Binding of the metal ions Cr +, Mn 2+, and Fe 3+ to the second-row hydrides BeH 2, BH 3, NH 3, OH 2, FH, and their associated anions BeH −, BH 2−, NH 2−, OH −, F −: a computational study

Abstract

We report results from a computational study of the binding in complexes formed from one of the transition metal ions Cr +, Mn 2+, or Fe 3+, each of which has five valence electrons outside an Argon core, and one of the second-row hydrides (BeH 2, BH 3, NH 3, OH 2, FH) or their associated anions (BeH −, BH 2 −, NH 2 −, OH −, F −). The high-spin (sextuplet) form of each of these monoliganded complexes is found to be lowest in energy. The metal cation consistently behaves as a Lewis acid in both the high- and low-spin configurations of these complexes in that there is a net transfer of electron density from the ligand to the metal ion. The underlying mechanisms that result in this transfer of charge from different types of hydride and anion ligands to Cr +, Mn 2+, and Fe 3+ are discussed.