Uncatalyzed And Ru(III) Catalyzed Oxidation Of Aliphatic Aldehydes By Pyridinium Chlorochromate In Aqua-Acetic Acid Medium

摘要

The kinetics of uncatalyzed and Ru(III) catalyzed oxidation of aliphatic aldehydes (Ald) viz. acetaldehdye, propionaldehdye, butyraldehyde and iso-butyraldehyde by pyridinium chlorochromate (PCC) was studied in aqua-acetic acid medium. The order in [PCC] was found to unity both in catalyzed and in uncatalyzed reactions. However, the order of [aldehyde] changed from unity to fractional order in the presence of Ru(III). On the basis of kinetic features a reaction between protonated PCC and aldehyde hydrate in the slow-step of uncatlayzed reaactoin was suggested. A mechanism involving the formation of a complex between Ru(III) and substrate is proposed for the catalyzed reaction. The oxidation products were identified as the corresponding carboxylic acids.