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Description
1,1ˈ-binaphthyl is an axially chiral molecule that crystallizes in either racemic phase, consisting of an equal number of both enantiomers in the unit cell or in a chiral phase where only one type of enantiomer is present. Thin film crystallization kinetics are strongly influenced by the presence of a solid substrate, where selective adsorption at the substrate–liquid interface promotes heterogeneous nucleation and complete chiral phase formation. This study further explores the deracemization of 1,1ˈ -binaphthyl through the influence of a chiral additive, 1,1ˈ-bi-2-naphthol. Structural characterization by Grazing Incidence XRD (GIXD) using synchrotron radiation confirms that thin films prepared by solution processing crystallize preferentially in the chiral phase. The extent of deracemization and enantioselectivity is further investigated using electronic circular dichroism (ECD). For the first time, the solid-state ECD spectra of 1,1ˈ-binaphthyl thin films are recorded using conventional ECD spectrometer and synchrotron-based Mueller Matrix Polarimetry (MMP). Since conventional ECD measurements cannot resolve intrinsic ECD from linear anisotropies such as linear dichroism (LD) and birefringence (LB), spatially resolved Mueller matrix polarimetry is employed to accurately extract true solid-state ECD. MMP mapping on the thin film samples reveals localized chiroptical responses within the 1,1ˈ-binaphthyl thin films, providing direct insight into enantioselective crystallization and spatially resolved chiral purity.