摘要
The kinetics of micellar-catalyzed oxidation of mannose by N-bromophthalimide was studied in the presence of sulfuric acid at 313 K. The orders of reaction with respect to [mannose], [oxidant], and [H+] were found to be fractional, first, and negative fractional order, respectively. Anionic micelles of sodium dodecyl sulfate showed a partial inhibitory effect, while cationic micelles of cetyltrimethylammonium bromide increased the reaction rate with the same kinetic behavior. The reaction was catalyzed by cationic micelles, because of favorable electrostatic/thermodynamic/ hydrophobic/hydrogen bonding between reactants and cationic micelles. Their catalytic roles are best explained by Berezin′s model. A variation of [phthalimide] showed that the rate of reaction decreased with increasing [phthalimide]. It was observed that, an increase of [mercuric acetate] had no effect on reaction velocity. The influence of salts on the reaction rate was also studied. The rate constant (kW), binding constants (KS+KO), and corresponding activation parameters (Ea, △H#, △S#, and △G#) were determined. A detailed mechanism with associated reaction kinetics is presented and discussed.
The kinetics of micellar-catalyzed oxidation of mannose by N-bromophthalimide was studied in the presence of sulfuric acid at 313 K. The orders of reaction with respect to [mannose], [oxidant], and [H^+] were found to be fractional, first, and negative fractional order, respectively. Anionic micelles of sodium dodecyl sulfate showed a partial inhibitory effect, while cationic micelles of cetyltrimethylammonium bromide increased the reaction rate with the same kinetic behavior. The reaction was catalyzed by cationic micelles, because of favorable electrostatic/thermodynamic/ hydrophobic/hydrogen bonding between reactants and cationic micelles. Their catalytic roles are best explained by Berezin's model. A variation of [phthalimide] showed that the rate of reaction decreased with increasing [phthalimide]. It was observed that, an increase of [mercuric acetate] had no effect on reaction velocity. The influence of salts on the reaction rate was also studied. The rate constant (kw), binding constants (Ks+Ko), and corresponding activation parameters (Ea, △H^#, △S^#, and △G^#) were determined. A detailed mechanism with associated reaction kinetics is presented and discussed.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2009年第2期319-326,共8页
Acta Physico-Chimica Sinica
基金
The project was supported by the Found of Chhattisgarh Council of Science and Technology (CGCOST), Raipur, (Chhattisgarh), India (621/CCOST/MRP/07)
关键词
胶枣催化
氧化
动力学
甘露糖
Micellar catalysis
Oxidation
Kinetics
Mannose
Berezin's model