STUDIES OF THE CE(III)/CE(IV) COUPLE IN MULTIPHASE SYSTEMS CONTAINING A PHASE-TRANSFER REAGENT .2. INDIRECT OXIDATIONS AND THE ELECTROLYTIC PREPARATION OF CERIC NITRATE

It is confirmed that in divided cells, the oxidation of Ce(III) to Ce(IV) is possible with good current efficiency in many electrolytes. On the other hand, it is difficult to achieve such efficiency in undivided cells, but it is possible using an emulsion of nitric acid/n-hexane containing tributylphosphate as the electrolyte. Other emulsions are less successful and the reasons are discussed. The oxidation of some toluenes and aromatic hydrocarbons by Ce(IV) in aqueous nitric acid/organic solvent emulsions containing a phase transfer reagent, tributylphosphate or tetrabutylammonium ion is reported. With toluenes, a number of products are formed and the relative yield depends most strongly on substituents; with p-xylene and p-methoxytoluene, reasonable yields of aldehydes were obtained with short reaction times.