Electronic Structure and Spectroscopic Properties of Group-7 Tri-Oxo-Halides MOX (M = Mn-Bh, X = F-Ts).

The 24 trioxide halide molecules MOX of the manganese group (M = Mn-Bh; X = F-Ts), which are iso-valence-electronic with the famous MnO ion, have been quantum-chemically investigated by quasi-relativistic density-functional and ab initio correlated approaches. Geometric and electronic structures, valence and oxidation numbers, vibrational and electronic spectral properties, energetic stabilities of the monomers in the gas phase, and the decay mode of MnOF have been investigated. The light Mn-3d species are most strongly electron-correlated, indicating that the concept of a closed-shell Lewis-type single-configurational structure [Mn(d) O(p) F(p)] reaches its limits. The concept of real-valued spin orbitals φ(r)·α and φ(r)·β breaks down for the heavy Bh-6d, At-6p and Ts-7p elements because of the dominating spin-orbit coupling. The vigorous decomposition of MnOF at ambient conditions starts by the autocatalyzed release of O and the formation of MnOF clusters, triggered by the electron-depleted "oxylic" character of the oxide ligands in MnOX.