Premium
A Study of Excitation Delocalization/Localization in Multibranched Chromophores by Using Fluorescence Excitation Anisotropy Spectroscopy
Author(s) -
Li Yang,
He Guiying,
Wang Xian,
Guo Qianjin,
Niu Yingli,
Xia Andong
Publication year - 2016
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201501001
Subject(s) - delocalized electron , chromophore , excitation , excited state , anisotropy , chemistry , spectroscopy , fluorescence anisotropy , molecular physics , fluorescence , dimer , atomic physics , photochemistry , physics , optics , organic chemistry , quantum mechanics
We describe a simple approach to study the excitation localization/delocalization in multibranched chromophores by using fluorescence excitation anisotropy spectroscopy at room temperature. As examples, the electronic excitations in three different multibranched chromophores (dimers) are investigated. For a weakly coupled dimer, fluorescence anisotropy is independent of excitation wavelength, due to localized excitation as well as the degenerate electronic excited states. In contrast, in the case of a strongly coupled dimer, owing to excitonic splitting, a redistribution of the excitation energy is demonstrated by the dependence of anisotropy spectra on the excitation wavelength, which leads to significant deviation from the anisotropy signal of localized excitation. In particular, based on the law of additivity for anisotropy, the degree of delocalized excitation can be simply estimated for a given dimer.