Dergiler / Turkish Journal of Chemistry / 2005 / Cilt: 29 - Sayı: 6
Investigation of Electron Transfer Reaction Between Diphenylbenzidine and Ascorbic Acid
- Sayfa
- 627–634
- DOI
- —
Özet
The kinetics of the reduction of diphenylbenzidine by ascorbic acid were investigated in the pH range 3.5 to 5.0. Diphenylbenzidine was prepared by the oxidation of diphenylamine with cerium(IV) sulfate tetra hydrate. The order of the reaction with respect to each of the reactants, i.e ascorbic acid (ASC), diphenylbenzidine (DPB) and H+ ,was found to be first. The following rate law is recommended: Rate = {k1 [C12H10N2C12H10] + k2K [C12H10N2C12H10][H+]}[C6H8O6] where k1 and k2 have the values of 2.0 \times 104 dm3mol-1 s-1 and 6.58 \times 103 dm3.mol-1.s-1 , respectively. K is the protonation constant of DPB, having a value of 476 dm3 mol-1. A possible mechanism for the reaction is also proposed.
Abstract
The kinetics of the reduction of diphenylbenzidine by ascorbic acid were investigated in the pH range 3.5 to 5.0. Diphenylbenzidine was prepared by the oxidation of diphenylamine with cerium(IV) sulfate tetra hydrate. The order of the reaction with respect to each of the reactants, i.e ascorbic acid (ASC), diphenylbenzidine (DPB) and H+ ,was found to be first. The following rate law is recommended: Rate = {k1 [C12H10N2C12H10] + k2K [C12H10N2C12H10][H+]}[C6H8O6] where k1 and k2 have the values of 2.0 \times 104 dm3mol-1 s-1 and 6.58 \times 103 dm3.mol-1.s-1 , respectively. K is the protonation constant of DPB, having a value of 476 dm3 mol-1. A possible mechanism for the reaction is also proposed.