Analyzing Electrochemiluminescence Mechanisms of Thiophene-Triazole-Thiophene Luminophores with In Situ Spectroscopy

Herein, we report the electrochemical and electrochemiluminescence (ECL) study of thiophene luminophores, 1‐[2,2′]bithiophenyl‐4‐yl‐4‐thiophen‐2‐yl‐1H‐[1,2,3]triazole (TTT) and 4‐thiophen‐2‐yl‐1‐thiophen‐3‐yl‐1H‐[1,2,3]triazole (TT), in N,N‐dimethylformamide (DMF). Differential pulse voltammetry was used to determine the oxidation and reduction potentials of the two compounds. TTT and TT in DMF exhibited relatively weak ECL efficiencies following the annihilation mechanism. However, ECL was enhanced with co‐reactants, persulfate, benzoyl peroxide, and tri‐n‐propylamine. In these experiments, TTT displayed stronger ECL activity than TT, due to the quasireversible nature of the reduction reactions. Spooling ECL spectroscopy was utilized to gain analytical insight into light‐emission mechanisms. It was shown that whereas these two thiophene compounds could form photoinduced excited monomers, excimers were generated mainly in their co‐reactant ECL paths. Lighten up: Electrochemical and electrochemiluminescence (ECL) studies of thiophene luminophores in N,N‐dimethylformamide are undertaken to gain mechanistic insight into their electrochemiluminescence mechanisms. Co‐reactant ECL studies with persulfate, benzoyl peroxide, and tri‐n‐propylamine are used to improve the ECL produced in annihilation experiments.