D. Guha et al., Luminol fluorescence quenching by triethyl amine and non-linear Stern-Volmer plot: Solvent effect, I J CHEM A, 38(8), 1999, pp. 760-767
Citations number
37
Categorie Soggetti
Chemistry
Journal title
INDIAN JOURNAL OF CHEMISTRY SECTION A-INORGANIC BIO-INORGANIC PHYSICAL THEORETICAL & ANALYTICAL CHEMISTRY
The interaction of 3-aminophthalhydrazide (luminol) with a quencher, trieth
yl amine (TEA) has been studied employing steady-state and nanosecond time
resolved emission spectroscopy. The bimolecular rate constant for fluoresce
nce quenching in water is found to be about two orders of magnitude higher
than that obtained in 1,4-dioxane (DIO). The Stern-Volmer (S-V) plot for fl
uorescence quenching exhibits positive deviation from linearity when water
is used as solvent. On the other hand, the S-V plot shows negative deviatio
n from linearity when DIO is used as a solvent. The rate constants obtained
in ethanol, dimethyl sulphoxide (DMSO) and DIO are found to be similar to
the rate constant for diffusional process. The possible interpretation of t
he quenching mechanism and nature of deviation from S-V plots have been dis
cussed in relation to the strength of interaction between the colliding spe
cies. It is shown that the rate of luminol fluorescence quenching is depend
ent on the nature of the solvent, being particularly fast in aqueous medium
.