Solvent dependent photophysical properties of dimethoxy curcumin
Solvent dependent photophysical properties of dimethoxy curcumin
复制标题
DOI：
10.1016/j.saa.2012.12.036
复制
发表时间：
2013-03-15
影响因子：
4.4
通讯作者：
Priyadarsini, K. Indira
中科院分区：
文献类型：
--
作者：
Barik, Atanu;Priyadarsini, K. Indira
二甲氧基姜黄素（DMC）是姜黄素的甲基化衍生物。为了了解环上取代对姜黄素物理性质的影响，在不同极性的有机溶剂中记录了DMC的稳态吸收光谱和荧光光谱，并与姜黄素的光谱进行了比较。与姜黄素一样，DMC的吸收光谱和荧光光谱都强烈依赖于溶剂极性，随着溶剂极性函数（Δ f）的增大，DMC的最大吸收峰位置发生红移，但在荧光峰位置上，上述效应更为明显。由斯托克斯位移对溶剂极性函数的依赖关系，估算出激发态和基态偶极矩之差为4.9D。在室温下，测定了DMC在不同溶剂中的荧光量子产率（phi（f））和荧光寿命（tau（f））。结果表明，随着溶剂极性的增加，phi（f）呈线性增加，这是由于系间交叉（ISC）过程导致的无辐射速率下降的原因。(C)2012 Elsevier B.V.保留所有权利。
Dimethoxy curcumin (DMC) is a methylated derivative of curcumin. In order to know the effect of ring substitution on photophysical properties of curcumin, steady state absorption and fluorescence spectra of DMC were recorded in organic solvents with different polarity and compared with those of curcumin. The absorption and fluorescence spectra of DMC, like curcumin, are strongly dependent on solvent polarity and the maxima of DMC showed red shift with increase in solvent polarity function (Delta f), but the above effect is prominently observed in case of fluorescence maxima. From the dependence of Stokes' shift on solvent polarity function the difference between the excited state and ground state dipole moment was estimated as 4.9 D. Fluorescence quantum yield (phi(f)) and fluorescence lifetime (tau(f)) of DMC were also measured in different solvents at room temperature. The results indicated that with increasing solvent polarity, phi(f) increased linearly, which has been accounted for the decrease in non-radiative rate by intersystem crossing (ISC) processes. (C) 2012 Elsevier B.V. All rights reserved.