Photophysical Properties of 7-(diethylamino)Coumarin-3-carboxylic Acid in the Nanocage of Cyclodextrins and in Different Solvents and Solvent Mixtures
Photophysical Properties of 7-(diethylamino)Coumarin-3-carboxylic Acid in the Nanocage of Cyclodextrins and in Different Solvents and Solvent Mixtures
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DOI：
10.1111/php.12000
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发表时间：
2013-03-01
影响因子：
3.3
通讯作者：
Seth, Debabrata
中科院分区：
文献类型：
--
作者：
Chatterjee, Aninda;Seth, Debabrata
通过稳态吸收、发射和时间分辨荧光光谱研究了 7-(二乙氨基)香豆素-3-羧酸 (7-DCCA) 在环糊精 (,,,,-CD)、不同纯溶剂和溶剂混合物中的光物理性质。我们观察到，随着-CD浓度的逐渐增加，荧光量子产率和寿命呈规律性下降，而随着-CD浓度的逐渐增加，荧光量子产率和寿命逐渐增加。随着尿素的添加，CDs 中 7-DCCA 的荧光量子产率和寿命增加。结合常数计算表明7-DDCA与-CD形成1:1复合物，并与-CD形成1:1和1:2（客体：主体）包合物。我们提出染料分子通过氢键与-CD形成封端络合物，加入尿素后氢键网络破裂，部分染料分子进入-CD的空腔内。在二恶烷-水混合物和乙二醇-乙腈混合物中研究了7-DCCA的光物理，以了解介质极性和粘度的影响。还在不同的纯溶剂中研究了 7-DCCA 的光物理学。研究发现7-DCCA的光物理取决于溶剂和溶剂混合物的结构特征。
The photophysical properties of 7-(diethylamino) coumarin-3-carboxylic acid (7-DCCA) were studied in cyclodextrins (, , ,-CDs), different neat solvents and solvent mixtures by using steady state absorption, emission and time-resolved fluorescence spectroscopy. We have observed that with gradual increase in concentration of -CD the fluorescence quantum yield and lifetime decreased in a regular pattern whereas with gradual increase in concentration of -CD the fluorescence quantum yield and lifetime gradually increased. With addition of urea, the fluorescence quantum yield and lifetime of 7-DCCA in CDs increased. Binding constant calculation shows that 7-DDCA forms 1:1 complex with -CD and with -CD it forms 1:1 and 1:2 (guest:host) inclusion complex. We proposed that the dye molecule formed capping complex with -CD by means of hydrogen bonding and after addition of urea the hydrogen bonding network broke down and part of dye molecule entered inside the cavity of -CD. The photophysics of 7-DCCA was studied in dioxane-water mixture and ethylene glycol-acetonitrile mixture to know the effect of polarity and viscosity of the media. The photophysics of 7-DCCA was also studied in different neat solvents. It was found that the photophysics of 7-DCCA depended on the structural feature of the solvents and solvent mixtures.