BSinGe4−n+ (n = 0−2): prospective systems containing planar tetracoordinate boron (ptB)

Abstract

The potential energy surface (PES) has been explored for BSinGe4−n+ (n = 0−2) systems using density functional theory (DFT). The global minima (1a, 1b, and 1c) of the considered systems contain a planar tetracoordinate boron (ptB) center. The neutral states of the systems do not have a ptB in the global minimum structures. The designed BGe4+, BSiGe3+, and BSi2Ge2+ systems have 18 valence electrons. The CCSD(T)/aug-cc-pVTZ level of theory has been applied to compute the relative energies of the low-lying isomers with respect to the global minima. The dynamical stability of BSinGe4−n+ (n = 0−2) systems is confirmed from the atom-centered density matrix propagation (ADMP) simulation over 20 ps of time at temperatures of 300 K and 500 K. The natural charge computations show that the charges on the ptB are highly negative, indicating strong σ-acceptance from the peripheral atoms. The 1a, 1b, and 1c structures of BGe4+, BSiGe3+, and BSi2Ge2+ systems, respectively, have σ/π-dual aromaticity as predicted from the nucleus-independent chemical shift (NICS) values.