Multicomponent Mechanochemical Synthesis of Cyclopentadienyl Titanium tert-Butoxy Halides, CpxTiXy(OtBu)4–(x+y) (x, y = 1, 2; X = Cl, Br)

Abstract

Titanium tert-butoxy halides of the formula CpxTiXy(OtBu)4–(x+y) (x, y = 1, 2; X = Cl, Br) have been prepared thorough milling the reagents without solvent. In the case of the chloride derivatives, Cp2TiCl2 is used as a starting material; in the case of the bromides, a mixture of LiCp, TiBr4, and Li[OtBu] is used. The stoichiometric ratios of the starting materials are reflected in the major products of the reactions. Single-crystal X-ray structures are reported for Cp2TiCl(OtBu), Cp2TiBr(OtBu), and CpTiBr2(OtBu), as well as for Cp2TiCl(OiPr) and a redetermination of Cp2TiCl(OMe). The tert-butoxy derivatives are notable for their nearly linear Ti–O–C angles (>170°) that reflect Ti–O π-bonding, an interpretation supported with density functional theory calculations.