Cyclobis[2,5-(thiophenedimethane)-4,4′-(triphenylamine)] versus Its S,S-Dioxidized Macrocycle: Global Antiaromaticity and Intramolecular Dynamics

Abstract

Fully conjugated macrocycles containing benzenoid rings rarely show global aromaticity/antiaromaticity. Herein, we report an annulene-like macrocycle CBTT and its S,S-dioxidized macrocycle DOCBTT with alternative quinoidal thiophene/1,1-dioxide thiophene and triphenyl amine moieties. They both showed temperature-dependent intramolecular dynamics and global antiaromatic character with 32π electrons at low temperature. However, CBTT and DOCBTT have different conjugated pathways.

Disruption of Antiaromaticity in Structurally Related Expanded Porphyrin-like Macrocycles with Benzene Linkers

“…Various spectral and theoretical studies suggest intramolecular conformational dynamics for these systems with 32π antiaromatic character. Despite their similarities, these macrocycles differ in macrocyclic conjugation pathways . Setsune and co-workers disclosed a C 3 symmetric nonaphyrin F comprising 1,4-phenylene linkers along with its planar trinuclear rhodium complex exhibiting nonaromaticity .…”

“…Despite their similarities, these macrocycles differ in macrocyclic conjugation pathways. 15 Setsune and co-workers disclosed a C 3 symmetric nonaphyrin F comprising 1,4-phenylene linkers along with its planar trinuclear rhodium complex exhibiting nonaromaticity. 16 In general, expanded porphyrins are exceptional candidates due to their conformational diversity and switchable aromaticity.…”