Synthesis, characterization, Hirshfeld surface analysis, and the study of antimicrobial, and acaricidal properties of copper(II) complexes with 2-(hydroxymethyl)benzimidazole ligand

Three new methylsalicylatocopper and four methylbenzoatocopper complexes with 2-(hydroxymethyl)benzimidazole with structures, [Cu(3-MeSal)2(2-MeBzim)2]∙2H2O (1), [Cu(4-MeSal)2(2-MeBzim)2] (2), [Cu(5-MeSal)2(2-MeBzim)2]∙2H2O (3), [Cu(2-MeBenz)2(2-MeBzim)2] (4), [Cu(3-MeBenz)2(2-MeBzim)2] (5), [Cu(4-MeBenz)2(2-MeBzim)2] (6), [Cu(4-MeBenz)2(2-MeBzim)2]∙EtOH (7), where 3-MeSal- = 3-methylsalicylate, 4-MeSal- = 4-methylsalicylate, 5-MeSal- = 5-methylsalicylate, 2-MeBenz- = 2-methylbenzoate, 3-MeBenz- = 3-methylbenzoate and 4-MeBenz- = 4-methylbenzoate anion and 2-MeBzim = 2-(hydroxymethyl)benzimidazole were synthesized. Solid-state complexes were characterized by diffraction methods, elemental analysis, UV/VIS, IR, and EPR measurements. Hirshfeld surface analyses were made for crystal structures of all complexes. Coordination polyhedron around the copper central atom is elongated tetragonal bipyramid and two molecules of 2-(hydroxymethyl)benzimidazole and two anions of methylsalicylate or methylbenzoate are bonded in a monodentate way to the copper center. For six prepared complexes the antimicrobial and acaricidal activities have been studied. Antifungal activity has been studies on fungal species Aspergillus fumigatus, Microsporum gypseum, and Candida albicans. Antibacterial activity has been studied on bacterial strains Escherichia coli, and Staphylococcus aureus, and acaricidal activity was determined on Phytoseiulus perimilis. Complexes 1, 2 and 3 almost entirely inhibited the growth of S. aureus and complexes 1, 5 and 6 practically completely suppressed the growth of yeast strain C. albicans.