B(C6F5)3 Adducts of TCNE− and TCNQ−Vanadium Complexes as New Building Blocks for Molecule-Based Magnets

The TCNX ligands TCNE and TCNQ reacted in toluene with Cp2V in the presence of B(C6F5)3 to yield, depending on the stoichiometry, the divanadium(III) complexes [(Cp2V)2{(C6F5)3B·(μ4-TCNX)·B(C6F5)3}] (X = Q (3), E (4)) or the vanadium(IV) dimers [Cp2V{(C6F5)3B·(μ4-TCNX)·B(C6F5)3}]2 (X = E (5), Q (6)), all containing [TCNX]2- ligands σ-bonded to vanadium through a nitrile nitrogen, as revealed by crystallographic (for 3−5) and magnetic studies (for 3−6).