Singly and doubly sulfone-inserted porphyrin arch-tape dimers

Abstract

A singly sulfone-inserted porphyrin arch-tape dimer was synthesized from 2-iodoporphyrin via stepwise transformations consisting of palladium-catalyzed cross-coupling reaction with bis(tributylstannyl) sulfide, tungsten-catalyzed oxidation with hydrogen peroxide, and oxidative fusion with AuCl3 and AgOTf. This new synthetic protocol enabled the synthesis of doubly sulfone-inserted arch-tape dimer as the first example of arch-tape dimer containing two neighboring seven-membered rings. These sulfone-inserted porphyrin arch-tape dimers were fully characterized by X-ray crystal structural analysis, NMR and UV/Vis/NIR absorption spectroscopies, cyclic voltammetry, and theoretical calculations. Furthermore, arch-to-arch inversion dynamics of arch-tape dimers were examined by subjecting newly synthesized mesityl-substituted porphyrin arch tapes to the variable temperature 1HNMR measurements.