Abstract

In this work, the electrochemical oxidation of 4-phenylurazole (1) and 4-(4-aminophenyl) urazole (2) in the presence of some Meldrum’s acid derivatives as nucleophiles was studied. Some new urazole derivatives were synthesized in water–ethanol (70:30 v/v) solutions via anodic oxidation of the urazoles (1 and 2). Because the electrochemical oxidation mechanisms of different electrophiles in the presence of Meldrum’s acids are different, the computational analysis was performed to analyze the mechanism of reactions. Cyclic voltammetry, controlled potential coulometry and spectroscopic methods were applied to obtain experimental results, and the theoretical results were calculated at DFT (B3LYP/6-311G (d,p)) level of theory. In this research, firstly, the effect of the ΔGtot on the oxidation potential was investigated, and it was found that the potential of the electrochemical oxidation of some urazole species is dependent on their ΔGtot. Secondly, the dependence of the electrochemical oxidation mechanism to ΔGtot for the urazole species (1 and 2) was studied. The results of this study showed why the mechanisms of the electrochemical oxidation of the studied species (1 and 2) in the presence of all three Meldrum’s acid derivatives are EC.