Non-ionic surfactant tritonX-100 act as an efficient catalyst for the oxidation of D-maltose by N-bromosuccinimide: A kinetic study

Abstract

Non-ionic micelle catalyzed oxidation of D-maltose by N-bromosuccinimide (NBS) was studied in acidic medium at 40oC. Under pseudo-first-order conditions the reaction rate is of first-, fractionaland negative fractional-order, respectively, in NBS, D-maltose and H2SO4. The determined stoichiometric ratio was 1:2 (D-maltose: NBS) and lactone was identified as the oxidized product of D-maltose. The catalytic role of non-ionic tritonX-100 (TX-100) micelle was best explained by the Berezin’s model. Variation of succinimide (NHS) showed that the rate of reaction decreased with increasing [NHS]. It was observed that, on increasing [mercuric acetate] there was no change in reaction velocity. The influence of salts on the reaction rate has also been studied. From the kinetic data, the rate constant (kw), binding constants (Ks+K0), and corresponding activation parameters have been evaluated. Based on the kinetic results and the product analysis, a suitable mechanism was proposed and rate law was derived as − d[NBS] dt = kK1K2[maltose][NBS]T [H][NHS]+K1[H]+K1K2[maltose] .