Structure, stability, and aromaticity of 2,4,6,1,3, 5-trisilatriphosphabenzene versus 2,4,6-trisilatriazine: A quantum chemical approach

摘要

Quantum chemical calculations were carried out at the M062X, B3LYP, and CCSD methods in order to examine the relative energies of 2,4,6,1,3,5-trisilatriphosphabenzene (2) and 2,4,6-trisilatriazine (1) compared to their isomer (mono, di and tri)silylenes. The relative energies of isomer silylenes are higher than the parent compound 2,4,6,1,3,5-trisilatriphosphabenzene (2). On the other hand, 2,4,6-trisilatriazine (1) is a higher energy compound than its silylene isomers. Both compounds 1 and 2 are aromatic that is supported by calculated geometries, nucleus-independent chemical shifts (NICS), para-delocalization indices (PDIs), resonance and isodesmic/homodesmic stabilization energies (RSEs and ISEs/HSEs, respectively). Both NICS(1) and PDIs predict that silylene isomers of 2 (except disilylene) are fairly aromatic and (all three) silylene isomers of 1 are marginally aromatic. (C) 2015 Elsevier B.V. All rights reserved.