Fluorescence quenching of biologically active carboxamide by aniline and carbon tetrachloride in different solvents using Stern-Volmer plots

Patil, NR and Melavanki, RM and Kapatkar, SB and Chandrashekhar, K and Patil, HD and Umapathy, Siva (2011) Fluorescence quenching of biologically active carboxamide by aniline and carbon tetrachloride in different solvents using Stern-Volmer plots. In: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 79 (5). pp. 1985-1991.

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Abstract

Fluorescence quenching of biologically active carboxamide namely (E)-2-(4-chlorobenzylideneamino)-N-(2-chlorophenyl)-4,5,6,7-tetrahydrobe nzo[b]thiophene-3-carboxamide [ECNCTTC] by aniline and carbon tetrachloride (CCl(4)) quenchers in different solvents using steady state method and time resolved method using only one solvent has been carried out at room temperature to understand the role of quenching mechanisms. The Stern-Volmer plot has been found to be linear for all the solvents studied. The probability of quenching per encounter p (p') was determined in all the solvents and was found to be less than unity. Further, from the studies of rate parameters and life time measurements in n-heptane and cyclohexane with aniline and carbon tetrachloride as quenchers have been shown that, the phenomenon of quenching is generally governed by the well-known Stern-Volmer (S-V) plot. The activation energy E(a) (or E(a)') of quenching was determined using the literature values of activation energy of diffusion E(d) and the experimentally determined values of p (or p'). It has been found that, the activation energy E(a) (E(a)') is greater than the activation energy for diffusion E(d) in all solvents. Hence, from the magnitudes of E(a) (or E(a)') as well as p (or p') infer that, the quenching mechanism is not solely due to the material diffusion, but there is also contribution from the activation energy. (C) 2011 Elsevier B.V. All rights reserved.

Item Type:	Journal Article
Publication:	Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Fluorescence quenching; ECNCTTC; Steady state and time resolved method; S-V plot; Activation energy; Material diffusion
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	16 Sep 2011 07:06
Last Modified:	16 Sep 2011 07:06
URI:	http://eprints.iisc.ac.in/id/eprint/40437

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