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Titolo:
Reactivities of D-mannitol and related alcohols toward chromium(VI) and chromium(IV)
Autore:
Perez-Benito, JF; Arias, C; Rodriguez, RM;
Indirizzi:
Univ Barcelona, Fac Quim, Dept Quim Fis, E-08028 Barcelona, Spain Univ Barcelona Barcelona Spain E-08028 uim Fis, E-08028 Barcelona, Spain
Titolo Testata:
JOURNAL OF PHYSICAL CHEMISTRY A
fascicolo: 7, volume: 105, anno: 2001,
pagine: 1150 - 1157
SICI:
1089-5639(20010222)105:7<1150:RODARA>2.0.ZU;2-6
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROGEN-PEROXIDE; AQUACHROMIUM(IV) ION; MECHANISM; OXIDATION; KINETICS; PERMANGANATE; ACID; MANGANESE(II); COMPENSATION; INTERMEDIATE;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
31
Recensione:
Indirizzi per estratti:
Indirizzo: Perez-Benito, JF Univ Barcelona, Fac Quim, Dept Quim Fis, Marti I Franques1, E-08028 Barcelona, Spain Univ Barcelona Marti I Franques 1 Barcelona Spain E-08028
Citazione:
J.F. Perez-Benito et al., "Reactivities of D-mannitol and related alcohols toward chromium(VI) and chromium(IV)", J PHYS CH A, 105(7), 2001, pp. 1150-1157

Abstract

The kinetics of the reactions between Cr(VI) and a homologous series of reductants, formed by CH3OH and polyalcohols of the type CH2OH(CHOH)(n-2)CH2OH with n = 2-6, have been studied in perchloric acid aqueous solutions. Therate law was: nu = k(4)[Cr(VI)][alcohol][H+](2). The activation parameterswere in the range DeltaH(not equal)degrees = 37.4-43.1 kJ mol(-1) and DeltaS(not equal)degrees: = (-168) - (-139) J K-1 mol(-1). The reactions were inhibited by the Cr(IV)-trapping agent Mn(II), and this effect was used to obtain the rate constants for the 2-electron reduction of the intermediate Cr(IV) by the alcohols (k(2) = 52.2-166 M-1 s(-1)). A mechanism is proposed according to which Cr(VI) is reduced by the alcohol of n carbon atoms through n(n + 1)/2 different reaction pathways involving chromate monoesters anddiesters as intermediates, whereas Cr(IV) is reduced through n reaction pathways by direct hydride-ion transfer.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 15:00:40