Some New Results on the Fischer-Hafner Synthesis of Vanadium Arenes

The biphasic liquid system formed in the Fisher–Hafner reduction of VCl3 in toluene contains the [V(g6-MeC6H5)2]+ cation which has been isolated in the solid state as the tetraphenylborato- (from aqueous solution) or as the [Al2Cl7]-, [Al4O2Cl10]2- and [catena- Al4O2Cl9]- salt (directly from the biphasic liquid system). The crystal structures of [V(h6-MeC6H5)2]2[Al4O2Cl10] (2), and [V(h6- MeC6H5)2][catena-Al4O2Cl9] (3), have been solved representing the first structural report of the [V(g6-MeC6H5)2]+ cation (compounds 2 and 3) and of the polymeric nonachlorodioxoaluminate anion [Al4O2Cl9]- (compound 3).