Temperature-dependent time-resolved fluorescence study of cinchonine alkaloid dication

Hirdyesh, Mishra and Sanjay, Pant and Tripathi, Hera B (2008) Temperature-dependent time-resolved fluorescence study of cinchonine alkaloid dication. In: Journal of Fluorescence, 18 (1). pp. 17-27.

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Abstract

Photo induced excited state dynamical processes of cinchonine alkaloid dication $(C^+^+)$ have been studied over a wide range of temperature using steady state and nanosecond time-resolved fluorescence spectroscopic techniques. The temperature-dependent fluorescence studies of $C^+^+$ clearly indicate the existence of two distinct emitting species having their own characteristic decay rates. The shorter-lived species shows a usual temperature dependence with increasing non-radiative deactivation at higher temperatures, while the longer-lived species show features resembling to the excited state solvent relaxation process with a large solvent relaxation time $(\tau_r \sim 6 ns)$. The species emitting in the lower energy side, having longer decay time is found to be more sensitive towards chloride ion quenching and has a charge transfer character. Further, concentration quenching with decrease in $\tau_r$ of long lived species shows the possibility of energy migration along with solvent relaxation in $C^+^+$.

Item Type:	Journal Article
Publication:	Journal of Fluorescence
Publisher:	Springer Netherlands
Additional Information:	This article copyright belongs to Springer Netherlands
Keywords:	Cinchonine; Solvent relaxation; Fluorescence quenching
Department/Centre:	Division of Biological Sciences > Molecular Biophysics Unit
Date Deposited:	25 Feb 2008
Last Modified:	19 Sep 2010 04:42
URI:	http://eprints.iisc.ac.in/id/eprint/13084

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