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Titolo:
Time-resolved fluorescence studies of aminostyryl pyridinium dyes in organic solvents and surfactant solutions
Autore:
Mishra, A; Behera, GB; Krishna, MMG; Periasamy, N;
Indirizzi:
Tata Inst Fundamental Res, Dept Chem Sci, Bombay 400005, Maharashtra, India Tata Inst Fundamental Res Bombay Maharashtra India 400005 arashtra, India Sambalpur Univ, Dept Chem, Jyoti Vihar 768019, India Sambalpur Univ JyotiVihar India 768019 Chem, Jyoti Vihar 768019, India
Titolo Testata:
JOURNAL OF LUMINESCENCE
fascicolo: 3, volume: 92, anno: 2001,
pagine: 175 - 188
SICI:
0022-2313(200102)92:3<175:TFSOAP>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
RESONANCE RAMAN-SCATTERING; CIS-TRANS-ISOMERIZATION; CYANINE DYES; STILBAZOLIUM BETAINE; ALKYL CHAIN; PHOTOISOMERIZATION; IODIDE; SOLUBILIZATION; MECHANISM; POLARITY;
Keywords:
micelles; quinoid isomer; charge transfer state; dye-solvent complex; aggregates;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
42
Recensione:
Indirizzi per estratti:
Indirizzo: Periasamy, N Tata Inst Fundamental Res, Dept Chem Sci, Homi Bhabha Rd, Bombay 400005, Maharashtra, India Tata Inst Fundamental Res Homi Bhabha Rd Bombay Maharashtra India 400005
Citazione:
A. Mishra et al., "Time-resolved fluorescence studies of aminostyryl pyridinium dyes in organic solvents and surfactant solutions", J LUMINESC, 92(3), 2001, pp. 175-188

Abstract

Absorption, fluorescence emission spectra and fluorescence lifetimes of N-alkyl-4-(p-N,N-dimethyl aminostyryl) pyridinium dyes of varying lengths of alkyl chain have been measured in different organic solvents (protic, dipolar aprotic and aprotic) and in different surfactant solutions. The spectra for the dyes are similar in a single solvent but vary with solvent type. The Stokes shift for the dye does not vary with the solvent parameter as predicted by Lippert-Mataga equation. The fluorescence decay of the dyes shows two lifetimes in organic solvents except in a few solvents where a single or three lifetimes were obtained. The lifetime results are interpreted in terms of emission from cis and quinoid (or intramolecular charge transfer, ICT) forms of the dye in the excited state. The spectra and fluorescence lifetime results for the cis isomer (synthesized as a stable compound) in organic solvents confirmed the coexistence of multiple species. In surfactant solutions, the spectra and fluorescence lifetimes of the dyes depend upon thelength of the alkyl chain of the dye and the concentration of the surfactant, namely, premicellar or post micellar. Dye-surfactant complexes were identified in a few cases in SDS and CTAB premicellar solutions. TX-100 surfactant is found to stabilize the cis isomer for all the dyes, whereas both SDS and CTAB surfactants stabilize the trans isomer predominantly. (C) 2001 Elsevier Science B.V. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/09/20 alle ore 07:12:33