Mannekutla J R, Mulimani B G, Inamdar S R
Laser Spectroscopy Programme, Department of Physics, Karnatak University, Dharwad 580003, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2008 Feb;69(2):419-26. doi: 10.1016/j.saa.2007.04.016. Epub 2007 Apr 24.
The effect of solvents on absorption and fluorescence spectra and dipole moments of coumarin 307 (C307) and coumarin 522B (C522B) have been studied extensively in various solvents, viz., general solvents, alcohols and binary mixtures (acetonitrile-benzene) at 298K. The bathchromic shift observed in absorption and fluorescence spectra of C307 and C522B with increasing solvent polarity indicates that transition involved are pi-->pi*. Solvatochromic correlations were used to obtain the ground and excited state dipole moments. The excited state dipole moments are observed to be greater than their ground state counterparts in all the solvents studied. Further, the experimentally obtained Deltamu were compared with those using normalized polarity terms E(T)(N) from Reichardt equation.
在298K下，已在各种溶剂中广泛研究了溶剂对香豆素307（C307）和香豆素522B（C522B）的吸收光谱、荧光光谱和偶极矩的影响，这些溶剂包括普通溶剂、醇类以及二元混合物（乙腈 - 苯）。随着溶剂极性增加，在C307和C522B的吸收光谱和荧光光谱中观察到的红移表明所涉及的跃迁是π→π*。利用溶剂化显色相关性获得基态和激发态偶极矩。在所研究的所有溶剂中，观察到激发态偶极矩大于其基态对应值。此外，将实验获得的Δμ与使用来自赖夏德特方程的归一化极性项E(T)(N)计算得到的结果进行了比较。
