Through chiral HPLC separation of rac-COTh and characterization using circular dichroism (CD) spectroscopy, the mirror-symmetric CD signals confirmed the existence of two enantiomers (Figure ). The study investigated the photo-induced conformational inversion behavior of these enantiomers in both solution and solid states, in the solid state with UV lamp irradiation (blue triangle line) at 298 K, irradiation wavelength: 254 nm. Concentration of the two enantiomers of COTh (-) and COTh (+) are 30 and 50 μM, respectively. Proposed decay pathways along the potential energy surface of COTh in dilute solution state (f) and solid state (g). Reproduced from Ref. with permission. Copyright (2019), Springer Nature.