| abstract |
Group 4 metal complexes useful as addition polymerization catalysts of the formula: (I) wherein G1 is a group containing from 1 to 40 atoms not counting hydrogen; T is a divalent bridging group of from 10 to 30 atoms not counting hydrogen, selected from mono- or di- aryl- substituted methylene or silylene groups or mono- or di- heteroaryl-substituted methylene or silylene groups, wherein at least one such aryl- or heteroaryl-substituent is substituted in one or both ortho- positions with a secondary or tertiary alkyl-group, a secondary or tertiary heteroalkyl group, a cycloalkyl group, or a heterocycloalkyl group, G2 is a C6-20 heteroaryl group containing Lewis base functionality, M is the Group 4 metal, X’’’’ is an anionic, neutral or dianionic ligand group, x’’’’ is a number from 0 to 5, and bonds, optional bonds and electron donative interactions are represented by lines, dotted lines and arrows respectively. |