Synthesis and Structure of Titanium(III) Bis(decamethyltitanocene) Oxide

Bis­(decamethyltitanocene) oxide, [(Cp*2Ti)2O] (1; Cp* = η5-C5Me5) has been obtained as a yellow crystalline solid after reacting equimolar amounts of the hydride [Cp*2TiH] and the hydroxide [Cp*2Ti­(OH)]. The solid-state structure of 1 revealed a linear Ti–O–Ti arrangement and a mutual, nearly perpendicular orientation of the bent-sandwich titanocene moieties; the length of both Ti–O bonds amounted to 1.9080(3) Å. A unique structural feature was a close-to-eclipsed conformation of the cyclopentadienyl ligands, attributed to the high steric congestion of 1. The molecule in toluene glass exhibited a triplet state EPR spectrum of rhombic symmetry, having zero field splitting D = 0.02159 cm–1 and E = 0.00230 cm–1. The 1H NMR spectrum of 1 in toluene-d8 displays a paramagnetic resonance at δ 4.3 ppm (Δν1/2 ≈ 270 Hz). Compound 1 reacts with 1 molar equiv of water to give [Cp*2Ti­(OH)]. In CD2Cl2, 1 is oxidized to yield the major product [(Cp*TiCl2)2O] and minor product [{Cp*Ti­(Cl)­O}3].