Elucidating the Quenching Mechanism of Tris(2,2'-bipyridyl)ruthenium(II) Complex in the Water-Glycerol Binary System Based on the Microscopic Structure of the Media.

Kinetic studies on the photochemical quenching reaction of the tris(2,2'-bipyridyl) ruthenium(II) complex ([Ru(bpy)3]2+) in water-glycerol binary media were conducted based on the Einstein-Smoluchowski (E-S) theory. Dynamic and static quenching behaviors were analyzed by comparing results from time-resolved spectroscopy and emission spectroscopy. While the dynamic quenching reaction aligns well with the E-S theory, static quenching was observed, leading to a notable increase in the overall photoquenching reaction rate constant. Employing chromatography and infrared spectroscopy, we correlated the microscopic molecular structure of the binary solvent system and the solvation environment around the emitters with the reaction mechanism. This correlation was found to correspond to ion pair formation and the confinement effect of the emitter, respectively.