Novel 1-D copper(II) coordination polymer based on 2,5-bis(pyridine-2-yl)-1,3,4-thiadiazole as bridging ligand: Synthesis, crystal structure, Hirshfeld surface analysis, spectroscopic characterizations and biological assessment

A new copper (II) mono-dimensional coordination polymer based on 2,5-bis(pyridine-2-yl)-1,3,4-thiadiazole (L) as bridging ligand, noted [CuLCl2]n, has been synthesized by reaction of L with copper salt (CuCl2·2H2O) and characterized by single crystal X-ray diffraction, Hirshfeld surface analysis, as well as UV–Visible, and FTIR techniques. The copper cation lies on an inversion centre and displays elongated octahedral coordination geometry. The equatorial positions are occupied by the N atoms of two ligands, whereas the axial positions are occupied by the chlorine atoms. The 1,3,4-thiadiazole and the pyridyl rings linked to the metal are approximately coplanar, with a maximum deviation from the mean plane of 0.330 (2) Å. The Cu2+ cations form the infinite chains parallel to c-axis and the organic molecules are linked to Cu atoms in zigzag chains building an infinity tape running along [0 0 1] direction. The cohesion of the polymeric complex structure is ensured by C–H⋯Cl weak hydrogen bonds and π–π interactions between pyridyl and thiadiazole rings forming a three-dimensional structure, as established by Hirshfeld surface analysis. This new 1-D copper coordination polymer exhibited elevated antimicrobial activity against several strains of the fungal phytopathogens Verticillium dahliae and Fusarium oxysporum fsp. melonis suggesting its use as a fungicide in crop protection.