Stabilization of 4-phenylurazole by electrografting on a nano-fibrillated mesoporous carbon modified electrode. Reactivity of anchored triazolinedione groups against Michael-type addition at electrode/electrolyte interface

Fabricartion of a redox-active electrode by modification of a glassy carbon electrode (GCE) with a unique ionic liquid derived fibrillated mesoporous carbon (IFMC) following the electrografting of 4-phenylurazole via electrochemical reduction of 4-(4-nitrophenyl)urazole in the presence of sodium nitrite has been described. The resulted electrode shows the prominent electrochemical performance. The efficiency of the electrode has been evaluated over the entire range of pHs. The oxidized form of ungrafted 4-phenyluazole, 4-phenyl-1,2,4-triazoline-3,5-dione, is highly unstable due to fast ring cleavage. In contrast to oxidation of the ungrafted 4-phenylurazole, the electrografted 4-phenyl-1,2,4-triazoline-3,5-dione exhibits a high stability in a wide range of pHs. The anchored 4-phenyl-1,2,4-triazoline-3,5-dione groups are reactive against Michael-type addition. Further modification of the electrode can be achieved by the Michael-type addition reaction of the triazolinedione groups with nucleophiles at the solid/liquid interface.