fluorescence laser spectrophotometer with a PTI GL-3300 nitrogen laser. Elemental analyses for C, H, and N were performed using Perkin Elmer Series II CHNS/O Analyzer 2400. Elemental analyses for iridium were provided by Galbraith Laboratories.

[000122] Unless otherwise noted, cited reagents and solvents were purchased from well-known commercial sources (such as Sigma-Aldrich of Milwaukee Wisconsin or Acros Organics of Geel Belgium, and were used as received without further purification.

[000123] Example 1 - Synthesis of 9'-f5-(qS,2R,4S)- bicvclo[2 lhept-5-en-2-vnpentyn-9Ή-9,3':6^9''-terc^^

41

4840-6681-1406.1 [000124] Triscarbazole (10.15 g, 20.4 mmol) and 2.5 equivalent of 5- (5-bromopentyl)-norbornene (10.0 mL, 50.3 mmol) were added into DMF (100 mL) under N₂. Then K₂C0₃ (13.99 g, 101.2 mmol) were added into the reaction mixture. The reaction was heated to 100 °C for 60 hours. The reaction mixture was then cooled to room temperature and water (50 mL) was added into the system to precipitate a yellow solid. The crude product was isolated by filtration and purified by recrystallization and silica gel column (CH₂C to give a white solid (12.1 g, 90 %). Ή NMR (400 MHz, CDCI3): δ 8.21 (s, br, 2H), 8.15 (d, J = 7.6 Hz, br, 4H), 7.65 (s, br, 4H), 7.38 (q, J= 8 Hz, 4H), 7.37 (s, br, 4H), 7.27 (dd, J_/ = 6.0 Hz, J₂ = 2.0 Hz, 2H), 7.25 (dd, J, = 6.0 Hz, J₂ = 2.0 Hz, 2H), 6.1 1 (dd, J, = 5.6 Hz, J₂ = 2.8 Hz, 1 H), 5.91 (dd, J, = 5.6 Hz, J₂ = 2.8 Hz, 1 H), 4.47 (t, J= 12 Hz, 2H), 2.75 (s, br, 2H), 2.06-1.94 (m, 3H), 1.85 (dd, J, = 1 1.2 Hz, J₂ = 4.0 Hz, 1 H), 1 .53-1 .06 (m, 8H), 0.49 (ddd, J_/ = 1 1.2 Hz, J₂ = 4.0 Hz, J₃ = 2.8 Hz, 1 H). ¹³C {H}NMR (100 MHz, CDC ): δ 142.06, 140.39, 137.29, 132.52, 129.51 , 126.16, 126.05, 123.59, 123.31 , 120.48, 120.04, 1 19.82, 1 10.32, 109.94, 49.82, 45.66, 43.91 , 42.74, 38.97, 34.94, 32.68, 29.40, 28.74, 27.89. Anal. Calcd. for C48H41N3: C, 87.37; H, 6.26; N, 6.37. Found: C, 87.28; H, 6.30; N, 6.37. HRMS (EI) [M⁺] calcd. for C₄8H4iN₃: 659.3300. found: 659.3285.

[000125] Methods for the synthesis of many similar polymerizable norbornenyl monomers linked to.carbazole groups, and norbornenyl homopolymers derived therefrom, were disclosed in WO 2009/080799, hereby incorporated herein by reference in its entirity.

[000126] Example 2 - Synthesis of Polymerizable Norbornenyl- Oxadiazole Monomer; 2-(3-((5-(bicvclo[2.2.11hept-5-en-2-vDpenryl)oxy)phenvD -5-(3-(5-(4-(tert-buryl)phenyl)-l,3,4-oxadiazol-2-yl)phenyl)-l,3,4-oxadiazole

42

4840-6681-1406.1

2-(3-((5-(bicyclo[2.2.1]hept-5-eri-2-yl)pentyl)oxy)phenyl)-5-(3-(&-(4-(/erf- butyl)phenyl)-1 ,3,4-oxadiazol-2-yl)phenyl)-1 ,3,4-oxadiazole

[000127] The synthesis of the 3-(5-(3-(5-(4-(tert-butyl)phenyl)-l ,3,4- oxadiazol-2-yl)phenyl)-l ,3,4-oxadiazol-2-yl)phenol bis-oxadiazole starting material

shown above, as well as the synthesis of a variety of additional polymerizable

norbornenyl-linked oxadiazole monomers, and homopolymers derived therefrom,

were described in WO 2009/080797, hereby incorporated herein by reference in its

entirety.

[000128] To a solution of 3-(5-(3-(5-(4-tert-Butylphenyl)- 1 ,3,4- oxadiazol-2-yl)phenyl)- l ,3,4-oxadiazol-2-yl)phenol (8.0 g, 18.24 mmol) and 5- (bromomethyl)bicycle[2,2, l ]hept-2-ene (5.0 g, 20.56 mmol) in DMF (100.0 ml) was

added 2CO3 (10.0 g, 72.36 mmol) at room temperature under stirring. The reaction

was carried out at 60°C for 18 h. After cooling, water (500.0 ml) was added. White

solid product was obtained by filtration. After dry, the crude product was purified by

silica gel column chromatography using dichloromethane/ethyl acetate (9 : 1 ) as

eluent. After removal of solvents, the product was purified by recrystallization from

dichloromethane/methanol. White solid product was obtained by filtration. After

vacuum dry, the product as a white solid in 7.1 g (64.5%) was obtained.

[000129] Ή NMR (400 MHz, CDCI3) δ: 8.83 (m, 1 H), 8.30 (m, 2 Hz), 8.08 (d, J= 8.4 Hz, 2 H), 7.70 -7.65 (m, 3 H), 7.56 (d, J = 8.4 Hz, 2 H), 7.42 (t, J =

8.0 Hz, 1 H), 7.06 (m, 1 H), 6.08 (q, J = 3.2 Hz, C=C-H, 0.85 H, endo), 6.06 (q, J =

3.2 Hz, 0.15 H, exo), 5.98 (q, J = 3.2 Hz, 0.15 H, exo), 5.89 (q, J = 3.2 Hz, 0.85 H,

endo), 4.03 (t, J = 6.8 Hz, 2 H, OCH₂), 2.72 (m, br, 1.7 H), 2.49 (s, br, 0.3 H), 1.96

(m, 1 H), 1.81 (m, 2.5 H), 1.46- 1.03 (m, 7.5 H), 0.47 (m, 1 H) ppm. ^{I 3}C NMR (100

MHz, CDC1₃) 5: 165.12, 165.01 , 163.60, 163.34, 159.56, 155.65, 136.91 , 132.33,

43

4840-6681-1406.1 130.21 , 129.96, 129.71 , 129.66, 126.90, 126.10, 125.13, 124.98, 124.91 , 124.61 , 120.74, 1 19.23, 1 18.79, 1 12.31, 68.34, 49.52, 45.37, 42.48, 38.65, 35.10, 34.65, 32.38, 31.09, 29.18, 28.38, 26.24 ppm. MS-EI (m/z): [M*] Calcd for C38H40N4O3, 600.3, 601.3, 602.3. found 600.3, 601.3, 602.3. Anal. Calcd for C38H40N4O3: C, 75.97; H, 6.71 ; N, 9.33. Found: C, 75.96; H, 6.76; N, 9.24.

[000130] Example 3 - Synthesis of A Norbornenyl Homopolymer Comprising Linked Bis-oxadiazole Moieties- Poly(2-(3-((5-((lS,2R,4S)- bicvclo|2.2.11hept-5-en-2-vnpentyl)oxy)phenvn-5-(3- 5- 4-(tert-butyl)phenyl)- l -oxadiazol-2-yl)phenyl)-l,3,4-oxadiazole); XH-I-98a

XH-l-98a

Poly(2-(3-((5-((1 S,2R,4S)-bicycta[2.2.1]hept- 5-en-2-yl)pentyl)oxy)phenyl)-5-<3-(5-(4-((eri- butyl)phenyl)-1,3,4-oxadiazol-2-yl)phenyl>- 1,3,4- ox adiazole)

[000131 ] 2-(3-((5-(bicyclo[2.2.1 ]hept-5-en-2-yl)pentyl)oxy)phenyl) -5- (3-(5-(4-(tert-butyl)phenyl)-l ,3,4-oxadiazol-2-yl)phenyl)-l ,3,4-oxadiazole (2.5406 g, 4.23 mmol) and the 1 st generation Grubbs catalyst (0.0034 g, 0.0041 mmol) were weighed and sealed in a glove box, respectively. Under N₂, the monomer and the catalyst were dissolved into ί 5 mL and 5 mL of anaerobic and anhydrous CH2CI2. Then the 5 mL CH2CI2 solution of the catalyst was added dropwise into the CH2CI2 solution of the monomer. The polymerization proceeded at room temperature and the Schlenk tube was covered by Aluminum foils. After 40 min, when the reaction appeared complete by TLC, the polymerization was quenched with vinyl ethyl ether (1 .0 mL). Then the reaction mixture was added dropwise to highly stirring acetone

44

4840-6681-1406.1 (200 mL) to precipitate out the polymer. The crude product was dried and purified by redissolving and reprecipitating process in acetone then methanol for three times to give an off-white solid (2.324 g, 92 %). Ή NMR (400 MHz, CDC1₃): ^8.69 (m, br, 1H), 8.19 (m, br, 2H), 8.00 (m, br, 2H), 7.59 (m, br, 2H), 7.50 (m, br, 2H), 7.33 (m, br, 1 H), 6.98 (m, br, 1 H), 5.26 (m, br, 2H), 3.96 (m, br, 2H), 2.91-1.73 (m, br, 6H), 1 .59-0.86 (m, br, 18H). Anal. Calcd. for C38H40N4O3: C, 75.97; H, 6.71 ; N, 9.33; Found: C, 75.91 ; H, 6.69; N, 9.34. GPC: Mn (kDa): 36; Mw (kDa): 58; PDI: 1.6.

[000132] The absorption and fluorescent emission spectra of XH-I-98a in dichloromethane are shown in Figure 1. Absorption maxima were observed at 289 nm and 227 nm, and a fluorescent emission maximum was observed at 366 nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 397 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 120 °C.

[000133] Example 4 - Synthesis of A Norbornenyl Homopolymer Comprising A Linked Triscarbazole Moiety- Poly(9'- 5-((lS,2R,4S)-

Poly-(9'-(5-((1S,2R,4S)-bicyclo[2.2.1]hept-5- en-2-yl)pentyl)-9'H-9,3':6',9"-tercarbazole)

[000134] 9'-(5-(( 1 S,2R,4S)-bicyclo[2.2.1 ]hept-5-en-2-yl)pentyl)-9'H-

9,3':6',9"-tercarbazole (2.5401 g, 3.85 mmol) and the 1 st generation Grubbs catalyst

(0.0029 g, 0.0035 mmol) were weighed and sealed in a glove box, respectively.

Under N₂, the monomer and the catalyst were dissolved into 15 mL and 5 mL of anaerobic and anhydrous CH₂C1₂, Then the 5 mL CH₂C1₂ solution of the catalyst was added dropwise into the CH₂C1₂ solution of the monomer. The polymerization

45

4840-6681-1406.1 proceeded at room temperature overnight. When the reaction appeared complete by TLC, quenched the polymerization with vinyl ethyl ether (1.0 mL). Then the reaction mixture was added dropwise to highly stirring acetone (200 mL) to precipitate out the polymer. The crude product was dried and purified by redissolving and reprecipitating process in acetone then methanol for three times to give an off-white solid (2.258 g, 89 %).

[000135] Ή NMR (400 MHz, CDC1₃): <?(ppm): 8.08 (m, br, 2H), 8.02 (m, br, 4H), 7.45 (m, br, 4H), 7.24 (m, br, 8H), 7.14 (m, br, 4H), 5.1 1 (m, br, 2H), 4.16 (m, br, 2H), 2.70-1.75 (m, br, 7H), 1 .24-0.93 (m, br, 8H). Anal. Calcd. for C48H41N3: C, 87.37; H, 6.26; N, 6.37. Found: C, 86.84; H, 6.23; N, 6.38. GPC: Mn (kDa): 23; Mw (kDa): 35; PDI: 1.5.

[000136] The absorption and fluorescent emission spectra of XH-I-98b in dichloromethane are shown in Figure 2. Absorption maxima were observed at 342 nm, 294 nm, 264 nm, and 239 nm, and fluorescent emission maxima was observed at 408 and 391 nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 445 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 206 °C.

[000137] Example 5 - Synthesis of A Random Norbornenyl Copolymer Comprising 1:1 BisOxadiazoIe and Triscarbazole Moieties; XH-I- 41

-1406.1 [000138] The norbornene-triscarbazole monomers, 9'-(5-((l S,2R,4S)- bicyclo[2.2.1 ]hept-5-en-2-yl)pentyl)-9'H-9,3':6',9"-tercarbazole (0.4956 g, 0.752 mmol) and norbornene-bisoxadiazole monomer 2-(3-((5-(bicyclo[2.2.1 ]hept-5-en-2- yl)pentyl)oxy)phenyl) -5-(3-(5-(4-(tert-butyl)phenyl)-l ,3,4-oxadiazol-2-yl)phenyl)- 1 ,3,4-oxadiazole (0.4549 g, 0.757 mmol), and the 1st generation Grubbs catalyst (0.0062 g, 0.00753 mmol) were weighed and sealed in two separate Schlenk tubes in a glove box, respectively. Under N₂, the monomers and the catalyst were dissolved into 8 mL and 4mL of anaerobic and anhydrous CH₂C1₂. Then the 4 mL CH₂C1₂ solution of the catalyst was added dropwise into the CH₂C1₂ solution of the monomers. The polymerization proceeded at room temperature for 4 hours. When the reaction appeared complete by TLC, quenched the polymerization with vinyl ethyl ether (0.5 mL). Then the reaction mixture was added dropwise to highly stirring CH3OH (200 mL) to precipitate out the polymer. The crude product was dried and purified by redissolving and reprecipitating process three times to give a off-white solid (XH-I-41, 0.775 g, 82 %).

[000139] Ή NMR (400 MHz, CDCI3): <?8.69 (m, br, 1 H), 8.12 (m, br, 4H), 8.03 (m, br, 6H), 7.50 (m, br, 9H), 7.27 (m, br, 8H), 7.15 (m, br, 5H), 6.98 (m, br, 1 H), 5.18 (m, br, 4H), 4.31 (m, br, 2H), 3.89 (m, br, 2H), 2.83-1.53 (m, br, 14H), 1.48-1.04 (m, br, 25H). Anal. Calcd. for C8₆H₈,N₇0₃: C, 81 .94; H, 6.48; N, 7.78. Found: C, 81.94; H, 6.29; N, 7.67. GPC: Mn (kDa): 47; Mw (kDa): 74; PDI: 1.6.

[000140] The absorption and fluorescent emission spectra of XH-I-41 in dichloromethane are shown in Figure 3. Absorption maxima were observed at 343, 294, and 238 nm, and fluorescent emission maxima was observed at 475, 407, and 390 nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 423 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 154 °C.

[000141 ] Example 6 - Synthesis of A Random Norbornenyl Copolymer Comprising 3:2 BisOxadiazole and Triscarbazole Moieties; XH-I- 53-c

47

-1406.1

[000142] The norbornene-triscarbazole monomers, 9'-(5-(( 1 S,2R,4S)- bicyclo[2.2.1]hept-5-en-2-yl)pentyl)-9'H-9,3':6',9"-tercarbazole (0.2995 g, 0.454 mmol) and norbornene-bisoxadiazole monomer 2-(3-((5-(bicyclo[2.2.1 ]hept-5-en-2- yl)pentyl)oxy)phenyl) -5-(3-(5-(4-(tert-butyl)phenyl)-l ,3,4-oxadiazol-2-yl)phenyl)- 1 ,3,4-oxadiazole (0.4134 g, 0.688 mmol), and the 1st generation Grubbs catalyst (0.0036 g, 0.0043 mmol) were weighed and sealed in two separate Schlenk tubes in a glove box, respectively. Under N₂, the monomers and the catalyst were dissolved into 7 mL and 3 mL of anaerobic and anhydrous CH2CI2. Then the 3 mL CH₂C1₂ solution of the catalyst was added dropwise into the CH₂C1₂ solution of the monomers. The polymerization proceeded at room temperature and the Schlenk tube was covered by Aluminum foils. After 6 hours, when the reaction appeared complete by TLC, quenched the polymerization with vinyl ethyl ether (0.5 mL). Then the reaction mixture was added dropwise to highly stirring acetone (200 mL) to precipitate out the polymer. The crude product was dried and purified by

48

-1406.1 redissolving and reprecipitating process for three times in acetone then methanol to give a off-white solid (XH-I-53c, 0.551 g, 77%).

[000143] ' H NMR (300 MHz, CDC ): δ 8.69 (m, br, 1.5H), 8.09 (m, br, 10.5H), 7.53 (m, br, 12H), 7.28 (m, br, 8H), 7.18 (m, br, 6H), 6.98 (m, br, 2H), 5.25 (m, br, 5H), 4.37 (m, br, 2H), 3.92 (m, br, 3H), 2.87-1.73 (m, br, 15H), 1.32-0.46 (m, br, 35H). Anal. Calcd. for C 105H101N9O4.5: C, 80.78; H, 6.53; N, 8.08. Found: C, 80.05; H, 6.52; N, 8.06. GPC: Mn (kDa): 47; Mw (kDa): 78; PDI: 1 .6.

[000144] The absorption and fluorescent emission spectra of XH-I-41 in dichloromethane are shown in Figure 4. Absorption maxima were observed at 343, 294, 287, and 238 nm, and fluorescent emission maxima was observed at 476, 390, 366, and 356 nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 406 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 146 °C.

[000145] Example 7 - Synthesis of A Diblock Norbornenyl Copolymer Comprising 1:1 BisOxadiazole and Triscarbazole Moieties; XH-I-

[000146] The norbornene-triscarbazole monomers, 9'-(5-((l S,2R,4S)- bicyclo[2.2.1 ]hept-5-en-2-yl)pentyl)-9'H-9,3':6',9"-tercarbazole (0.3055 g, 0.463

49

4840-6681-1406.1 mmol) and norbornene-bisoxadiazole monomer 2-(3-((5-(btcyclo[2.2.1 ]hept-5-en-2- yl)pentyl)oxy)phenyl) -5-(3-(5-(4-(tert-butyl)phenyl)- l ,3,4-oxadiazol-2-yI)phenyl)- 1 ,3,4-oxadiazole (0.2726 g, 0.454 mmol), and the 1 st generation Grubbs catalyst (0.0035 g, 0.0042 mmol) were weighed and sealed in three separate Schlenk tubes in a glove box, respectively. Under N₂, the monomer YZ-III-267a and the catalyst were dissolved into 4 mL and 2 mL of anaerobic and anhydrous CH₂C . Then the 2 mL CH2CI2 solution of the catalyst was added dropwise into the 4 mL CH₂C1₂ solution of the first monomer YZ-III-267a. After the Schlenk tube was covered by Aluminum foils, the polymerization proceeded at room temperature for 30 min. When the reaction appeared complete by TLC, transferred 4 mL of the reaction mixture into the second monomer XH-I-27a. Still cover the reaction mixture with aluminum foils and let it stir for another 30 min. The polymerization was quenched with vinyl ethyl ether (0.2 mL) after TLC confirmed the reaction was complete. Then the reaction mixture was added dropwise to highly stirring acetone (200 mL) to precipitate out the polymer. The crude product was dried and purified by redissolving and reprecipitating process for three times in acetone then methanol to give an off-white solid (XH-I-68a, 0.454 g, 79 %).

[000147] ¹ H NMR (400 MHz, CDCI3): δ 8.69 (m, br, 1 H), 8.19-8.01 (m, br, 1 1 H), 7.60-7.24 (m, br, 13H), 7.13-6.98 (m, br, 9H), 5.27 (m, br, 2H), 5.1 1 (m, br, 2H), 4.14 (m, br, 2H), 3.95 (m, br, 2H), 2.88-2.15 (m, br, 5H), 1 .82-1 .75 (m, br, 9H), 1.40-0.88 (m, br, 25H). Anal. Calcd. for C₈6H₈,N₇03: C, 81 .94; H, 6.48; N, 7.78. Found: C, 82.20; H, 6.43; N, 7.67. GPC: Mn (kDa):38; Mw (kDa): 62; PDI: 1.6.

[000148] The absorption and fluorescent emission spectra of XH-I-68a in dichloromethane are shown in Figure 5. Absorption maxima were observed at 342, 294, 264, and 238 nm, and fluorescent emission maxima were observed at 389 and 366 nm nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 410 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 144 ;°C.

[000149] Example 8 - A Physical Blend of A Norbornenyl- Bisoxadiazole Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolvmer XH-I-98b ; XH-I-69a

50

1-1406.1 [000150] Samples of XH-I-98a and XH-I-98b in a 1 : 1 ratio were physically blended to form sample XH-I-69a.

[000151 ] The absorption and fluorescent emission spectra of XH-I-69a dissolved in dichloromethane are shown in Figure 6. Absorption maxima were observed at 342, 294, 286, and 238 nm, and fluorescent emission maxima were observed at 382 and 366 nm. Thermogravimetric Analysis showed good thermal stability, with 5% mass lost at 406 °C, and differential scanning calorimetry showed peak attributable to a glass transition temperature at 136 °C.

[000152] Example 9 - An PLED Device Employing an Emissive Layer Comprising A 1:1 Blend of A Norbornenyl-Bisoxadiazole Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (6% Ir(ppy)i Emitter)

[000153] The following describes the construction and electronic testing of an OLED device comprising an emissive layer comprising a 1 : 1 (wt%) blend of a norbornenyl-bisoxadiazole homopolymer XH-I-98a (see synthesis Example 3) with a norbomenyl-triscarbazole homopolymer XH-I-98b (see synthesis Example 4), as Host in the OLED emissive layer. A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 7a, 7b, and 7c.

[000154] Indium tin oxide (ITO)-coated glass (Colorado Concept Coatings LLC) with a sheet resistivity of -15 Ω/sq was used as the substrate for the OLEDs fabrication. The ITO substrates were patterned with kapton tape and etched in acid vapor (1 :3 by volume, HN0₃: HC1) for 5 min at 60 °C. The substrates were cleaned in an ultrasonic bath of detergent water, rinsed with deionized water, and then cleaned in sequential ultrasonic baths of deionized water, acetone, and isopropanol. Each ultrasonic bath lasted for 20 minutes. Nitrogen was used to dry the substrates after each of the last three baths. This same procedure was used to prepare the ITO coated substrates for all the subsequent examples below.

[000155] For the Poly-TPD-F hole-transport layer, 10 mg of Poly-TPD- F were dissolved in 1 ml of chloroform (with purity of 99.8%, as distilled and degassed over night). 35 nm thick films were then spin coated (60s@l 500 rpm, acceleration 10,000rpm/s) onto the indium tin oxide (ITO) coated glass substrates,

51

4840-6681-1406.1 treated with an 0₂ plasma for 3 minutes prior to the deposition of the hole-transport material. Spin coating was carried out in a N₂ filled wet glove box. After spin- coating, a rectangular strip of the layer was removed at the edge of the substrate to expose ITO and ensure electrical contact to the anode; then, the sample was transferred to the wet glove box ante-chamber and subjected to vacuum for 15 minutes; then the sample was transferred back into the wet glove-box were it was baked for 15 min at 75 °C on a hot plate, after which the hot plate was turned off. The sample was removed from the hot plate only until its temperature was down to 40 °C. Finally the sample was exposed to 0.7 mW/cm² of UV illumination for 1 minute to crosslink the hole-transport layer.

[000156] For the emissive layer, 6 wt.% of Ir(ppy)3 was mixed with a blend of XH-I-98a and XH-I-98b, at a 1 : 1 weight ratio, and all materials dissolved in

1 ml of chlorobenzene ( purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated (60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crossl inked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes. Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The samples were then transferred, under a N₂ atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box.

[000157] For the hole-blocking and electron transport layer, a 40 nm thick BCP layer was vacuum deposited at a pressure below 2x 10^"7 Torr and at rates of 0.4 A/s, respectively. Then, a 2.4 nm of lithium fluoride (LiF), as an electron- injection layer, and a 200 nm-thick aluminum cathode were vacuum deposited through a shadow mask at a pressure below 3x 10^"7 Torr and at rates of 0.15 A/s and

2 A/s, respectively. The shadow mask used for the evaporation of the metal electrodes yield five devices with an area of roughly 0.1 cm² per substrate.

[000158] The device testing was done, immediately-after the deposition of the metal cathode, in an inert atmosphere and without exposing the devices to air. Luminance-current-voltage (L-l-V) characteristics of the devices were measured using a Keithley 2400 source meter for current-voltage measurements inside a nitrogen-filled glovebox with 0₂ and H₂0 levels < 20 and < 1 ppm, respectively.,

52

1-1406.1 The current-voltage measurements for all the subsequent OLED examples were carried out with the same instruments and via the same procedure for all the OLED examples below.

[000159] As can be seen from Figure 7c, the OLEDs employing the 1 : 1 polymer blends as hosts for a green guest emitter showed reasonable offset voltages of slightly over 8 volts, were quite bright with peak luminance greater than 10³ cd/m², and peak external quantum efficiencies above 16%.

[000160] Example 10 - An OLED Device Employing an Emissive Layer Comprising A 1 :1 Blend of A Norbornenyl-Bisoxadiazole Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (12% Ir(ppy)_j Emitter)

[000161 ] The same procedure as detailed in Example 9 was used to prepare an OLED, except that 12% Ir(ppy)₃ was employed in the emissive layer. A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 8a, 8b, and 8c.

[000162] As can be seen from Figure 8c, the OLEDs employing the 1 : 1 polymer blends as hosts for 12% of a green guest emitter showed reasonable offset voltages of slightly over 7 volts, were quite bright with peak luminance greater than 10³ cd/m², and peak external quantum efficiencies up to about 10%.

[000163] Example 11 - An OLED Device Employing an Emissive Layer Comprising A 1.5: 1 Blend of A Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (6% Ir(ppy)? Emitter)

[000164] The same procedure as detailed in Example 9 was used to prepare an OLED, except that the wt ratio of Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a to Norbornenyl-Triscarbazole Homopolymer XH-I-98b was changed to 1.5: 1 (6% Ir(ppy)3 was employed in the emissive layer). A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 9a, 9b, and 9c.

[000165] As can be seen from Figure 9c, the OLEDs employing the 1.5: 1 polymer blends as hosts for 6% of a green guest emitter showed reasonable

53

4840-6681-1406.1 offset voltages of slightly over 7 volts, were quite bright with peak luminance well over 10 cd/m , and peak external quantum efficiencies up to over 16%.

[000166] Example 12 - An PLED Device Employing an Emissive Layer Comprising A 1: 1.5 Blend of A Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (6% Ir(pppy)₃ Emitter)

[000167] The same procedure as detailed in Example 9 was used to prepare an OLED, except that the wt ratio of Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a to Norbornenyl-Triscarbazole Homopolymer XH-I-98b was changed to 1 : 1.5, and 6% of a slightly different but well known green emitter, lr(pppy)3 (structure shown below) was employed in the emissive layer. A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 10a, 10b, and 10c.

[000168] As can be seen from Figure 10c, the OLEDs employing the 1 : 1.5 polymer blends as hosts for 6% of a green guest emitter showed reasonable offset voltages of about 6 volts, were very bright with peak luminance well over 10³

2 2

cd/m , and peak external quantum efficiencies up to 28%. At 100 cd/m , the EQE was 21.0%, and luminescent efficiency was 71 cd/A; and at 1000 cd m², the EQE was 14.5%, and luminescent efficiency was 49 cd/A.

[000169] Example 13 - An OLED Device Employing an Emissive Layer Comprising A 1:1.5 Blend of A Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (6% Firpic Blue Emitter, PDOT:PSS As Hole Carrying Layer)

[000170] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a 1 : 1.5 wt ratio of Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a to Norbornenyl-Triscarbazole Homopolymer XH-I-98b. but (6% of Firpic blue emitter was employed in the emissive layer, and the water soluble and solution processable material PEDOT:PSS was used as the hole carrying layer.

[000171 ] For the hole transport layer, a 40 nm thick PEDOT: PSS A14083 layer was spin coated from the commercially available emulsion (60s@1500

54

-1406.1 _; rpm, acceleration 10,000 rpm/s) onto ITO coated glass substrates, in a N₂ illed wet glove box. After spin-coating, a rectangular strip of the PEDOT;PSS layer was removed at the edge of the substrate to expose ITO and ensure electrical contact to the anode; then the PEDOT:PSS coated substrate was baked for 10 min at 140 °C on a hot plate. The sample was removed from the hot plate only until its temperature was down to 40 °C. The addition of the emissive layer, electron carrying layer, and cathode layers were then carried out as previously described above.

[000172] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 11a, lib, and 11c.

[000173] As can be seen from Figure 11c, the OLEDs employing the 1 : 1.5 polymer blends as hosts for 6% of the blue guest emitter Firpic, and

PEDOT:PSS hole carrying layers showed reasonable offset voltages of 7-8 volts, and were reasonably bright with peak luminance well over 10³ cd/m², and but the observed peak external quantum efficiencies were only about 2%.

[000174] Example 14 - An OLED Device Employing an Emissive Layer Comprising A 1: 1.5 Blend of A Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (12% Firpic Blue Emitter. PDOT:PSS As Hole Carrying Layer. )

[000175] A similar procedure as detailed in Example 13 was used to prepare an OLED, using a 1 : 1.5 wt ratio of Norbornenyl-Bisoxadiazole

Homopolymer XH-I-98a to Norbornenyl-Triscarbazole Homopolymer XH-I-98b. but 12% of Firpic blue emitter was employed in the emissive layer, and the water soluble and solution processable material PEDOT:PSS was used as the hole carrying layer.

[000176] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 12a, 12b, and 12c.

[000177] As can be seen from Figure 12c, the OLEDs employing the 1 : 1.5 polymer blends as hosts for 12% of the blue guest emitter Firpic, and

PEDOT:PSS hole carrying layers, showed reasonable offset voltages of about 8 volts, and were reasonably bright with peak luminance well over 10³ cd/m², and but

55

-1406.1 the observed peak external quantum efficiencies increased to about 4.5%, as compared to about 2% in Example 13.

[0001 78] Comparative Example 15 - An OLED Device Employing an Emissive Layer Comprising A Random Copolymer of Norbornenyl- Bisoxadiazole Subunits With Norbornenyl-Triscarbazole Subunits, XH-I-41 As Host In the Emissive Layer (6% Ir(ppy)¾ Emitter)

[000179] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a random copolymer of norbomenyl-bisoxadiazole subunits with norbornenyl-triscarbazole subunits, XH-I-41 , see Example 5, in the emissive layer.

[000180] For the emissive layer, 6 wt.% of Ir(ppy)3 was mixed with XH-I-41 and both materials dissolved in 1 ml of chlorobenzene ( purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated (60s@ 1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N2 atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[0001 81 ] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 13a, 13b, and 13c.

[000182] As can be seen from Figure 13c, the OLEDs employing the random norbornenyl-oxadizole-carbazole as hosts showed reasonable offset voltages of about 8 volts, and were reasonably bright with peak luminance well over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 6%, which declined rapidly with increasing voltage and current.

[000183] Comparative Example 16 - An OLED Device Employing an Emissive Layer Comprising A Random Copolymer of 3:2 Norbornenyl- Bisoxadiazole Subunits With Norbornenyl-Triscarbazole Subunits, XH-I-53c As Host In the Emissive Layer (6% Ir(ppy)^ Emitter)

56

4840-6681-1406.1 [000184] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a random copolymer of nprbomenyl-bisoxadiazole subunits with norbornenyl-triscarbazole subunits in a 3:2 ratio, XH-I-53c, see Example 6, in the emissive layer.

[000185] For the emissive layer, 6 wt.% of Ir(ppy)₃ was mixed with XH-I-53c and both materials dissolved in 1 ml of chlorobenzene (purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated (60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[000186] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 14a, 14b, and 14c.

[000187] As can be seen from Figure 14c, the OLEDs employing the random norbornenyl-oxadizole-carbazole as hosts showed reasonable offset voltages of about 8 volts, and were reasonably bright with peak luminance well over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 10%, which declined rapidly with increasing voltage and current.

[000188] Comparative Example 17 - An OLED Device Employing an Emissive Layer Comprising A Diblock Copolymer of 1:1 Norbornenyl- Bisoxadiazole Subunits With Norbornenyl-Triscarbazole Subunits, XH-I-68a As Host In the Emissive Layer (6% Ir(ppy Emitter)

[000189] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a diblock copolymer of norbornenyl-bisoxadiazole subunits with norbornenyl-triscarbazole subunits in a 1 : 1 ratio, XH-I-68a, see Example 7, in the emissive layer.

[000190] For the emissive layer, 6 wt.% of Ir(ppy)₃ was mixed with XH-I-68a and both materials dissolved in 1 ml of chlorobenzene (purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated

57

4840-6681-1406.1 (60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N₂ atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[000191 ] A schematic of the structure of the OLED dev ice and graphs of the results of the electronic testing are shown in Figures 15a, 15b, and 15c.

[000192] As can be seen from Figure 15c, the OLEDs employing the random norbornenyl-oxadizole-carbazole as hosts showed reasonable offset voltages of about 8 volts, and were reasonably bright with peak luminance well over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 7%, which declined rapidly with increasing voltage and current.

[000193] Comparative Example 18 - An OLED Device Employing an Emissive Layer Comprising A Random Styrenic Copolymer of 1:1 Styrene- Bisoxadiazole Subunits With Styrene-Triscarbazole Subunits, YZ-IV-25, As Host In the Emissive Layer (6% Ir(ppy)¾ Emitter)

[000194] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a random styrenic copolymer of styrenyl-bisoxadiazole subunits with sty ture below.

58

4840-6681-1406.1 [000195] For the emissive layer, 6 wt.% of lr(ppy)3 was mixed with YZ-IV-25 and both materials dissolved in 1 ml of chlorobenzene (purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated (60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N₂ atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[000196] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 16a, 16b, and 16c.

[000197] As can be seen from Figure 16c, the OLEDs employing the random norbornenyl-oxadizole-carbazole as hosts showed reasonable offset voltages of about 8-9 volts, and were reasonably bright with peak luminance over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 9-10%, which declined rapidly with increasing voltage and current.

[000198] Comparative Example 19 - An OLED Device Employing an Emissive Layer Comprising A Styrenic Ambipolar Homopolymer

Comprising Both Oxadiazole and Carbazole Subunits, YZ-IV-13, As Host In the Emissive Layer (6% Ir(ppy)i Emitter)

[000199] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a homopolymer of styrenyl-subunits linked to both oxadiazole andcarbazole subunits in a 1 : 1 ratio, see structure below.

YZ-IV-13: Poly(2-(3-(4-vinylbenzyl)phenyl)-5- (3-carbazol-9-ylp enyl)-1 ,3,4-oxadiazole)

59

4840-6681-1406.1 [000200] For the emissive layer, 6 wt.% of Ir(ppy>3 was mixed with YZ-IV- 13 and both materials dissolved in 1 ml of chlorobenzene (purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated (60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N₂ atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[000201 ] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 17a, 17b, and 17c.

[000202] As can be seen from Figure 17c, the OLEDs employing the ambipoiar styrenic-oxadizole-carbazoie as hosts showed reasonable offset voltages of about 6.5 volts, and were reasonably bright with peak luminance over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 5%, which declined rapidly with increasing voltage and current.

[000203] Comparative Example 20 - An OLED Device Employing an Emissive Layer Comprising A Styrenic Ambipoiar Homopolvmer

Comprising Both One Oxadiazoie and Two Carbazole Subunits, YZ-IV-21, As Host In the Emissive Layer (6% Ir(ppy)a Emitter)

[000204] A similar procedure as detailed in Example 9 was used to prepare an OLED, using a homopolymer of styrenyl-subunits linked to both oxadiazoie and carbazole subunits in a 1 :2 ratio, see structure below.

YZ-IV-21 : Poly(2-(3-(4-vinylbenzyloxy)phenyl>-5- (3.5-di(oart3azol-9-yl)phenyl 1.3, -oxadiazole)

60

4840-6681-1406.1 I

[000205] For the emissive layer, 6 wt.% of Ir(ppy>3 was mixed with YZ-IV-21 and both materials dissolved in 1 ml of chlorobenzene (purity of 99.8%; distilled and degassed over night). 40-50 nm thick films were then spin coated

(60s@1000 rpm, acceleration 10,000 rpm/s) onto the UV crosslinked poly-TPD-F layer. After spin-coating, the samples were baked at 75 °C for 15 minutes.

Chlorobenzene was then used to remove the emissive layer in the area not covered by poly-TPD-F, exposing the ITO substrate to provide electrical contact to the anode. The coated devices were then transferred, under a N₂ atmosphere, into an SPECTROS from Kurt J. Lesker thermal deposition system directly connected to the wet-glove box, for deposition of the electron transfer layer and cathode.

[000206] A schematic of the structure of the OLED device and graphs of the results of the electronic testing are shown in Figures 18a, 18b, and 18c.

[000207] As can be seen from Figure 18c, the OLEDs employing the ambipolar styrenic-oxadizole-carbazole as hosts showed reasonable offset voltages of about 6 volts, and were reasonably bright with peak luminance over 10³ cd/m², and but the observed peak external quantum efficiencies started at a maximum of about 4%, which declined rapidly with increasing voltage and current.

[000208] Example 21 - Synthesis of Polymerizable Norbornenyl- Phenanthro inyl Monomers

[000209] (4-Bromophenoxy)(tert-butyl)dimethylsilane (10 mmol, 3 g) was dissolved in anhydrous THF (20 mL) and the solution was cooled to -78 °C. t- BuLi in pentane (1.7 M, 1 5 mL, 25.5 mmol) was added dropwise to initiate halogen/metal exchange. After complete addition, the mixture was allowed to warm up to room temperature by removing the cooling bath.

[000210] In a second flask, phenanthroline (5 mmol, 900 mg) was dissolved in 5 mL of anhydrous THF and added to the solution of lithium reagent, then the mixture was allowed to warm up to room temperature by removing the

61

4840-6681-1406.1 ice/water bath. After stirring for four hours, TLC analysis of the reaction mixture showed phenanthroline disappearance and a new spot appeared (Rf. 0.9, hexane:acetone=2: l ). The dark brown reaction mixture was quenched by pouring it into 5 mL of water, and the color changes into bright yellow. The organic phase was separated and the aqueous phase was extracted with dichloromethane (2x 10 mL). The combined organic phases were dried over Na₂S0₄ overnight, then treated with successive additions of Mn0₂ with effective magnetic stirring (4 g). The re- oxidation was easily followed by TLC and the disappearance of the yellow color, and was ended after the addition of another 2 g of Mn0₂. After the mixture was dried over Na₂S0₄, the black slurry could be easily filtered on through sintered glass and the filtrate evaporated to dryness by rotary evaporation. The crude material, isolated as yellow oil was purified by column chromatography (50 mL of silica gel, 500 mL hexanes:acetone=3: l as eluant). The solvent was removed from combined desired fractions to give yellow solid 740 mg, 38%).

[00021 1 ] (2-(4-(tert-butyldimethylsilyloxy)phenyl)- 1 , 10- phenanthroline): Ή NMR (300 MHz, CDC1₃): δ 9.22 (dd, J= 7.5, 2.1 Hz, 1 H), 8.26-8.21 (m, 4H), 8.03 (d, J= 1 1.0 Hz, 1 H), 7.71 (t, J = 7.5 Hz, 2H), 7.61 (dd, J= 7.5, 4.8 Hz, 1 H), 7.01-6.98 (m, 2H,), 1.01 (s, 9H), 0.24 (s, 6H). ^I3C NMR (75 MHz, CDCI3): 157.53, 157.642, 150.54, 146.62, 146.25, 136.89, 136.28, 133.19, 129.53, 129.26, 127.34, 126.62, 126.02, 122.98, 120.70, 120.69, 120.39, 25.95, 18.55, - 4.09. EI-MS (m/z): M⁺ calcd for C₂4H₂₆N₂OSi, 386.18; found 386.1. Anal. Calcd. for C₂₄H₂6N₂OSi: C, 74.57; H, 6.78; N, 7.25. Found: C, 74.63; H, 6.67; N, 7.19.

[000212] When the reaction was scaled up to 25 mmol, the yield was about 70%.

[000213] Step 2: Synthesis of 4-(l,10-phenanthrolin-2-yl)phenol

[000214] A 1 M solution of tetrabutylammonium fluoride (TBAF) (1.55 mmol, 1.55 mL) was added to a solution of 2-(4-(tert- butyldimethylsilyloxy)phenyl)-l ,10-phenanthroline (400 mg, 1.04 mmol) in THF (5

62

4840-6681-1406.1 mL) at 0 °C. The color turns from colorless to yellow. After 1.5 h, the reaction was quenched by 10 mL water, and white solid precipitated from the mixture solution. The filtered solid was washed with acetone (5 mL) and dried under vacuum to yield 180 mg white solid (yield: 64%). The solid is soluble in DMSO and slightly soluble in methanol, acetone and chloroform.

[00021 5] 4-(l,10-phenanthrolin-2-yl)phenol: Ή NMR (300 MHz, DMSO): δ 9.87 (S, 1 H), 9.12 (dd, J= 4.2, 1.8 Hz, IH), 8.47-8.43 (m, 2H), 8.30-8.23 (d, 3H), 7.92 (dd, J= 9.0, 4.2 Hz, 2H), 7.74 (dd, J- 8.1 , 4.2 Hz, 1 H), 6.91 -6.94 (m, 2H,). ^,3C NMR (75 MHz, DMSO): 159.78, 156.40, 150.45, 146.27, 145.89, 137.73, 136.88, 130.49, 129.58, 129.50, 127.51 , 127.12, 126.43, 123.85, 1 19.93, 1 16.31. EI-MS (w/z): M⁺ calcd for C|₈H,2N₂0, 272.09; found 272.1. Anal. Calcd. for Ci₈Hi₂N₂0 (JZ-I- 125): C, 79.39; H, 4.44; N, 10.29. Found: C, 79.29; H, 4.49; N, 10.29.

[000216] Step 3A: Synthesis of : 2-(4-(bicycle[2,2,l]hept-5en-2-

[000217] To a solution of 4-(l ,10-phenanthrolin-2-yl)phenol (500 mg, 1 .83 mmol) and bicyclo[2,2, l]hept-5-en-2-ylmethyl 4-methylbenzenesulfonate (764 mg, 2.75 mmol) in DMF ( 15.0 mL) was added Cs₂C0₃ (1.19 g, 3.66 mmol) at room temperature under stirring. The reaction mixture was heated to 100 °C in oil-bath for 3 h. When reaction mixture was cooled down to room temperature, and water (30.0 mL) was added. The product was extracted with ethyl acetate (20.0 mL x 3), the organic layer was collected and washed with water (50.0 mL x 6). After removal of organic solvents, the crude product was purified on silica gel column by eluting with hexanes/acetone (6: 1 ). After removal of solvent and drying under vacuum, pure product as solid foam was obtained in 540 mg (78.3 %) yield.

[00021 8] 2-(4-(bicyclo[2,2, 1 ]hept-5en-2-ylmethoxy)phenyl)-l , 10- phenanthroline: Ή NMR (300 MHz, CDCI3, δ): 9.23 (m, 1 H), 8.24 (m, 4 H), 8.07

63

-1406.1 (dd, J = 8.4, 3.6 Hz, 1 H), 7.75 (m, 2 H), 7.63 (m, 1 H), 7.07 (m, 2 H), 6.21 - 6.00 (m, 2 H, C=C-H, endo and exo), 4.15 - 3.62 (m, OCH₂, endo and exo, 2 H), 3.08 (s, br, nb, 0.5 H), 2.93 - 2.87 (m, br, nb, 1.5 H), 2.60 (m, nb, 1 H), 1 .95 (m, nb, 1 H), 1.50 (m, br, nb, 0.5 H), 1.41 - 1.28 (m, nb, 2 H), 0.68 (m, nb, 0.5 H). ^{I 3}C NMR (75 MHz, CDC1₃): 160.88, 157.55, 149.56, 145.15, 145.12, 137.80, 137.62, 137.08, 136.92, 136.91 , 136.70, 136.62, 131 .76, 131.67, 129.61 , 129.57, 127.46, 127.45, 127.13, 125.57, 125.55, 123.08, 120.55, 120.54, 1 15.01 , 72.60, 71.82, 49.68, 45.32, 44.15, 43.95, 42.50, 41.85, 38.82, 38.62, 29.90, 29.30. MS-EI (m/z): [M]⁺ calcd for C26H22N2O, 378.2, found 378.2. .

[000219] Step 3B: Synthesis of 2-(4-(5-(bicyclo[2.2.1]hept-5-en-2- yl)pe

[000220] To a solution of 4-(l , 10-phenanthrolin-2-yl)phenol (273 mg, 1.0 mmol) and 5-(5-bromopentyl)bicyclo[2.2.1]hept-2-ene (300 mg, 1.2 mmol) in DMF (10.0 mL) was added ₂C0₃ (270 mg, 2.0 mmol) at room temperature under stirring. The reaction mixture was then heated to 90 °C in oil-bath overnight. The reaction mixture was cooled down to room temperature, and water (30.0 mL) was added, and the product was extracted with ethyl acetate (20.0 mL x 3). The organic layer was collected and washed with water (50.0 mL x 6). After removal of organic solvents, the crude product was purified on silica gel column eluting with hexanes/acetone (6: 1 ). After removal of solvent and dried under vacuum, solid foam was obtained (100 %).

[000221 ] 2-(4-(5-(bicyclo[2.2.1 ]hept-5-en-2-yl)pentyloxy)phenyl)- 1 , 10- phenanthroline: Ή NMR (300 MHz, CDCI3, δ): 9.22 (dd, J, = 3.6 Hz, J₂ = 1.5 Hz, 1 H), 8.25 (d, J = 8.4 Hz, 2H), 8.08-8.02 (m, 2H), 7.87 (d, J= 7.4 Hz, 1 H), 7.56-7.46 (m, 3H), 6.97 (d, J = 8.4 Hz, 2H), 6.07 - 5.85 (m, C=C-H, endo and exo, 2 H), 3.95 - 3.90 (m, OCH₂, endo and exo, 2 H), 2.70 (s, br, nb, 1.5 H), 1 .95 - 1.86 (m, br, nb, 1 H), 1.81 - 1.67 (m, 3 H), 1.42-0.97 (m, 9 H), 0.40-0.45 (m, br, nb, 0.5 H). ¹³C NMR (75 MHz, CDCI₃): £ 160.64, 157.16, 150.35, 146.49, 146.13, 137.10, 136.80,

64

-1406.1 1-36.22, 132.58, 132.09, 129.44, 129.19, 127.23, 126.54, 125.84, 122.90, 120.03, 1 14.86, 68.24, 49.77, 45.60, 42.71 , 38.88, 34.88, 32.62, 29.48, 28.64, 26.49. MS-EI (m/z): [M]⁺ calcd for C30H30N2O, 434.2, found 434.3.

[000222] Example 22- Synthesis of a Norbornenyl-Phenanthrolinyl Homopolymer: Polv(2-(4-(bicvcle[2.2,llhept-5en-2-ylpentyloxy)phenvD-l,10- phenanthroline

[000223] 2-(4-(5-(Bicyclo[2.2.1 ]hept-5-en-2-yl)pentyloxy)phenyl)- 1 , 10-phenanthroline monomer (290 mg, 0.667 mmol), 3^rd generation Grubbs' Ru catalyst, and 5 mL CH2CI2 were mixed together in a dry box and stirred overnight. After removing the vessel from dry box, l mL ethyl vinyl ether was added to terminate the polymerization. Precipitating the product solution with ethyl ether (150 mL) results in a purple solid. The polymer was purified by dissolving it into 2 mL dichloromethane, then precipitating it with 150 mL ether. After three precipitations, the color of the polymer is still purple (90 mg, 31 %).

[000224] Ή NMR (300 MHz, CDC1₃):<5 9.16-9.10 (br, 1 H), 8.27-7.59 (br, 8H), 6.99-6.91 (br, 2H), 5.38-5.23 (br, 2H), 3.99-3.85 (br, 2H), 2.40-2.27 (br, 2H), 1.95-1.67 (br, 3H), 1.52-1.00 (br, 8 H).

[000225] Example 23- An PLED Device Employing an Emissive Layer Comprising A 1 : 1 Blend of A Norbornenyl-Bisoxadiazole Homopolymer Poly(2-(4-( bic yclo [2,2,11 hept-5en-2- ylpentyloxy)phenyl)- 1,10- phenanthroline)with A Norbornenyl-Triscarbazole Homopolymer XH-I-98b As Host In the Emissive Layer (6% Ir(ppy)¾ Emitter)

[000226] An OLED device employing an emissive layer comprising a 1 : 1 blend of the norbornenyl-phenanthrolinyl homopolymer poly(2-(4- (bicyclo[2,2, 1 ]hept-5en-2-pentlyJoxy)phenyl)- 1 , 10-phenanthroline(see Example 22) with A norbomenyl-triscarbazole homopolymer XH-I-98b(see Example 4) as host in the emissive layer (6% Ir(ppy)3 emitter) can be prepared by the procedure of Example 9, except that poly(2-(4-(bicyclo[2,2,l]hept-5en-2-ylmethoxy)phenyl)-

65

-1406.1 1 ,10-phenanthroline is substituted for the electron transporting norbornenyl- bisoxadiazole homopolymer XH-I-98a.

Conclusions

[000227] The above specification, examples and data provide exemplary description of the manufacture and use of the various compositions and devices of the inventions, and methods for their manufacture and use. In view of those disclosures, one of ordinary skill in the art will be able to envision many additional embodiments or sub-embodiments of the inventions disclosed and claimed herein to be obvious, and that they can be made without departing from the scope of the inventions disclosed herein. The claims hereinafter appended define some of those embodiments.

66

-1406.1

Claims

What is claimed is:

A composition comprising a blend of

a) at least one first norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted arylamine hole transporting side group, and

b) at least one additional norbornenyl polymer or copolymer comprising one or more norbornenyl subunits in the polymer backbone linked to at least one optionally substituted electron transporting side group.

The composition of claim 1 further comprising a non-polymeric luminescent guest emitter.

The composition of claim 2 wherein the luminescent guest emitter is a metal complex wherein the metal is Re, Ru, Os, Rh, Ir, Pd, Pt, Cu or Au.

The composition of claim 1 wherein the arylamine hole transporting side group comprises a monocarbazole, biscarbazole, triscarbazole or triarylamine side group.

The composition of claim 1 wherein the electron transporting side group comprises an optionally substituted oxadiazole derivative, pyridine derivative, triazole derivative or imidazole or benzimidazole side group.

The composition of claim 1 wherein the first norbornenyl polymer is a homopolymer wherein each norbornenyl subunit is linked to an optionally substituted monocarbazole, biscarbazole, triscarbazole or triarylamine side group.

The composition of claim 1 wherein the additional norbornenyl polymer is a homopolymer wherein each norbornenyl subunit is linked to an optionally substituted pyridine derivative, oxadiazole derivative, triazole derivative,or imidazole or benzimidazole side group.

8. The composition of claim 1 wherein

a) the first norbomenyl polymer or copolymer is a homopolymer

comprising norbomenyl subunits in the polymer backbone linked to at least one optionally substituted monocarbazole, biscarbazole, or triscarbazole side group, and

b) the additional norbomenyl polymer or copolymer is a homopolymer comprising norbomenyl subunits in the polymer backbone linked to at least one optionally substituted oxadiazole side group.

9. The composition of claim 1 further comprising a block copolymer

comprising at least a first block comprising one or more polymerized norbomenyl subunits in the block copolymer backbone linked to side groups comprising at least one optionally substituted monocarbazole, biscarbazole, triscarbazole or triarylamine group, and a second block comprising one or more polymerized norbomenyl subunits in the block copolymer backbone linked to side groups comprising at least one optionally substituted pyridine derivative, oxadiazole derivative, triazole derivative, or imidazole or benzimidazole sidegroup.

10. The composition of claim 9, wherein the subunits of the first norbomenyl polymer and the first block of the block copolymer are the same, and the subunits of the additional norbomenyl polymer and the second block of the block copolymer are the same.

11. The composition of any one of claims 1-9 wherein the weight ratio of the first norbomenyl polymer to the additional norbomenyl polymer is from about 1 :5 to about 5: 1.

68

4840-6681-1406.1

12. The composition of any one of claim 1-9 wherein the composition is a homogeneous amorphous phase with a glass transition temperature of at least 120°C.

13. The composition of any one of claim 1-9 wherein the composition comprises a mixture of at least two amorphous solid phases with a glass temperature of at least 120°C.

14. The composition of any one of claims 1-9 wherein the first norbornenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L¹ is an organic linking group,

b) R^c comprises at least one optionally substituted carbazole group

comprising the structure

69

4840-6681-1406.1

wherein:

R¹, R², R⁴, R⁵, R⁶, R⁷ are independently selected from a linear or branched C1-C12 alkyl group or H.

R is a linear or branched C1-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H.

15. The composition of any one of claims 1-9 wherein the first norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

L¹ is an organic linking group,

R^c comprises at least one optionally substituted carbazole group comprising the structure

70

4840-6681-1406.1 wherein:

1 2

R and R are independently selected from a linear or branched C1-C12 alkyl group or H.

R is a linear or branched C1-C12 alkyl group, a phenyl, bisphenyl or a phenyl-pyridyl group, or H.

The composition of any one of claims 1-9 wherein the first norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L¹ is an organic linking group,

b) R^c comprises at least one optionally substituted triarylamine group comprising the structure

Wherein:

R¹, R², R⁴, R⁵ is a linear or branched C1-C12 alkyl group or H.

The composition of any one of claims 1-9 wherein the norbomenyl polymer or copolymer la) comprises a plurality of subunits having the structure

wherein

a) L¹ is an organic linking group,

b) R^c comprises at least one optionally substituted triscarbazole group comprising the structure

wherein:

R¹, R², R⁴, R⁵ is a linear or branched C1-C12 alkyl group

18. The composition of any one of claims 12-17 wherein each of R¹, R², R⁴, R⁵,

R⁶ and R⁷ are hydrog

The composition of any of claim 12-17 wherein L has the structure

.0.

|— (CH₂)_Z— ¾^(CH₂)_Z^ ^(CH₂)_z i

wherein z and z' are independently selected integers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

72

4840-6681-1406.1 The composition of any one of claim 1-9 wherein the additional norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L is an organic linking group, and

b) R^ox comprises at least one optionally substituted 5-phenyl-l ,3,4- oxadiazole or triazole group comprising the structure.

wherein Z is:

and each optional R^b and R^c group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1 , 2, 3 or 4.

The composition of any one of claim 1-9 wherein the additional norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L is an organic linking group, and

73

4840-6681-1406.1 b) R^ox comprises at least one optionally substituted 5-phenyl-l,3,4- s

Y is a C6-C20 aryl or heteroaryl group, and

each optional R^a, R^b and R^c group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and each x is an independently selected integer 0, 1, 2, 3 or 4.

22. The composition of claim 21 wherein Y is phenyl, or pyridyl.

23. The composition of any one of claim 1-9 wherein the additional norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

74

4840-6681-1406.1

wherein

a) L is an organic linking group, and

b) R^ox comprises at least one optionally substituted 2,5-diphenyl-l ,3,4- oxadiazole or triazole group comprising the structure

wherein

wherein Z is: or

each optional R^a, R^b group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and

each x is an independently selected integer 0, 1 , 2, 3 or 4.

24. The composition of claims 20-23 wherein Z is oxygen.

25. The composition of any one of claim 1-9 wherein the additional norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L is an organic linking group, and

b) R^ox comprises at least one optionally substituted benzimidazole group comprising the structure

wherein

each optional R^a, R^b, and R^c group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, or f uoroalkoxy groups, and

each x is an independently selected integer 0, 1, 2, 3 or 4.

The composition of any one of claim 1-9 wherein the additional norbomenyl polymer or copolymer comprises a plurality of subunits having the structure

wherein

a) L is an organic linking group, and

b) R^ox comprises at least one optionally substituted phenanthroline group comprising the structure

wherein

each optional R^a or R^b, group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, f uoroalkoxy, aryl, or heteroaryl groups, and

each x is an independently selected integer 0, 1, or 2.

27. The composition of claims 18-26 wherein R^a is hydrogen and at least one R^b is t-butyl.

2

28. The composition of any one of claims 18-26 wherein L has the structure

|— 0-(CH₂)_z-| or \— (CH₂)_Z— O— \ wherein z and z' are independently selected integers 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or 12.

29. The composition of claim 9 wherein the first block comprises a plurality of subunits having the structure

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wherein

a) L¹ is an organic linking group,

R^c comprises at least one optionally substituted monocarbazole, biscarbazole, or triscarbazole group .

The composition of claim 29, wherein R^c comprises the structures

Wherein R 1 and R 2 are independently selected linear or branched Ci-

Ci2 alkyl groups or H.

31. The composition of claim 9 wherein the second block comprises a plurality of subunits having the structure

wherein

2

a) L is an organic linking group, and

b) R^ox comprises at least one optionally substituted 2 -phenyl- 1,3,4- oxadiazole group comprising the structure

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wherein

each optional R^b group is independently selected from hydrogen, fluoride, one or more linear or branched Ci_₂o alkyl, fluoroalkyl, alkoxy, or fluoroalkoxy groups, and

each x is an independently selected integer 0, 1 , 2, 3 or 4.

32. The composition of claim 9 wherein the block copolymer is present at a concentration of from about 0.1 to about 20 wt% of the composition.

33. An electronic device comprising the composition of any of the preceding claims.

34. An electronic device of claim 33 that is a light emitting diode.

35. The electronic device of claim 34 wherein the light emitting diode comprises an emission layer that comprises the composition.

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