Structure, stability and aromaticity of bis-heteropentalenes

Abstract

The molecular and electronic structures of bis-heteropentalenes have been studied by density functional (DFT) calculations. The results show that the 3,2-b isomers are the most thermodynamically stable while 3,4-c isomers are the least stable. The thermodynamic stability is discussed within the framework of topological charge stabilization. The aromaticity follows a different trend from stability, with 3,4-c isomer being the most aromatic. © 1997 Elsevier Science B.V.