Properties of Closed-Shell, Octahedral, Multiply-Charged Hexafluorometallates MF63-, M = Sc, Y, La, ZrF62-, and TaF6-

Abstract

Properties of multiply-charged hexafluorometallates MF63-, M = Sc, Y, La, ZrF62-, and TaF6-, have been examined at the SCF, MP2, and Becke3LYP levels of theory using the SBKJ pseudopotentials and extended one-electron basis sets. For MF63-, M = Sc, Y, La, our results suggest a different assignment of vibrational transitions than those quoted by Nakamoto1 and recorded by von Becker et al.2 For the series of isoelectronic complexes, we document that the discrepancy between the theoretical gas phase vibrational frequencies and those measured in condensed phase experiments increases as the Becke3LYP HOMO binding energies become more positive. The frequencies of stretching modes measured in condensed phase experiments are systematically higher than those calculated for the gas phase anions. We suggest that a partial charge transfer from the multiply-charged anions to countercations is responsible for the stiffening of vibrational modes in condensed phase environments. The vertical electron detachment energies were determined at the outer valence Green's function, MP2, and B3LYP levels. The binding energies of hexafluorometallates with respect to the energies of atomic ions were also calculated and only a small contribution of the electron correlation effects was found.