Hongwei Song, Zhuoran Kuang, Xian Wang
Jun 19, 2018
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0
Influential Citations
28
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Journal
The Journal of Physical Chemistry C
Abstract
The excited-state properties of 4-(dimethylamino)methoxychalcones (DEAMC) and its derivative 4-(dimethylamino)hydroxychalcones (DEAHC) were investigated in various solvents with different polarities by using steady-state and femtosecond transient absorption spectroscopy combined with quantum chemical calculations. It is found that their photophysical parameters such as fluorescence quantum yields, lifetimes, and excited-state relaxation paths strongly depend on the solvent polarity. Quantum-chemical calculations elucidate that the geometry of DEAMC in the ground state is slightly torsional whereas DEAHC adopts a near planar conformation stabilized by O–H···O chelated hydrogen bonds. Steady state spectra show that DEAHC is weak fluorescent in all solvents due to nonradiative relaxation in the excited enol and keto states, whereas the fluorescence quantum yield of DEAMC increases with the increasing of solvent polarities, and the emission yield is as large as 0.16 in acetonitrile. Femtosecond and nanosecond...