6. Ru(III) catalysis in oxidation of some amino acids by acid bromate: A kinetic study

Sheila Srivastava*, Sarika Singh,Pushpanjali Singh & Pooja Khare. 

Chemical Laboratories, Feroze Gandhi College, Raebareli- 229001, U.P., India.

E-mail: she_ila72@yahoo.com 

Abstract
 

Kinetic  investigations  on  Ru(III)  catalyzed  oxidation  of  dl -serine and  dl- threonine  have  been  made in  the  temperature  range  of  30°-45°C by  acidic  solution  of  potassium  bromate  in  the presence  of  mercuric  acetate as  a  scavenger . The rate showed zero order kinetics in bromate [BrO3‾] and order of reaction was one with respect to substrate and Ru(III) respectively. Increase in [Cl‾] showed positive effect, while increase in [H+] showed zero effect.

Negligible effect of mercuric acetate and ionic strength of the medium were observed. A transient complex, formed between [RuCl6]3- and amino acid in 1:1 ratio, disproportionates in a slow and rate determining step. Various activation parameters have been calculated. A suitable mechanism in agreement with observed kinetics has been proposed.

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