University of Qom Advances in Energy and Materials Research 3041-8836 2 6 2025 06 01 Halide-Modulated Cu–Hg Heterodinuclear Complexes as Potential Precursors for Functional Energy and Environmental Materials 12 18 4365 10.22091/jaem.2025.14486.1034 EN Akbar Gaemi Department of Chemistry, Faculty of Technical&Engineering, Saveh campus of Islamic Azad University, Saveh, Iran 0000-0002-6172-2416 Mohsen Mousavi Department of Chemistry, Faculty of Technical&Engineering, Saveh campus of Islamic Azad University, Saveh, Iran 0000-0002-9737-4994 Journal Article 2025 01 20 This study reports the synthesis and comprehensive structural characterization of three novel heterodinuclear complexes, [CuL{HgCl2(CH3OH)}] (1), [CuL{HgBr2}] (2) and [CuL{HgI2}] (3). These complexes were generated through the reaction of HgX2 salts (X- = Cl-, Br- and I-) with a copper(II) Schiff base complex, (where H2L = N,N′-bis(2-hydroxyphenylidene)-2,2′-dimethyl-1,3-propanediamine).<br />The resulting compounds were characterized using elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The structural analyses consistently revealed the formation of a heterodinuclear [CuIIHgII] core in all three species, with the central Cu(II) and Hg(II) ions bridged by the two phenolate oxygen atoms of the L ligand. <br />The coordination geometry around the Cu(II) center in all complexes is a distorted square planar (CuN2O2). In contrast, the coordination geometry of the Hg(II) ion is dependent on the coordinated halide: it adopts a distorted square pyramidal (HgO3Cl2) geometry in complex 1 (including a coordinated methanol molecule), but a tetrahedral (HgO2Br2 or HgO2I2) geometry in complexes 2 and 3, respectively. Supplementary crystallographic data for the three structures are registered with the CCDC as 1432472, 1432473, and 1432474.<br />The halide-dependent structural variation in the Hg(II) environment provides valuable insight for designing functional coordination materials. The robust Cu–Hg core and tunable electronic features highlight these complexes as potential precursors for optical, sensing, and environmental remediation materials within the broader field of energy and materials research.