Effect of Substituents on the Equilibrium between Trans and Perpendicular Conformers in the Triplet Excited State of Substituted Styrylpyrenes

Abstract

In the equilibrium between trans (3t*) and perpendicular (3p*) conformers in the triplet excited state of 1-styrylpyrenes, substitution by electron-accepting groups at the para-position of styryl group more effectively stabilizes 3t* than 3p*, therefore affording very high composition of their trans isomers at the photostationary state.