Solid-Grinded Cocrystals of Acridine and 3,5-Dinitrobenzoic Acid: A Cocrystal with Strong Cocrystallization Ability and Two-Photon Excited Fluorescence Property

The solvent-free fabrication of nonlinear optical (NLO) cocrystals is a challenge in view of the insufficient cocrystallization ability of most molecules. Here, we reported a charge-transfer (CT) cocrystal with a strong cocrystallization ability and a two-photon excited fluorescence (TPEF) property. The structural and optical properties were experimentally investigated by X-ray diffraction (XRD), Raman, Fourier transform infrared (FTIR), absorption, photoluminescence (PL), and two -photon excited fluorescence spectra. Furthermore, they were theoretically discussed by molecular electrostatic potential (MEP), Hirshfeld surface, reduced density gradient (RDG), frontier molecular orbitals (FMO), time-dependent density functional theory (TDDFT), and quadratic response calculations based on the DALTON program. Our work may be helpful for further "green" solvent-free fabrication of NLO materials.