Bimetallic catalytic complexes for the polymerisation of carbon dioxide and an epoxide

1. A dimeric catalyst wherein said dimeric catalyst comprises two monomeric subunits, wherein each monomeric subunit is a catalyst of formula (I):

wherein each R 1 and R 2 are independently hydrogen, alkyl, haloalkyl, aryl, halide, amine, a nitro group, an ether group, a silyl ether group, a nitrile group or an acetylide group;

each R 3 is independently alkylene, arylene or cycloalkylene;

each R 4 is independently H, alkyl, aryl or alkylaryl;

each E 1 is C, each E 2 is independently O, S or NH;

or each E 1 is N and each E 2 is O;

X is OCOCH 3 , OCOCF 3 , OSO 2 C 7 H 7 , OSO(CH 3 ) 2 or halide;

M is Zn(II), Cr(II), Co(II), Mn(II), Mg (II), Fe(II), Cr (III)—X, Co (III)—X, Mn (III)—X or Fe(III)—X;

and wherein the two monomeric subunits are linked by a bridging ligand X.

2. The dimeric catalyst as claimed in claim 1 , wherein said catalyst has the structure:

wherein:

X is OCOCH 3 , OCOCF 3 , OSO 2 C 7 H 7 , OSO(CH 3 ) 2 , or halide.

3. The dimeric catalyst as claimed in claim 1 , wherein said catalyst has the structure:

4. The dimeric catalyst as claimed in claim 1 , wherein each R 1 and R 2 are independently selected from hydrogen, tBu, Me, CF 3 , phenyl, F, Cl, Br, I, NMe 2 , NEt 2 , NO 2 , OMe, OSiEt 3 , CNMe, CN, or CCPh.

5. The dimeric catalyst as claimed in claim 1 , wherein each R 1 and R 2 are independently selected from hydrogen, tBu, Me, F, Cl, Br, I, or OMe.

6. The dimeric catalyst as claimed in claim 1 , wherein R 3 is ethylene, 2,2-dimethylpropylene, propylene, butylene, phenylene, cyclohexylene, or biphenylene.

7. The dimeric catalyst as claimed in claim 1 , wherein R 3 is 2,2-dimethylpropylene or propylene.

8. The dimeric catalyst as claimed in claim 1 , wherein R 4 is H, Me, Et, Bn, iPr, nBu, tBu, or Ph.

9. The dimeric catalyst as claimed in claim 1 , wherein R 4 is H.

10. The dimeric catalyst as claimed in claim 1 , wherein X is OCOCH 3 , OCOCF 3 , OSO 2 C 7 H 7 , OSO(CH 3 ) 2 , Cl, Br, or I.

11. The dimeric catalyst as claimed in claim 1 , wherein X is OCOCH 3 .

12. The dimeric catalyst as claimed in claim 1 , wherein each E 1 is C, and each E 2 is O.

13. The dimeric catalyst as claimed in claim 1 , wherein M is Zn(II), Cr(II), Co(II), Mg (II), Fe(II), Cr (III)—X, Co (III)—X, or Fe(III)—X.

14. The dimeric catalyst as claimed in claim 1 , wherein said dimeric catalyst comprises a bound water molecule.

15. The dimeric catalyst of claim 1 , wherein the monomeric subunits forming the dimeric catalyst have the same structure.

16. A mixture comprising the dimeric catalyst of claim 1 , wherein the monomeric subunits forming the dimeric catalyst have the same structure.

17. A process for the reaction of carbon dioxide with an epoxide in the presence of a catalyst as claimed in claim 1 .

18. The process as claimed in claim 17 , wherein the epoxide is selected from cyclohexene oxide, an alkylene oxide, or a substituted oxirane.

19. The process as claimed in claim 17 , wherein said process is carried out at 1 atmosphere.

20. A product of the process of claim 17 .

21. A process for the production of a dimeric catalyst as claimed in claim 1 , said process comprising reaction of a compound of formula (III)

with a metal complex comprising the groups M and X in the presence of water, wherein the groups X, R 1 , R 2 , R 3 , R 4 , M, E 1 and E 2 are as defined in claim 1 .

22. The process as claimed in claim 21 , wherein said reaction occurs in the presence of base.