摘要 |
<p>Possibly dicationic or partially dicationic Group 4 metal compounds having e.g. utility as addition polymerization catalysts, obtainable by contacting a charge-neutral complex having two Lewis basic anionic ligand groups, X, of formula (I), with at least 2 molar equivalents of a charge-neutral, Lewis acidic compound, A, such that ≥2 Lewis basic groups of the Group 4 metal coordination complex are abstracted or partially abstracted, wherein Y?1 and Y2¿ are independently anionic ligand groups that are covalently bonded to M by means of a sigma bond through an oxygen, phosphorus or nitrogen atom, and contain up to 50 atoms, not counting hydrogen, optionally joined through bridging group, J, and further optionally also contain a coordinate/covalent bond to M; J is an optional divalent bridging group having up to 20 atoms not counting hydrogen; j is 0 or 1; M is a Group 4 metal; X1 are independently Lewis bases; x1 is 0, 1, 2.</p> |