Investigating the structure and optical characteristics of two new organic-inorganic hybrid crystals

Using the solvent evaporation approach at room temperature (RT), we produced transparent single crystals of two new organic-inorganic hybrid materials: (C5H6NO)SO3NH2 (crystal 1: reaction by sulfamate and 4-hydroxypyridine) and (C3H5N2)SO3NH2 (crystal 2: reaction by sulfamate and imidazole). Both crystals have the same space structure and belong to the P21/c space group of the monoclinic crystal system, according to the results of X-ray single crystal diffraction. In crystals 1 and 2, sulfamic acid and organics (4-hydroxypyridine, imidazole) are alternatively positioned by hydrogen bonds to create a layered structure. Hydrogen bonds and electrostatic Coulomb forces connect the layers to one another. Powder XRD demonstrates the remarkable phase purity of both crystals. Furthermore, the optical properties of both crystals, including IR, UV absorption, and fluorescence spectra, have been investigated in detail. The presence of functional groups such as NH2 and C--C in the grown crystals was confirmed by Fourier transform infrared analysis. The optical band gaps for crystals 1 and 2 are about 4.33 and 4.31 eV, respectively, and the UV absorption findings show a low light absorption. According to the photoluminescence spectra, the two crystals have distinct fluorescence characteristics, with emission peaks of approximately 433 nm and 442 nm, apiece.