A New Inorganic–Organic Hybrid Crystal, (NH 3 (CH 2 ) 6 )NH 3 SnCl 6 : Synthesis, Crystal Structure, Vibrational, Thermal, Morphological Properties, and DFT Analysis

In this study, we investigated the structural, vibrational, and elemental properties of a new crystal, NH3(CH2)6NH3SnCl6, using a combination of experimental techniques (X-ray diffraction (XRD), scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), inductively coupled plasma-optical emission spectrometry (ICP-OES), infrared (IR), and Raman Spectroscopy) and theoretical methods (periodic density functional theory (DFT) with the B3LYP functional and the LanL2DZ basis set). X-ray diffraction analysis revealed that the compound crystallizes in the monoclinic system space group (P21/m, Z = 2), with lattice parameters: a = 14.1652 Å, b = 7.1967 Å, c = 9.2832 Å, and β = 122.793°. Scanning electron microscope (SEM) imaging and energy-dispersive spectroscopy (EDS) confirmed good crystallinity and a uniform elemental distribution. Inductively coupled plasma-optical emission spectrometry (ICP-OES) was used to verify the stoichiometry and elemental composition of the crystal. Thermal behavior was assessed through differential scanning calorimetry (DSC), which provided insights into the compound’s phase transition and thermal stability within the studied temperature range. The properties were analyzed using infrared (IR) and Raman Spectroscopy, and the vibrational to V/Z ratio was analyzed as a function of CH2 chain length and compared to related compounds of formula H3N(CH2)nNH3SnCl6 (2 ≤ n ≤ 5). Theoretical studies, using periodic density functional theory (DFT) with the B3LYP functional and the LanL2DZ basis set, were performed to investigate the structural and vibrational characteristics of crystalline H3N(CH2)nNH3SnCl6. A three-dimensional N–H···Cl hydrogen-bonding (HB) network was identified, and vibrational spectra were analyzed using factor group analysis. Symmetry reduction in the crystal lattice was found to cause mode splitting in the vibrational spectra. Hydrogen bonding was shown to influence both geometric and vibrational features of the material. Characteristic N–H, Sn–Cl, and C–H stretching as well as NH3, −CH2, and Cl–Sn–Cl bonding modes provided spectroscopic markers for hydrogen bond strength and structural symmetry across this compound series.