Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts
Eva Bednářová, Logan R. Beck, Tomislav Rovis, Samantha L. Goldschmid, Katherine A. Xie, Nicholas E. S. Tay, Benjamin D. Ravetz, Jun Li, Candice L. Joe
Abstract
Abstract The use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials. 1 Introduction 1.1 Scope 1.2 Measuring Ground-State Redox Potentials 1.3 Measuring Photophysical Properties 1.4 Synthesis of Osmium Complexes 2 Properties of Osmium Complexes 2.1 Redox Potentials of Os(L)2-Type Complexes 2.2 Redox Potentials of Os(L)3-Type Complexes 2.3 UV/Vis Absorption and Emission Spectroscopy 3 Conclusions