(RuBpy3)2+-bisterpyridinyl Triangle Promoted Singlet Oxygen (1O2) Photosensitization for Fast Oxidation of Sulfur Mustard Simulant

Abstract (RuBpy3)2+-bisterpyridine-based metallacycle T photosensitizer has been prepared by a facile single-step self-assembly process. Supramolecular self-assembly strategy greatly improved metallacycle T’s photosensitized ability due to its enhanced light-harvesting capability, smaller energy gap (ΔEST) between lowest excited singlet state (S1) and lowest excited triplet state (T1) along with excellent solubility which exhibiting higher efficiency for singlet oxygen (1O2) production than the ligand L and its pendant [(RuBpy3)2+·2PF6–]. In the practical photo-driven degradation of sulfur mustard simulant (2-chloroethyl ethyl sulfide, CEES), full conversion of toxic CEES to nontoxic CEESO has been achieved by metallacycle T with an extremely fast lifetime of 90 s (half lifetime t1/2= 25 s) and 100% selectivity (without formation of highly toxic CEESO2), while ligand L and [(RuBpy3)2+·2PF6–] needed 130 s and 330 s, respectively. This study demonstrated terpyridine-based novel supermolecules can serve as efficient scaffolds for effective enhancement of photosensitization.