Synthesis, crystal structure, vibrational study, optical characterization, Hirshfeld surface analysis and dielectric studies of a new indium-based hybrid material formulated as [(C9H8N)2(InCl6)·2(H2O)]

Abstract

A newly developed indium-based hybrid compound, [(C₉H₈N)₂(InCl₆)·2(H₂O)], was successfully synthesized using a slow evaporation method at room temperature. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed to observe the morphology and chemical composition of the particles. Structural analysis was performed through crystal X-ray diffraction (SXRD) and powder X-ray diffraction (PXRD) and revealed that the studied material crystallized in the triclinic P1 space group. The atom packing in this structure was characterized by the presence of alternating organic and inorganic layers along the b-axis. These arrangements were stabilized through multiple hydrogen bonds and centroid–centroid stacking interactions occurring between nearly parallel organic cations. Vibrational and optical properties were also explored using FT-IR and UV–Vis methods, respectively. Additionally, thermal analysis was performed via TGA/DTA and DSC measurements to assess the thermal stability and phase transformation of the title compound. Analysis of the Hirshfeld surface was carried out to examine the interactions between molecules. This allowed a quantitative assessment of the relative contribution of these interactions in the crystal structure. AC conductivity measurements (10⁻⁶ Ω⁻¹ cm⁻¹) confirmed the semiconductor character of the compound. The conductivity mechanism was attributed to the correlated barrier hopping (CBH) mechanism. Furthermore, electrical modulus measurements demonstrated the presence of grain effects.