Electron spin resonance of a series of biscyclopentadienyltitanium(III) hydrides. Deductions from solid-state spectra

Abstract

The e.s.r. spectra of a series of titanium(III) hydrides of general formula (π-C₅H₅)₂TiH₂M, where M = Na, Li, MgBr, AlCl₂, or AlH₂, have been investigated, with particular attention to the line-width trends. The spectra from the frozen solutions of some of the hydrides are reported, and one of these is discussed in detail. An approximately tetrahedral configuration is suggested for the titanium atom, with the unpaired electron in the 3d_z² orbital which lies along the symmetry axis between the cyclopentadienyl rings and bisecting the H–Ti–H angle. The results also suggest that on going across the series from the sodium hydride to the aluminium hydrides the H–Ti–H angle steadily decreases.