ansa group 4 metal bis (.mu. - aluminium) - substituted metallocene

摘要

Ansa bis( mu -substituted) Group 4 metal and aluminum compounds comprising a single Group 4 metal atom and two aluminum metal atoms corresponding to the formula: wherein: L' is a pi -bonded group, M is a Group 4 metal, Z is a divalent bridging group causing the complex to have an ansa structure, X independently each occurrence is a Lewis basic ligand group able to form a mu -bridging ligand group, and optionally the two X groups may be joined together, and A' independently each occurrence is an aluminum containing Lewis acid compound that forms an adduct with the metal complex by means of the mu -bridging groups, and optionally two A' groups may be joined together thereby forming a single difunctional Lewis acid containing compound, and a method of preparation comprising contacting a charge-neutral metallocene of a Group 4 metal having at least two Lewis basic groups with at least two molar equivalents of a charge-neutral aluminum coordination complex having Lewis acidic aluminum atoms such that at least two of the aluminum atoms of the aluminum coordination complexes bond to at least two of the Lewis basic groups of the metallocene.