Photoinduced oxidation of propan-2-ol by acid chromate

Abstract

The photoinduced oxidation of propan-2-ol by acid chromate has been studied (i) by flash photolysis, (ii) by quantum yield measurements at low light intensity, (iii) by e.s.r. measurements during photolysis of solutions containing a spin trap, and (iv) by e.s.r. measurements of glassy samples photolysed at –165°C. It was found that Cr^IV is formed in the primary processes, the most efficient of which involves the ester of acid chromate. The rate of formation of the ester was measured. A mechanism for the subsequent reactions of Cr^IV is given. In general the reactions of Cr^IV with another Cr^IV or with Cr^V are fast compared with the reaction of Cr^IV with propan-2-ol in the formation of 2-hydroxypropyl radicals. The reaction of Cr^IV with Cr^VI is immeasurably slow.