CHIRALITY-DEPENDENT INTERMOLECULAR INTERACTIONS PROBED BY TIME-RESOLVED CHIROPTICAL LUMINESCENCE MEASUREMENTS OF ENANTIO-DIFFERENTIAL EXCITED-STATE QUENCHING KINETICS

Time-resolved chiroptical luminescence (TR-CL) spectroscopy is used to measure the chirality dependence of dynamic excited-state quenching p rocesses in solution. Measurements are performed on a series of lumino phore-quencher systems in which the interacting molecular species have similar overall shapes and sizes, but differ with respect to one or m ore well-defined (and incrementally varied) elements of structural chi rality. The measurements yield rate constants for competing enantiospe cific quenching processes, and the relative values of these rate const ants provide information about both the degree and sense (handedness) of chiral discriminatory interactions between the luminophore and quen cher species. It is shown that both the degree and sense of chiral rec ognition/discrimination in the quenching processes are modulated by sm all changes in quencher structure.