| 摘要 |
The present invention relates to a compound having the formula La M (OR1 )b R2 c Xd wherein M is a metal selected from Ti, Zr and Hf; L is a ligand selected from permethylpentalene, (hydro)permethyl-pentalene, (hydro)pentalene, cyclopentadiene, indene and ethylene- or silane-bridged indene, preferably (bis)indene; R1 is a 1-6C alkyl, substituted or unsubstituted phenyl, or a substituted or unsubstituted phenylalkylene group; R2 is Me or Et; X is halogen; a = 1 to 3, b = 1 to 3, c = 0 or 1 and d = 0, 1, 2 or 3; and dimers thereof, the use of the compound as an initiator in the polymerisation of lactide monomer and a process for producing a polylactide performed by contacting a lactide monomer with the compound. |
