Synthesis of cationic titanocene complexes and their reactivity towards olefins and acetylenes.

Abstract:
Cationic titanocene complexes will be prepared by reactions of tris(pentafluorophenyl)borane, B(C6F5)3, with the simplest titanocene derivatives, e.g., stable titanocenes containing one silyl group at each tetramethylcyclopentadienyl ligand and permethyltitanocenes containing two vicinal methylene groups. The use of initial Ti(II) compounds will allow us to prepare Ti(III) cationic complexes which are only scarcely known. The process of breaking Ti-C bonds induced by the reaction with B(C6F5)3 will be investigated on a series of more complex ring-tethered titanacyclopentane derivatives or ansa-titanocene complexes with unsaturated bridges. The obtained cationic Ti(III) and Ti(IV) complexes will be investigated by X-ray analysis and spectroscopic methods, and their activity toward oligomerization or polymerization of alkenes and linear dimerization of alkynes will be examined.