Reaction of [Ti(cp)2(AsF6)2](cp =η-C5H5) toward S4N4and Se4N4: identification in solution of [Ti(cp)2(S4N4)][AsF6]2; synthesis and characterization of [Ti(cp)2F(AsF6)], [Ti(cp)2F2]·AsF3and [Ti(cp)F3]·AsF3

Abstract
The reaction of [Ti(cp)2(AsF6)2]2(cp =η-C5H5) with S4N4 in liquid sulphur dioxide gives [Ti(cp)2F(AsF6)]4 and S4N4·AsF55. The new complex 4 can be prepared in quantitative yield from [Ti(cp)2F2]1 and AsF5. Proton, 14N and 19F NMR spectroscopy reveals that SO2 solutions of 2 and S4N4 or 4 and 5 contain [Ti(cp)2(S4N4)][AsF6]23. In contrast Se4N4 is oxidized by 2 and leads to [(SeNSeNSe)2][AsF6]2, N2, AsF3 and 1. Complex 1 forms a stable adduct with AsF3, [Ti(cp)2F2]·AsF3, which was characterized by 1H NMR, IR and mass spectroscopy and elemental analysis. The monocyclopentadienyl analogue [Ti(cp)F3]·AsF3 can also be prepared in quantitative yield from [Ti(cp)Cl3] and Ag[AsF6].