Selective formation of luminescent chiral cocrystal: Molecular self-assembly of 2,2′-binaphthol and 2-(3-pyridyl)-1H-benzimidazole

Luminescent cocrystals have been received much attention in fluorescence imaging and sensor application. In this work, we report that the high-quality chiral luminescent cocrystal can be obtained through a molecular self-assembly process of 2,2'-binaphthol and 2-(3-pyridyl)-1H-benzimidazole. The assembly modes and stacking fashions of as-obtained cocrystal were determined by single crystal X-ray diffractometer. The structure and optical properties of the cocrystals were characterized by fluorescence emission, fluorescence decay, Raman and circular dichroism spectra. The results show that both the pristine co-assembled units (R-BINOL and S-BINOL) give rise to the R conformation within the final cocrystal, suggesting that the formation of cocrystal can be an effective way to achieve R/S-isomeric transformation of 2,2'-binaphthol. It is also expected that the co-crystallization approach has much flexibility and potential applications for the design and selective formation of chiral luminescent materials. (C) 2018 Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences. Published by Elsevier B.V. All rights reserved.