Polymerization of Michael-type and heterocyclic monomers

Abstract

A system for precision polymerization is disclosed comprising at least one Michael-type monomer and a metal compound MR.sup.1R.sup.2R.sup.3 as sole catalyst and initiator, wherein M is aluminum, gallium or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkenyl, linear, branched, or cyclic alkinyl, heterocycloalkinyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, nitro, nitroso, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkinyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkinyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkinyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms, or at least one electron-donating or electron-withdrawing group; with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic or heterocyclic group having 3 to 6 atoms, wherein a heterocyclic group has at least one hetero atom selected from the group consisting of O, S, and N; as well as processes for preparing polymers and the polymers obtained therewith.

Claims

1. A system for polymerization comprising a monomer component, and a metal compound as sole initiator, wherein the monomer component comprises at least one Michael-type monomer, and wherein the metal compound is MR.sup.1R.sup.2R.sup.3, wherein M is aluminum, gallium, or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group is optionally substituted by 1 up to the highest possible number of halogen atoms, or by at least one electron-donating or electron-withdrawing group; with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from the group consisting of O, S, and N.

2. The system for polymerization according to claim 1, comprising a) at least one Michael-type monomer, b) a compound MR.sup.1R.sup.2R.sup.3, wherein M, R.sup.1, R.sup.2, and R.sup.3 are as defined in claim 1, as sole initiator; c) optionally an organic solvent, wherein the initiator is adapted to the monomer such that for an electron deficient monomer the initiator is MR.sup.1R.sup.2R.sup.3 with a FIA of about 530 or less; for a monomer having medium electrophilicity the initiator is MR.sup.1R.sup.2R.sup.3 with a medium FIA of less than 530 and more than 393; and for an electron donating or electron-rich monomer the initiator is MR.sup.1R.sup.2R.sup.3 with a low FIA of 393 or more.

3. The system for polymerization according to claim 1 wherein the Michael-type monomer is a vinylphosphonate or mono- or dialkyllvinylphosphonate; a vinylsulfonate or mono- or dialkylsulfonate, a substituted or unsubstituted acrylate or methacrylate, a substituted or unsubstituted acrylamide or methacrylamide, acrylonitrile, a substituted or unsubstituted heteroaromatic vinyl compound, a substituted or unsubstituted vinyl ketone, acrolein, or an acrolein derivate, or a mixture of two or more thereof; or wherein the Michael-type monomer is butyl acrylate, isobutyl acrylate, tert. -butyl acrylate, isobornyl acrylate, furfuryl acrylate, glydidyl acrylate, butyl methacrylate, isobutyl methacrylate, tert. -butyl methacrylate, isobornyl methacrylate, furfuryl methacrylate, or glycidyl methacrylate, or a mixture thereof.

4. A system for polymerization comprising a monomer component and a metal compound as sole initiator, wherein the monomer component comprises at least one heterocyclic monomer selected from the group consisting of a substituted or unsubstituted lactone having up to 9 ring atoms, a substituted or unsubstituted lactam having up to 9 ring atoms, and a substituted or unsubstituted 1,4-dioxan-2,4-dione, or a mixture thereof, wherein each substituent independently is selected from linear, branched, or cyclic alkyl, alkenyl, alkynyl groups having up to 6 carbon atoms, linear, branched, or cyclic alkoxy groups having up to 6 carbon atoms, halogen, metallocenyl, hydroxy, carboxyl, aryl, or heteroaryl; and wherein the metal compound is MR.sup.1R.sup.2R.sup.3, wherein M is aluminum, gallium, or indium; each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group is optionally substituted by 1 up to the highest possible number of halogen atoms, or by at least one electron-donating or electron-withdrawing group; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from the group consisting of O, S, and N; with the proviso that only up to two of groups R.sup.1, R.sup.2, and R.sup.3 can be perfluorinated aryl or heterocycle; alkoxy, hydroxy, or halogen.

5. A system for polymerization comprising a monomer component and a metal compound as sole initiator, wherein the monomer component comprises a combination of CO.sub.2 and at least one comonomer selected from the group of substituted or unsubstituted oxirane with 3 or 4 ring atoms, substituted or unsubstituted aziridine or azetidine, or a mixture thereof; and wherein the metal compound is MR.sup.1R.sup.2R.sup.3, wherein M is aluminum, gallium, or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group is optionally substituted by 1 up to the highest possible number of halogen atoms, or by at least one electron-donating or electron-withdrawing group; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from the group consisting of O, S, and N; with the proviso that only up to two of groups R.sup.1, R.sup.2, and R.sup.3 can be perfluorinated aryl or heterocycle; alkoxy, hydroxy, or halogen.

6. The system for polymerization according to claim 1, wherein the monomer component comprises at least one Michael-type monomer and/or at least one heterocyclic monomer and/or a combination of CO.sub.2 and at least one comonomer selected from the group consisting of substituted or unsubstituted oxirane with 3 or 4 ring atoms, substituted or unsubstituted aziridine or azetidine, substituted or unsubstituted lactone having up to 9 ring atoms, substituted or unsubstituted lactam having up to 9 ring atoms, and substituted or unsubstituted 1,4-dioxan-2,4-dione, or a mixture thereof.

7. A process for polymerization of a monomer component using a metal compound as sole initiator, which comprises the steps: a) contacting a monomer component, wherein the monomer component comprises at least one of a Michael-type monomer; and/or at least one substituted or unsubstituted lactone having up to 9 ring atoms, substituted or unsubstituted lactam having up to 9 ring atoms, substituted or unsubstituted 1,4-dioxan-2,4-dione, or a mixture thereof and/or a combination of CO.sub.2 and at least one comonomer selected from the group of substituted or unsubstituted oxirane with 3 or 4 ring atoms, substituted or unsubstituted aziridine or azetidine, or a mixture thereof; with a metal compound MR.sup.1R.sup.2R.sup.3, optionally dissolved in an organic solvent, wherein M is aluminum, gallium, or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms, or by at least one electron-donating or electron-withdrawing group, with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from the group consisting of O, S, and N; and b) continuing the polymerization reaction with the same, additional or other monomer component to form a polymer.

8. The process according to claim 7 wherein the Michael-type monomer of step a) is independently selected from the group consisting of acrylates, acrylonitrile, vinylphosphonates, vinylsulfonates, and vinylpyridines and/or wherein the at least one Michael-type monomer of step b) is independently selected from the group consisting of vinylphosphonates, vinylsulfonates, substituted or unsubstituted acrylates and methacrylates, substituted or unsubstituted acrylamides, acrylonitrile, vinylpyridines, vinyl ketones, acrolein, and acrolein derivates.

9. The process according to claim 7, wherein the ratio of initiator to monomer is 1:0.5 to 2000:1.

10. A polymer produced by the process of claim 7.

11. The polymer according to claim 10, wherein the polymer is a polymer or copolymer of one or more of Michael monomers selected from the group consisting of vinylphosphonate, vinylsulfonate, substituted or unsubstituted acrylate and methacrylate, substituted or unsubstituted acrylamide, acrylonitrile, vinylpyridine, vinyl ketone, acrolein, and an acrolein derivate.

12. A process for preparing a functionalized polymer comprising contacting MR.sup.1R.sup.2R.sup.3, optionally dissolved in an organic solvent, with a monomer component as defined in claim 1, to form the functionalized polymer, wherein M is aluminum, gallium, or indium, each of R.sup.1 and R.sup.2 is independently F, I, Br or linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl, or alkoxy independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group is optionally substituted by 1 up to the highest possible number of halogen atoms; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from the group consisting of O, S, and N; and wherein R.sup.3 is a transferable group carrying at least one functional group.

13. The process for preparing a functionalized polymer according to claim 12, wherein the functional group is an olefinic group, an aromatic group, a heteroaromatic group, an alkynyl group, a mercapto group, a furfuryl group, a chemoactive or bioactive group, a nucleobase, wherein optionally the functionalized Michael-type monomer is furfuryl acrylate or furfuryl methacrylate.

14. The process for preparing a functionalized polymer according to claim 12, wherein the functional group is a luminescent unit or a unit eligible for inducing luminescence, wherein in formula I at least one groups of R.sup.1, R.sup.2, or R.sup.3 is [Z.sup.3Q], wherein Z.sup.3 is a single bond, C(R.sup.8R.sup.9), S, O, or N(R.sup.10), wherein R.sup.8, R.sup.9, R.sup.10, independently are hydrogen or linear or branched C.sub.1-C.sub.5-alkyl; wherein Q is an aromatic system comprising up to 3 aromatic rings, wherein the rings can independently be condensed or covalently linked, wherein the aromatic rings are independently 5- or 6-membered carbocyclic or heteroaromatic rings, at least one of which is a 5- or 6-membered heteroaromatic ring comprising at least one and up to 3 heteroatoms selected from the group consisting of N and S, wherein optionally Q has at least one unsubstituted carbon atom in a heteroaromatic ring in a position available for binding of an electrophilic substituent which is in vicinity to the heteroatom, wherein the system is optionally substituted by one or more substituents selected from linear or branched C.sub.1-C.sub.5-alkyl, C.sub.1-C.sub.5-alkoxy, amino, nitro, nitroso, cyano, halogen, C.sub.5-C.sub.10 aryl, C.sub.5-C.sub.10 heteroaryl, or C.sub.5-C.sub.10 aryloxy, with the proviso that Q has at least one unsubstituted carbon atom in a heteroaromatic ring in a position available for binding of an electrophilic substituent which is in vicinity to the heteroatom.

15. A process for preparing a polymer having increased syndio- or isotacticity comprising contacting MR.sup.1R.sup.2R.sup.3, optionally dissolved in an organic solvent, with a monomer component as defined in claim 1, to form a polymer, wherein M is aluminum, gallium, or indium, each of R.sup.1, R.sup.2, and R.sup.3, is independently F, I, Br or linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl, or alkoxy independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from the group consisting of O, S, and N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group is optionally substituted by 1 up to the highest possible number of halogen atoms; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from O, S or N, and wherein either all three groups R.sup.1, R.sup.2, and R.sup.3 are different or R.sup.1 and R.sup.2 are the same and R.sup.3 is different and is a bulky group.

16. A polymer produced by the process of claim 13.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows an .sup.19F-NMR (471 MHz, DMSO) spectrum of precipitated short-chained polyacrylonitrile produced with [Al(C.sub.6F.sub.5).sub.3]. Recorded with a Bruker AV500CRYO spectrometer. Expansion of the 167 to 137 ppm region.

(2) (a) NMR sample of the reaction solution, (b) NMR of the same sample after several precipitations.

(3) FIG. 2 shows a .sup.13C-NMR (125 MHz) spectrum of the polymer sample produced in example 4 in CDCl.sub.3 at 20 C., wherein S indicates signals corresponding to the syndiotactic content, A signals corresponding to the atactic content and I signals corresponding to the isotatic content of the polymer.

(4) FIG. 3 shows an ESI MS spectrum of tBuMA oligomers produced with [Al(nOct).sub.3]. One major series of peaks is evident: m/z=nM.sub.Mon+113+M.sub.H (red); M.sub.Mon=142, end groups: M.sub.nOct=113.

(5) FIG. 4 shows an ESI MS spectrum of IPox oligomers produced with [Al(C.sub.6H.sub.5).sub.3]. One major series of peaks is evident: m/z=nM.sub.Mon+77+M.sub.H (red); M.sub.Mon=111, end groups: M.sub.C6H5=77.

(6) FIG. 5 shows an ESI MS spectrum of IPox oligomers produced with [Al(CH.sub.3).sub.2Cp] and [Al(CH.sub.3).sub.2Cp*], respectively. One major series of peaks is evident: m/z=nM.sub.Mon+66+M.sub.H(red); M.sub.Mon=136.

(7) FIG. 6 shows a .sup.1H-NMR spectrum of poly(-caprolactone) produced with dimethyl-((6-methylpyridin-2-yl)methyl)aluminum as catalyst.

(8) FIG. 7 shows a .sup.1H-NMR spectrum of polylactide produced with dimethyl-(2-pyridinylmethyl)aluminum as catalyst.

(9) FIG. 8 shows a GPC chromatogram with a trace of polylactide (right peak) and poly(lactide co -Caprolactone) left side.

(10) FIG. 9 shows a .sup.1H-NMR spectrum of a poly(cyclohexenecarbonate) produced with dimethyl-(2-pyridinylmethyl)aluminum as catalyst and with a combination of cyclohexeneoxide and CO.sub.2 as comonomers.

(11) FIG. 10 shows a GPC chromatogram with a trace of a copolymer of diethylvinylphosphonate and rac-lactide.

(12) FIG. 11 shows an emission-spectrum of a poly(lactide) sample synthesized with dimethyl((6-methylpyridin-2-yl)methyl)aluminum as catalyst (left side). Emission maximum at 463 nm

DEFINITIONS

(13) The term metal compound refers to one compound or a mixture of compounds of formula I. The term used as sole catalyst/initiator means that only one or more metal compounds of formula I are used as catalyst/initiator. The term sole catalyst/initiator indicates that no further type of catalyst or initiator is necessary, in particular no Lewis base. It has been surprisingly found that a metal compound of formula I, as claimed, when used as sole catalyst is active for catalysis and/or initiation of polymerization of demanding monomers even without an -acidic site.

(14) It was found that the following aluminum compounds are not as active and therefore in one embodiment the metal compound does not comprise the following compounds: diethyl-[(4-methyl-pyridin-2-y)-methyl]aluminum, diethyl-(2-pyridinylmethyl)aluminum, or diethyl(quinolin-2-ylmethyl)aluminum.

(15) The term Michael-type monomer refers to a monomer having a vinyl group and conjugated thereto a double or triple bond, such as a carbonyl group or an unsaturated carbon-carbon-bond.

(16) The term demanding Michael-type monomer as used in this application refers to Michael-type monomers having a vinylogous system, which have electronically and/or sterically demanding properties, and which may not be polymerizable in good yields and/or high turnover frequencies and/or low PDIs by conventional catalysts. Examples for those demanding Michael-type monomers which can be polymerized with the catalyst/initiator systems and methods of the present invention are vinyl phosphonates, vinyl sulfonates, substituted or unsubstituted acrylamides, substituted or unsubstituted acrylates and methacrylates, like butyl acrylate, isobutyl acrylate, tert.-butyl acrylate, isobornyl acrylate, furfuryl acrylate, glydidyl acrylate, butyl methacrylate, isobutyl methacrylate, tert.-butyl methacrylate, isobornyl methacrylate, furfuryl methacrylate, glydidyl methacrylate, acrylonitrile, and other vinyl ketones, like acrolein and acrolein derivates, substituted or unsubstituted heteroaromatic monomers, like vinyl pyridine, oxazolines, among others.

(17) The term polymer comprises any type of polymer, i.e. homopolymer, copolymer, terpolymer etc. In particular shall the term polymer refer to polymers that are comprised of one or more type of monomers as defined in this application and in the claims.

(18) The term bulky refers to groups of formula I that are sterically and/or electronically encumbering, i.e. sterically hindering. Examples are tert.-butyl, substituted aryl or heteroaryl groups.

(19) The term precision polymerization when used in this application refers to polymerization of Michael-type monomers by using the catalyst and initiator of the present invention. This allows polymerization of monomers which are difficult or not (i.e. in a non-controllable manner) to polymerize by conventional anionic polymerization methods or radical polymerization methods. Furthermore this term relates to polymerization processes with a sufficient TOF i.e. short reaction time, which provide polymers with low polydispersity index, high yields, and with controllable molecular weight and tacticity.

(20) The term tactic or tacticity, respectively, includes syndiotacticity and isotacticity.

(21) Increased syndio- or isotacticity means that the percentage of syndio- or isotacticity is increased compared to average, by at least about 10%, in particular at least about 25% and preferably by at least about 40%.

(22) The term catalyst and initiator characterizes metal compounds of formula I which are active as initiators as well as catalysts for polymerization. The terms catalyst and initiator and catalyst are used interchangeably, as a catalyst of the present invention also has the function of an initiator.

(23) The term monomer component defines a component comprising the monomers to be polymerized with the catalyst or the process, respectively, of the present invention. The monomer component of the present invention comprises at least one Michael-type monomer and/or at least one heterocyclic monomer and/or a combination of carbondioxide and a heterocyclic monomer as defined in the claims and can comprise a mixture of monomers of different types, such as a mixture of different Michael-type monomers, a mixture of different types of heterocyclic monomers, a mixture of one or more Michael-type monomers and one or more heterocyclic monomers and a mixture of these monomers with carbon dioxide.

(24) The term monomer or type of monomer refers the class of monomers, not to a single molecule, except the context says otherwise. Thus, when a monomer is contacted with a catalyst this means that a suitable amount of the type of monomer mentioned is contacted with the catalyst.

(25) Groups like alkyl, alkenyl, alkynyl, or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, can be substituted or unsubstituted and substituents can be present up to the highest possible number, as long as the compounds retain the necessary properties.

(26) The term substituted when used in connection with groups like alkyl, alkenyl, alkynyl, or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, or acrylate or methacrylate, indicates that such a group is substituted by at least one substituent and up to the highest possible number of substituents, where the substituents are selected from linear, branched, or cyclic alkyl, alkenyl, alkynyl groups having up to 6 carbon atoms, linear, branched, or cyclic alkoxy groups having up to 6 carbon atoms, halogen, metallocenyl, nitro, nitroso, hydroxy, carboxyl, or aryl, such as phenyl or naphthyl, or heteroaryl.

(27) The term substituted by halogen when used in connection with carbon containing groups refers to partially or fully halogenated, such as perfluorinated groups. The term wherein each alkyl, alkenyl, alkynyl, or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms refers to such groups that can carry only one halogen, in particular chlorine, fluorine or bromine, or more halogen atoms. Any possible number of halogen atoms can be present on a group and the highest possible number of halogen atoms refers to groups wherein each hydrogen has been replaced by a halogen atom, in other words that are perhalogenated.

(28) The term donor substituted refers to substituents that can add to an electronic system, for example a system or sigma system, such as R, OR, SR, NR.sub.2, wherein R is linear or branched alkyl, such as methyl, ethyl, isopropyl, isobutyl, butyl, tert.-butyl, aryl, or heteroaryl as defined above.

(29) The terms electron-donating or electron-withdrawing group refer to groups that either are donors or acceptors of electrons or can add to or reduce an electronic system. Electron-donating or electron-withdrawing groups are well-known to the skilled person.

(30) The term with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy; refers to those compounds where R.sup.1, R.sup.2, and R.sup.3 are identical and, thus excludes MHal.sub.3, M(OH).sub.3 and M(OX).sub.3 as catalysts of the present invention.

(31) When for a metal compound two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group having 3 to 6 atoms this cyclic group in addition to metal comprises either only carbon atoms or carbon and hetero atoms selected from O, S or N. In other words the cyclic group comprises metal and 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms. One example is a glycol group where both oxygen atoms are bound to the metal, such aluminum.

(32) The term luminescent when used in the present description refers to a property of a compound to emit visible light after energetic excitation. The energetic excitation can be via UV light, electronically, chemically or by other energetic sources known to the person skilled in the art. Luminescence comprises emission of light in all visible colors. The term luminescence includes fluorescence, phosphorescence or other mechanisms of visible light emission.

(33) A luminescent component is a molecule that has luminescence or can be induced to be luminescent. A luminescent component can be an adduct of a metal compound of the present invention and a monomer, where the luminescent part can be contributed by a ligand of the metal compound or by a monomer, or it can be an oligomer or polymer with a luminescent unit, which has been obtained by using the metal compound and the monomer component of the present invention.

(34) The terms luminescent unit, luminescent element and luminescent group are used interchangeable and refer to groups that contribute to luminescence in a molecule. All of those can be part of the luminescent component.

DESCRIPTION OF THE INVENTION

(35) The present invention is concerned with a system of a metal compound that is active as catalyst and a monomer component for polymerization. In particular the present invention is concerned with an adapted pair of a catalyst and a monomer component. In one embodiment a metal compound of the present invention that is active for polymerization of Michael-type monomers as sole catalyst and initiator is a metal compound MR.sup.1R.sup.2R.sup.3, wherein M is aluminum, gallium or indium, each of R.sup.1, R.sup.2, and R.sup.3 independently is CI, F, I, Br, linear, branched or cyclic alkyl, heterocycloalkyl, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, nitro, nitroso, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl or alkoxy group independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from O, S or N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyl, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms, or at least one electron-donating or electron-withdrawing group; with the proviso that not all three groups R.sup.1, R.sup.2, and R.sup.3 are halogen, hydroxy, or alkoxy; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with M form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from O, S or N.

(36) The first step, when it is intended to polymerize a monomer, is to assess the electrophilicity or nucleophilicity, respectively, of the one or more monomers to be polymerized and then to choose a suitable catalyst. It has been found that the catalyst has to be adapted with regard to its activity. Michael-type monomers can have a broad range of electric properties. For the sake of simplicity Michael-type monomers can be classified in three groups: Group A: monomer with electron deficiency or high electrophilicity Examples are vinylpyridine, acrylonitrile; Group B: monomers having medium electrophilicity Examples are oxazolines, acrylates, acrylate esters methacrylates, methacrylate esters; and Group C: monomers having low electrophilicity or electron-rich monomers Examples are acrylamides, vinylphosphonates, vinylsulfonates.

(37) Heterocyclic monomers as defined in the claims, such as lactones, lactams, oxiranes, aziridines, azetidines, lactides, and glycolides, usually have medium to low electrophilicity.

(38) Catalysts that are active for the polymerization of the monomer component of the present invention, such as Michael-type monomers, can be found based on a classification in the above groups, i.e. based on the electrophilicity of the monomer. It seems that by combining a Michael-type monomer with an adapted catalyst, where the adaption can be done as described below, provides activation energy such that even very difficult to polymerize monomers can form polymers, such as vinyl sulfonates or vinyl phosphonates, vinyl pyridines or vinyl based monomers with substitution at the site.

(39) The evaluation of those parameters that influence the catalytic activity of the applied metal compound and the reactivity of the applied monomers can be achieved by using methods and values disclosed in the prior art. The gist of the present invention is the use of parameters that were known, but were used in other fields or for other reactions. It was found by the inventors, that on the one hand electrophilicity of a monomer and on the other hand affinity for fluoride ions of the metal compounds of formula I are useful parameters to determine a pair of monomer/catalyst that allows optimal polymerization.

(40) Thus, it was found that for the monomer reactivity towards the Group Transfer Polymerization (GTP) is a useful parameter. Methods to determine reactivity towards GTP have been described in the literature and scales have been established for the polymerization via rare earth metal-based catalysts. These methods can be used to classify monomers in groups A, B, or C as outlined below. In the below mentioned documents it is shown that coordination strength of the monomers towards a metal center can be determined via NMR experiments as well as copolymerization experiments. The reactivity of some common Michael-type monomers correlates with their coordination strength towards a metal center as well as with their pK.sub.a values in the following order:

(41) 2VP<iPOx<Methacrylates<Acrylates<Acrylamides<Vinylphosphonates Vinylsulfonates

(42) (See Salzinger, Stephan. Expansion of Rare Earth Metal-Mediated Group Transfer Polymerization to New Monomers. Diss. Technische Universitt Mnchen, 2013. (P. 218); Soller, Benedikt. Rare Earth Metal-Mediated Group Transfer Polymerization of Vinylphosphonates: Initiation, Propagation, and Stereoregularity. Technische Universitt Mnchen, Diss. Technische Universitt Munchen, 2016; Soller, Benedikt S., Stephan Salzinger, and Bernhard Rieger. Rare Earth Metal-Mediated Precision Polymerization of Vinylphosphonates and Conjugated Nitrogen-Containing Vinyl Monomers. Chemical reviews 116.4 (2015): 1993-2022; Zhang, Ning, et al. Rare earth metal-mediated group-transfer polymerization: from defined polymer microstructures to high-precision nano-scaled objects. Journal of the American Chemical Society 135.24 (2013): 8810-8813.)

(43) Thus, monomers can be classified as monomers of Group A (as defined above), that are weakly coordinating monomers with a low reactivity towards a GTP; as monomers of Group B (as defined above), that have a low to medium reactivity and coordination; or as monomers of group C (as defined above), that are very reactive and strongly coordinating monomers.

(44) It was found that ring type monomers or heterocyclic monomers, respectively as used in the present invention, such as lactone, lactam, substituted dione, oxirane, aziridine and azetidine, can be classified as medium to strong reactive and that a catalyst having medium to low activity, as defined below, has the best activity to provide for the ring opening and the polymerization.

(45) The monomer component comprises either only one type of monomer or a mixture of monomers. If a mixture of monomers is used, the catalyst is adapted to one of those, for example the first monomer that is added or the monomer with the best suited electrophilicity,

(46) As outlined above the monomer component can comprise at least one Michael-type monomer, and/or at least one type of monomer selected from a group comprising at least one lactone which can have up to 9 ring atoms, preferably up to 7 ring atoms and which can be substituted or unsubstituted; a lactam having up to 9 ring atoms, preferably up to 7 ring atoms which can be substituted or unsubstituted; or an 1,4-dioxan-2,4-dione which can be substituted or unsubstituted, and/or a combination of carbon dioxide and at least one monomer selected from oxiranes, azetidine, and aziridine. It is also possible to have a mixture of two or three of these monomers or of at least one of these monomers with other monomers.

(47) Lactones are well-known. Examples are -caprolactone, - or -butyrolactone. These monomers are of particular interest because they result when polymerized in polymers that are biodegradable.

(48) Methods for polymerizing lactones are known. However, for their polymerization either a combination of a Lewis acid and a Lewis base has to be used and/or the addition of an initiator, which is benzyl alcohol has to be used. Although a method for polymerizing lactones by using only an aluminum compound has been described, this cannot be used as after long reaction time only polymers with broad PDI can be obtained.

(49) Lactams are also well-known and result in polymers having very valuable properties. Examples for lactams that can be polymerized with a catalyst of the present invention are substituted or unsubstituted caprolactam, such as -caprolactam or N-vinylcaprolactam.

(50) A further group of monomers that result in polymers having desirable properties are polymers obtained from dioxan-diones, in particular lactides and glycolides or copolymers from lactide and glycolide. Lactide, glycolide, or lactide/glycolide polymers are biodegradable and are degraded in the human body with a predeterminable degradation rate. Therefore, this type of polymers is used for sutures, implants and delivery devices.

(51) The other useful parameter for finding a pair of monomer and catalyst is fluoride ion affinity index (FIA) which is used for the quantification of Lewis acidity. Although methods to determine acidity are well-known, these are not applicable to determine Lewis acidity, in particular for sterically demanding compounds. It was found that there is a good correlation between fluoride ion affinity of a compound, i.e. energy released upon the coordination of a fluoride ion to a Lewis acid center in kJ/mol and Lewis acidity. Therefore, high FIA values represent a strong Lewis acidic center. (see Haartz, J.; McDaniel, D. H. J. Am. Chem. Soc. 1973, 95, 8562; Larson, J.; McMahon, T. J. Am. Chem. Soc. 1985, 107, 766; Mller, L. O.; Himmel, D.; Stauffer, J.; Steinfeld, G.; Slattery, J.; Santiso-Quiones, G.; Brecht, V.; Krossing, I. Angew. Chem., Int. Ed. 2008, 47, 7659.)

(52) Ingo Krossing and others developed a method to determine the fluoride affinity index for Lewis acids. The FIA is an indicator for the acidity of the Lewis acid. It is known inter alia from N. Bartlett et al. (Inorg. Chem. 1984, 23, 3167-3173) that the fluoride ion affinity (FIA) is a reliable measure of the Lewis acidity, combining the strength of a Lewis acid A.sub.(g) with the energy that is released upon binding a fluoride ion F.sup.:

(53) ##STR00001##

(54) The higher the FIA of the parent Lewis acid A, the more stable it is towards decomposition on thermodynamic grounds. The simplest and most general access to reliable FIA values comprises the use of quantum chemical calculations in isodesmic reactions. The following table 1 shows calculated FIAs of a representative set of strong neutral Lewis acids.

(55) TABLE-US-00001 TABLE 1 Lewis acid/anion FIA Al(OR.sup.F).sub.3/[FAl(OR.sup.F).sub.3].sup. 537 Al(C.sub.6F.sub.5).sub.3/[FAl(C.sub.6F.sub.5).sub.3].sup. 530 AlI.sub.3/[FAlI.sub.3].sup. and AlBr.sub.3/[FAlBr.sub.3] 393

(56) The first compound in table 1 is too strong to be active as catalyst. The second compound, trispentafluorophenylaluminum (Al(C.sub.6F.sub.5).sub.3) having a high FIA of 530 is very strong and readily polymerizes monomers of group A. On the other hand, AlCl.sub.3, AlI.sub.3 and AlBr.sub.3 are very weak Lewis acids and do not polymerize any of the tested monomers. Thus, a suitable catalyst has a FIA of 530 down to more than 393. Metal compounds having a FIA in the range of 530 or below but not higher than 530 are suitable for polymerization of monomers of group A, those having a FIA in the medium range are suitable for monomers of group B, and those having a FIA of higher than 393 are suitable for monomers of group C.

(57) To confirm the above explanations experiments were carried out and the results showing the polymerization activity of monomers and catalysts are summarized in table 2. For example, polyacrylonitrile can be synthesized with extreme turnover frequencies (TOF) in high yields within a short timescale by the use of trispentafluorophenylaluminum (Al(C.sub.6F.sub.5).sub.3) as catalyst. (see table 2, exp. 1). Fluorine endgroups could be revealed through .sup.19F-NMR, which implies that one of the catalyst ligands has been transferred to the polymer chain end as previously mentioned (FIG. 1). If triphenylaluminum (Al(C.sub.6H.sub.5).sub.3) is used as catalyst for polyacrylonitrile, no polymerization can be observed, because its FIA, and thereby the Lewis acidity of this catalyst is not sufficient for the polymerization of monomers of group A due to the missing electron-withdrawing groups, e.g. fluoride groups (see table 2, exp. 2).

(58) While trispentafluorophenylaluminum (Al(C.sub.6F.sub.5).sub.3) is a suitable catalyst for the polymerisation of the less reactive and weakly coordinating monomers of group A, no polymerization can be observed when the same catalyst is applied for the polymerization of monomers of group B or C. Without being bound by theory, it is assumed that the Lewis acidity as shown by the high FIA of this catalyst is too strong for the polymerization of the more reactive monomers of group B. In fact, the use of the less acidic triphenylaluminum (Al(C.sub.6H.sub.5).sub.3) results in a successful polymerization of those monomers (see table 2, exp. 3).

(59) The same correlation can be observed when the Lewis acidity of the applied catalyst has a FIA in the medium range, i.e. well below 530 but also well above 393. Attempts to polymerize monomers of group B with less acidic Lewis acids such as triethylaluminum (Al(C.sub.2H.sub.5).sub.3) or triisobutylaluminum (Al(C.sub.4H.sub.9).sub.3) failed, confirming the above-mentioned assumption (table 2, exp. 4-5). In contrast to this, these catalysts perform well in the polymerization of monomers of group C. Triethylaluminum (Al(C.sub.2H.sub.5).sub.3) and triisobutylaluminum (Al(C.sub.4H.sub.9).sub.3) as well as trioctylaluminum (Al(C.sub.8H.sub.17).sub.3) polymerize monomers of group C such as dimethylacrylamide (table 2, exp. 6-8). Less acidic Lewis acids such as aluminumbromide (FIA: 393) and aluminumiodide (FIA: 393) are not active catalysts for the polymerization of the reactive and strongly coordinating monomers of group C, due to their low FIA (table 2, exp. 9-10)

(60) In summary, according to the present invention it is possible to identify suitable catalysts for polymerisation of demanding Michael-type monomers with these two useful parameters according to the following approach:

(61) Monomers of group A with a low reactivity and coordination strength need very strong Lewis acids with a high FIA in order to be successfully polymerized.

(62) Monomers of group C, on the other hand, i.e. highly reactive and coordinating monomers, do not require strong Lewis acids, and can therefore be polymerized by using weak Lewis acids, with a low FIA.

(63) Monomers of group B, i.e. with medium reactivity and coordination strength can be polymerized with Lewis acids having medium acidity.

(64) The critical point is that monomer and catalyst have to be adapted. If an electron-poor monomer shall be polymerized like acrylonitrile, a Lewis acid having a high fluoride affinity index has to be used. If an electron-rich monomer is polymerized, a Lewis acid having a low fluoride affinity index is used. For monomers that have a medium electron density a Lewis acid having a medium fluoride affinity index is used.

(65) Table 2 shows selected combinations of Lewis acids having different acidity and their suitability towards the GTP of various Michael-type monomers. For a better comparability, the reaction time has been kept constant. Quantitative Yields would have been achieved by extending the reaction time. The examples describe further combinations and conditions.

(66) TABLE-US-00002 TABLE 2 Exp. Mon. LA t[s] Mon./LA M.sub.n.sup.[b] Y [%].sup.[c] 1 AcN Al(C.sub.6F.sub.5).sub.3 30 1000 350 n.d. 74 2 tBuMA Al(C.sub.6F.sub.5).sub.3 3600 100 0 3 tBuMA Al(C.sub.6H.sub.5).sub.3 3600 100 23 1.06 62 4 tBuMA Al(C.sub.2H.sub.5).sub.3 3600 100 0 5 tBuMA Al(C.sub.4H.sub.9).sub.3 3600 100 0 6 DMAA Al(C.sub.2H.sub.5).sub.3 3600 100 235 1.52 57 7 DMAA Al(C.sub.4H.sub.9).sub.3 3600 100 20 1.35 80 8 DEVP Al(C.sub.8H.sub.17).sub.3 3600 100 n.d. n.d. 70 9 DEVP AlBr.sub.3 3600 100 0 10 DEVP Al(I).sub.3 3600 100 0 [a] Exp 1: total solvent volume 7.0 mL (solvent N,N-dimethylformamide),] Exp 2-10: total solvent volume 2.0 mL (solvent Toluene) T = 60 C. (exept Exp 1 = RT) .sup.[b]determined by GPC coupled with multi angle laser light scattering (MALS), reported in 10.sup.3 g/mol, .sup.[c]yield measured gravimetrically and by .sup.1H NMR spectroscopy.

(67) In summary, strong Al(III)-based Lewis acid catalysts are suitable for the polymerization of monomers of the group A, while they are not suitable for monomers of the other groups due to their high Lewis acidity. Weaker Lewis acids are required for the polymerization of monomers of the group B and C. Monomers of the group C require the lowest Lewis acidity and FIA in order to be successfully polymerized. The classification for the groups A, B, C is not strict and catalysts can be found that are useful in an overlapping range. Therefore, it might be possible to polymerize some monomers classified for group C with Lewis Acids found suitable for group B, in particular when the electrophilicity of the monomer is close to that of monomers of group B.

(68) With these parameters being defined, an approach for a polymerization of monomers by the method of the present invention can be as follows:

(69) At first, it is determined whether a monomer belongs to group A, B or C, either by comparison with known monomers or by its reactivity.

(70) At second, a catalyst with an adequate FIA/Lewis acidity is chosen. If the monomer has been assigned to Group A, a catalyst with a strong Lewis acidity and high FIA is applied. If a monomer has been assigned to Group B a catalyst with a weaker Lewis acidity and lower FIA is chosen. If a monomer belongs to group C a catalyst with a low Lewis acidity is selected.

(71) To evaluate if the two components of the systemcataylst and monomerare suitable, the polymerization activity can be tested. Any method for testing polymerization can be used, and the results of different runs are compared. In one embodiment, a catalyst is tested as follows: a metal compound of formula I is combined with a monomer for polymerization in a ratio of catalyst to monomer of 1:100 in an organic solvent, such as N,N-dimethyl formamide, at a temperature of 40 C. for 60 min. These conditions have been found useful for testing, but other conditions can be used as well, as long as the same conditions are used for comparison.

(72) Copolymers of the above mentioned monomers can be either random copolymers or block copolymers. The optimal ratios and conditions can be found with routine experiments by the skilled person.

(73) One advantage of the system of the present invention resides in the fact that no initiator or co-catalyst is necessary. It was found that with known methods, where benzyl alcohol is used as initiator, inevitably one molecule benzyl alcohol is found at the chain end of each polymer chain. This is due to the reaction mechanism, where as a first step the initiator is added to the activated site of the first monomer to be polymerized.

(74) In contrast thereto, the method of the present invention allows to choose the group that starts the reaction and, thus, will be present as end group in the final polymer chain. Whether a Michael-type monomer or a heterocyclic monomer is used for polymerization, the reaction will start by coordination of a ligand of the metal compound and the monomer thereby activating the monomer. This activation either results in an activated site on the Michael-type monomer or a ring opening reaction for the heterocyclic monomer. In both cases polymerization then continues from the created active sites which coordinate with the next monomer.

(75) A further subject of the present invention is a ring opening polymerization of copolymers derived from carbon dioxide and a comonomer which is selected from substituted or unsubstituted oxirane with 3 or 4 ring atoms or a substituted or unsubstituted aziridine or azetidine. It was found that polycarbonate copolymers can be obtained with a ring opening polymerization when using the catalysts of the present invention. In other words, a metal compound as defined in this application when used as sole catalyst and initiator is active enough to initiate the polymerization between carbon dioxide and at least one of the above-mentioned monomers.

(76) When using a catalyst of the present invention with adapted activity, polymers with high polymer weight, low dispersion rate can be obtained from the above mentioned monomers in short time and at relatively low temperatures. With an adapted pair of monomer and catalyst high turnover rates can be obtained in an hour or less, such as within 30 minutes or even less, such as 10 minutes.

(77) Generally, the process can be carried out in a broad temperature range, within 78 C. to 150 C. This is particularly useful, as polymerizations can be carried out at room temperature or shortly below or above which facilitates the reaction. Moreover, temperature is one parameter to adapt the reaction condition such that the desired polymer is obtained. The skilled person can find the optimal conditions by routine experiments.

(78) After the reaction has been terminated by the addition of a quenching reagent such as an alcohol the polymer is precipitated in an organic solvent and fully characterized via common analytical techniques. In the examples this method is also described. Some results of this method are shown in FIGS. 1-11 and in tables 2, 4, and 5.

(79) If the yield of the polymer as well as the initiator efficient of the reaction (expected molecular mass (M.sub.n(exp)/detected molecular mass M.sub.n(det)) are satisfactory (>50%) the chosen catalyst is suitable for the polymerization of this monomer. If the measured values are not satisfactory a Lewis acid with another Lewis acidity and FIA is chosen and the step is repeated.

(80) In the following table 3 useful combinations of pairs of monomer and catalyst are summarized. This table is a general guideline. When looking for another suitable pair it is useful to assess the monomer to one of groups A, B, and C and then select a catalyst based on the above explained rules or based on the following table 3.

(81) Table 3 shows examples of Lewis acids and their suitability for the polymerization of exemplary Michael-type Monomers of the previously defined groups A, B and C.

(82) TABLE-US-00003 TABLE 3 Group A Group B Group C AcN 4-VP ipOx MMA tBuMA EA tBuA DMAA Al(C.sub.6F.sub.5).sub.3 X X Al(C.sub.6H.sub.5).sub.3 X X X X X X Al(CH.sub.3).sub.2(SC.sub.6H.sub.5) X X X X X Al(CH.sub.3).sub.2(OC.sub.6H.sub.5) X X X X X Al(C.sub.4H.sub.9).sub.3 X X Al(C.sub.2H.sub.5).sub.3 X X Al(CH.sub.3).sub.3 X X V.sub.solvent = 2 mL, T = 40 C., t = 60 min.

(83) If an electron deficient monomer like acrylonitrile is combined with a metal compound having low acidity, like triphenylaluminum, no reaction takes place. If an electron-rich monomer like DMAA is reacted with a highly acid metal compound like aluminumtriperfluorophenyl no polymerization takes place. With the knowledge of the present invention it is possible to find the best suited catalyst and/or to fine-tune the system.

(84) When a pair of monomer and metal compound has been found, the reactivity in polymerization is tested as outlined above. If the reactivity is not sufficient, the metal compound can be adapted. If the acidity of the metal compound is too high, at least one of R.sup.1, R.sup.2, and R.sup.3 should be substituted by an electron donating group. If the metal compound is too active, at least one of R.sup.1, R.sup.2 and R.sup.3, should be substituted by an electron withdrawing group.

(85) Some useful compounds of formula I are shown in the following:

(86) ##STR00002## ##STR00003## ##STR00004## ##STR00005## ##STR00006## ##STR00007## ##STR00008##

(87) Metal compounds of formula I are either commercially available or can be prepared with known methods with commercially available products. One common technique is to contact commercially available chlorinated metal precursors such as chloro-dialkyl-aluminates and a potassium salt bearing the desired group, for example, pentamethylcyclopentadiene potassium which yields the desired aluminum compound. An example for a synthesis is shown in Scheme 1

(88) ##STR00009##

(89) The metal compounds of formula I are active as catalyst and initiator. Without being bound by theory, it is assumed that monomer and catalyst/initiator of the present invention react according to the following mechanism as shown in Scheme 2 (with aluminum as example):

(90) ##STR00010##

(91) The residues R.sup.1, R.sup.2 and R.sup.3 of the aluminum compound used as catalyst and initiator have an influence on the acidity and residues can be selected in each case for adjusting the Lewis acid strength. This means, if one or more of the groups R.sup.1, R.sup.2 and R.sup.3 are electron withdrawing groups (EWG), the Lewis acidity is increased, vice versa the Lewis acidity is decreased if R.sup.1 and/or R.sup.2 are electron donating groups. Therefore, the Lewis acidity can be adjusted and fine-tuned accordingly to the chemical polymerization requirements of a specific type of Michael-type monomer used. As an example, at least one of R.sup.1 and R.sup.2 can be an EWG like a fluorinated or perfluorinated alkyl or aryl, such as CF.sub.3, CF.sub.2CF.sub.3, C.sub.6F.sub.5, or an electron donating group like alkyl or cycloalkyl, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert.-butyl, neopentyl, octyl, phenyl, cyclopentadienyl, tetramethyl-cyclopentadienyl, pentamethyl-cyclopentadienyl.

(92) Furthermore, R.sup.1, R.sup.2 and R.sup.3 can have an influence on the steric interaction between the catalyst and initiator compound and the monomer which can also control tacticity It has been found that syndiotacticity can be increased, for example by at least 10%, in particular by at least 25% and preferably by at least 40%, by increasing the size of substituents at the core metal atom, i.e. at least one of R.sup.1, R.sup.2 and R.sup.3. When an asymmetric metal compound with at least one bulky group is used as catalyst for polymerizing dimethyl acrylamide syndiotacticity of the polymer obtained can be in the range of up to more than 80%, whereas when using a symmetric metal compound in particular one with small substitutents usually an atactic polymer is obtained.

(93) The use of the catalytic and initiator compounds of the present invention provides for kinetic advantages and results in higher turnover frequencies of up to 10,000 or even more, such as 50,000 to 100,000. Furthermore, it was found that catalyst activity, polymer yield, molecular mass of the final polymer and polydispersity index are dependent from the molar ratio of monomer to catalyst system, in other words the catalyst loading. It was found, that a high catalyst loading, i.e. a molar ratio of monomer/catalyst of less than 1000 results in a high yield, nearly stoichiometric monomer consumption and a low molecular mass. Thus, the molar ratio of monomer/catalyst system can for example be in a range of 1:0.5 to 2000:1, such as 1:1 to 1000:1.

(94) As outlined above many types of monomers can be polymerized with the system and the method of the present invention. Examples of demanding Michael-type monomers that can be polymerized in high yield, with high TOF and with interesting properties are vinylphosphonates, in particular diethylvinylphosphonate, or diisopropylvinylphosphonate; vinylsulfonates; substituted or unsubstituted acrylates and methacrylates, such as methylacrylate, butyl acrylate, isobutyl acrylate, tert.-butyl acrylate, isobornyl acrylate, furfuryl acrylate, glydidyl acrylate, hexylacrylate, methylmethacrylate, butyl methacrylate, isobutyl methacrylate, tert.-butyl methacrylate, isobornyl methacrylate, furfuryl methacrylate, glydidyl methacrylate; substituted or unsubstituted acrylamides, such as methacrylamide, dimethylacrylamide, di-isopropylacrylamide; acrylonitrile; vinylpyridines; vinyl ketones, such as vinylmethylketone; acrolein and acrolein derivates. Mixtures of these monomers can be used to prepare copolymers.

(95) The process of the present invention can be carried out in a broad temperature range. Polymerization reactions can be conducted with Michael-type monomers in a range of 115 C. to 150 C. In most cases, the process of the present invention can be carried out at about room temperature, which is advantageous as no heating or cooling is necessary. Activity of the catalyst and initiator compound can be increased, by lowering the temperature to 0 C. or below and very favourable results can be obtained. High conversion rates are obtained between about 0 C. and room temperature, i.e. 25 C. Thus, although the process can be used in a broad temperature range, in a preferred embodiment, the process is carried out at a temperature between 10 C. and 40 C., preferably between 0 and 25 C. The optimum temperature for a specific process can be found in routine tests depending on the catalyst and initiator compound, monomer and solvent used.

(96) In a preferred embodiment, the process of the present invention can be carried out under protection gas which can be selected from nitrogen, helium, argon, xenon and other protection gases known to the person skilled in the art.

(97) The process of the invention allows high polymeric yields such as at least 80% conversion of the monomers, or even between 90 and 100% or about 100%.

(98) The process of the present invention allows to also control polydispersity and to obtain polymers having a low to very low polydispersity index.

(99) The process of the present invention usually is carried out in a fluid medium which can be the monomer or an organic solvent which dissolves the monomer, in a salt melt, or a gas. The term organic solvent as used in the present application refers to a compound that is liquid at room temperature and/or process temperature. Organic solvents that are suitable for the preparation of polymers from monomers as defined are known and those that are used in the prior art can be used for the process of the present invention, too. Usually aromatic or aliphatic hydrocarbons, heteroaromatic and heteroaliphatic compounds, as long as they are liquid at process temperature, or ionic solvents are suitable. Also salt melts as well as supercritical CO.sub.2 can be used. Aromatic hydrocarbons that are very common in this field are preferred, such as toluene which is particularly useful.

(100) An organic solvent in the process of the present invention can have different functions: it can be used as inert carrier that not necessarily dissolves both components; i.e. metal catalyst and monomer component, it can be used to dissolve the monomer; it can be used as heat dissipating agent. Furthermore, the polarity of the solvent can have an influence on the tacticity. Thus, in cases where tacticity is an issue the polarity of the solvent has to be considered and a suitable solvent has to be selected. Furthermore, in some embodiments the monomer can be the solvent for the metal compound and no additional solvent is necessary. The amount of solvent is that which is usually used. By increasing or decreasing the amount of solvent, the activity and the duration can be influenced as it is well-known to the skilled person.

(101) The present invention is also concerned with the use of a metal compound of formula I as defined above and in the claims as catalyst and/or initiator for polymerization of a monomer component.

(102) The present invention also relates to polymers which are obtainable by a catalyst and initiator and by the processes of the present invention. As already indicated, according to the present invention polymers can be obtained that are characterized by having a terminal functional group such as an olefinic end group, an aromatic group, a heteroaromatic group, an alkynyl group, a mercapto group, a furfuryl group etc., or a chemoactive or bioactive group, for example a nucleobase. The terminal functional group can be used, to crosslink polymer chains, to immobilise polymer chains etc.

(103) Such a terminal group allows functionalization and chemical variation. Thus, the polymers can be functionalized in many different ways so that a versatile product is provided. The terminal group can be used for coupling other molecules like other polymers to form block copolymers. Another example is the introduction of chemoactive groups that can be used for further reactions, such as alkynes and thiols for click reactions, thiols and alkenes for thiol-ene chemistry, or initiators capable of initiating a radical polymerization. Those functional groups can be easily introduced and increase versatility. Furthermore, reactions with transition metal catalysts allow copolymerisation with olefinically unsaturated monomers like ethene or propene. Another option is the introduction of bioactive groups; for example introducing thiocholesterin or cholesterin and folic acid derivatives can increase membrane permeation or compatibility of the polymers.

(104) The present invention allows to obtain a mutliplicity of polymers with valuable properties. One example is a polymer or copolymer of one or more of Michael monomers selected from the group consisting of vinylphosphonate, in particular diethylvinylphosphonate, or diisopropylvinylphosphonate; vinylsulfonate, substituted or unsubstituted acrylate and methacrylate, such as methyl acrylate, butyl acrylate, isobutyl acrylate, tert.-butyl acrylate, isobornyl acrylate, furfuryl acrylate, glydidyl acrylate; butyl methacrylate, isobutyl methacrylate, tert.-butyl methacrylate, isobornyl methacrylate, furfuryl methacrylate, glydidyl methacrylate substituted or unsubstituted acrylamide, such as methacrylamide, dimethylacrylamide, acrylonitrile, vinylpyridine, vinyl ketone, acrolein or an acrolein derivate, or mixtures thereof.

(105) Furthermore, the system of the present invention allows to polymerize tactic polymers by selecting a catalyst that favours tacticity. Tactic polymers refers to polymers that have an increased syndio- or isotaciticity compared to an average syndio- or isotacticity of the polymer. Therefore, another subject of the present invention is a process for preparing a polymer having increased syndio- or isotacticity comprising contacting a a metal compound as sole catalyst and initiator, optionally dissolved in an organic solvent, with a monomer component, wherein the metal compound is MR.sup.1R.sup.2R.sup.3 wherein M is aluminum, gallium or indium, each of R.sup.1, R.sup.2, and R.sup.3, is independently CI, F, I, Br or linear, branched or cyclic alkyl, heterocycloalkyi, linear, branched or cyclic alkenyl, heterocycloalkenyl, linear, branched, or cyclic alkynyl, heterocycloalkynyl, linear, branched, or cyclic alkoxy, aryl, heteroaryl, aryloxy, silyl, metallocenyl, nitro, nitroso, hydroxy, or carboxyl, wherein each alkyl, alkenyl, alkynyl, or alkoxy independently has up to 12 carbon atoms, wherein each aryl or heteroaryl independently has 5 to 14 ring atoms, wherein any hetero group has at least one hetero atom selected from O, S or N, wherein each alkyl, alkenyl, alkynyl or alkoxy, heterocycloalkyi, heterocycloalkenyl, heterocycloalkynyl, aryl, heteroaryl, aryloxy group can be substituted by 1 up to the highest possible number of halogen atoms; and wherein either all three groups R.sup.1, R.sup.2, and R.sup.3 are different or R.sup.1 and R.sup.2 are the same and R.sup.3 is different and is a bulky group; or wherein two of R.sup.1, R.sup.2, and R.sup.3 together with Al form a substituted or unsubstituted cyclic group comprising 2 to 5 carbon atoms or 2 to 4 carbon atoms and 1 to 3 hetero atoms selected from O, S or N; wherein the monomer component comprises at least one Michael-type monomer and/or at least one heterocyclic monomer selected from the group consisting of a substituted or unsubstituted lactone having up to 9 ring atoms, a substituted or unsubstituted lactam having up to 9 ring atoms, or a substituted or unsubstituted 1,4-dioxan-2,4-dione, or a mixture thereof; and/or a combination of CO.sub.2 and at least one comonomer selected from the group of substituted or unsubstituted oxirane with 3 or 4 ring atoms, substituted or unsubstituted aziridine or azetidine.

(106) Polymers having increased syndio- or isotacticity are particularly valuable. For example can tacticity enhance biodegradability of polymers like lactide/glykolide polymers, butyrolactone derived polymers etc.

(107) A metal compound can for example carry one transferable group, one sterically encumbered group, like tert-butyl or heteroaryl, and one small group like methyl or ethyl.

(108) It has been found that by using an asymmetric metal compound of formula I as defined above it is possible to prepare polymers having increased syndio- or isotacticity. Without being bound by theory it is assumed that a polymer with enhanced tactic content is produced if the applied catalyst is substituted by ligands with different sterical encumberance. As soon as the initiating step takes place one of the catalyst ligands is transferred to the coordinating monomer. If the remaining catalyst ligands are of different sterical encumberance, the growing polymer chain will be directed to the less demanding ligand. Therefore, a preferred arrangement of growing polymer chain catalyst ligands and new monomer will take place. This preferred arrangement will result in the formation of a tactically enriched polymer.

(109) The system and the process of the present invention offer another very valuable option, i.e. to introduce functional groups by adapting the ligands of the metal compound. In one embodiment of the present invention this versatility of the catalyst is used to provide polymers with luminescent groups or with groups that can be induced to become luminescent. There is a high academic and economic interest in photoluminescent polymers, as they can be applied in various fields from analytics to biomedical applications. For example photoluminescent poly(lactone)s can be used in the cancer research as tumor markers (Jian Yang et al. Development of Intrinsically Photoluminescent and Photostable Polylactones. Advanced Materials, 2014, 26, 4491-449). Usually, in order to enable photoluminescent properties, molecules with a huge conjugated -System have to be chemically attached to the polymer chain end through post polymerization modifications such as thiol-ene click reactions or via the use of photoluminescent radical initiators. Both methods are complex to perform and are partly extremely cost intensive and time consuming. A further method to modify polymeric material in order to gain photoluminescent properties is the dotation of the polymeric samples with rare earth elements such as Europium (Bermudez et al. Highly Photostable Luminescent Poly(-caprolactone)siloxane Biohybrids Doped with Europium Complexes. Chemistry of Materials, 2007, 19 (16), 3892-3901).

(110) Surprisingly it was found that by use of the catalysts of the present invention, it is possible to synthesize polymers of the monomer components as defined in the claims without relying on complex syntheses or cost intensive processes. When using a catalyst of the present invention, a heterocyclic monomer as described coordinates to the metal center of the described catalyst. The polymerization is initiated by the transfer of one of the catalyst ligands as exemplified in Scheme 3. After a predetermined time, the reaction can be stopped by quenching and a polymer can be precipitated. Without being bound by theory it is assumed that in dependence of the structure of the transferred group a tautomerization can occur which results in a conjugated -System as exemplified in Scheme 3. This allows to tailor the wavelength of the emitted light by changing the catalyst ligand to be transferred.

(111) ##STR00011##

(112) The process for preparing luminescent polymers corresponds to the processes as defined above. It was found that just by using a specific type of catalyst and initator compound components having luminescence can be obtained. The process can be carried out with the same parameters as the process defined above. Preferably, heterocyclic monomers as defined above or a combination of carbondioxide with oxirane, aziridine, and/or azetidine are used as monomer component. Color of the luminescent polymer can range over the whole visible spectra. The color can for example be red, blue, green, yellow, orange, or violet.

(113) A further aspect of the present invention are the luminescent components obtainable by the above described process. The polymers obtained are biocompatible and the luminescent properties, e.g. fluorescence, color, can be controlled by choosing catalyst and monomers as described above.

(114) Without being bound by theory, it is assumed that the luminescence of the components results from the terminal group, i.e. the electrophilicly substituted heterocycle which is the initiator for the polymerization reaction.

(115) The color can be adjusted for any polymer by choosing metal ligand, monomer and electrophilic substitution. The desired luminescence color can be easily calculated by the absorption increments of respective substituents according to the Woodward-Fieser-rules which are known to the person skilled in the art. The polymer attached to the luminescent end group is not critical for the color of the polymer.

(116) With the catalytic active compounds and processes of the present invention polymers with many favourable properties can be obtained. These polymers can be used in many different fields, such as, photocatalytic reduction, optical fiber waveguides, pH-sensing, temperature sensing, molecular-recognition processes with photonic (fluorescence) signals, phase transfer catalysis, photoluminescent magnetic sensor (via complexation of magnetic metals), photoluminescence quenching assays, as for example developed for the analysis of proteins, among others.

EXAMPLES

(117) In the examples polymers were prepared and were tested using gel permeation chromatography (GPC) for detection. GPC was made using a WTC Dawn Heleos II MALS detector. GPC was carried out on a Varian LC-920 system with two PL polar gel columns and N,N-dimethyl formamide (0.025 M LiBr) (polyacrylonitrile) or tetrahydrofurane/water (0.025 M tetrabutylammoniumbromide) (vinylphosphonates and vinylpyridines)) or tetrahydrofurane (acrylates or methacrylates) were used as liquid medium. The retention times were recorded via a MALLS detector and via an integrated RI detector (356-LC). The GPC spectrum is shown in FIG. 2.

(118) The NMR spectra were recorded with an AV III 500C of Bruker and were evaluated with Top Spin 3 software.

(119) In the following examples specific embodiments of the present invention are shown without thereby limiting the scope of the invention.

(120) Monomers like acrylonitrile, methacrylates, and 2-isopropenyl-2-oxazoline were polymerized using an metal compound of formula I adapted in acidity. The conditions and results are shown in Tables 4 and 5. The method is described in detail below.

Example 1

(121) Polyacrylonitrile was synthesized using 3 different aluminum compounds as catalyst and initiator in the polymerization reaction. Different ratios of monomer/catalyst were used. For each run the catalyst was added to 7.0 ml N,N-dimethylformamide as solvent. The reaction temperature was 40 C. The results are shown in Table 4.

(122) TABLE-US-00004 TABLE 4 Selected results of the polymerization of acrylonitrile with different catalysts at 0 C. Run Lewis acid t [s] Mon./LA. Mn.sup.(a) Mw.sup.(a) D Y [%] TOF [h.sup.1] 1 Al(C.sub.6F.sub.5).sub.3 5 4000 105 168 1.59 4 115,000 2 Al(C.sub.6F.sub.5).sub.3 15 4000 30139 228 1.64 10 103,000 3 Al(C.sub.6F.sub.5).sub.3 30 4000 n.d. 692 n.d. 23 110,000 4 Al(C.sub.6F.sub.5).sub.3 150 8000 n.d. 1600 n.d. 46 88,000 5 Al(C.sub.6F.sub.5).sub.3 30 1000 n.d. 350 n.d. 74 89,000 6 Al(Ph).sub.3 600 2000 7 B(C.sub.6F.sub.5).sub.3 600 2000 .sup.(a)determined by GPC

(123) As can be seen acrylonitrile was polymerized very efficient with Al(C6F5)3 as acrylonitrile is an electron-deficient monomer and Al(C6F5)3 is a highly active catalyst, i.e. a strong Lewis acid. When a less strong Lewis acid was used, (Al(Ph3)3, no polymerisation took place. A boron compound that is known as catalyst was also tested and did not yield a polymer.

Example 2 (for Comparison)

(124) Acrylonitrile was used as monomer with AlCl.sub.3 as catalyst as known in the prior art. The reaction was performed in oven-dried glass reactor, AlCl.sub.3 (302 L, 12.5 mmol/L suspension in toluene) was added and cooled to 0 C. Acrylonitrile (500 L, 3.77 mmol, 400 mg, 2,000 equivalents) and thereafter tricyclohexylphosphine (PEt.sub.3) (151 L, 25.0 mmol/L solution in toluene, 1 equivalents) were added and the mixture was stirred for 15 min at 0 C. The reaction was stopped by adding a mixture of DMF-MeOHHCl (100:10:1). A sample was taken and an .sup.1H-NMR was recorded. The reaction yielded no polymer, although a Lewis base was added for activation.

Example 3

(125) Polymerisation experiments were carried out with different monomers and catalysts. The reaction time was 60 min. The catalyst was added to toluene as solvent, the total solvent volume was 2 mL. For experiment 11 pentane was used as solvent. The molecular mass was determined by GPC-MALS or dual angle laser light scattering in H.sub.2O/THF (9 g/L tetrabutylammonium bromide) or THF at 40 C., reported in 10.sup.3 g/mol, The yield was measured gravimetrically and by .sup.1H NMR spectroscopy, rr [%] was determined by .sup.13C NMR spectroscopy, 21. For experiment 14 ACF induces a cationic ring opening polymerization. The results are summarized in Table 5.

(126) As can be seen from the results in Table 5, polymerization occurs only when catalyst and monomer match.

(127) In experiment 8 a monomer of group B is reacted with a strong Lewis acid and no reaction is seen. In experiments 12 and 13 a too weak catalyst is used and no polymerization occurs. When using in experiments 9-11 a suitable Lewis acid the polymerization runs very well. The same effect is shown in experiments 14, with no polymerization with a strong catalyst versus experiments 15-18 with good results. These results confirm that by selecting a suitable metal compound difficult monomers can be polymerized that could not be polymerized by GTP until now.

(128) TABLE-US-00005 TABLE 5 Selected results of the polymerization of Methacrylates and Oxazolines with Al(III)-based catalysts in toluene. Exp. Mon LA Mon./LA T [ C.] M.sub.n.sup.[b] Y [%].sup.[c] rr [%].sup.[d] 8 tBuMA Al(C.sub.6F.sub.5).sub.3 100 60 9 tBuMA Al(nOct).sub.3 100 60 155 1.33 100 62 10 tBuMA Al(nOct).sub.3 100 rt 175 1.19 42 66 11 tBuMA Al(nOct).sub.3 100 rt 395 1.25 83 70 12 tBuMA Al(iBu).sub.3 100 rt 13 tBuMA Al(Me).sub.3 100 rt traces 14 IPox Al(C.sub.6F.sub.5).sub.3 100 rt .sup.0.sup.[e] 15 IPox Al(Ph).sub.3 150 60 18 1.29 59 46 16 IPox Al(Ph).sub.3 100 rt 12 1.19 34 63 17 IPox Al(Ph).sub.3 100 rt 63 1.05 55 72 18 IPox Al(Ph).sub.3 100 0 15 1.02 17 77 [a] Reaction time 60 min., total solvent volume 2 mL (solvent toluene, except exp. 11 pentane) .sup.[b]determined by GPC-MALS or dual angle laser light scattering in H.sub.2O/THF (9 g/L tetrabutylammonium bromide) or THF at 40 C., reported in 10.sup.3 g/mol. .sup.[c]yield measured gravimetrically and by .sup.1H NMR spectroscopy, .sup.[d]determined by .sup.13C NMR,.sup.21 .sup.[e]ACF induces a cationic ring opening polymerization.sup.22

Example 4

(129) A polymer with enriched tacticity was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3.

(130) N,N-dimethylacrylamide was polymerized in a total solvent volume of 2 mL tetrahydrofuran with a ratio of 100:1 of monomer to catalyst at room temperature. The applied catalyst was bis((furan-2-ylmethyl)thio)(methyl)aluminum:

(131) ##STR00012##

(132) After 2 minutes the reaction was quenched with methanol and the reaction solution was precipitated in pentane. The tacticity of the obtained polymer was quantified by .sup.13C-NMR-Spectroscopy. The resulting spectrum is depicted in FIG. 2. By performing a peak deconvolution the syndiotactic (rr) content of the polymer was determined to be 78%.

Example 5

(133) A polylactone was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. -Caprolactone was polymerized in a total solvent volume of 2.5 mL toluene with a ratio of 100:1 monomer to catalyst at 50 C. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(134) ##STR00013##

(135) After 10 minutes the reaction was quenched with methanol and the reaction solution was precipitated in pentane. Yields where determined via .sup.1H-NMR and gravimetric methods to be 100%. The .sup.1H-NMR spectrum of the precipitated polymer is depicted in FIG. 6. Molecular mass and dispersity of the resulting polymer were determined to be 20,000 g mol.sup.1 and PDI=1.15.

Example 6

(136) A polylactide was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. Rac-lactide was polymerized in a total solvent volume of 2.5 mL mesitylene with a ratio of 100:1 monomer to catalyst at 110 C. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(137) ##STR00014##

(138) After 30 minutes the reaction was quenched with methanol and the reaction solution was precipitated in pentane/EtOH=1:1. Yields where determined via .sup.1H-NMR and gravimetric methods to be 80%. The .sup.1H-NMR spectrum of the precipitated polymer is depicted in FIG. 7. Molecular mass and dispersity of the resulting polymer were determined to be 22,000 g mol.sup.1 and PDI=1.19.

Example 7

(139) A poly(lactide co -Caprolactone) was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. Rac-lactide was polymerized in a total solvent volume of 2.5 mL mesitylene with a ratio of 100:1 monomer to catalyst at 110 C. After full conversion, 100 equivalents of the second monomer componend -Caprolactone were added. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(140) ##STR00015##

(141) 10 minutes after the addition of a second monomer component the reaction was quenched with methanol and the reaction solution was precipitated in pentane/EtOH 1:1. Yields where determined via .sup.1H-NMR and gravimetric methods to be 82%. The GPC traced of the monomer (right peak) and the corresponding copolymer (left peak) are depicted in FIG. 8. Molecular mass and dispersity of the first block (polylactide) were determined to be 22,400 g mol.sup.1, PDI=1.2. Molecular mass and PDI of the copolymer (poly(lactide co -Caprolactone) were determined to be 27,000 g mol.sup.1 PDI=1.35. It is also clearly visible that the retention time of the copolymer is higher than the retention time of the corresponding lactide-homopolymer.

Example 8

(142) A Poly(cyclohexenecarbonate) was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. The catalyst was dissolved in 5 mL toluene and 1.5 mL cyclohexeneoxide were added at 80 C. to the reaction solution. The reactor was than pressurized with 30 bar CO.sub.2. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(143) ##STR00016##

(144) After 180 minutes the reaction was quenched by releasing the pressure and addition of methanol. The reaction solution was than precipitated in Methanol. Yields where determined via .sup.1H-NMR and gravimetric methods to be 76%. The .sup.1H-NMR spectrum of the precipitated copolymer is depicted in FIG. 9. Signals corresponding to polycarbonate linkages (=4.65 ppm) are clearly visible. Molecular mass and dispersity of the resulting copolymer were determined to be 10,000 g mol.sup.1 and PDI=1.37. The amount of incorporated CO.sub.2 was determined via .sup.1H-NMR to be 40%.

Example 9

(145) A copolymer of diethylvinylphosphonate and lactide was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. diethylvinylphosphonate was polymerized in a total solvent volume of 2.5 mL toluene with a ratio of 200:1 monomer to catalyst at 50 C. After full conversion the reaction temperature was raised to 120 C. and 50 equivalents of the second monomer component rac-lactide were added. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(146) ##STR00017##

(147) After 60 minutes the reaction was quenched by the addition of methanol. The reaction solution was then precipitated in pentane/EtOH=1:1. Yields where determined via .sup.1H-NMR and gravimetric methods to be 80%. The monomodal GPC trace of the copolymer is depicted in FIG. 10. Molecular mass and dispersity were determined to be 12,400 g mol.sup.1, PDI=1.22.

Example 11

(148) A polylactide was synthesized using a catalyst of formula I, wherein R.sup.1, R.sup.2R.sup.3. Rac-lactide was polymerized in a total solvent volume of 2.5 mL mesitylene with a ratio of 100:1 monomer to catalyst at 110 C. The applied catalyst was dimethyl((6-methylpyridin-2-yl)methyl)aluminum:

(149) ##STR00018##

(150) After 30 minutes the reaction was quenched with methanol and the reaction solution was precipitated in pentane/EtOH=1:1. Yields where determined via .sup.1H-NMR and gravimetric methods to be 80%. Molecular mass and dispersity of the resulting polymer were determined to be 22,000 g mol.sup.1 and PDI=1.19. Photoluminescence spectra were taken with an AVA-Spec 2048 from Avantes using a Prizmatix (LED Current controller) as light source. Samples were excited with a 365 nm source. The resulting spectrum and the polymer solution are depicted in FIG. 11. At an excitation wavelength of 365 nm the polymer emits light with a wavelength of 463 nm.