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Photophysical Properties of 7‐(diethylamino)Coumarin‐3‐carboxylic Acid in the Nanocage of Cyclodextrins and in Different Solvents and Solvent Mixtures
Author(s) -
Chatterjee Aninda,
Seth Debabrata
Publication year - 2012
Publication title -
photochemistry and photobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.818
H-Index - 131
eISSN - 1751-1097
pISSN - 0031-8655
DOI - 10.1111/php.12000
Subject(s) - solvent , coumarin , chemistry , carboxylic acid , photochemistry , nanocages , organic chemistry , catalysis
The photophysical properties of 7‐(diethylamino) coumarin‐3‐carboxylic acid (7‐ DCCA ) were studied in cyclodextrins (α , β , γ,‐ CD s), 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 β‐ CD the fluorescence quantum yield and lifetime decreased in a regular pattern whereas with gradual increase in concentration of γ‐ CD the fluorescence quantum yield and lifetime gradually increased. With addition of urea, the fluorescence quantum yield and lifetime of 7‐ DCCA in CD s increased. Binding constant calculation shows that 7‐ DDCA forms 1:1 complex with β‐ CD and with γ‐ CD it forms 1:1 and 1:2 (guest:host) inclusion complex. We proposed that the dye molecule formed capping complex with β‐ 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 β‐ 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.