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Titolo:
ROTATIONAL-DYNAMICS OF NEUTRAL RED - DO IONIC AND NEUTRAL SOLUTES EXPERIENCE THE SAME FRICTION
Autore:
DUTT GB; SINGH MK; SAPRE AV;
Indirizzi:
BHABHA ATOM RES CTR,DIV CHEM BOMBAY 400085 MAHARASHTRA INDIA BHABHA ATOM RES CTR,DIV SPECT BOMBAY 400085 MAHARASHTRA INDIA
Titolo Testata:
The Journal of chemical physics
fascicolo: 14, volume: 109, anno: 1998,
pagine: 5994 - 6003
SICI:
0021-9606(1998)109:14<5994:RONR-D>2.0.ZU;2-H
Fonte:
ISI
Lingua:
ENG
Soggetto:
MOLECULAR-REORIENTATION DYNAMICS; TRANSIENT-DICHROISM EXPERIMENTS; POLAR DYE PROBES; DIELECTRIC FRICTION; FLUORESCENCE ANISOTROPY; ELECTROLYTE-SOLUTIONS; BOUNDARY-CONDITION; MICROSCOPIC FRICTION; CHEMICAL MOLECULES; CONTINUUM MODELS;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
87
Recensione:
Indirizzi per estratti:
Citazione:
G.B. Dutt et al., "ROTATIONAL-DYNAMICS OF NEUTRAL RED - DO IONIC AND NEUTRAL SOLUTES EXPERIENCE THE SAME FRICTION", The Journal of chemical physics, 109(14), 1998, pp. 5994-6003

Abstract

The rotational dynamics of neutral and cationic forms of the phenazine dye neutral red has been studied in rr-alcohols, amides, and aproticsolvents using picosecond time-resolved fluorescence depolarization spectroscopy. While both the neutral and cationic forms of neutral red experienced more or less the same friction in alcohols, the cationic form experienced 16%-26% more friction in amides and aprotic solvents exceptions being formamide and propylene carbonate (PC). The results were analyzed in terms of the Stokes-Einstein-Debye (SED) hydrodynamic cheery and dielectric friction theories of Nee-Zwanzig and van der Zwan-Hynes. Both the Nee-Zwanzig and van der Zwan-Hynes dielectric friction theories overestimate the dielectric friction contribution for the neutral form of neutral red in alcohols. The rotational dynamics of neutral form of neutral red in N, N-dimethyl formamide (DMF), N, N-dimethyl acetamide (DMA), N, lr-dimethyl propionamide (DMP), and dimethyl sulphoxide (DMSO) is adequately described by the hydrodynamic model withthe stick boundary condition, However, it overestimates the friction experienced in formamide, and to a certain extent in PC wherein for both forms similar reorientation times were observed. As the cations arestrongly solvated by amides only 60%-70% of the friction experienced in DMF;, DMA, and DMP can be accounted for by the SED theory. (C) 1998American Institute of Physics. [S0021-9606(98)52038-7].

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 14/07/20 alle ore 05:54:46