Reduction-induced cyclization and redox reactions of fully methylated titanocene dichlorides bearing pendant alkenyldimethylsilyl groups, [TiCl2{η(5)-C5Me4(SiMe2R}2] (R=Vinyl and Allyl)
Abstrakt
A series of three ansa-titanocene monochlorides containing eta(5)-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{eta(5):eta(5)-C5Me4CH(Me)CH2CH2CH(Me)CH(Me)C5Me4}] (1a) and ansa-[TiCl{eta(5):eta(5)-C5Me4(CH2)(3)CH(Me)CH(Me)CH-CHCH2C3Me4}] (4a), and of the bridge-unsaturated titanocene dichloride complex ansa-[TiCl2{eta(5):eta(5)-C5Me4CH2CH-CH(CH2)(3)C5Me4}] (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.