Computational study of hybrid chalcogenoborate anions

Abstract

DFT and MP2 molecular orbital (MO) calculations were used to establish the structural and stability relationships for different members of chalcogenoborate anions within the following series: BSe x S 3 - x 3 - ( x = 0–3), B 2 Se x S 4 - x 2 - ( x = 0–4), B 2 Se x S 5 - x 2 - ( x = 0–5), and B 3 Se x S 6 - x 3 - ( x = 0–6). Full geometry optimization for each anion was performed at the PBE0 and MP2(full) levels of theory using the 6-311+G(2d) basis set. Molecular local minima for all species were confirmed by fundamental vibration calculations which have shown no imaginary vibrations. All anions adopt planar geometry. Clear similarity between the trends in different bond types and experimental results is observed. Relative stabilities of the anions have been calculated at the PBE0 and MP2 levels of theory and indicate that the stability of the anions within each series decreases with increasing selenium content. AIM and ELF analyses were used to probe the bonding in the B 2 E 5 2 - anions.