Structural Insight into Electrogenerated Chemiluminescence of Para-Substituted Aryl–Triazole–Thienyl Compounds

Abstract

There has been a strong push to develop new thiophene-based monomers to tailor the electrical and optical properties of the resulting polymers. However, the synthesis of these elaborated thienyl compounds is difficult to realize. Here, we report the successful click coupling of thienyl azides and para-substituted aryl alkynes to synthesize eight thiophene-based luminophores intended for electrochemical and electrochemiluminescence (ECL) study. These thiophenes could be separated into two series: monothienyl and bithienyl analogues and further categorized based on the nature of the ligand attachment to their phenyl rings (electron-donating or -withdrawing characteristics: NMe2, OMe, H, or F) on the other side of the triazole bridge. The electrochemical experiments indicated these compounds lacked stability when they were oxidized or reduced, with the exception of those with a dimethylamine ligand attached (quasireversible oxidations). Cyclic and differential pulse voltammetries revealed the redox potential...