Head-to-Tail Dimerization of 4-Fluoroacetophenone in the KOH/DMSO Superbase Suspension and Related SN Ar Reaction

Potassium superoxide as an intricate source of superoxide anion. Elucidating the composition of its samples in dimethyl sulfoxide by reactions with (5,10,15,20-tetraphenylporphinato)manganese(III) chloride and curcumin

The fundamentals and approbation of the new spectral assay for superoxide anion and KOH (inevitable impurity in KO₂ preparations) in a dimethyl sulfoxide (DMSO) solution of potassium superoxide (KO₂), a widely used source of superoxide anion in diverse chemical and biochemical studies, are disclosed. To assess the concentration of superoxide anion and KOH, it was proposed to use (5,10,15,20-tetraphenylporphinato)manganese(III) chloride as a spectrophotometric probe for superoxide anion and curcumin for the determination of KOH based on recently acquired spectral properties of curcumin in alkaline DMSO. We have found that the prepared solutions generate superoxide anion in the concentration of 1.7 mM and contain KOH in the concentration of 3 mM, which is close to the saturated concentration in anhydrous DMSO.