Photoredox Processes in the Aggregation and Gelation of Electron-Responsive Supramolecular Polymers Based on Viologen

Viologen-based ditopic bis-pyridinyl-triazole bidentate ligands self-assemble in the presence of palladium ions into supramolecular polymers whose structure is imposed by the directed formation of coordination bonds. Light-irradiation of these electron-responsive supramolecular materials triggers a photo-induced electron transfer yielding isolated π-radicals and dimers of radicals. The photoreduction events and the associated dimerization steps trigger a large-scale reorganization occurring within the supramolecular network yielding aggregates or gels depending on the irradiation conditions (power, duration). Detailed electrochemical, spectro-electrochemical and photochemical analyses were conducted to understand the mechanisms at stakes in these light-induced aggregation and gelation.

Clément Roizard, Vivien Andrieux, Shaymaa Al Shehimy, Shagor Chowdhury, Quentin Reynard-Feytis, Christophe Kahlfuss, Eric Saint-Aman, Floris Chevallier, Christophe Bucher, Thomas Gibaud and Denis Frath.

ECS Adv. 2022, 1, 020502, 10.1149/2754-2734/ac6ad4