Sev and pcu topological nets in one-pot newly synthesized mixed-ligand imidazole-containing Cu(II) coordination frameworks: Crystal structure, intermolecular interactions, theoretical calculations, magnetic behavior and biological activity

Novel mixed-ligand coordination frameworks, occurring concomitantly namely [Cu(Im)3(H2Cit)] (1) and [Cu(Im)2(HCit)]·HIm (2) (with Im = imidazole and H4Cit = citric acid) were obtained as a result of the one-pot reaction between imidazole, citric acid and copper chloride. The complexes were structurally characterized by elemental analysis, FTIR spectroscopy and X-ray diffraction. The two structures were found to be connected through 3D hydrogen-bonding networks examined by means of the Hirshfeld surface analysis which highlighted the presence of O–H⋯O, N–H⋯O and C–H⋯O H-bonds together with the π⋯lp interactions. A topological analysis of the underlying nets corresponding to the two hydrogen-bonded frameworks was carried out. Moreover, quantum chemical calculations were performed using the HF method with 6-31G(d) and LANL2DZ levels in the gas phase, and therefore the optimized structures, the IR, 1H NMR, 13C NMR spectra and the electronic structure descriptors were examined in detail. Furthermore, the magnetic properties of (1) and (2) were also investigated. The complexes showed remarkable antimicrobial and antifungal inhibition activities.