Electrogenerated chemiluminescence of iridium-containing ROMP block copolymer and self-assembled micelles

The electrochemical properties and electrogenerated chemiluminescence (ECL) of an Ir(ppy)2(bpy)(+)-containing ROMP monomer, block copolymer (containing Ir(ppy)2(bpy)(+) complexes, PEG chains, and butyl moieties), and self-assembled micelles were investigated. Following polymerization of the iridium complex, we observed multiple oxidation peaks for the block copolymer in cyclic voltammograms (CV) and differential pulse voltammograms (DPV), suggesting the presence of multiple environments for the iridium complexes along the polymer backbone. The ECL signals from monomer 1 and polymer 2 were reproducible over continuous CV cycles and stable over prolonged potential biases, demonstrating their robustness toward ECL-based detection. Comparison of the ECL signal of the block copolymer, containing multiple iridium complexes attached to the backbone, and the monomeric complex showed enhanced signals for the polymer. In fact, formation and reopening of the self-assembled micelles allowed recovery of the polymer and near complete retention of its original ECL intensity.