Kinetics and mechanism of the oxygenation of potassium nitronates. Evidence for a single electron transfer (SET) mechanism    

Summary

The oxygenation of the potassium salts of alkylnitronates in absolute DMSO leads to potassium nitrite (nitrate) and the corresponding aldehydes or ketones at 40°C. Kinetic measurements for potassium 1-propylnitronate (K-1-PN) resulted in the rate law -d[K-1-PN]/dt = k₂[K-1-PN][O₂]. The rate constant, activation enthalpy, and entropy at 313.16 K are as follows: k/M^-1 s^-1 = (1.43±0.04), DH^‡/kJ mol^-1 = 57±10 DS^‡/J mol^-1 K^-1 = -60±32. The presence of superoxide ion as a result of a SET from the nitronate to dioxygen was proved by NBT test.