Comprehensive analysis of a novel antimony-based organic-inorganic hybrid material: structural, vibrational, and hirshfeld surface investigations of (C8H14N2)[SbCl5]

Abstract

The novel organic-inorganic hybrid compound, N,N’-di(4-ethyl aminomethyl)pyridinium pentachloride antimonate (III), designated as (C₈H₁₄N₂)[SbCl₅], was synthesized and crystallized through a slow evaporation technique to facilitate comprehensive analysis of its crystal structure and molecular composition. Single-crystal X-ray diffraction revealed that this supramolecular compound crystallizes in the centrosymmetric space group P21/n within the orthorhombic system. The unit cell parameters were determined as follows: a = 10.8365(3) Å, b = 11.8067(3) Å, c = 12.0281(3) Å, and β = 106.920(3)°. The crystal structure was solved using direct methods and refined via the least squares technique, yielding final values of R₁ = 0.0218 and wR₂ = 0.0444. To further confirm the structure's stability and coherence, we investigated various interaction types and the contribution of hydrogen bonding to the overall molecular interactions through Hirshfeld surface analysis. This analysis, complemented by 2D fingerprint plots, highlighted the predominance of Cl⋯H/H⋯Cl interactions, which accounted for 59.1 % of the total interactions. Additionally, the study of crystal voids indicated that 7.1 % of the unit cell volume is composed of void space, contributing to the mechanical strength of the compound. Furthermore, FTIR spectroscopy and Raman scattering were utilized to identify the functional and molecular groups within the crystal by analyzing their vibrational modes.