화학공학소재연구정보센터
Chemical Physics Letters, Vol.664, 56-62, 2016
Excited-state symmetry breaking of linear quadrupolar chromophores: A transient absorption study
The photophysical properties of two highly symmetrical quadrupolar chromophores were studied by both steady-state and transient absorption spectroscopy. Their excited-state behavior is dominated by the solvent-induced Stokes shift of the stimulated-emission band. The origin of this shift is attributed to symmetry breaking that confers a non-vanishing dipole moment to the excited state of both compounds. This dipole moment is large and constant in DMSO, whereas symmetry breaking appears significantly slower and leading to smaller excited-state dipole in toluene. Time-dependant increase of the excited-state dipole moment induced by weak solvation is proposed to explain the results in toluene. (C) 2016 Elsevier B.V. All rights reserved.