Cyclic Six-Atomic Boron-Nitrides: Quantum-Chemical Consideration by Ab Initio CCSD(T) Method

By means of the CCSD(T)/6-311++G(df,p) and G4 quantum-chemical calculation methods, the calculation of the molecular and electronic structures of boron–nitrogen compounds having the B3N3 composition was carried out and its results were discussed. It was noted that seven isomeric forms with different space structures can exist; wherein, the most stable form is a distorted flat hexagon with alternating B and N atoms, with both B and N atoms forming regular triangles, but with different side lengths. The values of geometric parameters of molecular structures in each of these compounds are presented. Also, the key thermodynamic parameters of formation (enthalpy ΔfH0, entropy S0, Gibbs’ energy ΔfG0) and relative total energies of these compounds are calculated.