Chiroptical Spectroscopy of Mechanically Fragile Single Crystals Without Sample Degradation

Abstract This study presents a nondestructive method to evaluate solid-state circular dichroism (CD) and circularly polarized luminescence (CPL) without matrix dispersion. Chiral co-crystals of tartaric or malic acid with 1-aminopyrene were used as models. Conventional matrix preparation damaged the malic acid co-crystal, eliminating its CD signal. Using an in situ diffuse-reflectance CD spectrometer and CPL spectrometer with polarization analysis, we obtained artifact-free CD and CPL spectra without sample damage, enabling reliable chiroptical analysis of sensitive solid-state materials.