Synthesis of chlorotitanium(IV) Schiff-Base complexes and their application to styrene polymerization

摘要

A TiCl2(salen) complex and its derivatives with the formula TiCl2(L) L = salen(tBu), salen(di-Me), salen(di-tBu), salen(Me) were synthesized in high yield by reacting the Schiff-base ligands with TiCl4. TiCl2{salen(tBu)} and TiCl2{salen(di-tBu)} have been characterized by single-crystal X-ray diffraction. Styrene polymerizations carried out with TiCl2(salen) and its derivatives co-catalyzed by MAO yielded syndiotactic polystyrenes. The catalytic activity and syndiospecificity were dependent on the bulkiness of the; ortho substituents in the aryl ring of ligand.