Effect of coinage metal nanoparticles and zwitterionic surfactant on reduction of [Co(NH3)5Cl](NO3)2 by iron(II)

The reaction between [Co(NH3)5Cl](NO3)2 and Mohrʹs salt is strongly catalyzed by coinage metal sols and surfactant. The catalytic rate constant values prove that the rate is surface controlled. The rate also depends on dimension of sol particles. The amount of the micelle bound reduction of cobalt(III) complex is facilitated by nanoparticles. The micelles in turn help to increase the collision probability between the complex and the Mohrʹs salt whereas nanoparticles help the electron relay from Mohrʹs salt. For the first time this method depicts a simple reproducible way to demonstrate nanoparticle-catalyzed reduction of complex by Mohrʹs salt in an organized medium. We have studied the effect of zwitterionic micelles of N,N-dimethyl-N-dodecyl glycine betaine on the same reaction. The Menger and Portnoy model is used to analyze the kinetic data. We have also reported the binding constant and first order rate constant for the reaction in micellar pseudo phase and water.