Merging of a Perylene Moiety Enables a Ru<sup>II</sup> Photosensitizer with Long‐Lived Excited States and the Efficient Production of Singlet Oxygen
Marie‐Ann Schmid, Jannik Brückmann, Julian Bösking, Djawed Nauroozi, Michael Karnahl, Sven Rau, Stefanie Tschierlei
Abstract
Abstract Multichromophoric systems based on a Ru II polypyridine moiety containing an additional organic chromophore are of increasing interest with respect to different light‐driven applications. Here, we present the synthesis and detailed characterization of a novel Ru II photosensitizer, namely [(tbbpy) 2 Ru((2‐(perylen‐3‐yl)‐1 H ‐imidazo[4,5‐ f ][1,10]‐phenanthrolline))](PF 6 ) 2 RuipPer , that includes a merged perylene dye in the back of the ip ligand. This complex features two emissive excited states as well as a long‐lived (8 μs) dark state in acetonitrile solution. Compared to prototype [(bpy) 3 Ru] 2+ ‐like complexes, a strongly altered absorption ( ϵ =50.3×10 3 M −1 cm −1 at 467 nm) and emission behavior caused by the introduction of the perylene unit is found. A combination of spectro‐electrochemistry and time‐resolved spectroscopy was used to elucidate the nature of the excited states. Finally, this photosensitizer was successfully used for the efficient formation of reactive singlet oxygen.