[go: up one dir, main page]

WO2004096872A1 - Stabilisation de complexes de metaux de transition pour la catalyse dans des environnements divers - Google Patents

Stabilisation de complexes de metaux de transition pour la catalyse dans des environnements divers Download PDF

Info

Publication number
WO2004096872A1
WO2004096872A1 PCT/US2003/032172 US0332172W WO2004096872A1 WO 2004096872 A1 WO2004096872 A1 WO 2004096872A1 US 0332172 W US0332172 W US 0332172W WO 2004096872 A1 WO2004096872 A1 WO 2004096872A1
Authority
WO
WIPO (PCT)
Prior art keywords
ligand
catalyst
atom
transition metal
complex
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2003/032172
Other languages
English (en)
Inventor
Krzysztof Matyjaszewski
Nicolay V. Tsarevsky
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Carnegie Mellon University
Original Assignee
Carnegie Mellon University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/625,890 external-priority patent/US20040044152A1/en
Application filed by Carnegie Mellon University filed Critical Carnegie Mellon University
Priority to AU2003284050A priority Critical patent/AU2003284050A1/en
Publication of WO2004096872A1 publication Critical patent/WO2004096872A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
    • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
    • C08F20/04—Acids, Metal salts or ammonium salts thereof

Definitions

  • This present invention is directed towards the preparation and use of suitable transition metal complexes for use as catalysts.
  • the transition metal complexes may comprise heterodonor ligands.
  • the present invention is also directed toward a method of determining the suitability of a transition metal complex for use in a catalytic reaction, such as, but not limited to, atom transfer radical polymerization ("ATRP"), atom transfer radical addition (“ATRA”), atom transfer radical cyclization (“ATRC”), and other catalytic redox reactions.
  • ATRP atom transfer radical polymerization
  • ATRA atom transfer radical addition
  • ATRC atom transfer radical cyclization
  • the method assists in the approximate determination of the fundamental properties of the transition metal complex in a reaction media, such as, but not limited to, solubility, redox potential, stability towards ionic species, conditional radically transferable atom phylicity, and propensity toward disproportionaltion and therefore, the suitability of the complex to be used as a catalyst in the reaction media.
  • the method provides a basis for prediction and evaluation of the properties of a transition metal complex for a particular selective catalytic reaction in a broad range of reaction environments.
  • An understanding of the principles of the disclosed method allows a transition metal complex to be tuned to specific reaction medium by selecting a transition metal complex and ligand combination having the desired qualities. BACKGROUND OF THE INVENTION Transition metal complexes are used as catalysts for many organic reactions.
  • ligands in the transition metal complexes have been selected empirically, based on experience, from a multitude of molecules wherein the donor atoms in the ligand are generally the same element.
  • Several patents describe automated catalyst selection and evaluation systems that may be used to screen a multiplicity of variations in transition metal and catalyst compositions. Changes in catalytic capabilities, including reactivity, solubility and stability, have generally been accomplished merely by modifying the skeletal structure or the donor/acceptor properties of the substituents attached to skeleton of a known functional ligand.
  • ATRP One catalytic reaction process that uses catalytic transition metal complexes is ATRP.
  • the ATRP equilibrium can be expressed as:
  • the overall equilibrium constant for ATRP can be expressed as the product of the equilibrium constants for electron transfer between metal complex (KET), electron affinity of the halogen (KEA), bond homolysis of the alkyl halide (K B H) and heterolytic cleavage of the CU ⁇ -X bond or "halogen philicity" (K H p). Therefore, for a given alkyl halide R-X, more reducing catalysts will increase KATRP only if KHP stays constant.
  • Atom Transfer (Overall Equilibrium)
  • U.S. patent application 10/271,025 describes the Simultaneous Reverse and Normal Initiation (SR&NI) process of ATRP that is used in to initiate a polymerization processes in the Examples.
  • SR&NI Simultaneous Reverse and Normal Initiation
  • U.S. Patent No. 6,624,262 discloses fundamental parameters that should be considered when attempting to avoid disproportionation. Disproportionation of the higher oxidation state of the catalyst was reduced in United States Patent No. 6,624,262 by an addition of excess ligands to modify the catalyst environment.
  • Preprints 87, 59, 2002 discloses the preparation and use of bulky bidentate ligands comprising P with N or S or O donor atoms for olefin polymerization in the gaseous phase. No fundamental reason for selection of the donor atom is provided in the abstract. Also, in Polymer Preprints 2002, 43(2), 3, Sawamoto describes the use of ligands comprising phosphorous and nitrogen. These atoms are known to work together in conjunction with ruthenium as suitable counterion/ligand donor atoms for metal mediated polymerization for the polymerization of neutral nonionic organic monomers. Disclosed is an increase in catalytic activity of the ruthenium complexes via varying ligand-design strategies.
  • the ruthenium complex with a heterodonor ligand was used in a typical organic medium and the only effect noted was an increase in the rate of polymerization that was attributed to improved interaction of the amino donor group compared to amine group.
  • PCT publication WO 0151529 describes procatalysts comprising bidentate ligands, catalyst systems, and use in olefin polymerization.
  • the catalyst system comprises a transition metal complex and an alkyl aluminum compound.
  • the transition metal complex will not operate without the alkyl aluminum activator in this dual entity catalyst system.
  • the bidentate ligand is bound to the transition metal by two atoms selected from the group consisting of oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony, and bismuth, or mixtures thereof.
  • the catalysts are limited to transition metal comprising titanium, zirconium and hafnium.
  • PCT publication WO 0187996, (2001) also describes an olefin polymerization catalyst and process and polymer, polymer derivatives, lubricants and fuels thereof.
  • the catalyst described is one having a nitrogen coordinating group and a second coordinating group selected from oxygen, sulfur, selenium and tellurium groups and a metal compd. where the metal is a transition metal, boron, aluminum, germanium or tin.
  • the ligands are bidentate ligands and require two carbon atoms as spacers between the donor atoms.
  • thiolic ligands such as: 2-imidazolidine-thione (IMT), hydantoin (ID), 2-thiohydantoin (TIOID), rhodanine (RD), 2-mercaptoimidazole (MI), 2-mercapto-l-methylimidazole (MMI) and 2- mercaptopyridine (MPYR), which supposed that the co-ordination bond between sulphur and metal is stronger than the possible bond between nitrogen or oxygen and metal due to the minor difference in electronegativity existing between sulphur and metal compared with that existing between nitrogen or oxygen and metal.
  • IMT 2-imidazolidine-thione
  • ID hydantoin
  • TIOID 2-thiohydantoin
  • RD rhodanine
  • MI 2-mercaptoimidazole
  • MI 2-mercapto-l-methylimidazole
  • MMI 2-mercaptopyridine
  • MPYR 2-mercaptopyridine
  • the present invention in certain aspects is directed toward a catalytic process, comprising reacting free radically (co)polymerizable acidic monomers utilizing a suitable transition metal complex as a catalyst.
  • a catalyst is suitable for the reaction if the interactions of the catalyst with the reaction media and the reaction components do not prevent the catalyst from being active in the desired reaction.
  • the suitable catalyst may be at least partially soluble in the reaction media, possess a low redox potential, stability towards ionic species, low propensity to disproportionation, and sufficient conditional metal-radically transferable atom or group phylicity to act as a catalyst in the reaction media.
  • Embodiments of the transition metal complex comprises a heterodonor ligand.
  • the heterodonor ligands may be useful in catalytic reactions in aqueous, polar, acidic, ionic and basic media or with polar, acidic, ionic and basic monomers.
  • the heterodonor ligand may a bidentate or a multidentate ligand.
  • the heterodonor ligand may comprise a donor atom that cannot be protonated.
  • the transition metal complex may be desirable for the transition metal complex to have the following properties sufficient solubility such that at least a portion of the transition metal complex of both oxidation states is soluble in the reaction media, redox potential of less than 500mV, acidity stability constants of the protonated ligand greater than 10 "4 , conditional diproporportionation constant of less than 1000, and conditional metal-radically transferable atom or group phylicity of greater than 10.
  • the process is a catalytic process comprising reacting free radically (co)polymerizable acidic monomers utilizing a suitable transition metal complex as a catalyst, wherein the catalytic process is conducted in a polar media.
  • the transition metal complex can comprises a suitable heterodonor ligand.
  • the heterodonor ligand may have at least two donor atoms each independently selected from the group consisting of oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony, and bismuth.
  • Figures 3(a) and 3(b) illustrates dependence of [Cu ⁇ X] on the total concentration of Cu 11 or X, with one of the concentrations fixed at 0.02 M, Figure 3(a) or 0.05 M, Figure 3(b), the value of ⁇ ljX from 10-10 5 is given at each curve;
  • Figure 4 illustrates electronic spectra of CuBr 2 complex of MTAA, the same complex in the presence of 4-toluenesulfonic acid, and CuBr 2 in the presence of the acid, the spectra were measured in water;
  • Figure 5 illustrates plot of observed chemical shifts vs. concentration for peak maxima of Cu(I) complex of Na 2 EDTDAA, indicating two linear curve with intercepts near zero;
  • Figures 6(a) and 6(b) illustrates comparison of IR Spectra of Cu(II) EDTDA complexes with water and deuterium oxide;
  • Figure 7 illustrates UV/Vis spectra of Cu(II) EDTDAA complexes of various concentrations, the numbers at the curves indicate the number of equivalents of ligands added to the Cu(II);
  • Figure 8 illustrates calculation of extinction coefficients for Cu(II) EDTDAA complexes measure by UV/Vis spectra at two different wavelength (774 and 978 nm);
  • Figure 9 illustrates UV/Vis spectra for a series of complexes with different concentrations of Br, from no KBr to 800 equivalents;
  • Figure 10(a) illustrates ratio of absorption at different wavelengths taken from Figure 9 above UV/Vis spectra and
  • Figure 10(b) illustrates detailed examination of ratio of abso ⁇ tion at different wavelengths taken from Figure 9 between 400 and 1300 nm from UV/Vis spectra of Figure 10(a);
  • Figure 11 illustrates the detailed coleman plots of Figure 9 for a series of complexes with different concentrations of added p-toluenesulfonic acid
  • Figures 12(a) illustrates the polymerization rate for MAA in different solvents using CuBr/Na2EDTDA as catalysts including two concentrations of D 2 O/MeOH and D 2 O alone;
  • Figures 13(a) and 13(b) illustrates ATRP of methacrylic acid using two different catalysts wherein Figure 13(a) shows the kinetics and Figure 13(b) shows the evolution of degree of polymerization, DP, with conversion for the system using CuBr / Na 2 EDTDA catalyst; Figure 14 illustrates comparison of heterodonor ligand complexes and Cu(I)bpy catalyst complex for polymerization of MAA in water;
  • Figure 15(a) illustrates NMR spectra indicating protonation of bpy by MAA in water-methanol and Figure 15(b) illustrates the decomposition of Cu(bpy) 2 Br in the presence of MAA;
  • Figure 16 illustrates HEMA polymerization using EDTDAA-based catalyst (60% deactivator) at 60°C;
  • Figures 17(a) and 17(b) illustrates ATRP using various initial concentrations of initiator and Cu(II) deactivator wherein Figure 17(a) shows the kinetics of each reaction and Figure 17(b) shows the growth in molecular weight versus conversion for same systems as Figure 17(a).
  • This present invention is directed towards the preparation and use of transition metal complexes for use as catalysts.
  • Embodiments of the transition metal complexes may comprise heterodonor ligands.
  • the invention is also directed towards polymerization processes.
  • Embodiments of the process of the present invention include reacting or polymerizing acidic monomers in the presence of a catalyst, such as a suitable transition metal complex.
  • Further embodiments of the method include reacting or polymerizing ionic, acidic or basic monomers in the presence of a suitable transition metal catalyst comprising heterodonor ligands.
  • Further embodiments of the method include reacting or polymerizing ionic, acidic or basic monomers in the presence of a suitable single entity transition metal complex or unimolecular transition metal catalyst system, wherein the transition metal catalyst may comprise heterodonor ligands. Further embodiments of the method include reacting or polymerizing ionic, acidic or basic monomers in a aqueous, polar, acidic or basic media in the presence of a suitable transition metal catalyst comprising heterodonor ligands.
  • the polar media may comprise any polar compounds, such as, but not limited to, aqueous media, and alcohols.
  • the present invention is also directed toward a method of determining whether a proposed transition metal complex is a suitable catalyst for use specific a catalytic reaction, such as, but not limited to, atom transfer radical polymerization ("ATRP"), atom transfer radical addition (“ATRA”), and atom transfer radical cyclization (“ATRC”).
  • a catalytic reaction such as, but not limited to, atom transfer radical polymerization ("ATRP"), atom transfer radical addition (“ATRA”), and atom transfer radical cyclization ("ATRC”).
  • the method assists in the approximate determination of the fundamental properties of the transition metal complex in a reaction media, such as, but not limited to, solubility, redox potential, stability towards ionic species, conditional radically transferable atom phylicity, and propensity toward disproportionaltion and therefore, the suitability of the complex to be used as a catalyst in the reaction media, such as, but not limited to aqueous, ionic, acidic, basic, polar, as well as neutral organic media.
  • Embodiments of the processes of the present invention may comprise transition metal complex that include heterodonor ligands. In a heterodonor ligand, each donor atom contributes individually and in combination with the other heterodonor atom to the fundamental properties of the transition metal complex.
  • Embodiments of the method provide a basis for prediction and evaluation of the properties of a transition metal complex for a particular catalytic reaction in a broad range of reaction environments.
  • a fundamental understanding of the principles of the disclosed method allows the properties of the catalyst to be tuned to specific reaction medium by selecting the transition metal, the number and the properties of the donor atoms of the ligand and the other ligand substituents.
  • the two differing chemical functionalities of the donor atoms may be used to combine the properties of a dual entity catalyst system into one ligand to produce transition metal complex that may be used as a suitable single entity catalyst or unimolecular catalyst for use in reactions wherein only dual entity catalyst system have previously been suitable.
  • An embodiment of the invention comprises the direct controlled polymerization of unsaturated carboxylic acids in an aqueous media with a single entity transition metal complex added to the media as a catalyst.
  • the catalyst may change form in the reaction medium, for example, in some cases, two or more complexes are formed in the reaction medium.
  • Appropriate ligands may be complexed with a transition metal result in the formation of a suitable catalyst complex that will be at least partially soluble in the reaction media, will not be significantly protonated in the presence of acids or water, nor undergo significant disproportionation, and have the appropriate redox potential to control the reaction.
  • Embodiments of the heterodonor ligand in a transition metal complex may comprise any donor atoms, such as, but not limited to, oxygen, sulfur, selenium, tellurium, nitrogen, phosphorus, arsenic, antimony, and bismuth, or mixtures thereof depending on the targeted reaction.
  • Each of the donor atoms provides different properties to the resulting transitional metal. For example, generally donor atoms that are early in the periodic table, for instance, the first row, stabilize the lower oxidation state of the transition metal complex while those that appear later stabilize the higher oxidation state.
  • the electron density of the donor atom this affects the other properties, such as, the donation ability of the radically transferable atom or group and the relative steric properties, as well as other properties.
  • One skilled in the art will be able to determine the appropriate donor atoms to use for a particular reaction.
  • Another factor that has to be taken into account is the bulkiness of the ligand. See, Grubbs, R. H.; et al., Chem. Comm. 2003, 2272-2273.
  • the methods, transition metals, and processes of the present invention were validated by obtaining values for the parameters of the proposed catalyst complex and determining if the identified transition metal complex could act as a suitable catalyst for the desired reaction.
  • An embodiment of the present invention could be used to assist in the development of a copper complex comprising a ligand to act as a suitable catalyst for the reaction of unsaturated carboxylic acids in an aqueous media by an ATRP process.
  • An exemplified embodiment of a transition metal complex, method and process of the present invention is the preparation of a target catalyst that allowed the first successful attempt to directly polymerize methacrylic acid in aqueous media by a ATRP. This embodiment is described in detail.
  • the proposed catalyst in this exemplified embodiment is a unimolecular transition metal complex for the ATRP of free carboxylic acids in homogeneous aqueous solution.
  • the proposed catalyst is a transition metal complex comprising any mono, bi- or multi-dentate ligands.
  • a transition metal complex comprising heterodonor ligands was desired to provide the combination of properties in one complex such as those available in a two component catalyst system requiring a catalyst modifier in the reaction medium.
  • the ligands selected in this specific instance included ligands that comprised both an oxygen atom (O) and a sulfur atom (S) as donor atoms.
  • donor atoms were chosen for their favorable properties that may contribute to a suitable catalyst for polymerization of methacrylic acid in aqueous media by an ATRP.
  • sulfur atoms may not be easily protonated in the presence of acidic species and oxygen donor atoms may have the form of a neutral (such as a R-OH, a R-COOR, or ROR') or charged (such as a R-O " or a R-COO " ) donor substituant and still function as a donor. Therefore, a ligand comprising both donors may allow preparation of a single catalytic species that would allow direct transition metal mediated polymerization of acidic monomers in an aqueous media by a single entity catalyst.
  • ligands comprising only sulfur donor atoms may be good candidates for ligands for the ATRP of acidic monomers, since they form stable complexes that cannot be easily protonated, however, the redox potential of transition metal complexes with sulfur based ligands are often very high, and therefore the activation step of the ATRP process equilibrium is typically either very slow or does not occur, resulting in no or slow polymerization.
  • ligands comprising only oxygen donor atoms ethers and ketones but especially charged oxygen species such as phenoxides or carboxylates
  • Transition metal complexes comprising ligands containing oxygen are very reducing and therefore have a high catalytic activity.
  • the combination of these two different donor atoms, namely oxygen and sulfur, in the ligand of a transition metal complex should provide an appropriate balance of properties for the polymerization of acidic monomers in an aqueous media.
  • Initial exemplary transition metal complexes were copper complexes comprising methylthioacetic acid (MTAA) and similar compounds.
  • MTAA methylthioacetic acid
  • the properties of complex depend not only on the type of donor atom(s) within the ligand but also on whether these atom(s) are part of a ⁇ -based or a ⁇ -based electron systems.
  • the redox potential of the copper complexes of a similar ligand, HO 2 CCH 2 -SCH 2 CH 2 S-CH 2 CO 2 H is known to be significantly lower than the typical copper complexes with sulfur-only-based ligands, and is very close to the redox potential of the copper - pyridine complexes [Marchin, M A, J K Yandell, A W
  • typical reactions may involve various side reactions that may interfere with formation of the primary complex. These side reactions may alter the values for the stability constants of the complex of interest.
  • Typical side reactions may include the protonation of the ligand (especially significant when the ligand is a relatively strong base and the reaction media is acidic); formation of additional mixed complexes of the central atom with the solvent or other substances present in the system, such as monomers, salts, buffer components; and reactions with other components.
  • the stability constant of the complex of interest changes to a value which may be termed [Schwarzenbach, G. Die Komplexometrische Titration; 2nd ed.; Enke:
  • the formation of the complex MtL in the presence of both an acid which can protonate the ligand L yielding the acids HL, H2L, ... , HrL, and another ligand M, which can react with the metal Mt giving the complexes MtM, MtM2, ..., MtMp may be examined.
  • the stability constants of the complexes formed between the metal Mt and the ligand M are designated as ⁇ 2 , M» ⁇ • • > ⁇ p,M and acidity constants of the protonation of the ligand are Ka, 2 ,
  • conditional stability constant of the complex MtL is defined analogously to the constants obtained from equations (1), but using the total concentrations of all species containing
  • the alpha-coefficients for both the metal Mt and the ligand L may be introduced to show the significance of the side reactions (formation of complexes and the protonation). These coefficients are defined as follows: _ [Mt] tot -[MtL] [Mt] + [MtM] + - + [MtM p ] ⁇ , [MtM] , , [MtM,] ⁇ Mt " [Mt] - [Mt] ⁇ l +_ [Mtr + -- + ⁇ [Mtr ( )
  • equation (4) can be rewritten as:
  • the stability of the MtL complex decreases in the presence of acids and other complexing agents by a factor of ⁇ M L .
  • the ⁇ M coefficient may be low in the presence of a ligand M forming weak complexes with Mt or at low concenfrations of M.
  • the ⁇ L coefficient may be low for complexes MtL for which L is as weak base as possible (or the corresponding acids HL, HL 2 , ..., HL- are strong, i.e.
  • a suitable catalyst for use in embodiments of the process of the present invention may be considered to be sufficiently stable toward species participating in side reactions and have a low propensity toward ligand protonation if the all the Ka values of the ligand are greater than 10 .
  • all K* or ⁇ * ⁇ , ⁇ ; ganc i of the ligand should be greater than 10 "3 to provide a suitable catalyst complex.
  • equation (11) can be easily generalized to:
  • Equation (12) may be extended for the case when the ligand can react not only with protons but also with other metal ions Mt' present in the system. Clearly, in this case, additional alpha- coefficient for the ligand should be introduced, taking into account the formation of complexes between L and the other metal Mt'. In other words, CC L , H and ⁇ L,Mt' must be introduced in equation (12).
  • h(PMDETA ) refers to the acidity of the protonated PMDETA (i.e., the corresponding ammonium salts).
  • the acidity constants of bpy can be calculated in a manner, analogous to the one described above.
  • the ⁇ bpy - coefficient can be determined (see equation 8):
  • Ringbom A. J. Chem. Educ. 1958, 35, 282-288. Flaschka, H. A. IriEDTA Titrations; Wiley: New York, 1959. Ringbom, A; Harju, L. Anal. Chim. Ada 1972, 59, 33-47. Ringbom, A; Harju, L. Anal. Chim. Ada 1972, 59, 49-58. Ringbom, A.; Still, E. Anal. Chim. Ada 1972, 59, 143-146. Schwarzenbach, G.; Heller, j. Helv. Chim. Ada 1951, 34, 576-591: Tomkinson, J. C; Williams, R. J. P. J. Chem. Soc.
  • the redox potential of the couple CuVCu 11 can be calculated, provided that all stability constants are known.
  • stability constants of complexes can be determined using electrochemical measurements.
  • a suitable catalyst for use in embodiments of the processes of the present invention may be considered to have a sufficient redox potential if E is less than 500mV. In certain embodiments of the processes in which a higher reaction rate is desired, E may be less than 400mV, for the highest rates of reaction, E may be less than lOOmV for the fransition metal complex.
  • K d i Sp is the disproportionation equilibrium constant in the absence of any side reactions
  • S> and ⁇ ⁇ j are the overall stability constants of the complexes of Cu 1 and Cu 11 with the ligand L, respectively.
  • conditional constant of disproportionation Kdi sp is analogous to other conditional equilibrium constants discussed by Schwarzenbach, G., Die Komplexometrische Titration, 2 n Ed.,
  • conditional disproportionation constant can be expressed exactly as above (Eq. 2.4) but using the new definitions of the ⁇ -coefficients.
  • the outlined approach can be extended for more than two side reactions (i.e., with more than two ligands present); it should only be born in mind that the ⁇ -coefficient for each species (Cu 1 or Cu 11 ) is a sum of the ⁇ -coefficients for all of the side reactions, minus the number of these reactions plus one.
  • a suitable catalyst for use in embodiments of the process of the present invention may be considered to have a sufficiently low propensity toward disproportionation if all the K*dis P values of the transition metal complex are below 10 .
  • the K*di sp of the fransition metal complex may be desired to be below 10 2 or in embodiments wherein the concenfration of the activator species is to be maintained in greater quantities the K*di sp of the fransition metal complex may be desired to be less than 10 or even 10 "1 .
  • Another parameter to take into account in the selection of a suitable ATRP catalyst is the stability of the higher oxidation state of the complex or the stability of the fransition metal-halogen bond.
  • the following discussion will be based upon the example wherein the radically fransferable atom or group in the ATRP process is a halogen, but the same analysis could be considered for any other radically transferable atom or group.
  • the higher oxidation state the deactivator in redox reactions, dissociates easily, its concentration in the reaction system will be lowered and the deactivation process may consequently be slower which may ultimately lead to a poorly controlled reaction polymerization in some embodiments.
  • the ligand should be selected in such a way that the stability of the Cu(II)-X bond is sufficiently strong to persist in the reaction medium to form a suitable catalyst.
  • the rate of deactivation in ATRP Rdeact depends on the concentration of Cu 11 complex with coordinated halide ligand, i.e., on [Cu ⁇ X], and is given by
  • the calculation of the actual concenfration of deactivator (Cu ⁇ X) present in the reaction mixture will be the subject of the following discussion.
  • the reversible formation / dissociation of the Cu a -based ATRP deactivator (16) is characterized either by the overall (gross) or the stepwise stability (formation) constant, designated by ⁇ , ⁇ and Kj, ⁇ , respectively (the index 1 shows the number of coordinated ligands X):
  • a suitable catalyst for use in embodiments of the process of the present invention may be considered have a sufficiently stable transition metal-radically transferable atom or group bond if the conditional stability of the bond is above 10. In certain embodiments of the processes it may be desired that the conditional stability of the bond is greater than 1000 or more preferably greater than
  • Equations (21) and (22) may not be convenient to use because the concenfration of free, non-coordinated, halide ions are generally unknown quantities. It is more useful to determine the dependence of [Cu ⁇ X] and Rdeact on the total concentrations [Cu ⁇ ] to t and [X]tot, which can be done by solving a quadratic equation. Assume a Cu 11 compound (total concenfration [Cu ] to t) and a halide (total concenfration [X] tot ) are mixed.
  • heterodonor ligand is the sole ligand forming the complex.
  • the copper complexes of the tetradentate ligand ethyl- 1,2 dithiodiacrylic acid would be expected to be more stable than those of MTAA and more suitable for the formation of copper complexes for controlled polymerization of methacrylic acid in polar media.
  • the acid ligand (EDTDAA) is not soluble in water or methanol, but if it is converted to its sodium salt (Na 2 EDTDAA), a ligand readily soluble in both solvents is formed.
  • Cuprous bromide (CuBr) is readily soluble in an aqueous solution of Na 2 EDTDAA, giving a colorless solution of the cuprous complex.
  • the green Cu(II) complex is soluble to a sufficient degree as well. It has been reported [Augustin, M A, J K Yandell, A W Addison and K D Karlin (1981).
  • Cj tot is the sum of concenfrations of the initially added metal and ligand, and Pj is the product of these concentrations. If a fast (on the NMR time-scale) exchange between the free and the complexed ligand occurs, separate NMR signals of the two species (free ligand L and complexed ligand C) cannot be seen, but the observed chemical shift of the i-th peak of the ligand can be expressed as:
  • ⁇ j is the molar fraction of the complexed ligand in the j-th solution, i.e.:
  • equation (28) is simplified to:
  • this is a new approach that provides at least a qualitative, characterization (determination of chemical shifts, which gives very important structural information) of complexes, in which the free ligand exchanges rapidly with the complexed one, and provides a way to determine stability constants of fransition metal complexes in a number of environments.
  • this can be used to characterize the coordination of olefins to Cu(I), or any other fransition metal complex, and provide information on whether the complexed monomer is available for copolymerization with other olefins or with vinyl monomers etc.
  • the Cu(II) complexes of EDTDAA were also studied in order to determine if this species can act as deactivator in an ATRP reaction.
  • IR was employed to determine the mode of coordination of the ligand to the transition metal
  • UV/Vis specfroscopy was used to study stability.
  • the spectra indicate that the complex is hydrated or the water molecule is coordinated to the copper ion.
  • the same complex was prepared in D 2 O and the IR spectra of the deuterated and the "normal" hydrate are compared, Figure 6. The spectra show that water is coordinated to the copper ion.
  • the Cu(II) is pentacoordinated in these EDTDAA complexes and it is very likely that the water molecules can be displaced by other ligands such as halide anions, thus generating the necessary deactivating species for ATRP.
  • the spectra indicates that both the carboxylate oxygen and thioether sulfur atoms are involved. (Note the shift of the vibration frequency of the CS bond upon coordination. The shape of the band corresponding to asymmetric COO vibration also changes upon coordination due to the change of symmetry (C 2v in the ionic sodium salt to C s in the complex), indicating the participation of the carboxylate group in the complex-formation. [Nakamoto, K., Infrared and Raman Specfra of Inorganic and Coordination Compounds, Part B, 5 th Ed., Wiley, NY, 1997]) This means that EDTDAA does indeed act as a heterodonor ligand.
  • Figure 7 shows the electronic spectra of a series of solutions of different concenfrations of the Cu(II) complex of EDTDAA (prepared by mixing of solutions of CuSO 4 (to avoid complications by the presence of coordinating anions such as bromide) and Na 2 EDTDA in 1:1 molar ratio).
  • FIG. 10B This shows that more than two absorbing species are present, which makes the determination of the stability of the Cu(II)-Br bond very complicated.
  • the fransition metal complexes may include; [Cu ⁇ (EDTDA)(H 2 O)] (its existence was shown by IR specfroscopy), [Cu ⁇ (EDTDA)Br] ⁇ and [Cu ⁇ (EDTDA)].
  • polymeric structures with bridging EDTDA ligands may also be present.
  • the plot of l/(l-x)(n-x) vs. 1/x can be therefore used to determine K.
  • Na2EDTDAA which are to be used for the aqueous ATRP of acidic monomers.
  • the Cu(II) complexes of EDTDAA were studied by IR in order to determine the mode of coordination of the ligand, and by UV/Vis specfroscopy in order to study their stability.
  • the Cu(II) complex of EDTDAA was synthesized in the following way: 0.447 g (0.002 mol) of CuBr 2 was dissolved in 50 ml of methanol. This solution was added with stirring to a solution of 0.508 g (0.002 mol) of Na 2 EDTDA in a mixture of 50 ml of methanol and 25 ml of water. A light bluish-green precipitate was formed and was filtered from the solution after 1 hour and was washed with water followed by methanol on the filter. It was dried and studied by IR specfroscopy. The spectra of Na 2 EDTDA and the Cu(II) complex were recorded in nujol mulls.
  • the Cu(II) water complexes of EDTDAA were synthesized as follows. 0.005 M solutions of CuSO 4 and Na 2 EDTDA in water or deuterium oxide were mixed and the precipitated light green crystals were isolated, washed with water on the filter and dried in vacuum at 60-70°C for 3-4 days. The spectra of the two Cu(II) complexes were recorded in nujol mulls. They are shown in Figure 6.
  • Aqueous 0.1 M solutions of CuSO 4 (not the bromide as above in 1D1) and Na 2 EDTDA were used as the stock solutions. 0.25 mL of these solutions were mixed with various amounts of KBr (100-800 equivalents to Cu(II)), and diluted to 5 mL (total of 2.5xl0 "5 mol of both Cu(II) and the ligand were thus present in the solution).
  • the pH of a solution of MAA in water (1:1 by volume, i.e., 5.89 M) is approximately (assuming a K a value of 5xl0 "5 for MAA) 1.8.
  • the electronic spectra of 7x10 "3 M solutions of the complex in water alone and in the presence of 0.005 M and 0.02 M added p-toluenesulfonic acid (corresponding to pH 2.3 and 1.7, respectively) were taken and are presented in Figure 11.
  • the complex is therefore a suitable catalyst for an catalytic reaction in acidic media, for example, an ATRP. 2. Polymerization of methacrylic acid using bidentate heterodonor ligands to complex copper.
  • the ligand, MTAA, was dissolved in 1 ml of methanol, and the mixture was degassed by 4 f-p-t cycles. CuBr was then added to the frozen mixture, the flask was closed with a rubber septum, evacuated and back-filled with nitrogen several times. The CuBr dissolves slowly but completely at these conditions. Separately, the monomer was dissolved in 1 ml of methanol and the solution was degassed by 4 f-p-t-cycles. The solution of the ligand was then added, the flask was immersed in a thermostatted bath at 35°C, and the degassed initiator was added.
  • the pu ⁇ ose of these two experiments was to check if polymerization of MAA can occur when using the Cu Na 2 EDTDAA complex, and to evaluate the rate of the reaction as a function of reaction temperature and solvent composition.
  • Flaskl 0.24 g (0.94 mmol) of Na 2 EDTDAA in 1 ml of D 2 O. The solution was degassed by 5 f-p-t cycles and 0.0677 g (0.472 mmol) CuBr was added to the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask,and mixing at room temperature a clear solution was slowly formed.
  • Flask2 2 ml of MAA and 1 ml of D 2 O (for experiment nvt-maa3) or 1 ml of MeOH-d4
  • the targeted DP of the polyMAA was changed to 100.
  • the reaction was performed in water-methanol.
  • Flaskl 0.24 g (0.94 mmol) of Na 2 EDTDAA in 2 ml of D 2 O. The solution was degassed by 5 f-p-t cycles and 0.0678 g (0.472 mmol) CuBr was added over the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask, a clear solution was slowly formed.
  • Flask2 4 ml of MAA and 2 ml of MeOH-d4. The solution was degassed by 5 f-p-t cycles.
  • the polymers were analyzed by GPC using two independent techniques: directly, using aqueous GPC, and after conversion to polyMMA (by methylation by Mel in the presence of DBU; see example 5), using GPC as THF or DMF as the eluent.
  • the latter approach should give more precise values of the degree of polymerization since polyMMA standards are available for calibration.
  • Flaskl 0.2391 g (0.94 mmol) of Na 2 EDTDAA in 1 ml of D 2 O and 1 ml of MeOH- ⁇ V The solution was degassed by 5 f-p-t cycles and 0.0675 g (0.472 mmol) CuBr was added over the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask, a clear solution was slowly formed.
  • Flask2 4 ml of MAA (4.06 g, 0.047 mol) and 2 ml of MeOH- j. The solution was degassed by 5 f-p-t cycles. The solution in flask 2 was added to the first one. Slowly, a heterogeneous white mixture was formed (presumably, due to the insufficient solubility of the complex in the methanol- rich solvent). The reaction flask then immersed in a thermostated oil bath at 75°C and 250 ⁇ l of MePEGBiB was added. The kinetics of the reaction were followed by NMR. The results are summarized below. Experiment nvt-maalO
  • Flaskl 0.2395 g (0.94 mmol) of Na 2 EDTDAA in 2 ml of D 2 O. The solution was degassed by 5 f-p-t cycles and 0.0672 g (0.472 mmol) CuBr was added over the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask, a clear solution was formed.
  • Flask2 4 ml of MAA (4.06 g, 0.047 mol) was dissolved in 2 ml of MeOH-dj. The solution was degassed by 5 f-p-t cycles. The solution in flask 2 was added to the first one, and as in the previous reaction, a heterogeneous solution was formed. The flask was immersed in a thermostated oil bath at 75°C and 250 ⁇ l of MePEGBiB was added. The results are summarized in below.
  • Flaskl 0.2390 g (0.94 mmol) of Na 2 EDTDAA in 2 ml of D 2 O. The solution was degassed by 5 f-p-t cycles and 0.0671 g (0.472 mmol) CuBr was added over the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask, a clear solution was slowly formed.
  • Flask2 4 ml of MAA (4.06 g, 0.047 mol) and 2 ml of D 2 O.
  • the emulsion was degassed by 5 f-p-t cycles.
  • the emulsion in flask 2 was added to the first one.
  • a heterogeneous white mixture was formed (most probably, due to the insolubility of MAA in pure water rather than due to precipitation of the complex).
  • the reaction flask immersed in a thermostated oil bath at 75°C and 250 ⁇ l of MePEGBiB was added. The results are given below.
  • Experiment nvt-maal2 4 ml of MAA (4.06 g, 0.047 mol) and 2 ml of D 2 O.
  • the emulsion was degassed by 5 f-p-t cycles.
  • the emulsion in flask 2 was added to the first one.
  • a heterogeneous white mixture was formed (most probably, due
  • the ligand was dissolved in the mixture of solvents and the monomer and the formed solution was degassed by 5 fpt cycles. CuBr was then added to the frozen mixture, and the flask was closed and filled with nitrogen. A clear colorless solution was formed. The flask was immersed in the oil bath and the system immediately became heterogeneous. The macroinitiator was then injected. Samples were taken to follow the reaction kinetics; part of each sample was neutralized with anhydrous Na 2 CO 3 in deuterated water, and another part was kept for conversion of the polymer to polyMMA (after reaction with trimethylsilyldiazomethane) for GPC analysis against known standards.
  • Flaskl 0.2935 g (1.88 mmol) of bpy in 3 ml of D 2 O. The solution was degassed by 5 f-p-t cycles and 0.1348 g (0.944 mmol) CuBr was added over the frozen solution. The flask was closed, evacuated and back-filled with nitrogen several times. After warming up the flask, a heterogeneous dark brown mixture was formed.
  • Flask2 4 ml of MAA (4.06 g, 0.047 mol) was dissolved in 1 ml of MeOH-dj. The solution was degassed by 5 f-p-t cycles. The solution in flask 2 was added to the first one. A homogeneous solution was formed (i.e., the catalyst completely dissolved). However, no change in color was observed. The reaction flask immersed in a thermostated oil bath at 75°C and 250 ⁇ l of MePEGBiB was added. Again, no color change could be seen. The results are presented in Table 6. Table 6. Experiment nvt-maa9
  • Methacrylic acid can significantly protonate the bpy ligand.
  • MAA can coordinate to Cu(I), significantly stabilizing this state of the catalyst, and, therefore, making it inactive for activation.
  • one way to polymerize acidic monomers by ATRP is to find ligands which are not basic, coordinate to both Cu(I) and Cu( ⁇ ), giving soluble complexes with the appropriate electrode potential and halogen philicity of the Cu(II) complex.
  • Another approach is to find a solvent in which all reaction components are soluble, and in which the acidity of MAA is lower than in water (or basicity of bpy is lower than in water).
  • One potential candidate was DMF.
  • the reaction was performed using 2 ml of MAA and 2 ml of DMF. After degassing, a mixture of 0.0677 g(0472 mmol) of CuBr and 0.369 g (2.36 mmol, 5 eq. vs. Cu(I)) of bpy was added. The mixture was heated to 70°C and mePEGBiB was added (125 ⁇ l; targeted DP - 100). The reaction mixture stayed brown but no polymerization took place (0% conversion in 5h). This indicates that perhaps MAA deactivates (both by protonation of bpy and coordination to Cu) the ATRP catalyst in DMF. The same behavior was previously observed in pure water.
  • HEMA Hydroxyethyl methacrylate
  • the initial experiment was conducted in order to determine if the catalyst complex is capable of activating the 2-bromoester initiator.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)

Abstract

La présente invention a trait à l'identification ou la conception, la préparation et l'utilisation de complexes de métaux de transition destinés à être utilisés comme catalyseurs. Les complexes de métaux de transition peuvent comporter des ligands à différents atomes donneurs. La présente invention a également trait à un procédé de détermination de l'aptitude d'un complexe de métaux de transition à une utilisation dans une réaction catalytique, telle que, mais de manière non exclusive, la polymérisation radicalaire par transfert d'atomes, l'addition radicalaire par transfert d'atomes, la cyclisation radicalaire par transfert d'atomes, et d'autres réactions d'oxydoréduction catalytiques. Le procédé contribue à la détermination approximative des propriétés fondamentales du complexe de métaux de transition dans un milieu réactionnel, telles que, mais de manière non exclusive, la solubilité, le potentiel d'oxydoréduction, la stabilité vis-à-vis d'espèces acides, basiques, ou ioniques, l'affinité conditionnelle d'atomes de transfert radicalaire, et la tendance à la dismutation et par conséquent, l'aptitude du complexe à être utilisé comme catalyseur dans le milieu réactionnel. Le procédé fournit une base pour la prédiction et l'évaluation des propriétés d'un complexe de métaux de transition pour une réaction catalytique sélective particulière dans une large gamme de milieux réactionnels. Une compréhension des principes du procédé de l'invention permet l'adaptation d'un complexe de métaux de transition à un milieu réactionnel spécifique par la sélection d'une combinaison de complexe de métaux de transition et de ligand présentant les qualités souhaitées.
PCT/US2003/032172 2002-10-10 2003-10-09 Stabilisation de complexes de metaux de transition pour la catalyse dans des environnements divers Ceased WO2004096872A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2003284050A AU2003284050A1 (en) 2002-10-10 2003-10-09 Stabilization of transition metal complexes for catalysis in diverse environments

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US41759102P 2002-10-10 2002-10-10
US60/417,591 2002-10-10
US10/625,890 2003-07-23
US10/625,890 US20040044152A1 (en) 2000-10-06 2003-07-23 Polymerization processes for ionic monomers

Publications (1)

Publication Number Publication Date
WO2004096872A1 true WO2004096872A1 (fr) 2004-11-11

Family

ID=33422821

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2003/032172 Ceased WO2004096872A1 (fr) 2002-10-10 2003-10-09 Stabilisation de complexes de metaux de transition pour la catalyse dans des environnements divers

Country Status (2)

Country Link
AU (1) AU2003284050A1 (fr)
WO (1) WO2004096872A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4194440A1 (fr) 2021-12-10 2023-06-14 Adolphe Merkle Institute, University of Fribourg Réaction radicalaire par transfert d'atome à l'aide d'un catalyseur à base de peptide contenant un métal et auto-assemblage de peptides et un ion métallique

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997018247A1 (fr) * 1995-11-15 1997-05-22 Carnegie Mellon University Procedes ameliores, fondes sur la polymerisation de radicaux par transfert d'atomes (ou de groupements) et (co)polymeres nouveaux ayant des structures et des proprietes utiles

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1997018247A1 (fr) * 1995-11-15 1997-05-22 Carnegie Mellon University Procedes ameliores, fondes sur la polymerisation de radicaux par transfert d'atomes (ou de groupements) et (co)polymeres nouveaux ayant des structures et des proprietes utiles

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4194440A1 (fr) 2021-12-10 2023-06-14 Adolphe Merkle Institute, University of Fribourg Réaction radicalaire par transfert d'atome à l'aide d'un catalyseur à base de peptide contenant un métal et auto-assemblage de peptides et un ion métallique

Also Published As

Publication number Publication date
AU2003284050A1 (en) 2004-11-23

Similar Documents

Publication Publication Date Title
US7332550B2 (en) Stabilization of transition metal complexes for catalysis in diverse environments
US7064166B2 (en) Process for monomer sequence control in polymerizations
Pintauer et al. Structural aspects of copper catalyzed atom transfer radical polymerization
Ribelli et al. Atom transfer radical polymerization: billion times more active catalysts and new initiation systems
CA2258006C (fr) Catalyseur et procede de polymerisation
EP2069408B1 (fr) Polymérisation du radical vivant de monomères activés et non activés contenant des groupes latéraux à extraction d'électrons
Kickelbick et al. 4, 4′, 4 ″‐Tris (5‐nonyl)‐2, 2′: 6′, 2 ″‐terpyridine as ligand in atom transfer radical polymerization (ATRP)
JP5005155B2 (ja) イオンモノマーの重合方法
Wang et al. Controlled/" living" radical polymerization. Halogen atom transfer radical polymerization promoted by a Cu (I)/Cu (II) redox process
Tsarevsky et al. Copper-based ATRP catalysts of very high activity derived from dimethyl cross-bridged cyclam
WO2003066685A2 (fr) Agents de transfert de chaine pour polymerisation raft en milieu aqueux
JP2004510847A5 (fr)
EP0714416B1 (fr) Procede de polymerisation amorcee par des radicaux libres
Thevenin et al. Impact of Catalyzed Radical Termination (CRT) and Reductive Radical Termination (RRT) in Metal‐Mediated Radical Polymerization Processes
Wang et al. Hexamethylphosphoramide as a highly reactive catalyst for the reversible-deactivation radical polymerization of MMA with an in situ formed alkyl iodide initiator
JP6754124B2 (ja) 多分岐ポリマーの製造方法及び多分岐ポリマー
WO2004096872A1 (fr) Stabilisation de complexes de metaux de transition pour la catalyse dans des environnements divers
KR100918244B1 (ko) 중합 촉매 조성물 및 폴리머의 제조 방법
Yang et al. Thermal and photo-RAFT polymerization of 2, 2, 2-trifluoroethyl α-fluoroacrylate
JP2010518184A (ja) テレケリックポリマーの製造方法
Costa et al. Addressing the role of triphenylphosphine in copper catalyzed ATRP
Chen et al. The in situ atom transfer radical polymerization of MMA using the TD–FeCl 3–PPh 3 initiating system
Kwak et al. ATRP of styrene and methyl methacrylate with less efficient catalysts and with alkyl pseudohalides as initiators/chain transfer agents
Srivastava et al. N‐(n‐Alkyl)‐2‐pyridinemethanimine mediated atom transfer radical polymerization of lauryl methacrylate: Effect of length of alkyl group
CN100465196C (zh) 一种采用离子液体聚合引发体系制备高分子化合物的方法

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

DFPE Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed before 20040101)
121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP

WWW Wipo information: withdrawn in national office

Country of ref document: JP