METHOD FOR PREPARING POLYETHER CARBONATES

Abstract

The present invention relates to a method for preparing a high molecular weight polyether carbonate, by reacting an epoxide and carbon dioxide in the presence of a catalyst of formula (1), and a double metal cyanide (DMC) catalyst. The catalyst of formula (I) has the following structure:

##STR00001##

Claims

1. A high molecular weight polyether carbonate having the formula (IV)— ##STR00062## , wherein X is independently selected from OC(O)R.sub.x, OSO.sub.2R.sub.x, OSOR.sub.X, OSO(R.sub.X).sub.2, S(O)R.sub.x, OR.sub.x, phosphinate, halide, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, wherein each X may be the same or different and wherein X may form a bridge between M.sub.1 and M.sub.2; R.sub.x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl, n and m are integers, and R.sup.e1 and R.sup.e2 depend on the nature of the epoxide used to prepare the polyether carbonate.

2. A high molecular weight polyether carbonate according to claim 1, prepared by the method of reacting carbon dioxide and an epoxide in the presence of a double metal cyanide (DMC) catalyst and a catalyst of formula (I), wherein the catalyst of formula (I) has the following structure: ##STR00063## wherein M.sub.1 and M.sub.2 are independently selected from Zn(II), Cr(II), Co(II), Cu(II), Mn(II), Mg(II), Ni(II), Fe(II), Ti(II), V(II), Cr(III)-X, Co(III)-X, Mn(III)-X, Ni(III)-X, Fe(III)-X, Ca(II), Ge(II), AI(III)-X, Ti(III)-X, V(III)-X, Ge(IV)-(X).sub.2 or Ti(IV)-(X).sub.2; R.sub.1 and R.sub.2 are independently selected from hydrogen, halide, a nitro group, a nitrile group, an imine, an amine, an ether group, a silyl group, a silyl ether group, a sulfoxide group, a sulfonyl group, a sulfinate group or an acetylide group or an optionally substituted alkyl, alkenyl, alkynyl, haloalkyl, aryl, heteroaryl, alkoxy, aryloxy, alkylthio, arylthio, alicyclic or heteroalicyclic group; R.sub.3 is independently selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene, heteroarylene or cycloalkylene, wherein alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene and heteroalkynylene, may optionally be interrupted by aryl, heteroaryl, alicyclic or heteroalicyclic; R.sub.5 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl or alkylaryl; E.sub.1 is C, E.sub.2 is O, S or NH or E.sub.1 is N and E.sub.2 is O; E.sub.3, E.sub.4, E.sub.5 and E.sub.e are selected from N, NR.sub.4, O and S, wherein when E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are N, is , and wherein when E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are NR.sub.4, O or S, is ; R.sub.4 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl, -alkylC(O)OR.sub.19 or -alkylC☰N or alkylaryl; X is independently selected from OC(O)R.sub.x, OSO.sub.2R.sub.x, OSOR.sub.X, OSO(R.sub.x).sub.2, S(O)R.sub.x, OR.sub.x, phosphinate, halide, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, wherein each X may be the same or different and wherein X may form a bridge between M.sub.1 and M.sub.2; R.sub.x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl; and G is absent or independently selected from a neutral or anionic donor ligand which is a Lewis base.

3. The high molecular weight polyether carbonate of claim 1, wherein n and m are integers of 1 or more.

4. The high molecular weight polyether carbonate of claim 1, wherein m/(n+m) is from greater than zero to less than 1.

5. The high molecular weight polyether carbonate of claim 1, wherein m/(n+m) is greater than about 0.50 to about 0.95.

6. The high molecular weight polyether carbonate of claim 1, wherein the sum of all m and n groups is from 4 to 200.

7. The high molecular weight polyether carbonate of claim 1, wherein m + n ≥ 10, or m+ n ≥ 20, or m + n ≥ 100, or m + n ≥ 200, or m + n ≥ 500, or m + n ≥ 1,000.

8. The high molecular weight polyether carbonate of claim 1, wherein m/(n+m) is from about 0.15 to about 0.85.

9. The high molecular weight polyether carbonate of claim 1, wherein m/(n+m) is from about 0.20 to about 0.80.

10. The high molecular weight polyether carbonate of claim 1, wherein m/(n+m) is from about 0.25 to about 0.75.

11. The high molecular weight polyether carbonate of claim 1, wherein the high molecular weight polyether carbonate has a molecular weight of at least about 25,000 Daltons.

12. The high molecular weight polyether carbonate of claim 1, wherein the high molecular weight polyether carbonate has a molecular weight of at least about 50,000 Daltons.

13. The high molecular weight polyether carbonate of claim 1, wherein the high molecular weight polyether carbonate has a molecular weight of at least about 100,000 Daltons.

14. The high molecular weight polyether carbonate of claim 1, wherein R.sup.e1 and R.sup.e2 are independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl, or adjacent R.sup.e1 and R.sup.e2 groups may be taken together to form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms (e.g. O, N or S).

15. The high molecular weight polyether carbonate of claim 1, wherein R.sup.e1 and R.sup.e2 are independently selected from H or optionally substituted alkyl, or adjacent R.sup.e1 and R.sup.e2 groups may be taken together to form a five or six membered alkyl ring.

16. The high molecular weight polyether carbonate of claim 1, wherein each occurrence of R.sup.e1 and/or R.sup.e2 .sub.is the same.

17. The high molecular weight polyether carbonate of claim 1, wherein each occurrence of R.sup.e1 and/or R.sup.e2 is not the same.

18. The high molecular weight polyether carbonate of claim 1, wherein the PDI of the polymer is greater than about 1, preferably greater than about 2, more preferably greater than about 3.

19. The high molecular weight polyether carbonate of claim 1, wherein the polymer is a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer.

20. The high molecular weight polyether carbonate of claim 1, wherein the polymer is a random copolymer or a statistical copolymer.

Description

DETAILED DESCRIPTION

[0100] The present invention provides a method for reacting an epoxide with carbon dioxide in the presence of a catalyst of formula (I), a double metal cyanide (DMC) catalyst, and a starter compound, wherein the DMC catalyst contains at least two metal centres, cyanide ligands, and a first and a second complexing agent, wherein the first complexing agent is a polymer.

Catalysts of Formula (I)

[0101] The catalyst of formula (I) has the following structure:

##STR00029##

wherein: [0102] M.sub.1 and M.sub.2 are independently selected from Zn(II), Cr(II), Co(II), Cu(II), Mn(II), Mg(II), Ni(II), Fe(II), Ti(II), V(II), Cr(III)-X, Co(III)-X, Mn(III)-X, Ni(III)-X, Fe(III)-X, Ca(II), Ge(II), Al(III)-X, Ti(III)-X, V(III)-X, Ge(IV)-(X).sub.2 or Ti(IV)-(X).sub.2; [0103] R.sub.1 and R.sub.2 are independently selected from hydrogen, halide, a nitro group, a nitrile group, an imine, an amine, an ether group, a silyl group, a silyl ether group, a sulfoxide group, a sulfonyl group, a sulfinate group or an acetylide group or an optionally substituted alkyl, alkenyl, alkynyl, haloalkyl, aryl, heteroaryl, alkoxy, aryloxy, alkylthio, arylthio, alicyclic or heteroalicyclic group; [0104] R.sub.3 is independently selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, arylene, heteroarylene or cycloalkylene, wherein alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene and heteroalkynylene, may optionally be interrupted by aryl, heteroaryl, alicyclic or heteroalicyclic; [0105] R.sub.5 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl or alkylaryl; [0106] E.sub.1 is C, E.sub.2 is O, S or NH or E.sub.1 is N and E.sub.2 is O; [0107] E.sub.3, E.sub.4, E.sub.5 and E.sub.6 are selected from N, NR.sub.4, O and S, wherein when E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are N, is , and wherein when E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are NR.sub.4, O or S, is ; R.sub.4 is independently selected from H, or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, heteroaryl, alkylheteroaryl, -alkylC(O)OR.sub.19 or -alkylC≡N or alkylaryl; [0108] X is independently selected from OC(O)R.sup.x, OSO.sub.2R.sup.x, OSOR.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, QR.sup.x, phosphinate, halide, nitrate, hydroxyl, carbonate, amino, amido or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, wherein each X may be the same or different and wherein X may form a bridge between M.sub.1 and M.sub.2; [0109] R.sub.x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl or heteroaryl; and [0110] G is absent or independently selected from a neutral or anionic donor ligand which is a Lewis base.

[0111] Each of the occurrences of the groups R.sub.1 and R.sub.2 may be the same or different, and R.sub.1 and R.sub.2 can be the same or different.

[0112] Preferably R.sub.1 and R.sub.2 are independently selected from hydrogen, halide, amino, nitro, sulfoxide, sulfonyl, sulfinate, and an optionally substituted alkyl, alkenyl, aryl, heteroaryl, silyl, silyl ether, alkoxy, aryloxy or alkylthio. Preferably each occurrence of R.sub.2 is the same. Preferably, each occurrence of R.sub.2 is the same, and is hydrogen.

[0113] Both occurrences of R.sub.1 may be the same, and may be selected from hydrogen, halide, amino, nitro, sulfoxide, sulfonyl, sulfinate, silyl, silyl ether and an optionally substituted alkyl, alkenyl, aryl, heteroaryl, alkoxy, aryloxy or alkylthio. For example, both occurrences of R.sub.1 may be the same, and may be selected from hydrogen, halide, sulfoxide, and an optionally substituted alkyl, heteroaryl, silyl, alkylthio or alkoxy. Exemplary options for R.sub.1 (which may both be the same) include hydrogen, methyl, t-butyl, methoxy, ethoxy, alkylthio, trialkylsilyl such as trimethylsilyl or triethylsilyl, bromide, methanesulfonyl, or piperidinyl, e.g. both occurrences of R.sub.1 may be the same, and may be selected from methyl, t-butyl or trialkylsilyl.

[0114] Preferably, each occurrence of R.sub.2 is hydrogen and each R.sub.1 is independently selected from hydrogen, halide, amino, nitro, sulfoxide, sulfonyl, sulfinate, and optionally substituted alkyl, alkenyl, aryl, heteroaryl, silyl, silyl ether, alkoxy, aryloxy, alkylthio, arylthio, such as hydrogen, C.sub.1-6 alkyl (e.g. haloalkyl), alkoxy, aryl, halide, nitro, sulfonyl, silyl and alkylthio, for example, .sup.tBu, iPr, Me, OMe, H, nitro, SO.sub.2Me, SiEt.sub.3, SiMe.sub.3, SMe, halogen or phenyl.

[0115] It will be understood that each occurrence of R.sup.1 may be the same, and each occurrence of R.sub.2 may be the same, and R.sub.1 may be different to R.sub.2.

[0116] It will be appreciated that the group R.sub.3 can be a disubstituted divalent alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl or heteroalkynyl group which may optionally be interrupted by an aryl, heteroaryl, alicyclic or heteroalicyclic group, or may be a disubstituted aryl or cycloalkyl group which acts as a bridging group between two nitrogen centres in the catalyst of formula (I). Thus, where R.sub.3 is an alkylene group, such as dimethylpropylenyl, the R.sub.3 group has the structure —CH.sub.2—C(CH.sub.3).sub.2—CH.sub.2—. The definitions of the alkyl, aryl, cycloalkyl etc groups set out above therefore also relate respectively to the divalent alkylene, arylene, cycloalkylene etc groups set out for R3, and may be optionally substituted. Exemplary options for R3 include ethylenyl, 2,2-fluoropropylenyl, 2,2-dimethylpropylenyl, propylenyl, butylenyl, phenylenyl, cyclohexylenyl or biphenylenyl. When R3 is cyclohexylenyl, it can be the racemic, RR- or SS- forms.

[0117] R.sub.3 can be independently selected from substituted or unsubstituted alkylene and substituted or unsubstituted arylene, preferably substituted or unsubstituted propylenyl, such as propylenyl and 2,2-dimethylpropylenyl, and substituted or unsubstituted phenylenyl or biphenylenyl. Preferably both occurrences of R.sub.3 are the same. Even more preferably R.sub.3 is a substituted propylenyl, such as 2,2-di(alkyl)propylenyl, especially 2,2-di(methyl)propylenyl.

[0118] R.sub.3 can be independently selected from substituted or unsubstituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene, arylene or cycloalkylene. Preferably, R.sub.3 is selected from substituted or unsubstituted alkylene, cycloalkylene, alkenylene, heteroalkylene and arylene. More preferably, R.sub.3 is selected from 2,2-dimethylpropylenyl, —CH.sub.2 CH.sub.2 CH.sub.2—, —CH.sub.2CH(CH.sub.3)CH.sub.2—, —CH.sub.2C(CH.sub.2C.sub.6H.sub.5).sub.2CH.sub.2—, phenylene, —CH.sub.2 CH.sub.2—, —CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2—, —CH.sub.2 CH.sub.2N (CH.sub.3) CH.sub.2 CH.sub.2—, 1,4-cyclohexandiyl or —CH.sub.2CH.sub.2CH (C.sub.2H.sub.5)—. Still more preferably R.sub.3 is selected from 2,2-dimethylpropylenyl, —CH.sub.2 CH.sub.2 CH.sub.2—, —CH.sub.2CH(CH.sub.3)CH.sub.2—. —CH.sub.2C(CH.sub.2C.sub.6H.sub.5).sub.2CH.sub.2—, —CH.sub.2CH.sub.2CH (C.sub.2H.sub.5)—, —CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2—. More preferably still, R.sub.3 is selected from 2,2-dimethylpropylenyl, —CH.sub.2C(CH.sub.2C.sub.6H.sub.5).sub.2CH.sub.2—, CH.sub.2CH(CH.sub.3)CH.sub.2 and —CH.sub.2 C(C.sub.2H.sub.5).sub.2 CH.sub.2—.

[0119] Most preferably R.sub.3 is a substituted propylenyl, such as 2,2-di(alkyl)propylenyl, more preferably 2,2-dimethylpropylenyl.

[0120] As set out above, E.sub.3, E.sub.4, E.sub.5 and E.sub.6 are each independently selected from N, NR.sub.4, O and S. The skilled person will understand that if any of E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are N, is , and if any of E.sub.3, E.sub.4, E.sub.5 or E.sub.6 are NR.sub.4, O or S, is . Preferably, E.sub.3, E.sub.4, E.sub.5 and E.sub.6 are each independently selected from NR.sub.4, O and S.

[0121] Preferably each R.sub.4 is independently selected from hydrogen, and an optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroalkyl, heteroalkenyl, heteroalkynyl, heteroaryl, -alkylC(O)OR.sub.19 or-alkylC=N. Each R.sub.4 may be the same or different. Preferably, R.sub.4 is selected from hydrogen, and an optionally substituted alkyl, alkenyl, alkynyl, aryl, heteroalkyl, heteroalkenyl, heteroalkynyl or heteroaryl. Exemplary options for R.sub.4 include H, Me, Et, Bn, iPr, tBu or Ph, and —CH.sub.2—(pyridine). Preferably each R.sub.4 is hydrogen or alkyl.

[0122] Preferably each R.sub.5 is independently selected from hydrogen, and optionally substituted aliphatic or aryl. More preferably, each R.sub.5 is independently selected from hydrogen, and optionally substituted alkyl or aryl. Even more preferably, each R.sub.5 is the same, and is selected from hydrogen, and optionally substituted alkyl or aryl. Exemplary R.sub.5 groups include hydrogen, methyl, ethyl, phenyl and trifluoromethyl, preferably hydrogen, methyl or trifluoromethyl. Even more preferably, each R.sub.5 is hydrogen.

[0123] Preferably both occurrences of E.sub.1 are C and both occurrences of E.sub.2 are the same, and selected from O, S or NH. Even more preferably, both occurrences of E.sub.1 are C and both occurrences of E.sub.2 are O.

[0124] The skilled person will appreciate that the macrocyclic ligand of the catalyst of formula (I) may be symmetric, or may be asymmetric.

[0125] When the macrocyclic ligand is symmetric, it will be appreciated that each occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 will be the same. For example, each occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 may be NR.sub.4 (and each R.sub.4 may be the same). It will be understood that E.sub.3, E.sub.4, E.sub.5 and E.sub.6 may be the same and may be NH. In other words, the catalyst of formula (I) may have the following structure:

##STR00030##

[0126] When the macrocyclic ligand is symmetric, it will be appreciated that each occurrence of R.sub.1 may be the same, each occurrence of R.sub.2 may be the same, each occurrence of R.sub.3 may be the same, each occurrence of R.sub.5 may be the same, each occurrence of E.sub.1 may be the same, and each occurrence of E.sub.2 may be the same (although R.sub.1, R.sub.2, R.sub.3 and R.sub.5 are not necessarily the same as each other), and E.sub.3, E.sub.4, E.sub.5 and E.sub.6 are the same.

[0127] For example, each occurrence of R.sub.2, and R.sub.5 may be hydrogen, each occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 are NR.sub.4, and each R.sub.4 is hydrogen or alkyl, each occurrence of R.sub.3 may be substituted or (II) unsubstituted alkylene, cycloalkylene, alkenylene, heteroalkylene and arylene, each occurrence of R.sup.1 may be selected from hydrogen, halogen, sulfoxide or substituted or unsubstituted alkyl, heteroaryl, silyl, alkylthio or alkoxy, both occurrences of E.sub.1 may be C and both occurrences of E.sub.2 may be O.

[0128] When the ligand of the catalyst of formula (I) is asymmetric, it will be appreciated that at least one of the occurrences of the groups R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, E.sub.1 or E.sub.2 may be different from the remaining occurrences of the same group, or at least one occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 is different to a remaining occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6. For example each occurrence of R.sub.3 may be different, or each occurrence of R.sub.1 may be different.

[0129] It will also be appreciated that E.sub.3 and E.sub.5 may be the same, and E.sub.4 and E.sub.6 may be the same, but E.sub.3 and E.sub.5 are different to E.sub.4 and E.sub.6. It will also be appreciated that E.sub.3 and E.sub.4 may be the same, and E.sub.5 and E.sub.6 may be the same, but E.sub.3 and E.sub.4 are different to E.sub.5 and E.sub.6. Alternatively one occurrence of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 is different to the remaining occurrences of E.sub.3, E.sub.4, E.sub.5 and E.sub.6 (and the remaining three occurrences are the same).

[0130] For example, E.sub.3, E.sub.4 and E.sub.5 may be -NR.sub.4 where R.sub.4 is H, and R.sub.6 may be NR.sub.4 where R.sub.4 is alkyl. Furthermore, E.sub.3 and E.sub.5 may be NR.sub.4 where R.sub.4 is H, and E.sub.4 and E.sub.6 may be NR.sub.4 where R.sub.4 is alkyl, or E.sub.3 and E.sub.4 may be NR.sub.4 where R.sub.4 is H, and E.sub.5 and E.sub.6 may be NR.sub.4 where R.sub.4 is alkyl. Thus, it will be appreciated that each E.sub.3, E.sub.4, E.sub.5 and E.sub.6 is preferably NR.sub.4, where at least one occurrence of R.sub.4 is different to the remaining occurrences of R.sub.4.

[0131] For the catalysts of formula (I), (symmetric and asymmetric), each X is independently selected from OC(O)R.sup.x, OSO.sub.2R.sup.x, OS(O)R.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, OR.sup.x, phosphinate, halide, nitro, hydroxyl, carbonate, amino, nitrate, amido and optionally substituted, aliphatic, heteroaliphatic (for example silyl), alicyclic, heteroalicyclic, aryl or heteroaryl. Preferably each X is independently OC(O)R.sup.x, OSO.sub.2R.sup.x, OS(O)R.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, OR.sup.x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl. Even more preferably, each X is independently OC(O)R.sup.x, OR.sup.x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x. Preferred optional substituents for when X is aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl include halogen, hydroxyl, nitro, cyano, amino, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl, Each X may be the same or different and preferably each X is the same. It will also be appreciated that X may form a bridge between the two metal centres.

[0132] R.sup.x is independently hydrogen, or optionally substituted aliphatic, haloaliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl, alkylaryl, or heteroaryl. Preferably, R.sup.x is alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl. Preferred optional substituents for R.sup.x include halogen, hydroxyl, cyano, nitro, amino, alkoxy, alkylthio, or substituted or unsubstituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl (e.g. optionally substituted alkyl, aryl, or heteroaryl).

[0133] Exemplary options for X include OAc, OC(O)CF.sub.3, halogen, OSO(CH.sub.3).sub.2, Et, Me, OMe, OiPr, OtBu, Cl, Br, I, F, N(iPr).sub.2 or N(SiMe.sub.3).sub.2, OPh, OBn, salicylate, dioctyl phosphinate, etc.

[0134] Preferably each X is the same, and is selected from OC(O)R.sup.x, OR.sup.x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x, R.sup.x is alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl or alkylaryl. More preferably each X is the same and is OC(O)R.sup.x, OR.sup.x, halide, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x. Still more preferably each X is the same and is OC(O)R.sup.x, More preferably still each X is the same and is selected from OAc, O.sub.2CCF.sub.3, or O.sub.2C(CH.sub.2).sub.3Cy. Most preferably each X is the same and is OAc.

[0135] Preferably each R.sup.x is the same and is selected from an optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. More preferably each R.sup.x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or alkylaryl. Still more preferably each R.sup.x is the same and is an optionally substituted alkyl, alkenyl, heteroalkyl; or cycloalkyl. More preferably still R.sup.x is an optionally substituted alkyl, heteroalkyl or cycloalkyl. Most preferably R.sup.x is an optionally substituted alkyl.

[0136] It will be appreciated that preferred definitions for X and preferred definitions for R.sup.x may be combined. For example, each X may be independently OC(O)R.sup.x, OSO.sub.2R.sup.x, OS(O)R.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, OR.sup.x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl, (for example silyl), aryl or heteroaryl, e.g. each may be independently OC(O)R.sup.x, OR.sup.x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x, and R.sup.x may be optionally substituted alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl.

[0137] As detailed above, M.sub.1 and M.sub.2 are independently selected from any of: Zn(II), Cr(III)-X, Cr(II), Co(III)-X, Co(II), Cu(II), Mn(III)-X, Mn(II), Mg(II), Ni(II), Ni(III)-X, Fe(II), Fe(III)-X, Ca(II), Ge(II), Ti(II), Al(III)-X, Ti(III)-X, V(II), V(III)-X, Ge(IV)-(X).sub.2 or Ti(IV)-(X).sub.2.

[0138] Preferably, at least one of M.sub.1 and M.sub.2 is selected from Zn(II), Cr(III)-X, Co(II), Mn(II), Mg(II), Ni(II), Fe(II), and Fe(III)-X, more preferably at least one of M.sub.1 and M.sub.2 is selected from Mg(II), Zn(II), and Ni(ii), for example, at least one of M1 and M.sub.2 is Ni(II).

[0139] It will be appreciated that M.sub.1 and M.sub.2 may be the same or different. For example, M.sub.1 and/or M.sub.2 may be selected from Zn(II), Cr(III)-X, Co(II), Mn(II), Mg(II), Ni(II), Fe(II), and Fe(III)-X, more preferably M.sub.1 and/or M.sub.2 is selected from Mg(II), Zn(II) and Ni(II), for example, M.sub.1 and/or M.sub.2 is Ni(II).

[0140] Exemplary combinations of M.sub.1 and M.sub.2 include Mg(II) and Mg(II), Zn(II) and Zn(II), Ni(II) and Ni(II), Mg(II) and Zn(II), Mg(II) and Ni(II), Zn(II) and Co(II), Co(II) and Co(III), Fe(III) and Fe(III), Zn(II) and Fe(II), or Zn(II) and Ni(II).

[0141] It will be appreciated that when one of M.sub.1 or M.sub.2 is Cr(III), Co(III), Mn(III), Ni(III), Fe(III), Al(III), Ti(III) or V(III) the catalyst of formula (I) will contain an additional X group co-ordinated to the metal centre, wherein X is as defined above. It will also be appreciated that when one of M.sub.1 or M.sub.2 is Ge(IV) or Ti(IV), the catalyst of formula (III) will contain two additional X group co-ordinated to the metal centre, wherein X is as defined above. In certain embodiments, when one of M.sub.1 or M.sub.2 is Ge(IV)-(X).sub.2 or Ti(IV)-(X).sub.2, both G may be absent.

[0142] When G is not absent, it is a group which is capable of donating a lone pair of electrons (i.e. a Lewis base). In certain embodiments, G is a nitrogen-containing Lewis base. Each G may be neutral or negatively charged. If G is negatively charged, then one or more positive counterions will be required to balance out the charge of the complex. Suitable positive counterions include group 1 metal ions (Na.sup.+, K.sup.+, etc), group 2 metal ions (Mg.sup.2+, Ca.sup.2+, etc), imidazolium ions, a positively charged optionally substituted heteroaryl, heteroaliphatic or heteroalicyclic group, ammonium ions (i.e. N(R.sup.12).sub.4.sup.+), iminium ions (i.e. (R.sup.12).sub.2C=N(R.sup.12).sub.2.sup.+, such as bis(triphenylphosphine)iminium ions) or phosphonium ions (P(R.sup.12).sub.4.sup.+), wherein each R.sup.12 is independently selected from hydrogen or optionally substituted aliphatic, heteroaliphatic, alicyclic, heteroalicyclic, aryl or heteroaryl. Exemplary counterions include [H-B].sup.+ wherein B is selected from triethylamine, 1,8-diazabicyclo[5.4.0]undec-7-ene and 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene.

[0143] G is preferably independently selected from an optionally substituted heteroaliphatic group, an optionally substituted heteroalicyclic group, an optionally substituted heteroaryl group, a halide, hydroxide, hydride, a carboxylate and water. More preferably, G is independently selected from water, an alcohol (e.g. methanol), a substituted or unsubstituted heteroaryl (imidazole, methyl imidazole (for example, N-methyl imidazole), pyridine, 4-dimethylaminopyridine, pyrrole, pyrazole, etc), an ether (dimethyl ether, diethylether, cyclic ethers, etc), a thioether, carbene, a phosphine, a phosphine oxide, a substituted or unsubstituted heteroalicyclic (morpholine, piperidine, tetrahydrofuran, tetrahydrothiophene, etc), an amine, an alkyl amine trimethylamine, triethylamine, etc), acetonitrile, an ester (ethyl acetate, etc), an acetamide (dimethylacetamide, etc), a sulfoxide (dimethylsulfoxide, etc), a carboxylate, a hydroxide, hydride, a halide, a nitrate, a sulfonate, etc. In some embodiments, one or both instances of G is independently selected from optionally substituted heteroaryl, optionally substituted heteroaliphatic, optionally substituted heteroalicyclic, halide, hydroxide, hydride, an ether, a thioether, carbene, a phosphine, a phosphine oxide, an amine, an alkyl amine, acetonitrile, an ester, an acetamide, a sulfoxide, a carboxylate, a nitrate or a sulfonate. In certain embodiments, G may be a halide; hydroxide; hydride; water; a heteroaryl, heteroalicyclic or carboxylate group which are optionally substituted by alkyl, alkenyl, alkynyl, alkoxy, halogen, hydroxyl, nitro or nitrile. In preferred embodiments, G is independently selected from halide; water; a heteroaryl optionally substituted by alkyl (e.g. methyl, ethyl etc), alkenyl, alkynyl, alkoxy (preferably methoxy), halogen, hydroxyl, nitro or nitrile. In some embodiments, one or both instances of G is negatively charged (for example, halide). In further embodiments, one or both instances of G is an optionally substituted heteroaryl. Exemplary G groups include chloride, bromide, pyridine, methylimidazole (for example N-methyl imidazole) and dimethylaminopyridine (for example, 4-methylaminopyridine).

[0144] It will be appreciated that when a G group is present, the G group may be associated with a single M metal centre as shown in formula (I), or the G group may be associated with both metal centres and form a bridge between the two metal centres, as shown below in formula (IIa):

##STR00031##

Wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, M.sub.1, M.sub.2, G, X, E.sub.1 and E.sub.2, are as defined for formula (I) and formula (II).

[0145] The skilled person will understand that, in the solid state, the catalysts of the first aspect may be associated with solvent molecules such as water, or alcohol (e.g. methanol or ethanol). It will be appreciated that the solvent molecules may be present in a ratio of less than 1:1 relative to the

[0146] (IIa)

[0147] molecules of catalyst of the first aspect (i.e. 0.2:1, 0.25:1, 0.5:1), in a ratio of 1:1, relative to the molecules of catalyst of the first aspect, or in a ratio of greater than 1:1, relative to the molecules of catalyst of the first aspect.

[0148] The skilled person will understand that, in the solid state, the catalysts of the first aspect may form aggregates. For example, the catalyst of the first aspect may be a dimer, a trimer, a tetramer, a pentamer, or higher aggregate.

[0149] Exemplary catalysts of formula (I) are as follows:

##STR00032##

##STR00033##

##STR00034##

##STR00035##

##STR00036##

##STR00037##

##STR00038##

##STR00039##

##STR00040##

##STR00041##

##STR00042##

##STR00043##

##STR00044##

##STR00045##

##STR00046##

##STR00047##

##STR00048##

##STR00049##

##STR00050##

##STR00051##

##STR00052##

##STR00053##

##STR00054##

[0150] Where M.sub.1, M.sub.2, G and X are as defined above for formula (I), and it will be appreciated that one or both G groups may be absent.

[0151] For example, at least one of M.sub.1 and M.sub.2 may be selected from Zn(II), Cr(III)-X, Co(II), Mn(II), Mg(II), Ni(II), Fe(II), and Fe(III)-X, e.g. at least one of M.sub.1 and M.sub.2 may be selected from Mg(II), Zn(II) and Ni(II), for example, at least one of M.sub.1 and M.sub.2 may be Ni(II).

[0152] As set out above, M.sub.1 and M.sub.2 may be the same or different. For example, M.sub.1 and/or M.sub.2 may be selected from Zn(II), Cr(III)-X, Co(II), Mn(II), Mg(II), Ni(II), Fe(II), and Fe(III)-X, preferably M.sub.1 and/or M.sub.2 is selected from Mg(II), Zn(II) and Ni(II), for example, M.sub.1 and/or M.sub.2 is Ni(II). Exemplary combinations of M.sub.1 and M.sub.2 include Mg(II) / Mg(II), Zn(II) / Zn(II), Ni(II) / Ni(II), Mg(II) / Zn(II), Mg(II) / Ni(II), Zn(II) / Ni(II).

[0153] For example, each X may be independently OC(O)R.sup.x, OSO.sub.2R.sup.x, OS(O)R.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, OR.sup.x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl (for example silyl), aryl or heteroaryl, e.g. each may be independently OC(O)R.sup.x, OR.sup.x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x. For example, R.sup.x may be alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl.

[0154] For example, if either G are present, G may be independently selected from halide; water; a heteroaryl optionally substituted by alkyl (e.g. methyl, ethyl etc), alkenyl, alkynyl, alkoxy (preferably methoxy), halogen, hydroxyl, nitro or nitrile, e.g. one or both instances of G (if present) can be chloride, bromide, pyridine, methylimidazole (for example N-methyl imidazole) and dimethylaminopyridine (for example, 4-methylaminopyridine).

[0155] The skilled person will appreciate that the above definitions may be combined. For example, for the catalysts above, M.sub.1 and M.sub.2 may be the same or different, and may be selected from Zn(II), Cr(III)-X, Co(II), Mn(II), Mg(II), Ni(II), Fe(II), and Fe(III)-X; each X may be independently OC(O)R.sup.x, OSO.sub.2R.sup.x, OS(O)R.sup.x, OSO(R.sup.x).sub.2, S(O)R.sup.x, OR.sup.x, halide, nitrate, hydroxyl, carbonate, amino, nitro, amido, alkyl (e.g. branched alkyl), heteroalkyl (for example silyl), aryl or heteroaryl, e.g. each may be independently OC(O)R.sup.x, OR.sup.x, halide, carbonate, amino, nitro, alkyl, aryl, heteroaryl, phosphinate or OSO.sub.2R.sup.x; R.sup.x may be alkyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, cycloalkyl, or alkylaryl; G may be absent or if present, may be independently selected from halide; water; a heteroaryl optionally substituted by alkyl (e.g. methyl, ethyl etc), alkenyl, alkynyl, alkoxy (preferably methoxy), halogen, hydroxyl, nitro or nitrile.

[0156] Thus, the skilled person will understand that the above exemplary catalysts of formula (I) encompass, but are not restricted to, the following catalysts: [0157] [L.sup.1Ni.sub.2(OAc).sub.2], [L.sup.1Mg.sub.2(OAc).sub.2], [L.sup.1Zn.sub.2(OAc).sub.2], [L.sup.1MgZn(OAc).sub.2], [L.sup.1MgNi(OAc).sub.2], [0158] [L.sup.1Ni.sub.2(CO.sub.2CF.sub.3).sub.2], [L.sup.1Mg.sub.2 CO.sub.2CF.sub.3).sub.2], [L.sup.1Zn.sub.2(CO.sub.2CF.sub.3).sub.2], [L.sup.1MgZn(CO.sub.2CF.sub.3).sub.2], [L.sup.1MgNi(CO.sub.2CF.sub.3).sub.2], [0159] [L.sup.1Ni.sub.2(CO.sub.2.sup.tBu).sub.2], [L.sup.1Mg.sub.2(CO.sub.2.sup.tBu).sub.2], [L.sup.1Zn.sub.2(CO.sub.2.sup.tBu).sub.2], [L.sup.1MgZn(CO.sub.2tBu).sub.2], [L.sup.1MgNi(CO.sub.2.sup.tBu).sub.2], [0160] [L.sup.1Ni.sub.2(OPh).sub.2], [L.sup.1Mg.sub.2(OPh).sub.2], [L.sup.1Zn.sub.2(OPh).sub.2], [L.sup.1MgZn(OPh).sub.2], [L.sup.1MgNi(OPh).sub.2], [0161] [L.sup.1Ni.sub.2(Ph).sub.2], [L.sup.1Mg.sub.2(Ph).sub.2], [L.sup.1Zn.sub.2(Ph).sub.2], [L.sup.1MgZn(Ph).sub.2], [L.sup.1MgNi(Ph).sub.2], [0162] [L.sup.1Nb(O.sup.iPr).sub.2], [L.sup.1Mg.sub.2(O.sup.iPr).sub.2], [L.sup.1Zn.sub.2(O.sup.iPr).sub.2], [L.sup.1MgZn(O.sup.iPr).sub.2], [L.sup.1MgNi(O.sup.iPr).sub.2], [0163] [L.sup.1Ni.sub.2(C.sub.6F.sub.5).sub.2], [L.sup.1Mg.sub.2(C.sub.6F.sub.6).sub.2], [L.sup.1Zn.sub.2(C.sub.6F.sub.5).sub.2], [L.sup.1MgZn(C.sub.6F.sub.5).sub.2], [L.sup.1MgNi(C.sub.6F.sub.5).sub.2], [0164] [L.sup.1Ni.sub.2Cl.sub.2], [L.sup.1Mg.sub.2Cl.sub.2], [L.sup.1Zn.sub.2Cl.sub.2], [L.sup.1MgZnCl.sub.2], [L.sup.1MgNiCl.sub.2], [0165] [L.sup.1Ni.sub.2Br.sub.2], [L.sup.1Mg.sub.2Br.sub.2], [L.sup.1Zn.sub.2Br.sub.2], [L.sup.1MgZnBr.sub.2], [L.sup.1MgNiBr.sub.2], [0166] [L.sup.1Ni.sub.2l.sub.2], [L.sup.1Mg.sub.2l.sub.2], [L.sup.1Zn.sub.2l.sub.2], [.sub.L.sup.1MgZnl.sub.2], [L.sup.1 MgNil.sub.2], [0167] [L.sup.1Ni.sub.2(OC(O)(CH.sub.2).sub.4CH.sub.3).sub.2], [L.sup.1Mg.sub.2(OC(O)(CH.sub.2).sub.4CH.sub.3).sub.2], [L.sup.1Zn.sub.2(OC(O)(CH.sub.2).sub.4CH.sub.3).sub.2], [0168] [L.sup.1MgZn(OC(O)(CH.sub.2).sub.4CH.sub.3).sub.2], [L.sup.1MgNi(OC(O)(CH.sub.2).sub.4CH.sub.3).sub.2], [0169] [L.sup.1Ni.sub.2(OC(O)(CH.sub.2).sub.6CH.sub.3).sub.2], [L.sup.1Mg.sub.2(OC(O)(CH.sub.2).sub.6CH.sub.3).sub.2], [L.sup.1Zn.sub.2(OC(O)(CH.sub.2).sub.6CH.sub.3).sub.2], [0170] [L.sup.1MgZn(OC(O)(CH.sub.2).sub.6CH.sub.3).sub.2], [L.sup.1MgNi(OC(O)(CH.sub.2).sub.6CH.sub.3).sub.2], [0171] [L.sup.1Ni.sub.2(OC(O)(CH.sub.2).sub.10CH.sub.3).sub.2], [L.sup.1Mg.sub.2(OC(O)(CH.sub.2).sub.10CH.sub.3).sub.2], [L.sup.1Zn.sub.2(OC(O)(CH.sub.2).sub.10CH.sub.3).sub.2], [0172] [L.sup.1MgZn(OC(O)(CH.sub.2).sub.10CH.sub.3).sub.2], [L.sup.1MgNi(OC(O)(CH.sub.2).sub.10CH.sub.3).sub.2], [0173] [L.sup.1Ni.sub.2(OC(O)C.sub.6F.sub.5).sub.2], [L.sup.1Mg.sub.2(OC(O)C.sub.6F.sub.5).sub.2], [L.sup.1Zn.sub.2(OC(O)C.sub.6F.sub.5).sub.2], [L.sup.1MgZn(OC(O)C.sub.6F.sub.5).sub.2], [0174] [L.sup.1MgNi(OC(O)C.sub.6F.sub.5).sub.2], [0175] [L.sup.1Ni.sub.2Cl.sub.2(methylimidazole)], [L.sup.1Mg.sub.2Cl.sub.2(methylimidazole)], [L.sup.1Zn.sub.2Cl.sub.2(methylimidazole)), [0176] [L.sup.1MgZnCl.sub.2(methylimidazole)], [L.sup.1MgNiCl.sub.2(methylimidazole)], [0177] [L.sup.1Ni.sub.2Cl.sub.2(pyridine)], [L.sup.1Mg.sub.2Cl.sub.2(pyridine)], [L.sup.1Zn.sub.2Cl.sub.2(pyridine)], [L.sup.1MgZnCl.sub.2(pyridine)], [0178] [L.sup.1MgNiCl.sub.2(pyridine)], [0179] [L.sup.1Ni.sub.2Cl.sub.2(dimethylaminopyridine)], [L.sup.1Mg.sub.2Cl.sub.2(dimethylaminopyridine)], [0180] [L.sup.1Zn.sub.2Cl.sub.2(dimethylaminopyridine)], [L.sup.1MgZnCl.sub.2(dimethylaminopyridine)], [0181] [L.sup.1MgNiCl.sub.2(dimethylaminopyridine)], [0182] [L.sup.1Ni.sub.2Br.sub.2(dimethylaminopyridine)], [L.sup.1Mg.sub.2Br.sub.2(dimethylaminopyridine)], [0183] [L.sup.1Zn.sub.2Br.sub.2(dimethylaminopyridine)], [L.sup.1MgZnBr.sub.2(dimethylaminopyridine)], [0184] [L.sup.1MgNiBr.sub.2(dimethylaminopyridine)], [0185] [L.sup.1Ni.sub.2(bis(4-methoxy)phenyl phosphinate).sub.2], [L.sup.1Mg.sub.2(bis(4-methoxy)phenyl phosphinate).sub.2], [0186] [L.sup.1Zn.sub.2(bis(4-methoxy)phenyl phosphinate).sub.2], [L.sup.1MgZn(bis(4-methoxy)phenyl phosphinate).sub.2], [0187] [L.sup.1MgNi(bis(4-methoxy)phenyl phosphinate).sub.2], [0188] [L.sup.1Ni.sub.2(adamantyl carbonate).sub.2], [L.sup.1Mg.sub.2(adamantyl carbonate).sub.2], [L.sup.1Zn.sub.2(adamantyl carbonate).sub.2], [0189] [L.sup.1MgZn(adamantyl carbonate).sub.2], [L.sup.1MgNi(adamantyl carbonate).sub.2], [0190] [L.sup.1Ni.sub.2(diphenylphosphinate).sub.2], [L.sup.1Mg.sub.2(diphenylphosphinate).sub.2], [L.sup.1Zn.sub.2(diphenylphosphinate).sub.2], [0191] [L.sup.1MgZn(diphenylphosphinate).sub.2], [L.sup.1MgNi(diphenylphosphinate).sub.2], [0192] [L.sup.2Ni.sub.2(OAc).sub.2], [L.sup.2Mg.sub.2(OAc).sub.2], [L.sup.2Zn.sub.2(OAc).sub.2], [L.sup.2MgZn(OAc).sub.2], [L.sup.2MgNi(OAc).sub.2], [0193] [L.sup.3Ni.sub.2(OAc).sub.2], [L.sup.3Mg.sub.2(OAc).sub.2], [L.sup.3Zn.sub.2(OAc).sub.2], [L.sup.3MgZn(OAc).sub.2], [L.sup.3MgNi(OAc).sub.2], [0194] [L.sup.4Ni.sub.2(OAc).sub.2], [L.sup.4Mg.sub.2(OAc).sub.2], [L.sup.4Zn.sub.2(OAc).sub.2], [L.sup.4MgZn(OAc).sub.2], [L.sup.4MgNi(OAc).sub.2], [0195] [L.sup.5Ni.sub.2(OAc).sub.2], [L.sup.5Mg.sub.2(OAc).sub.2], [L.sup.5Zn.sub.2(OAc).sub.2], [L.sup.5MgZn(OAc).sub.2], [L.sup.5MgNi(OAc).sub.2], [0196] [L.sup.6Ni.sub.2(OAc).sub.2], [L.sup.6Mg.sub.2(OAc).sub.2], [L.sup.6Zn.sub.2(OAc).sub.2], [L.sup.6MgZn(OAc).sub.2], [L.sup.6MgNi(OAc).sub.2], [0197] [L.sup.7Ni.sub.2(OAc).sub.2], [L.sup.7Mg.sub.2(OAc).sub.2], [L.sup.7Zn.sub.2(OAc).sub.2], [L.sup.7MgZn(OAc).sub.2], [L.sup.7MgNi(OAc).sub.2], [0198] [L.sup.8Ni.sub.2(OAc).sub.2], [L.sup.8Mg.sub.2(OAc).sub.2], [L.sup.8Zn.sub.2(OAc).sub.2], [L.sup.8MgZn(OAc).sub.2], [L.sup.8MgNi(OAc).sub.2], [0199] [L.sup.9Ni.sub.2(OAc).sub.2], [L.sup.9Mg.sub.2(OAc).sub.2], [L.sup.9Zn.sub.2(OAc).sub.2], [L.sup.9MgZn(OAc).sub.2], [L.sup.9MgNi(OAc).sub.2], [0200] [L.sup.10Ni.sub.2(OAc).sub.2], [L.sup.10Mg.sub.2(OAc).sub.2], [L.sup.10Zn.sub.2(OAc).sub.2], [L.sup.10MgZn(OAc).sub.2], [L.sup.10MgNi(OAc).sub.2], [0201] [L.sup.11Ni.sub.2(OAc).sub.2], [L.sup.11Mg.sub.2(OAc).sub.2], [L.sup.11Zn.sub.2(OAc).sub.2], [L.sup.11MgZn(OAc).sub.2], [L.sup.11MgNi(OAc).sub.2], [0202] [L.sup.12Ni.sub.2(OAc).sub.2], [L.sup.12Mg.sub.2(OAc).sub.2], [L.sup.12Zn.sub.2(OAc).sub.2], [L.sup.12MgZn(OAc).sub.2], [L.sup.12MgNi(OAc).sub.2], [0203] [L.sup.13Ni.sub.2(OAc).sub.2], [L.sup.13Mg.sub.2(OAc).sub.2], [L.sup.13Zn.sub.2(OAc).sub.2], [L.sup.13MgZn(OAc).sub.2], [L.sup.13MgNi(OAc).sub.2], [0204] [L.sup.14Ni.sub.2(OAc).sub.2], [L.sup.14Mg.sub.2(OAc).sub.2], [L.sup.14Zn.sub.2(OAc).sub.2], [L.sup.14MgZn(OAc).sub.2], [L.sup.14MgNi(OAc).sub.2], [0205] [L.sup.15Ni.sub.2(OAc).sub.2], [L.sup.15Mg.sub.2(OAc).sub.2], [L.sup.15Zn.sub.2(OAc).sub.2], [L.sup.15MgZn(OAc).sub.2], [L.sup.15MgNi(OAc).sub.2], [0206] [L.sup.16Ni.sub.2(OAc).sub.2], [L.sup.16Mg.sub.2(OAc).sub.2], [L.sup.16Zn.sub.2(OAc).sub.2], [L.sup.16MgZn(OAc).sub.2], [L.sup.16MgNi(OAc).sub.2], [0207] [L.sup.17Ni.sub.2(OAc).sub.2], [L.sup.17Mg.sub.2(OAc).sub.2], [L.sup.17Zn.sub.2(OAc).sub.2], [L.sup.17MgZn(OAc).sub.2], [L.sup.17MgNi(OAc).sub.2], [0208] [L.sup.18Ni.sub.2(OAc).sub.2], [L.sup.18Mg.sub.2(OAc).sub.2], [L.sup.18Zn.sub.2(OAc).sub.2], [L.sup.18MgZn(OAc).sub.2], [L.sup.18MgNi(OAc).sub.2], [0209] [L.sup.19Ni.sub.2(OAc).sub.2], [L.sup.19Mg.sub.2(OAc).sub.2], [L.sup.19Zn.sub.2(OAc).sub.2], [L.sup.19MgZn(OAc).sub.2], [L.sup.19MgNi(OAc).sub.2], [0210] [L.sup.20Ni.sub.2(OAc).sub.2], [L.sup.20Mg.sub.2(OAc).sub.2], [L.sup.20Zn.sub.2(OAc).sub.2], [L.sup.20MgZn(OAc).sub.2], [L.sup.20MgNi(OAc).sub.2], [0211] [L.sup.21Ni.sub.2(OAc).sub.2], [L.sup.21Mg.sub.2(OAc).sub.2], [L.sup.21Zn.sub.2(OAc).sub.2], [L.sup.21MgZn(OAc).sub.2], [L.sup.21MgNi(OAc).sub.2], [0212] [L.sup.22Ni.sub.2(OAc).sub.2], [L.sup.22Mg.sub.2(OAc).sub.2], [L.sup.22Zn.sub.2(OAc).sub.2], [L.sup.22MgZn(OAc).sub.2], [L.sup.22MgNi(OAc).sub.2], [0213] [L.sup.23Ni.sub.2(OAc).sub.2], [L.sup.23Mg.sub.2(OAc).sub.2], [L.sup.23Zn.sub.2(OAc).sub.2], [L.sup.23MgZn(OAc).sub.2], [L.sup.23MgNi(OAc).sub.2], [0214] [L.sup.1Co.sub.2(OAc).sub.3], [L.sup.1ZnCol.sub.2], [L.sup.1ZnFe(OAc).sub.2], [L.sup.1ZnFeBr.sub.2], [L.sup.1ZnFeCl.sub.2], [L.sup.1ZnFel.sub.2], [0215] [L.sup.1ZnCo(OAc).sub.2], [L.sup.1ZnCoCl.sub.2], [L.sup.1ZnCoBr.sub.2], [L.sup.1Fe.sub.2Cl.sub.4], [L.sup.1Co.sub.2Cl.sub.2(methylimidazole)], [0216] [L.sup.1Co.sub.2Cl.sub.2(pyridine)], [L.sup.1Co.sub.2Cl.sub.3][H-DBU].sup.+, and [L.sup.1Co.sub.2Cl.sub.3][H-MTBD].sup.+.

[0217] The skilled person will appreciate that in any of the above complexes, any one ligand defined by “L” may be replaced by another ligand defined by a different “L”. For example, in complexes which refer to L.sup.1, this ligand may be replaced by any of the ligands defined by L.sup.2 to L.sup.22.

Double Metal Cyanide (DMC) Catalyst

[0218] DMC catalysts are complicated compounds which comprise at least two metal centres and cyanide ligands. The DMC catalyst additionally comprises a first and a second complexing agent, wherein the first complexing agent is a polymer.

[0219] The DMC catalyst may also comprise water and/or a metal salt and/or an acid (e.g. in non-stoichiometric amounts).

[0220] The first two of the at least two metal centres may be represented by M′ and M″.

[0221] M′ may be selected from Zn(II), Ru(II), Ru(III), Fe(II), Ni(II), Mn(II), Co(II), Sn(II), Pb(II), Fe(III), Mo(IV), Mo(VI), Al(III), V(V), V(VI), Sr(II), W(IV), W(VI), Cu(II), and Cr(III), M′ is preferably selected from Zn(II), Fe(II), Co(II) and Ni(II), even more preferably M′ is Zn(II).

[0222] M″ is selected from Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV), and V(V), preferably M″ is selected from Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II), more preferably M″ is selected from Co(II) and Co(III).

[0223] It will be appreciated that the above preferred definitions for M′ and M″ may be combined. For example, preferably M′ may be selected from Zn(II), Fe(II), Co(II) and Ni(II), and M″ may preferably selected form be Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II). For example, M′ may preferably be Zn(II) and M″ may preferably be selected from Co(II) and Co(III).

[0224] If a further metal centre(s) is present, the further metal centre may be further selected from the definition of M′ or M″.

[0225] The second complexing agent may be selected from ethers, ketones, esters, amides, alcohols, ureas and the like. For example, the second complexing agent may be selected from propylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol etc. It will be appreciated that the alcohol may be saturated or may contain an unsaturated moiety (e.g. a double or triple bond).

[0226] Preferably, the second complexing agent is tert-butyl alcohol, or dimethoxymethane, more preferably, the second complexing agent is tert-butyl alcohol.

[0227] The DMC catalyst may contain further (e.g. a third) complexing agent(s). The further (eg. Third) complexing agent(s) may be selected form the definitions of the first or second complexing agents. For example, the further (e.g. third) compelxing agent(s) may be selected from ethers, ketones, esters, amides, alcohols, ureas, polyethers, polycarbonate ethers or polycarbonates.

[0228] The first complexing agent is a polymer. The polymer is preferably a polyether, a polycarbonate ether or a polycarbonate. The first complexing agent (i.e. the polymer) is preferably present in an amount of from about 5% to about 80% by weight based on the total weight of the DMC catalyst, more preferably in an amount of from about 10% to about 70% by weight based on the total weight of the DMC catalyst, more preferably in an amount of from about 20% to about 50% by weight based on the total weight of the DMC catalyst.

[0229] Suitable polyethers for use in the present invention include those produced by ring-opening polymerisation of cyclic ethers, and include epoxide polymers, oxetane polymers, tetrahydrofuran polymers, and the like. Any method of catalysis can be used to make the polyethers. The polyethers can have any desired end groups, including, for example, hydroxyl, amine, ester, ether, or the like. Preferred polyethers for use in the present invention are polyether polyols having between 2 and 8 hydroxyl groups. It is also preferred that polyethers for use in the present invention have a molecular weight between about 1,000 Daltons and about 10,000 Daltons, more preferably between about 1,000 Daltons and about 5,000 Daltons. Polyether polyols useful in the DMC catalyst of the present invention include PPG polyols, EO-capped PPG polyols, mixed EO-PO polyols, butylene oxide polymers, butylene oxide copolymers with ethylene oxide and/or propylene oxide, polytetramethylene ether glycols, and the like. Preferred polyethers include PPGs, such as PPG polyols, particularly diols and triols, said PPGs having molecular weights of from about 250 Daltons to about 8,000 Daltons, more preferably from about 400 Daltons to about 4,000 Daltons.

[0230] Suitable polycarbonate ethers for use in the DMC catalyst of the present invention may be obtained by the catalytic reaction of alkylene oxides and carbon dioxide in the presence of a suitable starter or initiator compound. The polycarbonate ethers can also be produced by other methods known to the person skilled in the art, for example by partial alcoholysis of polycarbonate polyols with di- or tri-functional hydroxy compounds. The polycarbonate ethers preferably have an average hydroxyl functionality of 1 to 6, more preferably 2 to 3, most preferably 2.

[0231] Suitable polycarbonates for use in the DMC catalyst of the present invention may be obtained by the polycondensation of difunctional hydroxy compounds (generally bis-hydroxy compounds such as alkanediols or bisphenols) with carbonic acid derivatives such as, for example, phosgene or bis[chlorocarbonyloxy] compounds, carbonic acid diesters (such as diphenyl carbonate or dimethyl carbonate) or urea. Methods for producing polycarbonates are generally well known and are described in detail in for example “Houben-Weyl, Methoden der organischen Chemie”, Volume E20, Makromolekulare Stoffe, 4.sup.th Edition, 1987, p. 1443-1457, “Ullmann’s Encyclopedia of Industrial Chemistry”, Volume A21, 5.sup.th Edition, 1992, p. 207-215 and “Encyclopedia of Polymer Science and Engineering”, Volume 11, 2.sup.nd Edition, 1988, p. 648-718. Aliphatic polycarbonate diols having a molecular weight of from about 500 Daltons to 5000 Daltons, most highly preferably from 1000 Daltons to 3000 Daltons, are particularly preferably used. These are generally obtained from non-vicinal diols by reaction with diaryl carbonate, dialkyl carbonate, dioxolanones, phosgene, bischloroformic acid esters or urea (see for example EP-A 292 772 and the documents cited therein). Suitable non-vicinal diols are in particular 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, bis-(6-hydroxyhexyl)ether, 1,7-heptanediol, 1,8-octanediol, 2-methyl-1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,4-bis-hydroxymethyl cyclohexane, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, alkoxylation products of diols with ethylene oxide and/or propylene oxide and/or tetrahydrofuran with molar masses up to 1000 Daltons, preferably between 200 Daltons and 700 Daltons, and in rarer cases the dimer diols, which are obtainable by reducing both carboxyl groups of dimer acids, which in turn can be obtained by dimerisation of unsaturated vegetable fatty acids. The non-vicinal diols can be used individually or in mixtures. The reaction can be catalysed by bases or transition metal compounds in the manner known to the person skilled in the art.

[0232] Other polymers that may be useful in present invention include poly(tetramethylene ether diols). Poly(tetramethylene ether diols) are polyether polyols based on tetramethylene ether glycol, also known as polytetrahydrofuran (PTHF) or polyoxybutylene glycol. These poly(tetramethylene ether diols) comprise two OH groups per molecule. They can be produced by cationic polymerisation of tetrahydrofuran (THF) with the aid of catalysts.

[0233] Preferably, the first complexing agent is a polyether, and the second complexing agent is tert-butyl alcohol. Preferably, the polyether is a PPG (e.g. a PPG polyol) having a molecular weight of from about 250 Daltons to about 8,000 Daltons, more preferably from about 400 Daltons to about 4,000 Daltons

[0234] Suitable acids for use in the DMC catalyst of the present invention may have the formula H.sub.rX”’, where X‴ is an anion selected from halide, sulfate, phosphate, borate, chlorate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, preferably X‴ is a halide, r is an integer corresponding to the charge on the counterion X‴. For example, when X‴ is Cl.sup.-, r will be 1, i.e. the salt will be HCl.

[0235] If present, preferred acids for use in the DMC catalyst of the present invention having the formula H.sub.rX‴ include the following: HCl, H.sub.2SO.sub.4, HNO.sub.3, H.sub.3PO.sub.4, HF, HI, HBr, H.sub.3BO.sub.3 and HClO.sub.4. HCl, HBr and H.sub.2SO.sub.4 are particularly preferred.

[0236] It will also be appreciated that an alkali metal salt (e.g. an alkali metal hydroxide such as KOH) may be added to the reaction mixture during synthesis of the DMC catalyst. For example, the alkali metal salt may be added to the reaction mixture after the metal salt (M'(X′).sub.p) has been added to the metal cyanide salt ((Y)q[M″(CN).sub.b(A).sub.c]).

[0237] The DMC catalysts which are useful in the invention may be produced by treating a solution (such as an aqueous solution) of a metal salt with a solution (such as an aqueous solution) of a metal cyanide salt in the presence of a first and a second complexing agent, where the first complexing agent is a polymer. Suitable metal salts include compounds of the formula M'(X′).sub.p, wherein M′ is selected from Zn(II), Ru(II), Ru(III), Fe(II), Ni(II), Mn(II), Co(II), Sn(II), Pb(II), Fe(III), Mo(IV), Mo(VI), Al(III), V(V), V(VI), Sr(II), W(IV), W(VI), Cu(II), and Cr(III), and M′ is preferably selected from Zn(II), Fe(II), Co(II) and Ni(II), even more preferably M′ is Zn(II). X′ is an anion selected from halide, hydroxide, oxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, preferably X′ is halide, p is an integer of 1 or more, and the charge on the anion multiplied by p satisfies the valency of M′. Examples of suitable metal salts include zinc chloride, zinc bromide, zinc acetate, zinc acetonylacetonate, zinc benzoate, zinc nitrate, iron(II) sulphate, iron (II) bromide, cobalt(II) chloride, cobalt(II) thiocyanate, nickel(II) formate, nickel(II) nitrate, and mixtures thereof.

[0238] Suitable metal cyanide salts include compounds of the formula (Y)q[M”(CN).sub.b(A).sub.c], wherein M″ is selected from Fe(II), Fe(III), Co(II), Co(III), Cr(II), Cr(III), Mn(II), Mn(III), Ir(III), Ni(II), Rh(III), Ru(II), V(IV), and V(V), preferably M″ is selected from Co(II), Co(III), Fe(II), Fe(III), Cr(III), Ir(III) and Ni(II), more preferably M″ is selected from Co(II) and Co(III). Y is a proton or an alkali metal ion or an alkaline earth metal ion (such as K.sup.+), A is an anion selected from halide, hydroxide, oxide, sulphate, cyanide oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate. q and b are integers of 1 or more, preferably b is 4 or 6. c may be 0 or an integer of 1 or more. The sum of the charges on the ions Y, CN and A multiplied by q, b and c respectively (e.g. Y x q + CN x b + A x c) satisfies the valency of M″. Examples of suitable metal cyanide salts include potassium hexacyanocobaltate(III), potassium hexacyanoferrate(II), potassium hexacyanoferrate(III), calcium hexacyanocobaltate(III), lithium hexacyanocolbaltate(III), and mixtures thereof.

[0239] Suitable second complexing agents include ethers, ketones, esters, amides, alcohols, ureas and the like, such as propylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol etc. It will be appreciated that the alcohol may be saturated or may contain an unsaturated moiety (e.g. a double or triple bond).

[0240] The first complexing agent is a polymer. The first complexing agent is preferably a polymer selected from a polyether, a polycarbonate ether and a polycarbonate. Suitable polyethers, polycarbonate ethers and polycarbonates for use as the first complexing agent are described above.

[0241] In one common preparation, several separate solutions may be prepared and then combined in order. For example, the following solutions may be prepared: [0242] 1. a solution of a metal cyanide (e.g. potassium hexacyanocobaltate) [0243] 2. a solution of a metal salt e.g. (zinc chloride (excess)) [0244] 3. a solution of a second complexing agent (e.g. tert-butyl alcohol) [0245] 4. a solution of a first complexing agent, which is a polymer (e.g. PPG diol).

[0246] In this method, solutions 1 and 2 are combined immediately, followed by slow addition of solution 3, preferably whilst stirring rapidly. Solution 4 may be added once the addition of solution 3 is complete, or shortly thereafter. The catalyst is removed from the reaction mixture via filtration, and is subsequently washed with a solution of the first and second complexing agents.

[0247] If water is desired in the DMC catalyst, then the above solutions (e.g. solutions 1 to 4) may be aqueous solutions.

[0248] However, it will be understood that anhydrous DMC catalysts (i.e. DMC catalysts without any water present) may be prepared if the solutions described in the above preparations are anhydrous solutions. To avoid hydrating the DMC catalyst and thereby introducing water molecules, any further processing steps (washing, filtration etc.) may be conducted using anhydrous solvents.

[0249] In one common preparation, several separate solutions may be prepared and then combined in order. For example, the following solutions may be prepared: [0250] 1. a solution of a metal salt (e.g. zinc chloride (excess)) and a second complexing agent (e.g. tert-butyl alcohol) [0251] 2. a solution of a metal cyanide (e.g. potassium hexacyanocobaltate) [0252] 3. a solution of a first and a second complexing agent, the first of which is a polymer (e.g. a solution of polypropylene glycol diol and tert-butyl alcohol)

[0253] In this method, solutions 1 and 2 are combined slowly (e.g. over 1 hour) at a raised temperature (e.g. above 25° C., such as about 50° C.) while stirring (e.g. at 450 rpm). After addition is complete the stirring rate is increased for 1 hour (e.g. up to 900 rpm). The stirring rate is then decreased to a slow rate (e.g. to 200 rpm) and solution 3 is added quickly with low stirring. The mixture is filtered.

[0254] The catalyst solids may be re-slurried in a solution of the second complexing agent at high stirring rate (e.g. about 900 rpm) before addition of the first complexing agent at low stirring rate (e.g. 200 rpm). The mixture is then filtered. This step may be repeated more than once. The resulting catalyst cake may be dried under vacuum (with heating e.g. to 60° C.).

[0255] Alternatively, after the mixture is first filtered it can be re-slurried at a raised temperature (e.g. above 25° C., such as about 50° C.) in a solution of the first complexing agent (and no second or further complexing agent) and then homogenized by stirring. It is then filtered after this step. The catalyst solids are then re-slurried in a mixture of the first and second complexing agents. For example, the catalyst solids are re-slurried in the second complexing agent at a raised temperature (e.g above 25° C., such as about 50° C.) and subsequently the first complexing agent is added and mixture homogenized by stirring. The mixture is filtered and the catalyst is dried under vacuum with heating (e.g. to 100° C.).

[0256] For example, the DMC catalyst may comprise:

##STR00055##

[0257] Wherein M′ and M″ are as defined above, d, e, f and g are integers, and are chosen to such that the DMC catalyst has electroneutrality. Preferably, d is 3. Preferably, e is 1. Preferably f is 6. Preferably g is 2. Preferably, M′ is selected from Zn(II), Fe(II), Co(II) and Ni(II), more preferably M′ is Zn(II). Preferably M″ is selected from Co(III), Fe(III), Cr(III) and Ir(III), more preferably M″ is Co(III).

[0258] It will be appreciated that any of these preferred features may be combined, for example, d is 3, e is 1, f is 6 and g is 2, M′ is Zn(II) and M″ is Co(III).

[0259] Suitable DMC catalysts of the above formula may include zinc hexacyanocobaltate(III), zinc hexacyanoferrate(III), nickel hexacyanoferrate(II), and cobalt hexacyanocobaltate(III).

[0260] There has been a lot of development in the field of DMC catalysts, and the skilled person will appreciate that the DMC catalyst may comprise, in addition to the formula above, further additives to enhance the activity of the catalyst. Thus, while the above formula may form the “core” of the DMC catalyst, the DMC catalyst additionally comprises stoichiometric or non-stoichiometric amounts of a first and a second complexing agent, where the first complexing agent is a polymer. The DMC catalyst may also comprise stoichiometric or non-stoichiometric amounts of one or more additional components, such as an acid, a metal salt, and/or water.

[0261] For example, the DMC catalyst may have the following formula:

##STR00056##

[0262] Wherein M′, M″, d, e, f and g are as defined above. M‴ can be M′ and/or M″. X″ is an anion selected from halide, hydroxide, oxide, sulphate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, isothiocyanate, carboxylate and nitrate, preferably X′ is halide, i is an integer of 1 or more, and the charge on the anion X″ multiplied by i satisfies the valency of M‴, r is an integer that corresponds to the charge on the counterion X‴. For example, when X‴ is Cl, r will be 1. I is a number between 0.1 and 5. Preferably, I is between 0.15 and 1.5.

[0263] R.sup.c is the second complexing agent, and may be as defined above. For example, R.sup.c may be an ether, a ketone, an ester, an amide, an alcohol (e.g. a C.sub.1-8 alcohol), a urea and the like. Examples of R.sup.c include propylene glycol, (m)ethoxy ethylene glycol, dimethoxyethane, tert-butyl alcohol, ethylene glycol monomethyl ether, diglyme, triglyme, methanol, ethanol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, 3-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-pentyn-3-ol, for example, R.sup.c may be tert-butyl alcohol or dimethoxyethane. Most preferably R.sup.c is tert-butyl alcohol.

[0264] j is a positive number, and may be between 0.1 and 6.

[0265] It will be appreciated that if the water, metal salt and/or acid are not present in the DMC catalyst, h, k and/or I will be zero respectively. If the water, metal salt and/or acid are present, then h, k and/or I are a positive number and may, for example, be between 0 and 20. For example, h may be between 0.1 and 4. k may be between 0 and 20, e.g. between 0.1 and 10, such as between 0.1 and 5.

[0266] Pol represents the first complexing agent, which is a polymer. Pol is preferably selected from a polyether, a polycarbonate ether, and a polycarbonate. The first complexing agents (e.g. “Pol”) is present in an amount of from about 5% to about 80% by weight of the DMC catalyst, preferably in an amount of from about 10% to about 70% by weight of the DMC catalyst, more preferably in an amount of from about 20% to about 50% by weight of the DMC catalyst..

[0267] As set out above, DMC catalysts are complicated structures, and thus, the above formula including the additional components is not intended to be limiting. Instead, the skilled person will appreciate that this definition is not exhaustive of the DMC catalysts which are capable of being used in the invention.

Starter Compound

[0268] The starter compound which may be used in the method of the invention comprises at least two groups selected from a hydroxyl group (-OH), a thiol (-SH), an amine having at least one N-H bond (-NHR'), a group having at least one P—OH bond (e.g. —PR'(O)OH, PR’(O)(OH).sub.2 or —P(O)(OR')(OH)), or a carboxylic acid group (-C(O)OH).

[0269] Thus, the starter compound which is useful in the method of the invention may be of the formula (III):

##STR00057##

[0270] Z can be any group which can have 2 or more -R.sup.Z groups attached to it. Thus, Z may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkylheteroarylene or alkylheteroarylene group. Preferably Z is alkylene, heteroalkylene, arylene, or heteroarylene.

[0271] It will be appreciated that a is an integer which is at least 2, preferably a is in the range of between 2 and 8, preferably a is in the range of between 2 and 6.

[0272] Each R.sup.Z may be —OH, —NHR', —SH, —C(O)OH, —P(O)(OR')(OH), —PR'(O)(OH).sub.2 or —PR'(O)OH, preferably R.sup.Z is selected from —OH, —NHR' or —C(O)OH, more preferably each R.sup.z is —OH, —C(O)OH or a combination thereof (e.g. each R.sup.z is -OH).

[0273] R′ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, preferably R′ is H or optionally substituted alkyl.

[0274] It will be appreciated that any of the above features may be combined. For example, a may be between 2 and 8, each R.sup.Z may be —OH, —C(O)OH or a combination thereof, and Z may be selected from alkylene, heteroalkylene, arylene, or heteroarylene.

[0275] Exemplary starter compounds include diols such as 1,2-ethanediol (ethylene glycol), 1-2-propanediol, 1,3-propanediol (propylene glycol), 1,2-butanediol, 1-3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,4-cyclohexanediol, 1,2-diphenol, 1,3-diphenol, 1,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1,4-cyclohexanedimethanol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500 g/mol, such as PPG 425, PPG 725, PPG 1000 and the like, triols such as glycerol, benzenetriol, 1,2,4-butanetriol, 1,2,6-hexanetriol, tris(methylalcohol)propane, tris(methylalcohol)ethane, tris(methylalcohol)nitropropane, trimethylol propane, polypropylene oxide triols and polyester triols, tetraols such as calix[4]arene, 2,2-bis(methylalcohol)-1,3-propanediol, erythritol, pentaerythritol or polyalkylene glycols (PEGs or PPGs) having 4-OH groups, polyols, such as sorbitol or polyalkylene glycols (PEGs or PPGs) having 5 or more —OH groups, or compounds having mixed functional groups including ethanolamine, diethanolamine, methyldiethanolamine, and phenyldiethanolamine.

[0276] For example, the starter compound may be a diol such as 1,2-ethanediol (ethylene glycol), 1-2-propanediol, 1,3-propanediol (propylene glycol), 1,2-butanediol, 1-3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,2-diphenol, 1,3-diphenol, 1,4-diphenol, neopentyl glycol, catechol, cyclohexenediol, 1,4-cyclohexanedimethanol, poly(caprolactone) diol, dipropylene glycol, diethylene glycol, tripropylene glycol, triethylene glycol, tetraethylene glycol, polypropylene glycols (PPGs) or polyethylene glycols (PEGs) having an Mn of up to about 1500 g/mol, such as PPG 425, PPG 725, PPG 1000 and the like. It will be appreciated that the starter compound may be 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,12-dodecanediol, poly(caprolactone) diol, PPG 425, PPG 725, or PPG 1000.

[0277] Further exemplary starter compounds may include diacids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid or other compounds having mixed functional groups such as lactic acid, glycolic acid, 3-hydroxypropanoic acid, 4-hydroxybutanoic acid, 5-hydroxypentanoic acid.

Reaction Conditions

[0278] The method of the invention may be carried out at pressures of between about 1 bar and about 60 bar carbon dioxide, e.g. between about 1 bar and about 30 bar carbon dioxide, for example between about 1 to about 20 bar, such as between about 1 and about 15 bar carbon dioxide.

[0279] The method of the invention is capable of preparing polycarbonate ether polyols at pressures that are within the limits of existing polyether polyol equipment used in industry (e.g. 10 bar or less). Therefore, the method of the invention is capable being carried out at pressures of between about 1 bar and about 10 bar, for example, the reaction is capable of being carried out at a pressure of about 5 bar or less carbon dioxide. Under these conditions, the method of the invention is still capable of producing polycarbonate ether polyols having a varying amount of carbonate linkages, and may produce a polyol having a high content of carbonate linkages.

[0280] The method of the invention may be carried out in the presence of a solvent, however it will also be appreciated that the reaction may be carried out in the absence of a solvent. When a solvent is present, it may be toluene, hexane, t-butyl acetate, diethyl carbonate, dimethyl carbonate, dioxane, dichlorobenzene, methylene chloride, propylene carbonate, ethylene carbonate, acetone, ethyl acetate, propyl acetate, n-butyl acetate, tetrahydrofuran (THF), etc.

[0281] The epoxide which is used in the method may be any containing an epoxide moiety. Exemplary epoxides include ethylene oxide, propylene oxide, butylene oxide and cyclohexene oxide.

[0282] The epoxide may be purified (for example by distillation, such as over calcium hydride) prior to reaction with carbon dioxide. For example, the epoxide may be distilled prior to being added to the reaction mixture comprising the catalysts.

[0283] The process may be carried out at a temperature of about 0° C. to about 250° C., for example from about 40° C. to about 140° C., e.g. from about 50° C. to about 110° C., such as from about 60° C. to about 100° C., for example from about 70° C. to about 100° C., e.g. from about 55° C. to about 80° C. The duration of the process may be up to about 168 hours, such as from about 1 minute to about 24 hours, for example from about 5 minutes to about 12 hours, e.g. from about 1 to about 6 hours.

[0284] The method of the invention may be carried out at low catalytic loading. For example, the catalytic loading of the catalyst of formula (I) may be in the range of about 1:1,000-300,000 [catalyst of formula (I)]:[epoxide], such as about 1:1,000-100,000 [catalyst of formula (I)]:[epoxide], e.g. in the region of about 1:10000-50,000 [catalyst of formula (I)]:[epoxide], for example in the region of about 1:10,000 [catalyst of formula (I)]:[epoxide]. The ratios above are molar ratios.

[0285] The ratio of the catalyst of formula (I) to the DMC catalyst may be in the range of from about 300:1 to about 0.1:1, for example, from about 120:1 to about 0.25:1, such as from about 40:1 to about 0.5:1, e.g. from about 30:1 to about 0.75:1 such as from about 20:1 to about 1:1, for example from about 10:1 to about 2:1, e.g. from about 5:1 to about 3:1. These ratios are mass ratios.

[0286] The starter compound may be present in amounts of from about 200:1 to about 1:1, for example, from about 175:1 to about 5:1, such as from about 150:1 to about 10:1, e.g. from about 125:1 to about 20:1, for example, from about 50:1 to about 20:1, relative to the catalyst of formula (I). These ratios are molar ratios.

[0287] The starter may be pre-dried (for example with molecular sieves) to remove moisture. It will be understood that any of the above reaction conditions described may be combined. For example, the reaction may be carried out at 20 bar or less (e.g. 10 bar or less) and at a temperature in the range of from about 50° C. to about 130° C., for example, from about 50° C. to about 110° C., such as from about 60° C. to about 100° C., e.g. from about 70° C. to about 100° C.

[0288] The method may be a batch reaction, a semi-continuous reaction, or a continuous reaction.

Polyols

[0289] The method of the invention is capable of preparing polycarbonate ether polyols, which are capable of being used, for example, to prepare polyurethanes.

[0290] The method of the invention is capable of producing polycarbonate ether polyols in which the amount of ether and carbonate linkages can be controlled. Thus, the invention provides a polycarbonate ether polyol which has n ether linkages and m carbonate linkages, wherein n and m are integers, and wherein m/(n+m) is from greater than zero to less than 1, It will therefore be appreciated that n ≤ 1 and m ≤ 1.

[0291] For example, the method of the invention is capable of preparing polycarbonate ether polyols having a wide range of m/(n+m) values. It will be understood that m/(n+m) may be about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

[0292] Thus, the method of the invention makes it possible to prepare polycarbonate ether polyols having a high proportion of carbonate linkages, e.g. m/(n+m) may be greater than about 0.50, such as from greater than about 0.55 to less than about 0.95, e.g. about 0.65 to about 0.90, e.g. about 0.75 to about 0.90. The method of the invention is able to prepare polyols having a high ratio of m/(n+m) under mild conditions, for example, under pressures of about 20 bar or below, such as 10 bar or below.

[0293] For example, the polycarbonate ether polyols produced by the method of the invention may have the following formula (IV):

##STR00058##

[0294] It will be appreciated that the identity of Z and Z′ will depend on the nature of the starter compound, and that the identity of R.sup.e1 and R.sup.e2 will depend on the nature of the epoxide used to prepare the polycarbonate ether polyol, m and n define the amount of the carbonate and ether linkages in the polycarbonate ether polyol.

[0295] The skilled person will understand that in the polymers of formula (IV), the adjacent epoxide monomer units in the backbone may be head-to-tail linkages, head-to-head linkages or tail-to-tail linkages.

[0296] It will also be appreciated that formula (IV) does not require the carbonate links and the ether links to be present in two distinct “blocks” in each of the sections defined by “a”, but instead the carbonate and ether repeating units may be statistically distributed along the polymer backbone, or may be arranged so that the carbonate and ether linkages are not in two distinct blocks.

[0297] Thus, the polycarbonate ether polyol prepared by the method of the invention (e.g. a polymer of formula (IV)) may be referred to as a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer.

[0298] The skilled person will appreciate that the wt% of carbon dioxide incorporated into a polymer cannot be definitively used to determine the amount of carbonate linkages in the polymer backbone. For example, two polymers which incorporate the same wt% of carbon dioxide may have very different ratios of carbonate to ether linkages. This is because the “wt% incorporation” of carbon dioxide does not take into account the length and nature of the starter compound. For instance, if one polymer (Mn 2000 g/mol) is prepared using a starter with a molar mass of 100 g/mol, and another polymer (Mn also 2000 g/mol) is prepared using a starter having a molar mass of 500 g/mol, and both the resultant polymers have the same ratio of m/n then the wt% of carbon dioxide in the polymers will be different due to the differing proportion of the mass of the starter in the overall polymer molecular weight (Mn). For example, if m/(m+n) was 0.5, the two polyols described would have carbon dioxide contents of 26.1 wt% and 20.6 wt% respectively.

[0299] As highlighted above, the method of the invention is capable of preparing polyols which have a wide range of carbonate to ether linkages (e.g. m/(n+m) can be from greater than zero to less than 1), which, when using propylene oxide, corresponds to incorporation of up to about 43 wt% carbon dioxide. This is surprising, as DMC catalysts which have previously reported can generally only prepare polyols having a ratio of carbonate to ether linkages of up to 0.75 , and these amounts can usually only be achieved at high pressures of carbon dioxide, such as 30 bar, more commonly 40 bar or above.

[0300] Furthermore, catalysts which are used to prepare polycarbonate polyols can typically achieve a ratio of carbonate to ether linkages of about 0.95 or above (usually about 0.98 or above), and thus also incorporate a high wt% of carbon dioxide. However, these catalysts are not capable of preparing polyols having a ratio of carbonate to ether linkages below 0.95. The carbon dioxide wt% can be moderated by changing the mass of the starter: the resultant polyols contain blocks of polycarbonate. For many applications this is not desirable, as polycarbonates produced from epoxides and carbon dioxide are less thermally stable than polyethers and block copolymers can have very different properties from random or statistical copolymers.

[0301] All other things being equal, polyethers have higher temperatures of degradation than polycarbonates produced from epoxides and carbon dioxide. Therefore, a polyol having a statistical or random distribution of ether and carbonate linkages will have a higher temperature of degradation than a polycarbonate polyol, or a polyol having blocks of carbonate linkages. Temperature of thermal degradation can be measured using thermal gravimetric analysis (TGA).

[0302] As set out above, the method of the invention prepares a random copolymer, a statistical copolymer, an alternating copolymer, or a periodic copolymer. Thus, the carbonate linkages are not in a single block, thereby providing a polymer which has improved properties, such as improved thermal degradation, as compared to a polycarbonate polyol. Preferably, the polymer prepared by the method of the invention is a random copolymer or a statistical copolymer.

[0303] The polycarbonate ether polyol prepared by the method of the invention may be of formula (IV), in which n and m are integers of 1 or more, the sum of all m and n groups is from 4 to 200, and wherein m/(m+n) is in the range of from greater than zero to less than 1.00. As set out above, m/(n+m) may be from about 0.05, about 0.10, about 0.15, about 0.20, about 0.25, about 0.25, about 0.30, about 0.35, about 0.40, about 0.45, about 0.50, about 0.55, about 0.60, about 0.65, about 0.70, about 0.75, about 0.80, about 0.85, about 0.90, about 0.95, or within any range prepared from these specific values. For example, m/(n+m) may be from about 0.05 to about 0.95, from about 0.10 to about 0.90, from about 0.15 to about 0.85, from about 0.20 to about 0.80, or from about 0.25 to about 0.75, etc.

[0304] The skilled person will also appreciate that the polyol must contain at least one carbonate and at least one ether linkage. Therefore it will be understood that the number of ether and carbonate linkages (n+m) in the polyol will be ≥ a. The sum of n+m must be greater than or equal to “a”.

[0305] Each R.sup.e1 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl. Preferably R.sup.e1 may be selected from H or optionally substituted alkyl.

[0306] Each R.sup.e2 may be independently selected from H, halogen, hydroxyl, or optionally substituted alkyl, alkenyl, alkynyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, heteroalkyl or heteroalkenyl. Preferably R.sup.e2 may be selected from H or optionally substituted alkyl.

[0307] It will also be appreciated that R.sup.e1 and R.sup.e2 may together form a saturated, partially unsaturated or unsaturated ring containing carbon and hydrogen atoms, and optionally one or more heteroatoms (e.g. O, N or S). For example, R.sup.e1 and R.sup.e2 may together form a 5 or six membered ring.

[0308] As set out above, the nature of R.sup.e1 and R.sup.e2 will depend on the epoxide used in the reaction. If the epoxide is cyclohexene oxide (CHO), then R.sup.e1 and R.sup.e2 will together form a six membered alkyl ring (e.g. a cyclohexyl ring). If the epoxide is ethylene oxide, then R.sup.e1 and R.sup.e2 will both be H. If the epoxide is propylene oxide, then R.sup.e1 will be H and R.sup.e2 will be methyl (or R.sup.e1 will be methyl and R.sup.e2 will be H, depending on how the epoxide is added into the polymer backbone). If the epoxide is butylene oxide, then R.sup.e1 will be H and R.sup.e2 will be ethyl (or vice versa). If the epoxide is styrene oxide, then R.sup.e1 may be hydrogen, and R.sup.e2 may be phenyl (or vice versa).

[0309] It will also be appreciated that if a mixture of epoxides are used, then each occurrence of R.sup.e1 and/or R.sup.e2 may not be the same, for example if a mixture of ethylene oxide and propylene oxide are used, R.sup.e1 may be independently hydrogen or methyl, and R.sup.e2 may be independently hydrogen or methyl.

[0310] Thus, R.sup.e1 and R.sup.e2 may be independently selected from hydrogen, alkyl or aryl, or R.sup.e1 and R.sup.e2 may together form a cyclohexyl ring, preferably R.sup.e1 and R.sup.e2 may be independently selected from hydrogen, methyl, ethyl or phenyl, or R.sup.e1 and R.sup.e2 may together form a cyclohexyl ring.

[0311] Z′ corresponds to R.sup.z, except that a bond replaces the labile hydrogen atom. Therefore, the identity of each Z′ depends on the definition of R.sup.z in the starter compound. Thus, it will be appreciated that each Z′ may be —O—, —NR'—, —S—, —C(O)O—, —P(O)(OR')O—, —PR’(O)(O—).sub.2 or —PR'(O)O— (wherein R′ may be H, or optionally substituted alkyl, heteroalkyl, aryl, heteroaryl, cycloalkyl or heterocycloalkyl, preferably R′ is H or optionally substituted alkyl), preferably Z′ may be —C(O)O—, —NR'— or —O—, more preferably each Z′ may be —O—, —C(O)O— or a combination thereof, more preferably each Z′ may be —O—.

[0312] Z also depends on the nature of the starter compound. Thus, Z may be selected from optionally substituted alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene, heteroalkynylene, cycloalkylene, cycloalkenylene, hererocycloalkylene, heterocycloalkenylene, arylene, heteroarylene, or Z may be a combination of any of these groups, for example Z may be an alkylarylene, heteroalkylarylene, heteroalkylheteroarylene or alkylheteroarylene group. Preferably Z is alkylene, heteroalkylene, arylene, or heteroarylene, e.g. alkylene or heteroalkylene. It will be appreciated that each of the above groups may be optionally substituted, e.g. by alkyl.

[0313] The variable a will also depend on the nature of the starter compound. The skilled person will appreciate that the value of a in formula (IV) will be the same as a in formula (III). Therefore, for formula (IV), a is an integer of at least 2, preferably a is in the range of between 2 and 8, preferably a is in the range of between 2 and 6.

[0314] The skilled person will also appreciate that the value of a will influence the shape of the polyol prepared by the method of the invention. For example, when a is 2, the polyol of formula (IV) may have the following structure:

##STR00059##

Where Z, Z′, m, n, R.sup.e1 and R.sup.e2 are as described above for formula (IV).

[0315] For example, when a is 3, the polyol of formula (IV) may have the following formula:

##STR00060##

[0316] Where Z, Z′, m, n, R.sup.e1 and R.sup.e2 are as described above for formula (IV).

[0317] The skilled person will understand that each of the above features may be combined. For example, R.sup.e1 and R.sup.e2 may be independently selected from hydrogen, alkyl or aryl, or R.sup.e1 and R.sup.e2 may together form a cyclohexyl ring, each Z′ may be —O—, —C(O)O— or a combination thereof (preferably each Z′ may be —O—), and Z may be optionally substituted alkylene, heteroalkylene, arylene, or heteroarylene, e.g. alkylene or heteroalkylene, and a may be between 2 and 8.

[0318] The polyols produced by the method of the invention are preferably low molecular weight polyols. It will be appreciated that the nature of the epoxide used to prepare the polycarbonate ether polyol will have an impact on the resulting molecular weight of the product. Thus, the upper limit of n+m is used herein to define “low molecular weight” polymers of the invention.

[0319] The method of the invention can advantageously prepare a polycarbonate ether polyol having a narrow molecular weight distribution. In other words, the polycarbonate ether polyol may have a low polydispersity index (PDI). The PDI of a polymer is determined by dividing the weight average molecular weight (M.sub.w) by the number average molecular weight (M.sub.n) of a polymer, thereby indicating the distribution of the chain lengths in the polymer product. It will be appreciated that PDI becomes more important as the molecular weight of the polymer decreases, as the percent variation in the polymer chain lengths will be greater for a short chain polymer as compared to a long chain polymer, even if both polymers have the same PDI.

[0320] Preferably the polymers produced by the method of the invention have a PDI of from about 1 to less than about 2, preferably from about 1 to less than about 1.75, more preferably from about 1 to less than about 1.5, even more preferably from about 1 to less than about 1.3.

[0321] The M.sub.n and M.sub.w, and hence the PDI of the polymers produced by the method of the invention may be measured using Gel Permeation Chromatography (GPC). For example, the GPC may be measured using an Agilent 1260 Infinity GPC machine with two Agilent PLgel .Math.-m mixed-E columns in series. The samples may be measured at room temperature (293 K) in THF with a flow rate of 1mL/min against narrow polystyrene standards (e.g. polystyrene low easivials supplied by Agilent Technologies with a range of Mn from 405 to 49,450 g/mol). Optionally, the samples may be measured against poly(ethylene glycol) standards, such as polyethylene glycol easivials supplied by Agilent Technologies.

[0322] Preferably, the polymers produced by the method of the invention may have a molecular weight in the range of from about 500 Da to about 10,000 Da, preferably from about 700 Da to about 5,000 Da, preferably from about 800 Da to about 2,000 Da. The term “molecular weight” refers to number average molecular weight unless otherwise indicated.

[0323] The invention also provides a polymerisation system for the copolymerisation of carbon dioxide and an epoxide, comprising: [0324] d. A catalyst of formula (I) as defined herein, [0325] e. A DMC catalyst as defined herein, and [0326] f. A starter compound as herein.

[0327] It will also be appreciated that the polyols prepared by the method of the invention may be used for further reactions, for example to prepare a polyurethane, for example by reacting a polyol composition comprising a polyol prepared by the method of the invention with a composition comprising a di- or polyisocyanate.

[0328] The skilled person will also appreciate that it may be possible to use other catalysts which are known to prepare polycarbonates via the reaction of an epoxide and carbon dioxide either as well as, or instead of, the catalysts of formula (I). For example, catalysts as defined in WO 2010/028362 are considered for this purpose.

EXAMPLES

Methods

.SUP.1.H NMR Analysis

[0329] The assessment of polyether and polycarbonate content of the polyethercarbonate polyols has been reported in a number of different ways. In order to calculate the molar carbonate content and the CO.sub.2 wt% in the polyethercarbonate polyols, the method described in US2014/0323670 was used herein. The method is as follows:

[0330] The samples were dissolved in deuterated chloroform and measured on a Bruker spectrometer. The relevant resonances in the .sup.1H-NMR spectra used for integration (in the case that 1,6-hexanediol is used as a starter) were:

TABLE-US-00001 .sup.1H NMR resonance (ppm) Protons from repeating units No of protons A (1.08-1.18) CH.sub.3 of Polyether 3 B (1.18-1.25) CH.sub.3 of Polycarbonate end groups 3 C (1.26-1.38) CH.sub.3 of Polycarbonates 3 D (1.45-1.49) CH.sub.3 of cyclic carbonate 3 E (1.64-1.75) or (1.40-1.48) CH.sub.2 of hexanediol 4 F (2.95-2.99) CH of propylene oxide 1

[0331] The resonances A, C-F have been previously defined for polyethercarbonates containing a low proportion of carbonate linkages in the methods described in US2014/0323670. An extra resonance (B, 1.18-1.25 ppm) has been identified that is only present in significant quantities in polyethercarbonates with a high carbonate content. It has been assigned (by 2D NMR) as a

[0332] terminal propylene CH.sub.3 group between a carbonate unit and a hydroxyl end group. It is therefore added to the total carbonate units (C) as described in US2014/0323670.

[0333] Carbonate/ether ratio (m/n+m): molar ratio of carbonate and ether linkages:

[00001]$\frac{m}{m+n}=Rc=\frac{B+C}{A+B+C}$

CO.sub.2 wt % in polyol: amount of CO.sub.2 incorporated into the total polyol:

[00002]$CO2wt\%=\frac{\left(C+B\right)\times 44}{\left(A\times 58\right)+\left(\left(B+C\right)\times 102\right)+\left(0.75\times \left(E\times 118\right)\right)}\times 100$

[0334] Wherein 44 is the mass of CO.sub.2 within a carbonate unit, 58 is the mass of a polyether unit, 102 is the mass of a polycarbonate unit and 118 is the mass of the hexanediol starter (the factor 0.75 is added as the hexanediol resonance corresponds to 4 protons whilst all the other resonances correspond to 3). This is the total proportion of CO.sub.2 that is present in the entire polyol. If other starters are used it is appreciated the relevant NMR signals, relative integrations and molecular weights will be used in the calculation.

[0335] Furthermore, resonance C can be broken down into two different resonances. From 1.26-1.32 ppm (C.sup.1) corresponds to the propylene CH.sub.3 in a polymer unit between a carbonate and an ether linkage (a polyethercarbonate, PEC linkage) whilst the resonance from 1.32-1.38 ppm (C.sup.2) comes from a propylene CH.sub.3 in a polymer unit in between two carbonate linkages (a polycarbonate, PC linkage). The ratio of PEC, PC and PE linkages gives an indication of the structure of the polymer. A completely blocked structure will contain very few PEC linkages (only those at the block interfaces), whilst a more random structure will include a significant proportion of PEC linkages where both polyether and polycarbonate units are adjacent to each other in the polymer backbone. The ratio of these two units gives an indication of the structure.

[0336] Polyethercarbonate/polycarbonate linkage ratio:

[00003]$R_{PEC}=\frac{C^1}{C^1+C^2}$

Gel Permeation Chromatography

[0337] GPC measurements were carried out against narrow polydispersity poly(ethylene glycol) or polystyrene standards in THF using an Agilent 1260 Infinity machine equipped with Agilent PLgel Mixed-E columns.

Mass Spectroscopy

[0338] All mass spectrometry measurements were performed using a MALDI micro MX micromass instrument.

Example 1

Synthesis of DMC Catalyst According to US 5,482,908 Example 1 (Catalyst 1)

[0339] The synthesis described in Example 1 of US 5,482,908 was followed except the 4000 molecular weight polypropylene glycol diol was replaced with a 2000 molecular weight polypropylene glycol diol:

[0340] Potassium hexacyanocobaltate (8.0 g) was dissolved in deionised (DI) water (140 mL) in a beaker (solution 1). Zinc chloride (25 g) was dissolved in DI water (40 mL) in a second beaker (solution 2). A third beaker containing solution 3 was prepared: a mixture of DI water (200 mL), tert-butyl alcohol (2 mL) and polyol (2 g of a 2000 mol. wt. polypropylene glycol diol). Solutions 1 and 2 were mixed together using a mechanical stirrer. Immediately a 50/50 (by volume) mixture of tert-butyl alcohol and DI water (200 mL total) was added to the zinc hexacyanocobaltate mixture, and the product was stirred vigorously for 10 min. Solution 3 (polyol/water/tert-butyl alcohol mixture) was added to the aqueous slurry of zinc hexacyanocobaltate and the product stirred magnetically for 3 min. The mixture was filtered under pressure to isolate the solids. The solid cake was reslurried in tert-butyl alcohol (140 mL), DI water (60 mL), and an additional 2 g of the 2000 mol. wt. polypropylene glycol diol. Then mixture was stirred vigorously for 10 min. and filtered. The solid cake was reslurried in tert-butyl alcohol (200 mL) and an additional 1 g of 2000 mol. wt. polypropylene glycol diol and stirred vigorously for 10 minutes, then filtered. The resulting solid catalyst was dried under vacuum (<1 mbar) at 50° C. to constant weight. The yield of dry, powdery catalyst was 8.5 g.

Example 2

Synthesis of DMC Catalyst According to WO2012/156431 Example 1 (Catalyst 2)

[0341] The synthesis described in Example 1 was followed except that the polypropylene glycol of MWn 400 was replaced with a polypropylene glycol of MWn 425.

1.SUP.st Step

[0342] Potassium hexacyanocobaltate (7.5 g) was dissolved in DI water (100 mL) in a beaker (solution A). Zinc chloride (75 g) and tert-butyl alcohol (50 mL) were dissolved in DI water (275 mL) in a second beaker (solution B). Solution B was heated at a temperature of 50° C. Subsquently, solution A was slowly added for 30 minutes to solution B whilst stirring at 400 rpm. The aqueous zinc chloride and tert-butyl alcohol solution and the cobalt salt solution were combined using a stirrer to intimately and efficiently mixed both aqueous solutions. The mixture was held post-reacting for 30 minutes at the same temperature to form a slurry of zinc hexacyanocobaltate.

[0343] A third solution (solution C) was prepared by dissolving a 425 mol. wt. diol (8 g, polypropylene glycol) in DI water (50 mL) and tert-butyl alcohol (2 mL). Solution C (PPG/water/tert-butyl alcohol mixture) was added to the aqueous slurry zinc hexacyanocobaltate for 5 minutes and the product was stirred for an additional 10 minutes. The mixture was filtered under pressure to isolate the solid.

2.SUP.nd Step

[0344] The solid cake was reslurried in DI water (150 mL) for 30 minutes at a temperature of 50° C. and subsequently, additional 425 mol. wt. polypropylene glycol (2 g) was added. The mixture was stirred for 10 minutes then filtered.

3.SUP.rd Step

[0345] The solid cake obtained after the second step was reslurried in tert-butyl alcohol (185 mL) for 30 minutes at a temperature of 50° C. and subsequently, additional 425 mol. wt. diol polypropylene glycol (1 g) was added. The mixture was homogenised by stirring for 5 minutes and filtered. The resulting solid catalyst was dried under vacuum at 100° C. and <1 mbar to constant weight. Yield of powdered catalyst 8 g.

Example 3: Synthesis of DMC Catalyst 3

[0346] The DMC catalyst used in this example was prepared according to the method reported in Journal of Polymer Science; Part A: Polymer Chemistry, 2002, 40, 1142. In brief, 1.0 g of K.sub.3Co(CN).sub.6 was dissolved in a mixture solvent of 13 g distilled water and 2 g tert-butyl alcohol. 6 g of ZnCl.sub.2 was dissolved in a mixture solvent of 13 g water and 4 g tert-butyl alcohol, and then this mixture was added slowly to the K.sub.3Co(CN).sub.6 solution over a period of 20 minutes, whilst stirring. The mixture was then stirred for a further 40 minutes and then centrifugal separation was performed to yield a white precipitate. The precipitate was dispersed in a mixture solvent of 16 g water and 16 g tert-butyl alcohol, and stirred for 20 minutes, and then the precipitate was separated by centrifuge. This washing procedure was repeated 3 times. The white precipitate was then dispersed in 50 g tert-butyl alcohol, and then stirred for 20 minutes, followed by centrifugal separation to obtain a white precipitate. The washing with tert-butyl alcohol was then repeated once more. The solvent was then removed under reduced pressure at 60° C. for 8 hours. The resultant compound is understood to have the formula Zn.sub.3[Co(CN).sub.6].sub.2 .Math. hZnCl.sub.2 .Math. 0.5H.sub.2O .Math. 2[(CH.sub.3).sub.3COH].

Example 4: Synthesis of Catalyst 4

[0347] Catalyst 4 was prepared as described in PCT/GB2016/052676 (W02017/037441).

##STR00061##

X=OAc

Example 5: Copolymerisation of Propylene Oxide and Carbon Dioxide Using Two Catalysts

[0348] 5 mg of the DMC catalyst (1, 2 or 3) as referred to above was taken into a 100 mL oven dried reactor along with 1,6-hexanediol (0.51 g). The catalyst and starter were dried at 110-120° C. under vacuum for 1-2 hours. The reactor was cooled down to room temperature and a propylene oxide (PO; 15 mL) solution of catalyst 4 (51.5 mg) was injected into the vessel via a syringe under continuous flow of CO.sub.2 gas. The vessel was heated to the desired temperature and filled to the desired CO.sub.2 pressure. The reaction was continued for 16 hours. Once the reaction was finished, the reactor was cooled to below 10° C. and the pressure was released. NMR and GPC were measured immediately. The reactions run at 75° C. contained no unreacted PO. Reactions at 65° C. contained between 3-14% unreacted PO.

TABLE-US-00002 Run DMC Catalyst Temp (°C) Pressure (bar) % Carbonate linkages CO.sub.2 wt % Mn PDI 1 1 60 10 60 29.0 2400 2.38 2 2 60 10 53 27.1 1400 1.97 3 1 75 10 36 20.8 2200 1.71 4 2 75 10 40 22.7 2300 1.98

[0349] Runs 1-4 in Table 1 demonstrate the ability of the dual catalyst system to produce high carbonate content polyethercarbonate polyols using a DMC catalyst that contains two coordinating agents wherein one of the coordinating agents is a polymer. The high carbonate content polyols were produced under 10 bar pressure which is a fraction of the pressure that would be necessary to produce this much carbonate content using the DMC catalysts alone. Furthermore, the polyethercarbonate polyols do not require a starter with a high molecular weight (e.g. >500 Mn).

TABLE-US-00003 Run DMC Catalyst P (bar) % Carbonate linkages CO.sub.2 wt % Selectivity % PO Conv. % Mn PDI 5 2 (PPG/TBA) 5 44 23.6 69 89 1900 2.26 6 3 (TBA) 5 47 24.6 62 84 1500 1.73

[0350] Runs 5 and 6 in Table 2 were carried out as per runs 1-4, except they were run at 60° C. and only 5 bar pressure of CO.sub.2. Run 5 was carried out using DMC catalyst 2 that contained two complexing agents, tert-butyl alcohol (TBA) and PPG diol. Run 6 was carried out using DMC catalyst 3 that only contained TBA and not the first polymer complexing agent. It can be clearly seen that both the selectivity for polymer and the PO conversion were significantly improved by using DMC catalyst 2 containing the PPG diol.

Example 5

Synthesis of DMC Catalyst 5

[0351] The DMC catalyst used in this example was prepared according to the method reported in European Polymer Journal, 2017, 88, 280-291, catalyst E. K.sub.3[Co(CN).sub.6].sub.2(0.77 g) was dissolved in 80 ml of mili-Q water and ZnCl.sub.2 (1.77 g) in 210 ml of miliQ water and 50 ml of tBuOH. Both solutions were mixed and vigorously stirred 15 min at 50° C. After 13 min PEG 1000 was added to the mixed solution, the white suspension was centrifugated 6 min at 5000 rpm. The isolated slurry was resuspended with strong stirring during 20 min in 100 ml of a t-BuOH: H.sub.2O (50:50) solution and it was centrifugated as previous. The solid was resuspended in 100 ml of 100% t-BuOH and stirred for 30 min, filtered (omnipore PTFE membrane filter, 0.1 micrometer, Merck Milipore) and dried under vacuum at 50° C. during 30 h.

Example 6

Example 6: Copolymerisation of Propylene Oxide and Carbon Dioxide Using Two Catalysts

[0352] 5 mg of the DMC catalyst (2, 3 or 5) as referred to above was taken into a 100 mL oven dried reactor along with 1,12-dodecanediol (1.3 g). The catalyst and starter were dried at 110-120° C. under vacuum for 1-2 hours. The reactor was cooled down to room temperature and a propylene oxide (PO; 15 mL) solution of catalyst 4 (51.5 mg) was injected into the vessel via a syringe under continuous flow of CO.sub.2 gas. The vessel was heated to 75° C. and filled to 5 bar CO.sub.2 pressure. The reaction was continued for 16 hours. Once the reaction was finished, the reactor was cooled to below 10° C. and the pressure was released. NMR and GPC were measured immediately.

TABLE-US-00004 Run DMC catalyst % carbonate linkages CO.sub.2 (wt%) PO Conv. % Mn PDI 6 3 (TBA) 17 10.8 93 1900 1.30 7 5 (PEG/TBA) 40 21.4 100 2400 1.39 8 2 (PPG/TBA) 31 16.7 98 1900 1.46

[0353] The catalysts were tested with dodecanediol as a starter. Run 6 demonstrates the performance of catalyst 3, made with only tert-butyl alchohol as a complexing agent and not the first polymer complexing agent. In comparison, runs 7 & 8 use catalysts 5 and 2 which contain a polymer complexing agent, PEG-1000 and PPG-425 respectively. These catalysts were demonstrated to produce polyols with substantially more carbonate linkages and with higher PO conversion, further demonstrating the benefit of having these two complexing agents present in the DMC catalyst. Beneficially, runs 6 & 7 demonstrate that the combination of catalyst 4 and DMC catalysts with two complexing agents can be used to incorporate high amounts of CO.sub.2 even under low pressures such as 5 bar.

Example 7

Example 7: Copolymerisation of Propylene Oxide and Carbon Dioxide Using Two Catalysts

[0354] 5 mg of the DMC catalyst 5 as referred to above was taken into a 100 mL oven dried reactor along with 1,6-hexanediol (1.02 g). The catalyst and starter were dried at 110-120° C. under vacuum for 1-2 hours. The reactor was cooled down to room temperature and a propylene oxide (PO; 15 mL) solution of catalyst 4 (51.5 mg) was injected into the vessel via a syringe under continuous flow of CO.sub.2 gas. The vessel was heated to 60 C and filled to 10 bar CO.sub.2 pressure. The reaction was continued for 16 hours. Once the reaction was finished, the reactor was cooled to below 10° C. and the pressure was released. NMR and GPC were measured immediately. The reaction produced a polymer with 68% carbonate linkages (31 wt% CO.sub.2), a selectivity of 97% and a molecular weight of 1550, with a PDIof 1.53.

Example 8

[0355] 5 mg of the DMC catalyst 5 as referred to above was taken into a 100 mL oven dried reactor along with propoxylate glycerol (Mn 260, 0.78mL). The catalyst and starter were dried at 110-120° C. under vacuum for 1-2 hours. The reactor was cooled down to room temperature and a propylene oxide (PO; 15 mL) solution of catalyst 4 (45 mg) was injected into the vessel via a syringe under continuous flow of CO.sub.2 gas. The vessel was heated to 70° C. and filled to 5 bar CO.sub.2 pressure. The reaction was continued for 16 hours. Once the reaction was finished, the reactor was cooled to below 10° C. and the pressure was released. NMR and GPC were measured immediately. The reaction produced a polymer with 40% carbonate linkages (21 wt% CO.sub.2), a selectivity of 94% and a molecular weight of 2800, with a PDIof 1.25.