Synthesis and Structure of Cp*2TiH, Cp*2TiH2Li(tmed), and [Cp*2TiOLi(THF)]2

Abstract

The solid-state crystal structure of the d1 hydride Cp*2TiH shows that it has a bent sandwich structure with an open Cp*(centroid)−Ti−Cp*(centroid) angle of 150°. The crystal structure contains two molecules in the asymmetric unit, and the hydridic hydrogen atom is located and refined with isotropic thermal parameters to a Ti−H distance of 1.69(5) and 1.84(4) A in each independent molecule; the average Ti−H distance is 1.76 A. In each molecule, the Ti−H vector lies on the idealized C2 axis of the bent metallocene. The addition of n-BuLi and Me2NCH2CH2NMe2 (tmed) in hexane to Cp*2TiH or the addition of [Li(tmed)]2C10H8 to Cp*2TiCl gives the anionic dihydride Cp*2Ti(μ-H)2Li(tmed). The hydride atoms are not located in the X-ray diffraction experiment, but electron paramagnetic resonance spectra show coupling to two equivalent hydrogen nuclei, AHiso = 9.6 G. In addition, coupling to 7Li, confirmed by the preparation of the 6Li isotopomer, shows that the unpaired electron couples with each hydridic hydrogen an...