A study on the aromaticity and main conjugation pathways of triphyrin(2.1.1) and its heteroanalogues

Abstract

The Topological Resonance Energy method was used to investigate the aromaticity of triphyrin(2.1.1) and its heteroanalogues. The calculations from indices of local aromaticity, such as Bond Resonance Energy (BRE) and Circuit Resonance Energy (CRE), enabled us to identify the origins of the aromaticity as well as the main conjugation pathways. The BRE and CRE results revealed that the macrocyclic delocalization pathways corresponding to the 14π-electron aromatic systems are not major contributors to global aromaticity. Instead, the five-membered rings show themselves to be the main contributors to the aromaticity of these molecules.