HK1066019A - Electroactive fluorene copolymers and devices made with such polymers - Google Patents

Description

Electroactive fluorene copolymers and devices made with such copolymers

Background

Field of the invention

The present invention relates to electroactive fluorene copolymers. The invention also relates to an electronic device wherein the active layer and the device comprise such a polymeric material.

Description of related Art

Organic electronic devices, such as devices that emit light, such as light emitting diodes that make up displays, exist in many different types of electronic equipment. In all of these devices, the photoactive layer is sandwiched between two electrical contact layers. At least one of the electrical contact layers is light transmissive so light can pass through the electrical contact layer. Upon application of electricity across the electrical contact layers, light from the photoactive layer passes through the light-transmitting electrical contact layers.

It is known to use organic electroluminescent compounds as active components in light-emitting diodes. Simple organic molecules, such as anthracene, thiadiazole derivatives, and coumarin derivatives, are known to exhibit electroluminescence. Several classes of light emitting polymers have also been disclosed. They include, for example, poly (1, 4-phenylenevinylene) and derivatives; polythiophenes, in particular poly (3-alkylthiophene) and poly (p-phenylene). Alkyl and dialkyl derivatives of polyfluorenes are also disclosed in U.S. Pat. Nos. 5708130 and 5900327.

There remains a need for photoactive compounds having improved efficiency and methods for their preparation.

Summary of the invention

The present invention relates to a copolymer comprising at least one first monomer unit and at least one second monomer unit, wherein the at least one first monomer unit has the structural formula I shown in figure 1 and the at least one second monomer unit is selected from the group consisting of: (1) an aromatic radical having the structure II shown in fig. 2, (2) a 6-membered ring heteroaromatic radical having the structure III shown in fig. 6, (3) a 5-membered ring heteroaromatic radical having the structure IV shown in fig. 7, (4) an aromatic radical having the structure V shown in fig. 8, (5) a fused ring aromatic radical having the structure VI shown in fig. 9, the structure VII shown in fig. 10, and the structures VIII-XI shown in fig. 11, and (6) combinations thereof, wherein:

in each of the structural formulae I, II, III, IV, V, VI, VII, VIII-XI:

r, which may be the same or different at each occurrence, is a substituent on a carbon atom selected from: hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, F, -CN, -OR¹、-CO₂R¹、C_ψH_θF_λ、-OC_ψH_θF_λ、-SR¹、-N(R¹)₂、-P(R¹)₂、-P(R¹)₂、-SOR¹、-SO₂R¹、-NO₂β -dicarbonyl having the structural formula XII shown in figure 12 and further described below as "structural formula XII"; or adjacent R groups together may form a 5-or 6-membered cycloalkyl, aryl, or heteroaryl ring, wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

ψ is an integer of 1 to 20, and θ and λ are integers satisfying the following equation A1:

θ + λ is 2 ψ + 1; (equation A1);

in each of structural formulae II, III, IV, V, VI, VII, VIII and XI:

e, which may be the same or different at each occurrence, is a single bond or a linking group selected from arylene and heteroarylene;

in structural formula IV:

a is independently C or N, γ is 0 or an integer selected from 1 or 2, such that if two A's are N, γ is 0; or if one A is N and one A is C, γ is 1; or if both A's are C, γ is 2;

q is O, S, SO₂Or NR¹Wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

in structural formula V:

q1 is carbonyl, O, S, SO₂Or NR¹Wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

w is H, alkyl or heteroalkyl; or two W together may represent a single bond;

in structural formula VI:

two E are in the 1, 4-, 1, 5-, 1, 8-, 2, 3-or 2, 6-positions;

in structural formula VII:

two E are in the 1, 4-, 1, 5-, 1, 8-, 2, 3-, 2, 6-or 9, 10-positions;

in structural formula VIII:

the first E is at position 1, 2 or 3; the second E is at position 6, 7 or 8;

in structural formula IX:

the first E is at position 2, 3 or 4; the second E is at position 7, 8 or 9;

in structural formula XII:

R²selected from the group consisting of hydrogen, alkyl, aryl, heteroalkyl, and heteroaryl;

δ is 0 or an integer from 1 to 12.

The invention is also directed to organic electronic devices having at least one electroactive layer comprising the above copolymers.

The term "alkyl" as used herein means a group derived from an aliphatic hydrocarbon and includes straight chain, branched chain and cyclic groups, which may be unsubstituted or substituted. The term "heteroalkyl" means a group derived from an aliphatic hydrocarbon having at least one heteroatom in the main chain, which group may be unsubstituted or substituted. The term "aryl" means a group derived from an aromatic hydrocarbon, which may be unsubstituted or substituted. The term "heteroaryl" means a radical derived from an aromatic group containing at least one heteroatom, which radical may be unsubstituted or substituted. The term "arylene" means a group derived from an aromatic hydrocarbon having two points of attachment, which group may be unsubstituted or substituted. The term "heteroarylene" means a group derived from an aromatic hydrocarbon having at least one heteroatom and two points of attachment, which group may be unsubstituted or substituted. The phrase "adjacent to," when used to refer to layers in a device, does not necessarily refer to: one layer next to the other. On the other hand, the phrase "contiguous R groups" is used to denote R groups that are adjacent to each other in a chemical formula (i.e., a plurality of R groups are linked to a plurality of atoms with bonds). The term "photoactive" is used in connection with any material that exhibits electroluminescence and/or photosensitivity. The term "electroactive" relates to any material exhibiting hole transport/injection properties, electron transport/injection properties, electroluminescence and/or photosensitivity. The term "monomeric unit" refers to a repeating unit in a polymer. In addition, the IUPAC numbering system is used throughout, wherein groups from the periodic table are numbered 1-18 from left to right (chemical and physical CRC handbook, 81 th edition, 2000).

Drawings

FIG. 1 is structural formula I and structural formula I (a) of a first monomer unit for use in the present invention.

FIG. 2 is a structural formula II of a second monomer unit for use in the present invention.

FIG. 3 shows the structural formulas II (a) -II (j) of the second monomer unit used in the present invention.

FIG. 4 shows the structural formula II (k) -II(s) of the second monomer unit used in the present invention.

FIG. 5 shows the structural formula II (t) -II (z) of the second monomer unit used in the present invention.

FIG. 6 shows the structural formula III and the structural formulae (a) to (ii) (g) of the second monomer unit used in the present invention.

FIG. 7 shows structural formula IV and structural formulae IV (a) -II (h) of the second monomer unit used in the present invention.

FIG. 8 shows the structural formula V and the structural formulae V (a) -II (e) of the second monomer unit used in the present invention.

FIG. 9 shows the structural formula VI and structural formulae VI (a) -II (d) of the second monomer unit used in the present invention.

FIG. 10 is structural formula VII and structural formula VII (a) of a second monomer unit for use in the present invention.

FIG. 11 is a graphic representation of the structural formula VIII-structural formula IX of the second monomer unit used in the present invention.

FIG. 12 is structural formula XII of a substituent of a second monomer unit used in the present invention.

FIG. 13 is a schematic representation of an electronic device that can be loaded with the copolymer of the present invention.

Detailed description of the preferred embodiments

The copolymer of the present invention contains the above-mentioned at least one first monomer unit and at least one second monomer unit.

In a first preferred embodiment, the copolymer does not comprise vinylidene monomer units. In a second preferred embodiment, the composition of the copolymer is: optionally a suitable end capping group and at least one first monomer unit of formula I and at least one second monomer unit selected from formula II, formula III, formula IV, formula V, formula VI, formula VII, formula VIII, formula XI, formula X, and formula XI.

In a third preferred embodiment, each R group in each of structural formula I, structural formula II, structural formula III, structural formula IV, structural formula V, structural formula VI, structural formula VII, structural formula VIII, structural formula XI, structural formula X, and structural formula XI is selected from:

hydrogen;

an alkyl group;

an aryl group;

a heteroalkyl group;

a heteroaryl group;

F；

-CN；

-P(R¹)₂、-SOR¹wherein R is¹Each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

-NO₂；

a β -dicarbonyl having the structure XII shown in figure 12 and described further above;

-C_ψH_θF_λ；

-OC_ψH_θF_λ；

-OR¹、-CO₂R¹、-SR¹、-N(R¹)₂and-SO₂R¹Wherein R is¹Is a linear or branched alkyl group of 1 to 20 carbon atoms, or a linear or branched heteroalkyl group; or adjacent R groups together may form a 5-or 6-membered ring selected from cycloalkyl, aromatic and heteroaromatic rings. In the example where adjacent R groups together form a5 or 6-membered ring selected from an aromatic ring and a heteroaromatic ring, the aromatic and heteroaromatic rings are preferably unsubstituted.

First monomer unit

The first monomer unit is a fluorenyl unit of the structural formula I shown in figure 1. Preferred R groups are alkyl groups having 1 to 30 carbon atoms, heteroalkyl groups having one or more heteroatoms S, N of 1 to 30 carbon atoms, or O, aryl groups having 6 to 20 carbon atoms, heteroaryl groups having 2 to 20 carbon atoms and one or more heteroatoms S, N or O. Examples of suitable R groups include n-butyl and isobutyl, various pentyl, linear or branched; hexyl radicals, octyl radicals, including 2-ethylhexyl, up to hexadecyl and with or without olefinic unsaturation; phenyl, thiophene, carbazole, alkoxy, phenoxy and cyano. More preferred R groups on the carbon atom at the 9-position of the fluorene monomer unit are straight and branched C₆-C₁₂An alkyl group. More preferred R groups on the phenyl ring of the fluorene monomer unit are H, C₆-C₁₂Alkoxy, phenoxy, C₆-C₁₂Alkyl, phenyl or cyano.

Examples of suitable first monomer units are shown in FIG. 1 as structural formula I (a).

Second monomer unit

The second monomer unit can be selected from the structural formulas II-XI described below.

Structural formula II:

the second monomer unit may be selected from aryl groups having the structure shown in formula II in figure 2. The R group is preferably selected from:

hydrogen;

an alkyl group;

an aryl group;

a heteroalkyl group;

a heteroaryl group;

F；

-CN；

-NO₂；

a β -dicarbonyl having the structural formula XII shown in figure 12 and described further above;

-C_ψH_θF_λ；

-OC_ψH_θF_λand

-P(R¹)₂、-SOR¹，-OR¹、-CO₂R¹、-SR¹、-N(R¹)₂and-SO₂R¹Wherein R is¹Is a linear or branched alkyl group of 1 to 20 carbon atoms, or a linear or branched heteroalkyl group; or adjacent R groups together may form a 5-or 6-membered ring selected from cycloalkyl, aromatic and heteroaromatic rings.

Alternatively, the R group in structure II may be selected from:

partially or fully fluorinated alkyl groups having 1 to 12 carbon atoms, especially CF₃；

Alkoxy having 1 to 12 carbon atoms; esters having 3 to 15 carbon atoms;

-SR¹、-N(R¹)₂、-P(R¹)₂、-SOR¹、-SO₂R¹wherein R is¹Is an alkyl group having 1 to 12 carbon atoms;

-NO₂and

a β -dicarbonyl having the structural formula XII shown in figure 12, wherein:

in structural formula XII:

r is an alkyl group having 1 to 12 carbon atoms, and δ is 0, 1, or 2.

Examples of suitable second monomeric units having structural formula II are shown in FIGS. 3-5 as structural formulae II (a) -II (z), wherein:

in structures II (v) -II (y):

r is as described above for each of structural formulae I, II, III, IV, V, VI, VII, VIII-XI.

Structural formula III:

alternatively, the second monomer unit can be a divalent 6-membered ring heteroaromatic group having a structure as shown in structure III in FIG. 6. Preferred R groups are hydrogen, C₆-C₁₂Alkyl radical, C₆-C₂₀Aryl radical, C₂-C₂₀A heteroaryl group. Examples of suitable E linking groups include pyridinylene, -C₅H₄N-) and bipyridinyl (bipyridinidinidinyl, -C)₅H₄N-C₅H₄N-)。

Examples of second monomer units having structure III are shown in FIG. 6 as structures III (a) -III (g).

Structural formula IV:

alternatively, the second monomer unit can be a 5-membered ring heteroaromatic group having a structure as shown in structure IV in FIG. 7. Preferred R groups are hydrogen, C₁-C₁₂Alkyl (or, C)₁-C₅Alkyl or C₆-C₁₂Alkyl group), C₆-C₂₀Aryl radical, C₂-C₂₀Heteroaryl, more preferably C₆-C₁₂And (4) an aryl group. Examples of suitable E linking groups include pyrrolylene (pyrrolediyl, -C₄H₃N-) and thienylene (thiophenediyl, -C)₄H₃S-)。

Examples of suitable second monomeric units of formula IV are those of formulae IV (a) -IV (h) shown in FIG. 7, wherein:

in structural formula IV (a):

r is as described above for each of structural formulae I, II, III, IV, V, VI, VII, VIII-XI.

In structural formula IV (h):

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl.

Structural formula V:

alternatively, the second monomer unit may be an aromatic group having a structure as shown in structure V in fig. 8. The R group is preferably hydrogen, C₁-C₁₂Alkyl (or, C)₁-C₄Alkyl or C₆-C₁₂Alkyl group), C₆-C₂₀Aryl radical, C₂-C₂₀A heteroaryl group. Preferably, two W represent a single bond.

Examples of suitable second monomeric units of this type are units having the structure of formula v (a) -v (e), where:

in structures V (a), V (b):

r is as described above for each of structural formulae I, II, III, IV, V, VI, VII, VIII-XI.

In structural formula V (e):

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl.

Structure VI-structure XI:

alternatively, the second monomer unit can be a divalent fused aromatic radical having a structure as shown in structure VI in FIG. 9, structure VII in FIG. 10, structure VIII-XI in FIG. 11. Preferred R groups are hydrogen, C₆-C₁₂Alkyl radical C₆-C₂₀Aryl and C₂-C₂₀A heteroaryl group.

In formula VI, E is preferably in the 1, 4-, 1, 5-, 1, 8-, 2, 3-, or 2, 6-position. Examples of suitable second monomer units of formula VI are shown in FIG. 9, formulas VI (a) -VI (d).

In formula VII, E is preferably in the 1, 4-, 1, 5-, 1, 8-, 2, 3-, 2, 6-or 9, 10-position. Examples of suitable second monomer units of formula VII are shown in FIG. 10 formula VII (a).

In the copolymers of the present invention, the R groups are essentially pendant from the polymer backbone. Thus, the final choice of the R group should take into account the role these side chains play in the final polymer properties. These properties include electronic properties, solubility, processability, film-forming properties, enhancing or reducing inter-chain interactions, resulting in solubility in organic solvents, resulting in compatibility with the host polymer in the blend, causing a high dielectric constant to solvate the ions, enhancing ion mobility, and the like. In addition, when the R group is substituted, the steric influence response of these substituents is taken into account in the choice of substituents.

In the copolymer of the present invention, more than one second monomer unit may be present together with the first monomer unit. The relative molar ratio of the first monomer unit to the at least one second monomer unit can be from 99.9: 0.1 to 1: 99 or 99.5: 0.5 to 10: 90; or from 99: 1 to 20: 80, or from 99: 1 to 50: 50. The incorporation of the monomers in forming the polymer may be random or controlled, with the result that copolymers include, but are not limited to, random copolymers, alternating copolymers, and block copolymers.

Synthesis of

The copolymers of the present invention can generally be prepared by three known synthetic routes. In the first synthesis, as described by Yamamoto in the progress of polymer science, vol.17, page 1153 (1992), dihalogen derivatives of monomer units are reacted with stoichiometric amounts of zero-valent nickel compounds, such as bis (1, 5-cyclooctadiene) nickel (O). In the second approach, as described by Colon et al in journal of Polymer science, part A, Polymer chemistry edition, volume 28, page 367 (1990). The dihalogen derivative of the monomer unit is reacted with a catalytic amount of a Ni (II) compound in the presence of a stoichiometric amount of a substance capable of reducing divalent nickel ions to zero-valent nickel. Suitable materials include zinc, magnesium, calcium and lithium. In a third synthesis, a dihalogen derivative of one monomer unit is reacted with a derivative of another monomer unit having two reactive groups selected from boronic acids, boronic esters and boranes in the presence of a zero-valent palladium catalyst, such as tetrakis (triphenylphosphine) Pd, as described in us patent 5962631 and published PCT application WO 00/53565.

In some embodiments of the invention, the copolymer may be reacted with an end-capping compound to convert the reactive end groups to non-reactive end groups. The end-capping compound is generally added to the preformed polymer and the polymerization is terminated. The end-capping compound is typically an aromatic compound having a single reactive group, such as an aromatic ring having a single halide group or a boronic acid or boronic acid ester group. Examples of suitable end-capping compounds include 9-bromoanthracene, 4-bromo-1, 2-dimethoxybenzene, 1-bromopyrene, iodobenzene, bromobenzene, 2-bromo-9-fluorenone, and phenylboronic acid. End capping groups may also be designed to add functionality such as charge mobility and color shift. It may also affect interchain aggregation.

Electronic device

The invention also relates to an electronic device comprising at least one photoactive layer, which layer is located between two electrical contact layers, wherein at least one electroactive layer of the device comprises a copolymer according to the invention. As shown in fig. 13, a typical device 100 has an anode layer 110 and a cathode layer 150, and electroactive layers 120, 130 and optionally 140 between the anode 110 and cathode 150. Adjacent to the anode is a hole injection/transport layer 120. Adjacent to the cathode is an optional layer 140 comprising an electron injecting/transporting material. Between the hole injection/transport layer 120 and the cathode (or optional electron transport layer) is a photoactive layer 130. The copolymers of the present invention may be used in the hole injection/transport layer 120 and/or the photoactive layer 130 and/or the optional electron injection/transport layer 140.

The device typically also includes a support (not shown) adjacent to the anode or cathode. Typically supported adjacent the anode. The support may be flexible or rigid, organic or inorganic. Generally, glass or flexible organic films can be used as supports. The anode 110 is an electrode particularly effective for injecting or collecting positive charge carriers or the like. The anode is preferably made of a material comprising a metal, mixed metal, alloy, metal oxide or mixed metal oxide. Suitable metals include group 11 metals, metals in groups 4, 5, and 6, and group 8-10 transition metals. If the anode is light-transmissive, mixed metal oxides of groups 12, 13 and 14, such as indium-tin oxide, are typically used. The anode 110 may also comprise an organometallic such as polyaniline as described in "Flexiblelight-emitting diodes from soluble controlling Polymer", Nature vol.357, pp477-479 (11/6 1992).

The anode layer 110 is typically applied by physical vapor deposition or spin casting. The term "physical vapor deposition" refers to various deposition methods involving being carried out in a vacuum. For example, physical vapor deposition includes all forms of sputtering, including ion beam sputtering, and all forms of vapor deposition, such as electron beam evaporation and resistive evaporation. A particular form of physical vapor deposition that is useful is radio frequency magnetron sputtering.

The copolymers of the present invention can function as hole transport materials in layer 120. Other materials that facilitate hole transport include: n, N ' -diphenyl-N, N ' -bis (3-methylphenyl) - [1, 1 ' -biphenyl ] group]-4, 4 '-diamine (TPD) and bis [4- (N, N' -diethylamino) -2-methylphenyl](4-methylphenyl) methane (MPMP), void transport polymers such as Polyvinylcarbazole (PVK), (phenylmethyl) polysilane, poly (3, 4-ethylenedioxythiophene) (PEDOT), Polyaniline (PANI); electron and hole transport materials such as 4, 4-N, N' -dicarbazole Biphenyl (BCP); or a light emitting material having good electron and hole transport properties, than chelated oxinoid compounds, such as tris (8-hydroxyquinoline) aluminum (Alq)₃)。

The hole injection/transport layer 120 may be coated using conventional methods, including: spin coating, casting, and printing, such as gravure printing. The coating of the layer may also be by ink jet printing, thermal patterning or physical vapor deposition.

Typically, the anode 110 and the hole injection/transport layer 120 are patterned. It will be appreciated that the pattern may vary as desired. The first flexible composite barrier structure may be coated, for example, with a pattern of patterned mask or photoresist on the first flexible composite barrier structure prior to coating with the first electrical contact layer material. Or the layers may be applied as an integral layer and subsequently patterned using, for example, photoresist and wet chemical etching. The hole injection/transport layer may also be applied in an ink jet printing, lithographic printing or thermal transfer printing pattern.

Depending on the application of device 100, photoactive layer 130 may be a layer of material (e.g., in a photodetector) that is activated by application of a voltage to a light-emitting layer (e.g., in a light-emitting diode or light-emitting electrochemical cell) that responds to radiant energy and generates a signal with or without application of a bias voltage. Examples of photodetectors include phototubes, photoresistors, photoswitches, phototransistors, phototubes, and photovoltaic cells, which terms are as described in markus, John, Electronics and microelectronics Dictionary, 470 and476(McGraw-Hill, inc. 1966).

When device 100 is a light emitting device, photoactive layer 130 will emit light when a sufficient bias voltage is applied to the electrical contact layers. The copolymer of the present invention may be used in the light emitting active layer 130. Other known luminescent materials include small molecule materials such as Tang, U.S. patent 4356429; materials described in Van Slyke et al, U.S. patent 4539507, relevant portions of which are incorporated herein by reference. Alternatively, these materials may be polymeric materials such as those described by Friend et al in U.S. patent 5247190, Heeger et al in U.S. patent 5408109, Nakano et al in U.S. patent 5317169, relevant portions of which are incorporated herein by reference. The luminescent material may be dispersed in a matrix of another material, with or without additives, but is preferably in the form of a layer alone. The active organic layer typically has a thickness in the range of 50-500 nm.

When electronic device 100 is a photodetector, photoactive layer 130 responds to radiant energy and generates a signal with or without a bias voltage. Materials that respond to radiant energy and can produce a signal without a bias voltage (as in the case of photoconductive cells, photoresistors, photoswitches, phototransistors, phototubes) include, for example, many conjugated polymers and electroluminescent materials. Materials that respond to radiant energy and can produce a signal under bias (as in the case of a photoconductive cell or photovoltaic cell) include materials that chemically react to light and thereby produce a signal. These photosensitive chemically reactive materials include, for example, many conjugated polymers and electroluminescent and photoluminescent materials. Specific examples include, but are not limited to, MEH-PPV ("Optocoupler trade from chemical polymers", G.Yu, K.Pakbaz, and A.J.Heeger, Journal of electronic materials, Vol.23, pp925-928 (1994)); and MEH-PPV compositions with CN-PPV ("effective photoresists from interconnecting Polymer networks', J.J.M.Halls et al. (Cambridge group) Nature Vol.376, pp498-500, 1995).

Photoactive layers 130 containing active organic materials can be coated from solution by conventional methods including spin coating, casting, and printing. Depending on the nature of the material, the active organic material can be applied directly by a vapor deposition process. Reactive polymer precursors can also be coated and then converted to polymers, typically by heating.

The cathode 150 is an electrode that is particularly effective for injecting, or collecting, electrons or negative charge carriers. The cathode may be any metal or nonmetal having a lower work function than the first electrical contact layer (in this case, the anode). The material of the second contact layer may be selected from the group consisting of alkali metals of group 1 (e.g., Li, Cs), group 2 (alkaline earth metals), group 12 metals, rare earth metals, lanthanides and actinides. Such as aluminum, indium, calcium, barium and magnesium and combinations thereof may also be used.

The cathode layer 150 is often applied by physical vapor deposition methods. Typically, the cathode layer is printed patterned as discussed above with respect to the anode layer 110 and the conductive polymer layer 120. The cathode layer can be patterned using similar processing methods.

Optional layer 140 may serve to facilitate electron transport and may also serve as a buffer or sealing layer to prevent quenching outside the layer interface. This layer preferably promotes electromigration and reduces quenching. Examples of electron transport materials for optional layer 140 include metal chelated 8-hydroxyquinoline (oxinoid) compounds, such as tris (8-hydroxyquinoline) aluminum (Alq)₃) Phenanthroline-based compounds, such as 2, 9-dimethyl-4, 7-diphenyl-1, 10-phenanthroline (DDPA) or 4, 7-diphenyl-1, 10-phenanthroline (DPA), pyrrole compounds, such as 2- (4-biphenyl) -5- (4-tert-butylphenyl) -1, 3, 4-oxadiazole (PBD) and 3- (4-biphenyl) -4-phenyl-5- (4-tert-butylphenyl) -1, 2, 4-Triazole (TAZ).

Other layers are known in organic electronic devices. For example, there may be a layer (not shown) between the conductive polymer layer 120 and the active layer 130 to facilitate positive charge transport and/or band gap matching of the layers, or to act as a protective layer. Similarly, additional layers may be present between the active layer 130 and the cathode layer 150 to facilitate negative charge transport and/or band gap matching between the layers, or to function as a protective layer. Layers known in the art may be used. In addition, any of the above layers may be composed of two or three layers. Alternatively, some or all of the inorganic anode layer 110, the conductive polymer layer 120, the active layer 130, and the cathode layer 150 may be surface treated to increase the charge carrier transport efficiency. The choice of materials for each of the constituent layers is preferably determined by a tradeoff, the goal of providing a device with high device efficiency.

The device 100 may be fabricated by sequentially depositing the layers on a suitable substrate. Substrates such as glass and polymeric films may be used. In most cases, the anode is coated onto a substrate and the layers are formed therefrom. However, the cathode may be applied to the substrate first, and the layers added in reverse order. In general, the different layers have the following thickness ranges: the inorganic anode 110, 500-5000 angstroms, preferably 1000-2000 angstroms; a conductive polymer layer, 50-2500 angstroms, preferably 200-2000 angstroms; light emitting layer 130, 10-1000 angstroms, preferably 100-800 angstroms; optionally an electron transport layer 140, 50-1000 angstroms, preferably 200-800 angstroms; the cathode 150, 200-10000 angstroms, preferably 300-5000 angstroms.

Examples

The following examples illustrate certain features and advantages of the present invention. They are illustrative of the invention and not limiting. All percentages are by weight unless otherwise indicated.

Examples 1 to 5 and examples 1A to A5

Examples 1-5 illustrate the preparation of copolymers of the present invention using dihalogen monomers and zero-valent nickel. The copolymers were characterized by number average molecular weight (Mn) determined by Nuclear Magnetic Resonance (NMR) and Gel Permeation Chromatography (GPC).

Example 1

DMF (5 ml) was added under inert conditions to a 50 ml Schlenck tube equipped with a stirring bar containing bis (1, 5-cyclooctadiene) nickel (O) (1.23 g, 4.48 mmol), 2, 2' -bipyridine (0.70 g, 4.48 mmol), and 1, 5-cyclooctadiene (0.48 g, 4.48 mmol). The subsequent dark blue/violet solution was stirred at 60 ℃ for 30 minutes, then a solution of the first monomer, 2, 7-diiodo-9, 9-bis (2-ethylhexyl) fluorene (1.08 g, 1.68 mmol) and the second monomer, 2, 5-bis (p-bromophenyl) -N- (p-hexylphenyl) pyrrole (0.30 g, 0.56 mmol) in toluene (20 ml) was added via syringe. The reaction mixture was then stirred at 75 ℃ for 5 days. The mixture was cooled to room temperature and precipitated into a solution of methanol (100 ml), acetone (100 ml) and concentrated hydrochloric acid (5 ml). After stirring for two hours, the mixture was filtered. The solid residue was then dissolved in chloroform and reprecipitated into a solution of methanol (100 ml), acetone (100 ml) and concentrated hydrochloric acid (5 ml). After stirring for 1 hour, the mixture was filtered. Finally, the residue was washed with methanol, water and methanol in this order and dried in vacuo. The molecular weights are given in table 1 below.

Example 1A

The procedure of example 1 was repeated except that the reaction mixture was stirred at 75 ℃ for 24 hours instead of 5 days. In addition, after the mixture was filtered, the resulting solid was redissolved in chloroform and precipitated in pure methanol before the residue was washed with methanol, water and methanol in order and dried under vacuum. Essentially the same molecular weights as provided in table 1 below were obtained.

Examples 2 to 5

The procedure of example 1 was repeated using 2, 7-dibromo-9, 9-bis (2-ethylhexyl) fluorene as the first monomer and a different second monomer, and iodobenzene as the end-capping group. The reaction mixture without the blocking agent was heated and stirred for 4 days, the iodobenzene blocking agent was added and the mixture was stirred for a further day at 75 ℃. The copolymers are summarized in table 1 below.

Examples 2A to 5A

The procedure of examples 2-5 was repeated except that bromobenzene was added instead of iodobenzene as the end-capping group. The reaction mixture was heated with stirring for 24 hours instead of 4 days before the bromobenzene blocking agent was added, and the mixture was stirred for an additional hour instead of one day. The resulting copolymers were similar to those summarized in table 1 below.

TABLE 1 fluorene copolymers

Examples	A first monomer r	Second monomer	Ratio of first to second to capping agent*	Mn
					1	Diiodo	2, 5-bis (p-bromophenyl) -N- (p-hexylphenyl) pyrrole	3∶1∶0	47200
2	Dibromo radical	3, 5-Dibromobenzoic acid methyl ester	10∶1∶1.1	68700
					3	Dibromo radical	2, 5-Dibromobenzoic acid methyl ester	10∶1∶1.1	98400
4	Dibromo radical	2, 5-bis (4-bromophenyl) oxadiazoles	10∶1∶1.1	67300
					5	Dibromo radical	2, 7-dibromo-9-fluorenone	10∶1∶1.1	60900

This ratio is the molar ratio of the starting materials

Examples 6 and 6A

This example illustrates the preparation of fluorene copolymers using dihalo monomers, diboronate monomers and palladium catalysts.

Example 6

Toluene (10 ml) was added to a 50 ml Schlenck tube containing 2, 7-diiodo-9, 9-bis (2-ethylhexyl) fluorene (1.07 g, 1.66 mmol) and 1, 4-benzenediboronic acid bis (neopentyl glycol) cyclic ester (0.50 g, 1.66 mmol) under an argon atmosphere equipped with a stirring bar. Then tetrakis (triphenylphosphine) palladium (O) (19 mg, 0.0166 mmol) and degassed aqueous potassium carbonate (2M, 7.0 ml) were added to the tube. The solution was heated in an oil bath at 100 ℃ for 48 hours with vigorous stirring. The end-capping agent 4-methylphenylboronic acid (50 mg, 0.33 mmol) was added and the mixture was heated with stirring for 12 hours. The mixture was cooled to room temperature and then precipitated into a solution of methanol (100 ml), acetone (100 ml) and concentrated hydrochloric acid (5 ml). After stirring for 2 hours, the mixture was filtered. The solid residue was then dissolved in chloroform and reprecipitated into a solution of methanol (100 ml), acetone (100 ml) and concentrated hydrochloric acid (5 ml). After stirring for 1 hour, the mixture was filtered. Finally, the residue was washed with methanol, water and methanol in this order and dried in vacuo. The molecular weight (Mn) of the resulting copolymer was 8800.

Example 6A

Toluene (10 ml) was added to a 50 ml Schlenck tube containing 2, 7-diiodo-9, 9-bis (2-ethylhexyl) fluorene (1.07 g, 1.66 mmol) and 1, 4-benzenediboronic acid bis (neopentyl glycol) cyclic ester (0.50 g, 1.66 mmol) under an argon atmosphere equipped with a stirring bar. Then tetrakis (triphenylphosphine) palladium (O) (19 mg, 0.0166 mmol) and degassed aqueous potassium carbonate (2M, 7.0 ml) were added to the tube. The solution was heated in an oil bath at 100 ℃ for 48 hours with vigorous stirring. The first capping agent, phenylboronic acid (50 mg, 0.33 mmol) was added and the mixture was heated with stirring for 1 hour. A second blocking agent bromobenzene (50 mg) was added and the mixture was stirred with heating for 1 hour. Then, the mixture was cooled to room temperature and precipitated into a methanol solution. The mixture was filtered and the residue was washed with methanol and dried in vacuo. The molecular weight (Mn) of the resulting copolymer was 8800.

Examples 7 to 17

The copolymers of examples 1-5 above were tested as luminophores in substrate-supported anode modified light emitting diodes having the layers shown in fig. 13. The anode used was Indium Tin Oxide (ITO), supported by a glass substrate. The hole injection/transport layer is ITO spin-coated on a glass substrate. The hole injection/transport layer is poly (3, 4-ethylenedioxythiophene), PEDOT (Baytron  P, available from Bayer, germany) having a thickness of about 2000 angstroms, or a bilayer of PEDOT and Polyvinylcarbazole (PVK) having a total thickness of about 2000 angstroms. The copolymer was dissolved in toluene to form a 2.0% (w/v) solution, filtered through a 0.22 micron filter, and spin coated on the hole injection/transport layer. The target thickness of the copolymer layer is 800 angstroms with actual thicknesses generally in the range of 500-1000 angstroms.

For the cathode, 1X 10 in vacuum^-6At torr, barium and aluminum layers were sequentially vapor deposited on top of the EL layer. The final thickness of the barium layer was 30 angstroms; the thickness of the aluminum layer was 3000 angstroms. Device performance was tested in a dry box with a calibrated Si photodiode. The results are given in table 2 below.

TABLE 2

Examples	EL polymer	Hole injection/transport	Voltage at 100 kan/m	Kam/an at 25 mA	Kang/an (in milliampere)	Kan/square meter (in the volt)	QE% (in volt)
								7	Example 1	PEDOT				849 (12V)	0.18 (12V)
8	Example 1	PEDOT/PVK				669(14 volt)	0.11(14 volts)
								9	Example 1	PVK				3970(14 volt)	0.62(14 volts)
10	Example 2	PEDOT/PVK	8.6	0.76	0.86(34 milliamps)
								11	Example 2	PVK	6.6	0.06	0.068(55 milliamps)
12	Example 3	PEDOT/PVK	9.1	1.19	1.22(35 milliamp)
								13	Example 3	PVK	6.9	0.2	0.22(20 milliamps)
14	Example 4	PEDOT/PVK	＞10	0.68	0.87(3 mA)
								15	Example 4	PVK	9.1	0.46	0.50(50 milliamps)
16	Example 5	PEDOT/PVK	＞10	1.14	3.74(0.04 milliamp)
								17	Example 5	PVK	＞10	1.2	1.5(8 milliamps)

While the invention has been described with respect to what is presently considered to be the preferred examples, it is to be understood that the invention is not limited to the disclosed examples. On the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent arrangements and functions.

Claims (14)

1. A copolymer comprising at least one first monomer unit having the structure I shown in fig. 1 and at least one second monomer unit selected from the group consisting of (1) an aromatic group having the structure II shown in fig. 2, (2) a 6-membered ring heteroaromatic group having the structure III shown in fig. 6, (3) a 5-membered ring heteroaromatic group having the structure IV shown in fig. 7, (4) an aromatic group having the structure V shown in fig. 8, (5) a fused ring aromatic group having the structure VI shown in fig. 9, the structure VII shown in fig. 10, and the structures VIII-XI shown in fig. 11, and (6) combinations thereof, wherein:

in each of the structural formulae I, II, III, IV, V, VI, VII, VIII-XI:

r, which may be the same OR different at each occurrence, is a substituent on a carbon atom selected from the group consisting of hydrogen, alkyl, aryl, heteroalkyl, heteroaryl, F, -CN, -OR¹、-CO₂R¹、C_ψH_θF_λ、-OC_ψH_θF_λ、-SR¹、-N(R¹)₂、-P(R¹)₂、-SOR¹、-SO₂R¹、-NO₂β -dicarbonyl having the structural formula XII shown in figure 12 and further described below as "structural formula XII"; or adjacent R groups together may form a 5-or 6-membered cycloalkyl, aryl, or heteroaryl ring, wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

ψ is an integer of 1 to 20, and θ and λ are integers satisfying the following equation A1:

θ + λ is 2 ψ + 1; (equation A1);

in each of structural formulae II, III, IV, V, VI, VII, VIII and IX:

e, which may be the same or different at each occurrence, is a single bond or a linking group selected from arylene and heteroarylene;

in structural formula IV:

a is independently C or N, γ is 0 or an integer selected from 1 or 2, such that if two A's are N, γ is 0; or, if one a is N and one a is C, γ is 1; or if both A are C, then γ is 2;

q is O, S, SO₂Or NR¹Wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

in structural formula V:

Q¹is a carbonyl group, O,S、SO₂Or NR¹Wherein:

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

w is H, alkyl or heteroalkyl; or two W together may represent a single bond;

in structural formula VI:

two E are in the 1, 4-, 1, 5-, 1, 8-, 2, 3-or 2, 6-positions;

in structural formula VII:

two E are in the 1, 4-, 1, 5-, 1, 8-, 2, 3-, 2, 6-or 9, 10-positions;

in structural formula VIII:

the first E is at position 1, 2 or 3; the second E is at position 6, 7 or 8;

in structural formula IX:

the first E is at position 2, 3 or 4; the second E is at position 7, 8 or 9;

in structural formula XII:

R²selected from the group consisting of hydrogen, alkyl, aryl, heteroalkyl, and heteroaryl;

6 is 0 or an integer from 1 to 12.

2. The copolymer of claim 1, wherein the plurality of R groups in the one or more units of the at least one first monomer unit are each selected from alkyl groups having from 1 to 30 carbon atoms; heteroalkyl having 1 to 30 carbon atoms and one or more heteroatoms S, N, or O; aryl having 6 to 20 carbon atoms, heteroaryl having 2 to 20 carbon atoms and one or more heteroatoms S, N or O.

3. The copolymer of claim 1, wherein the copolymer is free of any vinylidene monomer units.

4. The copolymer of claim 1, wherein each R group in each of structural formula I, structural formula II, structural formula III, structural formula IV, structural formula V, structural formula VI, structural formula VII, structural formula VIII, structural formula IX, structural formula X, and structural formula XI is selected from:

hydrogen;

an alkyl group;

an aryl group;

a heteroalkyl group;

a heteroaryl group;

F；

-CN；

-P(R¹)₂、-SOR¹wherein R is¹Each of which, when present, may be the same or different, is a substituent on a heteroatom and is selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

-NO₂；

a β -dicarbonyl having the structural formula XII shown in figure 12;

-C_ψH_θF_λ；

-OC_ψH_θF_λ；

-OR¹、-CO₂R¹、-SR¹、-N(R¹)₂and-SO₂R¹Wherein R is¹Is a linear or branched alkyl group of more than 20 carbon atoms, or a linear or branched heteroalkyl group.

5. The copolymer of claim 1, wherein at least one R group in the one or more units of the at least one first monomer unit is independently selected from the group consisting of linear and branched n-butyl; straight and branched chain isobutyl groups; straight and branched chain pentyl; hexyl and octyl with or without olefinic unsaturation; phenyl, thiophene, carbazole, alkoxy, phenoxy and cyano.

6. The copolymer of claim 1, wherein at least one R group in the one or more units of the at least one first monomer unit is independently selected from H, C₆-C₁₂Alkoxy, phenoxy, C₆-C₁₂Alkyl, phenyl and cyano.

7. The copolymer of claim 1, wherein the one or more units of the at least one second monomeric unit are selected from the group consisting of structural formulas ii (a) -ii (z), iii (a) -iii (g), iv (a) -iv (h), v (a) -v (e), vi (a) -vi (d), and vii (a), wherein:

in structures II (v) -II (y), IV (a), V (a), and V (b):

r is as described above for each of structural formulae I, II, III, IV, V, VI, VII, VIII-XI;

in structural formula IV (h):

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom and is selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl;

in structural formula V (e):

R¹each of which, when present, may be the same or different, is a substituent on a heteroatom and is selected from the group consisting of alkyl, aryl, heteroalkyl, and heteroaryl.

8. The copolymer of claim 1, wherein one or more units of the at least one second monomeric unit has structure II, wherein R is selected from:

hydrogen;

an alkyl group;

an aryl group;

a heteroalkyl group;

a heteroaryl group;

F；

-CN；

-NO₂；

a β -dicarbonyl having the structural formula XII shown in figure 12;

-C_ψH_θF_λ；

-OC_ψH_θF_λ(ii) a And

-P(R¹)₂、-SOR¹，-OR¹、-CO₂R¹、-SR¹、-N(R¹)₂and-SO₂R¹Wherein R is¹Is a linear or branched alkyl group of 1 to 20 carbon atoms, or a linear or branched heteroalkyl group.

9. The copolymer of claim 1, wherein one or more units of the at least one second monomeric unit has the structure II, wherein R is selected from the group consisting of:

partially or fully fluorinated alkyl groups having 1 to 12 carbon atoms;

alkoxy having 1 to 12 carbon atoms;

esters having 3 to 15 carbon atoms;

SR¹、-N(R¹)₂、-P(R¹)₂、-SOR¹、-SO₂R¹wherein R is¹Is an alkyl group having 1 to 12 carbon atoms;

-NO₂(ii) a And

a β -dicarbonyl having the structural formula XII shown in figure 12, wherein:

in structural formula XII:

r is an alkyl group having 1 to 12 carbon atoms, 6 is 0, 1, or 2.

10. An electronic device comprising at least one electroactive layer (120, 130, 140) comprising the copolymer of any of claims 1-9.

11. An electronic device comprising at least one hole injection/transport layer, characterized in that one or more of said at least one hole injection/transport layer comprises a copolymer according to any of claims 1 to 9.

12. An electronic device comprising at least one electron injection/transport layer, characterized in that one or more of said at least one electron injection/transport layer comprises a copolymer according to any of claims 1 to 9.

13. The copolymer of any one of claims 1-9, further comprising an end capping group comprising an aryl group.

14. The device of claim 10, wherein the device is selected from the group consisting of a light emitting device, a photodetector, and a photovoltaic device.