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Title: Association of nitrophenols to sodium dodecylsulfate micelles

The luminescence quenching of tris(2,2{prime}-bipyridine)ruthenium(II) Ru(bpy){sub 3}{sup 2+} by 2-, 3-, and 4-nitrophenol (NO{sub 2}PhOH), in their protonated forms, has been studied by static and time-resolved techniques in water and sodium dodecyl sulfate (SDS) aqueous solution. In water, the biomolecular rate constants were obtained separately from both techniques and they were coincident. The values were close to the diffusional limit. In the presence of SDS micelles at a fixed detergent concentration, the Stern-Volmer plots of {tau}{sup 0}/{tau} vs quencher total concentration ([Q]{sub t}) were linear in the whole range of [Q]{sub t} used. However, the Stern-Volmer plots of the ratio I{sup 0}/I vs [Q]{sub t} in SDS micelles showed an upward deviating curve. From these plots of I{sup 0}/I, the concentrations of the NO{sub 2}PhOHs in the micellar pseudophase were measured. The treatment of the data of both types of measurements let the authors determine the association constants (K) of the NO{sub 2}PhOHs to SDS micelles and the exit (k{sub {minus}}) and entrance (k{sub +}) rate constants of NO{sub 2}PhOHs to the micelles. The K values obtained from either static or time-resolved luminescence techniques were in agreement within experimental error. An electron-transfer mechanism was also proposed for the quenching reactionmore » of the excited state Ru(bpy){sub 3}{sup 2+} by nitrophenols in which the metallic complex is oxidized.« less
Authors:
;  [1]
  1. Univ. Nacional de Rio Cuarto (Argentina)
Publication Date:
OSTI Identifier:
596996
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Colloid and Interface Science; Journal Volume: 195; Journal Issue: 1; Other Information: PBD: 1 Nov 1997
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; WATER TREATMENT; NITROPHENOL; WASTE WATER; SURFACTANTS; MICELLAR SYSTEMS; ELECTRON TRANSFER; RUTHENIUM COMPLEXES; SOLUBILITY