Influence of sodium dodecyl sulfate/TritonX-100 micelles on the oxidation of D-fructose by chromic acid in presence of HClO(4).
The kinetics of oxidation of D-fructose by chromic acid in aqueous and aqueous surfactant (sodium dodecyl sulfate, SDS, and alkylphenyl polyethylenglykol, TX-100) media have been investigated in the presence of HClO(4). The reaction is acid catalyzed and is associated with an induction period which is dependent on [H(+)], [surfactant] and temperature. The order of oxidation during induction under [D-fructose]>[chromic acid] conditions is fractional in each reagent in both media. The rate constant was found to increase with [Mn(II)]. A mechanism has been proposed for the reaction. The micelles produce a catalytic effect in the range of SDS and TX-100 concentrations used, and the effect is explained by means of the pseudo-phase mass-action model. In the presence of SDS, the reaction is inhibited by electrolytes (NH(4)Br, NaBr, LiBr), and the inhibition order Na(+)>Li(+)>NH(4)(+) is explained on the basis of electrostatic considerations. The rate constant (k(m)), binding constants (K(S) and K(F)), and corresponding activation parameters (E(a), delta H( not equal ) and delta S( not equal )) have been evaluated and discussed. The order of reactivities of different sugars is found as: D-fructose>D-arabinose>D-xylose approximately D-glucose.
D002840:Chromates / Q000737:chemistry*; D005632:Fructose / Q000737:chemistry*; D007700:Kinetics; D008823:Micelles; D015394:Molecular Structure; D017830:Octoxynol / Q000737:chemistry*; D010084:Oxidation-Reduction; D012492:Salts / Q000494:pharmacology; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry; D013696:Temperature
D002840:Chromates; D008823:Micelles; D012492:Salts; D013501:Surface-Active Agents; D005632:Fructose; D012967:Sodium Dodecyl Sulfate; D017830:Octoxynol; C034944:chromic acid