Synthesis, Crystal Structure, Optical Properties and Stability of New Bismuth‐Based Organic‐Inorganic Compounds (C6H9N2)aBibXc (X=Cl, Br, I)

Abstract We report a series of high‐quality, low‐dimension, and bismuth‐based organic‐inorganic hybrid single crystals (C 6 H 9 N 2 ) a Bi b X c (X=Cl, Br, I) fabricated via a simple hydrothermal method. The crystal structure, intermolecular interactions, morphology, chemical groups, bond characterization, and optical and thermal stability of the samples were detailed via X‐ray single crystal diffractomete, Hirshfeld surface analysis, field scanning electron microscopy (FSEM), fourier transform infrared spectrometer (FTIR), Raman, thermal gravimetric (TG), and Ultraviolet‐visible (UV‐vis) diffuse reflectance spectra. The results indicated that the (C 6 H 9 N 2 ) 2 BiCl 5 and (C 6 H 9 N 2 ) 2 BiBr 5 crystals displayed a monoclinic system with a P21/n space group at room temperature; the (C 6 H 9 N 2 )BiI 4 crystal was P21/c. Meanwhile, the band gap could be continuously adjusted between 3.2 eV and 1.6 eV via the nature of halide ligands. The samples also have good thermal stability. The starting decomposition temperature of (C 6 H 9 N 2 ) 2 BiCl 5 , (C 6 H 9 N 2 ) 2 BiBr 5 , and (C 6 H 9 N 2 )BiI 4 were 200 °C, 250 °C, and 300 °C, respectively. Therefore, this kind of organic‐inorganic hybrid compounds will be assumed to be a promising candidate for optical and electronic applications.