Acta Phys. -Chim. Sin. ›› 2009, Vol. 25 ›› Issue (02): 319-326.doi: 10.3866/PKU.WHXB20090221

• ARTICLE • Previous Articles     Next Articles

Micelle Catalyzed Oxidation of Mannose by N-Bromophthalimide in the Presence of Sulfuric Acid

KATRE Yokraj; SINGH Minu; PATIL Sangeeta; SINGH Ajaya K.   

  1. Department of Chemistry, Kalyan Post Graduate College, Bhilai Nagar, Durg, (C.G.)-490006, India; Department of Chemistry, Vishwanath Yadav Tamaskar Post Graduate Autonomous College, Durg, (C.G.)-490023, India
  • Received:2008-07-18 Revised:2008-10-20 Published:2009-01-16
  • Contact: KATRE Yokraj

Abstract: 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 sodiumdodecyl 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.

Key words: Micellar catalysis, Oxidation, Kinetics, Mannose, Berezin’s model