Formation of vanadium-arene complex anions and their photoelectron spectroscopy

Vanadium-arene complex anions, V1(arene)m− (m = 1, 2; arene = benzene, fluorobenzene, and toluene) were synthesized by the gas phase reaction of laser vaporized metal atoms with aromatic compound vapors. According to the 18-electron rule, it was anticipated that bis(benzene)vanadium should be stabilized by an electron attachment. However, it was experimentally concluded that bis(benzene)vanadium has negative electron affinity. The photoelectron spectra for the observed complex anions were measured, and the electronic configurations of metal-arene complexes and their structures are discussed.