A Family of RuII Photosensitizers with High Singlet Oxygen Quantum Yield: Synthesis, Characterization, and Evaluation

A series of Ru-II-based photosensitizers were synthesized and extensively characterized. The ligand utilized to coordinate ruthenium was a pyridine-quinoline hybrid bearing an anthracene moiety, and it was combined with commercially available 2,2-bipyridine (bpy) for the heteroleptic complexes. The produced bichromophoric complexes show very strong and wide UV/Vis absorption bands. The ability of these complexes to act as triplet photosensitizers in the production of singlet oxygen was thoroughly studied by utilizing the photooxidation of 1,3-diphenylisobenzofuran as the test reaction. The most efficient photosensitizer in this new family of Ru-II complexes affords singlet oxygen quantum yields and production-rate efficiencies up to two times higher than those of the benchmark [Ru(bpy)(3)](2+) parent complex.