OXIDATION OF ORGANIC AMIDE IONS BY MOLECULAR-OXYGEN - STRUCTURE AND PROPERTIES OF POSSIBLE INTERMEDIATES

Using ab initio RHF/4-31G and AM1 methods, three types of possible in termediates RR'NO2- (RR'NO2H) (R,R' = H, Me, Ph) were studied in the c ourse of organic amide ion oxidation by O2. Both methods predict therm odynamic stability to increase according to [GRAPHICS] Relative energi es of the isomers II and I were found to be, on average, 12.0 and 23.5 kcal mol-1 (4-31G), and 19.5 and 45.3 kcal mol-1 (AM1), respectively . On the basis of a brief analysis of literature data, and our earlier kinetic and present theoretical studies, a mechanism of molecular oxy gen attachment to the primary and secondary organic amide ions is prop osed. The mechanism includes consecutive isomerization of the initiall y formed intermediates I into the more stable species II and III.