Effect of solvent polarity on the fluorescence quenching of TMC molecule by aniline in benzene–acetonitrile mixtures

2016 ◽  
Vol 94 (11) ◽  
pp. 1125-1132 ◽  
Author(s):  
Ashok H. Sidarai ◽  
Vani R. Desai ◽  
Shirajahammad M. Hunagund ◽  
Mahantesha Basanagouda ◽  
Jagadish S. Kadadevarmath
Keyword(s):  
Fluorescence Quenching ◽  
Rate Constants ◽  
Transient State ◽  
Solvent Polarity ◽  
Coumarin Derivative ◽  
Solvent Mixtures ◽  
Positive Deviation ◽  
Diffusion Limited ◽  
Quenching Process ◽  
Volmer Plot

The fluorescence quenching of coumarin derivative, 6-methoxy-4-p-tolyloxymethyl-chromen-2-one by aniline is carried out in different solvent mixtures of benzene and acetonitrile at room temperature. The quenching is found to be appreciable and a positive deviation from linearity is observed in the Stern–Volmer plot in all the solvent mixtures. Various rate constants for fluorescence quenching processes have been estimated using a sphere of action static quenching model and a finite sink approximation model. From the positive deviation of linear Stern–Volmer plots and dependence of rate constants on the polarity of the solvents, it has been inferred that the quenching process is diffusion-limited, and static as well as dynamic quenching processes are responsible for the observed positive deviation in the Stern–Volmer plot. Further, both models have been found to agree well with transient state also in pure acetonitrile and benzene solvents.

Role of solvent polarity on fluorescence quenching of 3MOCE in binary solvent mixtures

2020 ◽  
Author(s):  
S. Vaijayanthimala ◽  
Kalpana Sharma ◽  
Raveendra Melavanki ◽  
P. Bhavya ◽  
U. Meghana ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Solvent Polarity ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures ◽  
Role Of Solvent

scholarly journals Fluorescence Quenching of DMB by Aniline in Benzene-Acetonitrile Mixture

2016 ◽  
Vol 65 ◽  
pp. 32-36 ◽  
Author(s):  
Ashok H. Sidarai ◽  
Vani R. Desai ◽  
Shirajahammad M. Hunagund ◽  
Mahantesha Basanagouda ◽  
Jagadish S. Kadadevarmath
Keyword(s):  
Fluorescence Quenching ◽  
Room Temperature ◽  
Solvent Mixture ◽  
Static Quenching ◽  
Solvent Mixtures ◽  
Dynamic Quenching ◽  
Approximation Model ◽  
Positive Deviation ◽  
Coumarin Dye ◽  
Static And Dynamic Quenching

The fluorescence quenching of coumarin dye namely 4-(2,6-dibromo-4-methyl-phenoxymethyl)-benzo[h]chromen-2-one [DMB] has been studied by aniline, in a different solvent mixture of benzene (BN) and acetonitrile (AN) at room temperature. The quenching is found to be appreciable and shows positive deviation from linearity in the Stern-Volmer (S-V) plots for all the solvent mixtures. The various rate parameters responsible for fluorescence quenching have been determined using a sphere of action static quenching model and finite sink approximation model. The magnitudes of these rate parameters indicate that positive deviation in the S-V plot is due to both static and dynamic quenching processes.

Effect of fluorescence quenching on 6BAAC in different solvents

2014 ◽  
Vol 92 (1) ◽  
pp. 41-45 ◽  
Author(s):  
N.R. Patil ◽  
R.M. Melavanki
Keyword(s):  
Fluorescence Quenching ◽  
Empirical Relation ◽  
Static Quenching ◽  
Einstein Relation ◽  
Positive Deviation ◽  
Quenching Rate ◽  
R And D ◽  
Diffusion Limited ◽  
Quenching Mechanisms ◽  
Static And Dynamic Quenching

The fluorescence quenching studies of 6-bromo-3-azidoacetyl coumarin (6BAAC) by aniline in four different solvents, namely acetonitrile, benzene, dioxane, and toluene, were carried out at room temperature to understand quenching mechanisms. The Stern–Volmer plots have been found to be nonlinear with a positive deviation for all the solvents studied. To interpret these results we have invoked the ground state complex formation and sphere of action static quenching models. Using these models various quenching rate parameters have been determined. The magnitudes of these parameters suggest that the sphere of action static quenching model agrees well with the experimental results. Hence the positive deviation is attributed to the static and dynamic quenching. Further, with the use of the finite sink approximation model, it was possible to check these bimolecular reactions as diffusion-limited and to estimate independently distance parameter R′ and mutual diffusion coefficient D. Finally an effort has been made to correlate the values of R′ and D with the values of the encounter distance R and the mutual coefficient D determined using Edward’s empirical relation and the Stokes–Einstein relation.

Influence of silver nanoparticles on absorption and fluorescence properties of laser dyes

2014 ◽  
Vol 92 (2) ◽  
pp. 163-167 ◽  
Author(s):  
H.R. Deepa ◽  
H.M. Suresh Kumar ◽  
M. Basanagouda ◽  
J. Thipperudrappa
Keyword(s):  
Silver Nanoparticles ◽  
Fluorescence Quenching ◽  
Room Temperature ◽  
Chemical Reduction ◽  
Mie Theory ◽  
Laser Dyes ◽  
Dynamic Quenching ◽  
Positive Deviation ◽  
Absorption And Fluorescence Spectroscopy ◽  
Quenching Process

The interaction of silver nanoparticles with four laser dyes, namely, LD-425, LD-489, LD-473, and LD-423, dispersed in methanol has been studied at room temperature by absorption and fluorescence spectroscopy. The silver nanoparticles were synthesized by chemical reduction and estimated size is 11 nm according to Mie theory. The changes in absorption spectrum of these dyes with the addition of silver nanoparticles suggest possible interaction with the silver nanoparticles. The magnitudes of the association constants are estimated using the Benesi–Hildebrand model. Fluorescence quenching has been observed for all the dyes with the addition of silver nanoparticles of different concentrations. The Stern–Volmer plots of fluorescence quenching in the case of LD-425 and LD-489 are found to be linear, suggesting the fluorescence quenching is because of the dynamic quenching process. But in the case of LD-473 and LD-423, the Stern–Volmer plots are nonlinear showing positive deviation and the fluorescence quenching in these dyes is because of static quenching processes. Also, it is found that the fluorescence quenching is not solely due to diffusion.

scholarly journals Solvent Effect on Fluorescence Quenching of 7, 8 Benzo‑4‑azido Methyl Coumarin by Aniline

2013 ◽  
Vol 12 (1) ◽  
pp. 69-85 ◽  
Author(s):  
R M Melavanki ◽  
N R Patil ◽  
D Nagaraja ◽  
H D Patil ◽  
J S Kadadevarmath ◽  
...  
Keyword(s):  
Fluorescence Quenching ◽  
Empirical Relation ◽  
Biologically Active ◽  
Static Quenching ◽  
Einstein Relation ◽  
Positive Deviation ◽  
Quenching Rate ◽  
R And D ◽  
Diffusion Limited ◽  
Static And Dynamic Quenching

Fluorescence quenching of biologically active studies of 7, 8 benzo-4-azidomethyl coumarin (7BAMC) by aniline in four different organic solvents namely benzene, dioxane, tetrahydrofuran and acetonitrile has been carried out at room temperature with a view to understand the quenching mechanisms. The Stern–Volmer (S-V) plot has been found to be non-linear with a positive deviation for all the solvents studied. In order to interpret these results we have invoked the ground state complex formation and sphere of action static quenching models. Using these models various quenching rate parameters have been determined. The magnitudes of these parameters suggest that sphere of action static quenching model agrees well with the experimental results. Hence the positive deviation is attributed to the static and dynamic quenching. Further, with the use of Finite Sink approximation model, it was possible to check these bimolecular reactions as diffusion-limited and to estimate independently distance parameter R’ and mutual diffusion coefficient D. Finally an effort has been made to correlate the values of R’ and D with the values of the encounter distance R and the mutual coefficient D determined using the Edward’s empirical relation and Stokes – Einstein relation.

scholarly journals Analysis of Fluorescence Quenching of BPBD by Aniline in Toluene

2013 ◽  
Vol 12 (1) ◽  
pp. 87-98
Author(s):  
J Thipperudrappa ◽  
S M Hanagodimath
Keyword(s):  
Steady State ◽  
Fluorescence Quenching ◽  
Room Temperature ◽  
Static Quenching ◽  
Approximation Model ◽  
Positive Deviation ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Steady State Method ◽  
Volmer Plot

Fluorescence quenching of 2-(4'-t-Butylphenyl)-5-(4"-biphenylyl)-1,3,4-oxadiazole (BPBD) by aniline in toluene has been carried out at room temperature by steady state and time resolved fluorescence spectroscopy. The Stern-Volmer plot by steady state method has been found to be non-linear showing a positive deviation, whereas by time-resolved method it is linear. In order to interpret these results we have used the ground state complex and sphere of action static quenching models. Using these models various rate parameters have been determined. Based on these models, with finite sink approximation model, we conclude that positive deviation Stern-Volmer plot is due to the simultaneous presence of dynamic and static quenching processes.

scholarly journals Fluorescence Quenching Studies on the Interactions between Chosen Fluoroquinolones and Selected Stable TEMPO and PROXYL Nitroxides

2021 ◽  
Vol 22 (2) ◽  
pp. 885
Author(s):  
Krzysztof Żamojć ◽  
Irena Bylińska ◽  
Wiesław Wiczk ◽  
Lech Chmurzyński
Keyword(s):  
Fluorescence Quenching ◽  
Rate Constants ◽  
Quenching Rate ◽  
Time Resolved ◽  
Radiative Processes ◽  
Diffusion Limited ◽  
Fluoroquinolone Antibiotics ◽  
Quenching Efficiency ◽  
Bimolecular Quenching ◽  
The Impact

The influence of the stable 2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO) nitroxide and its six C4-substituted derivatives, as well as two C3-substituted analogues of 2,2,5,5-tetramethylpyrrolidynyl-N-oxyl (PROXYL) nitroxide on the chosen fluoroquinolone antibiotics (marbofloxacin, ciprofloxacin, danofloxacin, norfloxacin, enrofloxacin, levofloxacin and ofloxacin), has been examined in aqueous solutions by UV absorption as well as steady-state and time-resolved fluorescence spectroscopies. The mechanism of fluorescence quenching has been specified and proved to be purely dynamic (collisional) for all the studied systems, which was additionally confirmed by temperature dependence experiments. Moreover, the selected quenching parameters—that is, Stern–Volmer quenching constants and bimolecular quenching rate constants—have been determined and explained. The possibility of electron transfer was ruled out, and the quenching was found to be diffusion-limited, being a result of the increase in non-radiative processes. Furthermore, as the chosen nitroxides affected the fluorescence of fluoroquinolone antibiotics in different ways, an influence of the structure and the type of substituents in the molecules of both fluoroquinolones and stable radicals on the quenching efficiency has been determined and discussed. Finally, the impact of the solvent’s polarity on the values of bimolecular quenching rate constants has been explained. The significance of the project comes from many applications of nitroxides in chemistry, biology and industry.

Effect of Solvent Polarity on the Fluorescence Quenching of Biologically Active 5BAMC by Aniline in Binary Solvent Mixtures

2010 ◽  
Vol 20 (6) ◽  
pp. 1175-1180 ◽  
Author(s):  
Raveendra M. Melavanki ◽  
Raviraj A. Kusanur ◽  
Jagadish S. Kadadevaramath ◽  
Manohar V. Kulkarni
Keyword(s):  
Fluorescence Quenching ◽  
Solvent Polarity ◽  
Biologically Active ◽  
Binary Solvent ◽  
Solvent Mixtures ◽  
Binary Solvent Mixtures ◽  
Effect Of Solvent
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