New binuclear alkyl and half-sandwich cyclopentadienyl imido titanium complexes containing acetamidinate and benzamidinate supporting ligands

Chloride metathesis reactions of the binuclear titanium N,N′-bis(cyclohexyl)acetamidinato-μ-imido compound [Ti2(μ-NBut)2{MeC(NC6H11)2}2Cl2] (1) and the mononuclear N,N′-bis(trimethylsilyl)benzamidinato-imido analogue [Ti(NBut){PhC(NSiMe3)2}Cl(py)2] (2) are described. Thus, reaction of 1 or 2 with LiC5R5 (R=H or Me) gave the half-sandwich compounds [Ti(NBut){MeC(NC6H11)2}(η-C 5H5)] and [Ti(NBut){PhC(NSiMe3)2}(η-C5Me5)], respectively. These compounds are also accessible from [Ti(NBut)(η-C5R5)Cl(L)] (R=H or Me; L=py or 4-NC5H4But) and the appropriate lithium amidinate. Treatment of 1 with MeLi gave the binuclear 12-electron methyl derivative [Ti2(μ-NBut)2{MeC(NC6H11)2}2(Me)2] which has been crystallographically characterised