From structure to function: a one-dimensional palladium(ii) hybrid for real-sample hydroquinone detection

Abstract

A novel one-dimensional (1D) organic–inorganic hybrid compound, (C₄H₇N₂)[PdCl₃(H₂O)], was synthesized through the reaction of palladium(II) chloride with 2-methylimidazole in an aqueous acidic medium. The structure was elucidated through single-crystal X-ray diffraction studies and consists of infinite chains of [PdCl₃(H₂O)] units connected via edge-sharing octahedra, stabilized by extensive hydrogen bonding and π⋯π stacking interactions involving the organic cations. Infrared spectroscopy confirmed the presence of key functional groups and intermolecular interactions. UV-vis diffuse reflectance spectroscopy indicated significant absorption in the UV range, with an optical band gap of 2.18 eV, indicating semiconducting behavior. The material's structural characteristics and optical behavior suggest its suitability for applications in photocatalysis, sensing, and proton conduction. An electrochemical sensor exhibiting high sensitivity and selectivity for hydroquinone (HQ) detection was developed and tested using differential pulse voltammetry. This sensor demonstrated a low detection limit of 0.02 µM and exhibited a broad linear response range spanning 0.02 to 10 µM. It maintained outstanding performance even when common interfering substances were present. Application to real samples provided recovery rates between 95.4% and 102.4%, underscoring its potential for use in environmental surveillance and quality control purposes.