Structural, spectroscopic, thermal and biological insights into a new cadmium halide-based organic–inorganic hybrid material

Abstract

A novel cadmium halide-based organic–inorganic hybrid material, (2A4PH)2[CdBr4] (where 2A4PH denotes the 2-amino-4-methylpyridinium cation), was synthesized at room temperature using a Schlenk method and comprehensively characterized by single-crystal X-ray diffraction, spectroscopic, thermal, and biological investigations. The compound crystallizes in the monoclinic space group P21/n and consists of isolated tetrahedral [CdBr4]2− anions incorporated within a matrix of protonated aminopyridinium cations. The crystal structure is stabilized by an extensive network of N–H⋯Br hydrogen bonds and π–π stacking interactions, which contribute to the overall cohesion of the hybrid framework. Hirshfeld surface analysis highlights the predominance of H⋯Br contacts among the intermolecular interactions, while FTIR and Raman spectroscopy confirm the characteristic vibrational modes of the organic and inorganic components. Thermal analysis (TGA/DSC) reveals good thermal stability over a moderate temperature range, followed by a decomposition process leading to the formation of CdBr2. Furthermore, the biological potential of (2A4PH)2[CdBr4] was investigated through antioxidant and α-amylase inhibition assays. The hybrid material exhibited notable radical-scavenging activity toward DPPH and ABTS radicals, whereas a lower ferric-reducing capacity was observed. Enzyme inhibition studies demonstrated a mixed-type inhibition mechanism against α-amylase. These findings provide valuable insights into the structure–property relationships of cadmium halide-based hybrid materials and highlight (2A4PH)2[CdBr4] as a promising multifunctional hybrid system with potential relevance in bioactive material applications.