Handed Mirror Symmetry Breaking at the Photo-Excited State of π-Conjugated Rotamers in Solutions

Abstract

The quest to decode the evolution of homochirality of life on earth has stimulated research at the molecular level. In this study, handed mirror symmetry breaking, and molecular parity violation hypotheses of systematically designed π-conjugated rotamers possessing anthracene and bianthracene core were evinced via circularly polarized luminescence (CPL) and circular dichroism (CD). The CPL signals were found to exhibit a (−)-sign, and a handed dissymmetry ratio, which increased with viscosity of achiral solvents depending on the rotation barrier of rotamers. The time-resolved photoluminescence spectroscopy and quantum efficiency measurement of these luminophores in selected solvents reinforced the hypothesis of a viscosity-induced consistent increase of the (−)-sign handed CPL signals.