Solid-state structures of persubstituted titanocene chlorides bridged with long aliphatic ansa-chains

A series of three ansa-titanocene monochlorides containing η5-tetramethylcyclopentadienyl ligands bridged by five- or eight-membered aliphatic chains were prepared via reduction of the corresponding dichlorides with half molar equivalent of magnesium and characterized by spectral methods. The solid-state structures of the monochloride complexes ansa-[TiCl{η5:η5-C5Me4CH(Me)CH2CH2CH(Me)CH(Me)C5Me4}] (1a) and ansa-[TiCl{η5:η5-C5Me4(CH2)3CH(Me)CH(Me)CHCHCH2C5Me4}] (4a), and of the bridge-unsaturated titanocene dichloride complex ansa-[TiCl2{η5:η5-C5Me4CH2CHCH(CH2)5C5Me4}] (3) were determined by single-crystal X-ray diffraction. All the compounds show bent metallocene structures with the ansa-chain situated in a side position with respect to Cg, Ti, Cg (Cg=centroid of the cyclopentadienyl ligand) plane. Angles subtended by the least-squares planes of the cyclopentadienyl rings and conformation of the ansa-chains indicates the absence of steric strain in the metallocene framework.