Deactivation mechanism of the green fluorescent chromophore
Deactivation mechanism of the green fluorescent chromophore
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DOI：
10.1021/jp0540095
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发表时间：
2006-03-09
影响因子：
3.3
通讯作者：
Agmon, N
中科院分区：
文献类型：
--
作者：
Gepshtein, R;Huppert, D;Agmon, N
We report time-resolved fluorescence data for the anion of p-hydroxybenzylidene dimethylimidazolinone (p-HBDI), a model chromophore of the green fluorescence protein, in viscous glycerol-water mixtures over a range of temperatures, T. The markedly nonexponential decay of the excited electronic state is interpreted with the aid of an inhomogeneous model possessing a Gaussian coordinate-dependent sink term. A nonlinear least-squares fitting routine enables us to achieve quantitative fits by adjusting a single activation parameter, which is found to depend linearly on 1/T. We derive an analytic expression for the absolute quantum yield, which is compared with the integrated steady-state fluorescence spectra. The microscopic origins of the model are discussed in terms of two-dimensional dynamics, coupling the phenyl-ring rotation to a swinging mode that brings this flexible molecule to the proximity of a conical intersection on its multidimensional potential energy surface.
