Electronic structures and spectra of hexakisphenylisocyanide complexes of Cr(0), Mo(0), W(0), Mn(I), and Mn(II)

Electronic absorption spectra of M(CNPh)6 [M = Cr(0), Mo(0), W(0)], [Mn(CNPh)6]Cl, and [Mn (CNPh)6](PF6)2 are reported. Each of the M(CNPh)6 complexes exhibits three intense metal-to-ligand charge transfer (MLCT) absorption bands between 20.8 and 32.7 kK. The lowest MLCT bands are observed at 29.9 and 31.1 kK in the electronic spectrum of Mn (CNPh)6+. Low energy bands at 18.2 and 20.4 kK in [Mn(CNPh)6]2+ are assigned to vibronic components of a σ(CNPh) → dπ charge transfer transition. The unique electronic structural properties of arylisocyanide complexes are apparently related to the π conjugation of aromatic ring orbitals with the out-of-plane π*(CN) function. © 1976.