کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5400616 | 1505916 | 2013 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Picosecond spectral relaxation of curcumin excited state in toluene-alcohol mixtures
ترجمه فارسی عنوان
آرامش طیفی پیکوسوکند حالت مشتق شده کورکومین در مخلوط تولوئن و الکل
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کلمات کلیدی
کرکومین، پویایی حل، انتقال پروتون، تولوئن الکل مخلوط،
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
چکیده انگلیسی
Excited state photophysics of Curcumin in a binary solvent mixture of toluene and five different alcohols (Methanol, Ethanol, 1-Propanol, 1-Butanol and 1-Octanol) are compared with an instrument time resolution of ~40Â ps. As the alcohol mole-fraction is varied from zero to unity, the observed trends in the fluorescence quantum yield and lifetime of the pigment in toluene-alcohol mixtures changes significantly in going from Methanol to 1-Octanol. This is attributed to the different degree of modulation of the non-radiative rates associated with the excited state intermolecular H bonding between the pigment and the alcohol. Fluorescence decays taken at the red edge of the emission spectrum started to show measurable rise times (200-30Â ps) the magnitude of which decreased gradually with increasing alcohol mole-fraction. As a consequence the solvation times in the binary mixture were observed to slow down considerably at certain solvent compositions compared to that in neat alcohol. However, in toluene-1-Octanol mixture, the rise times and corresponding solvation times did not show a dependence on the 1-Octanol mole-fraction. The observed results suggest that viscosity, polarity and hydrogen bonding property of the alcohol solvent plays an important role in the excited state processes of the pigment in toluene-alcohol mixture.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Luminescence - Volume 144, December 2013, Pages 169-175
Journal: Journal of Luminescence - Volume 144, December 2013, Pages 169-175
نویسندگان
R.K. Saini, K. Das,