ISSN:
0894-3230
Schlagwort(e):
diphenylmethanols
;
chloramine-B
;
oxidation
;
kinetics, HCl medium
;
ruthenium(III)
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
,
Physik
Notizen:
---The kinetics of oxidation of six para-substituted diphenylmethanols (Y-DPM, where Y=H, Cl, Br, NO2, CH3 and OCH3) by sodium N-chlorobenzenesulphonamide [chloramine-B (CAB)] in the presence of HCl and catalysed by RuCl3 in 30% (v/v) methanol medium was studied at 35 °C. The experimental rate law is rate=k′[CAB]0[DPM]x0[RuCl3]y[H+]z, where x, y and z are fractions. Addition of reaction product, benzenesulphonamide (BSA), retards the reaction. An increase in the dielectic constant of the medium decreases the rate. Rate studies in D2O medium showed that the solvent isotope effect k′(H2O)/k′(D2O)=0·53. Proton inventory studies were carried out using H2O-D2O mixtures. The rates correlate satisfactorily with the Hammett σ relationship and the plot is biphasic. The reaction constant ρ is -2·8 for electron-releasing groups and -0·31 for electron-withdrawing groups at 35 °C. The activation parameters ΔH
Zusätzliches Material:
5 Ill.
Materialart:
Digitale Medien
Permalink
