Titanium(IV) complexes bearing the (CpC)− ligand

Abstract

CpCH is a chiral cyclopentadienide-type ligand consisting of a CpH core with two annulated dibenzocycloheptatriene wings. Due to the presence of the seven-membered rings, the wings are bent making CpCH a novel, intrinsically chiral CpH derivative. Starting from ClTi(OiPr)3 and (CpC)-, obtained by deprotonation of CpCH with BuLi, the titanium (IV) half-sandwich complex (CpC)Ti(OiPr)3 was obtained. Further treatment of (CpC)Ti(OiPr)3 with an excess of Me3SiI gave the iodo derivative (CpC)Ti(OiPr)I2 in good yields. Both complexes could structurally be characterized by means of single crystal X-ray crystallography. Direct conversion of (CpC)- with TiCl4 resulted in oxidation of the anionic ligand and thus formation of the CC bridged dimer (CpC)2.