Chiral Methylbenzylpyridinium-Based Organic-Inorganic Lead Halides for Water-Resistant Photoluminescence Materials

Chiral organic-inorganic metal halide (OIMH) materials are gaining increasing attention as candidates for asymmetric materials due to their unique photoelectric, chiral optic, and spintronic properties. The introduction of chirality into OIMHs is usually achieved by the use of chiral organic cations, while previous studies often focus on primary ammonium cations derived from commercially available chiral amines, limiting the tunability of the OIMH materials. Herein, we report the use of Zincke reactions to synthesize chiral N-substituted pyridinium salts, namely, (R)/(S)-methylbenzylpyridinium (R/S-MBnP) chloride and the corresponding 1D chiral OIMHs, (R/S-MBnP)PbX3 (X = Cl, Br, and I). The chirality of the pyridinium salts and the corresponding OIMHs is confirmed by circular dichroism (CD) spectroscopy, and the crystal structure is revealed by single-crystal X-ray diffraction (XRD). The photoluminescence (PL) and PL decay lifetimes were measured. The stability against water is monitored by powder XRD. This study demonstrates that Zincke reactions offer high tunability of organic cations for chiral OIMH materials.