Inorganic analogues of cyclic organic molecules
Ab initio SCFMO calculations are given for inorganic systems related to the hydrocarbon rings C3H3 +, C3H6, C4H4, C4H8, and C6H6. The molecules studied belong to the same symmetry group and/or are isoelectric with the hydrocarbon rings, and include H3 +, H4, H6, N3 +, N4, N6, O3, O4, and several others. Preferred geometries and energies are reported for single-ζ and double-ζ basis sets. The relationship between the hydrocarbon rings and their inorganic analogues is shown. Although lone-pair repulsions destabilize the inorganic rings, their possible existence as molecules, intermediates, and transition states is discussed.