When Better Quenching Means Lower Yields: Electrostatic Control of Cage Escape.

ABSTRACT: Photoredox catalysis often relies on excited-state quenching data to rationalize performance, yet such metrics can obscure the impact of solvent cage escape on overall efficiency. We report a systematic study of the effect of electrostatic interactions on the excited-state quenching, cage escape, and back-electron transfer processes in a benchmark system comprising methyl viologen (MV²⁺) and differently carboxylated ruthenium polypyridyl complexes with net charges from 2+ to 4-. Increasing electrostatic attraction between photosensitizer and MV²⁺ enhances the quenching rate constant (k _q ) up to the diffusion limit but simultaneously suppresses cage escape quantum yields, resulting in an inverse correlation between k _q

SUBMITTER: Bianco A 

PROVIDER: S-EPMC12856654 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature