Evaluations of Molecular Structure and Aromaticity of C₅Ch₅ and C₆Ch₆ (Ch=S, Se, Te)

Abstract

The so-called oxocarbons, with cyclic polymer form of CO unit as (CO)_n, have attracted considerable interest for many years. However, pseudo-oxocarbons of chalcogen substitutions, (CCh)_n (Ch=S, Se, Te) have not yet been investigated by theoretical calculations in a systematic way. In this contribution, we report the DFT-based evaluations of molecular structures and NICS values for (CCh)₅ and (CCh)₆. It is shown that the planarity of molecules is enhanced for heavier chalcogens. Additionally, the NICS evaluation indicates that (CTe)₆ has an aromaticity comparable to that of benzene as a reference.