V, Nb, and Ta complexes with benzene in solid argon: An infrared spectroscopic and density functional study

Vanadium, niobium, and tantalum metal atoms, produced by laser ablation, are reacted with benzene vapor diluted in argon and codeposited onto a 7 K CsI window. The resulting reaction products are trapped. and the M(C6H6) and M(C6H6)(2) complexes are identified by benzene isotopic substitution (C6H6, (C6H6)-C-13, C6D6). Density functional theory (DFT) frequency calculations are used to support molecular complex assignments. On the basis of the computed energies and a comparison of calculated and observed vibrational isotopic shifts, the ground electronic states and geometrics are predicted. The bonding and electronic interactions in these molecules are discussed on the basis of the observed aromatic C-C breathing modes activated in the complexes.