Monocyclopentadienylchlorooxotitanium(IV) Dimers, Trimers and Tetramers

High-yield syntheses (≥90%) of the monocyclopentadienyloxochloro complexes [(TiLCl2)2(μ-O)] 2, [(TiLCl)4(μ-O)4] 3, [(TiL)4(μ-O)6] 4 and [(TiLCl)3(μ-O)3] 5 have been achieved by hydrolysis of the precursors [TiLCl3] 1 [L = η5-C5H5, C5H4Me, C5H4(SiMe3) or C5Me5]. In addition [Ti{η5-C5H4(SiMe3)}Br 3] 7, [Ti4{η5-C5H4(SiMe 3)}4Br4(μ-O)4] 8 and [Ti4{η5-C5H4(SiMe 3)}4(NCS)4(μ-O)4] 9 have been prepared. The structures of the cyclic trimer 5 (L = η5-C5Me5) and tetramer 9 have been determined by X-ray analysis: 5, monoclinic, space group P21/c, a = 16.724(2), b = 8.958(1), c = 22.871(2) Å, β = 91.73(1)°, Z = 4 and R = 0.065 for 3159 independent observed reflections; 9, monoclinic, space group Cc, a = 24.527(2), b = 12.520(2), c = 18.931(2) Å, β = 115.46(2)°, Z = 4 and R = 0.060 for 3088 independent observed reflections. The electronic configurations of complexes 2-5 have been calculated by extended-Hückel molecular orbital calculations.