The cooperative influence of Ag(I) and sodium lauryl sulfate micelles on the oxidation rate of D-mannitol by acidic KMnO4

Oxidation of organic substrate by KMnO4 is fascinating because such process proceeds via different mechanistic pathway. No research has examined how metal catalysts affect carbohydrate oxidation by acidic KMNO4 in micellar environments. The impact of sodium lauryl sulfate (SLS) micelles on the Ag(I) facilitated oxidation kinetics of D-mannitol by KMnO4 has been investigated in the aqueous micellar media. The progression of the oxidation process is assessed by monitoring the decrease in absorbance, employing the pseudo-first-order condition as an indicator for [H+], [Mn(VII)], [Na2SO4], [D-mannitol], [Ag(I)], and [SLS]. The examined reaction shows fractional-first-order kinematics for [D-mannitol], [H+], and Ag(I), and first-order for [Mn(VII)] across the examined concentration range. The spectrophotometric kinetic investigation revealed that both Ag(I) and SLS catalyze the oxidation independently, yet their combined influence is significantly more pronounced. Ag(I) significantly increases the oxidation rate (5.5 times). Interestingly, the kinetic profile demonstrated an increase in the observed rate constant values (7.2 fold) corresponding to an increase in surfactant concentration. The combination of Ag(I) and SLS micelles produces an 11.5-fold enhancement in the oxidation rate of D-mannitol. The electrostatic attraction between the charged micelle and Mn(VII) promotes the proximity of the oxidizing species to the substrate (D-mannitol), which is typically solubilized in a micellar environment, thus enhancing the oxidation process. A credible mechanism that corresponds with the kinetic findings has been emphasized, alongside an analysis of the Piszkiewicz model, to elucidate the apparent catalytic influence of SLS micellar environments.