Syntheses, Supramolecular Structures and Antibacterial Activities of Five Helical Transition Complexes with 5‐Chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic Acid

Abstract

Five new transition metal complexes [Cu(HL)2(H2O)2] (1), [Cu(HL)2(phen)] (2), [Cu(HL)2(H2O)]2(4,4′‐bipy) (3), [Zn(HL)2(H2O)2]·(4,4′‐bipy) (4), [Ag(HL)(4,4′‐bipy)]n (5), (H2L=5‐chloro‐1‐phenyl‐1H‐pyrazole‐3,4‐dicarboxylic acid, phen=1,10‐phenanthroline; 4,4′‐bipy=4,4′‐bipyridine) have been synthesized and characterized. Complexes 1, 2 and 4 exhibit monomeric structures, 3 shows a dinuclear structure, 5 displays 1D chain structure, and all extend to 3D supramolecular network via rich hydrogen bonds. Complexes 1, 2, 3, 5 comprise single helical chains, while complex 4 generates quadruple‐stranded helical chains. Furthermore, the antibacterial activities of the titled complexes against bacterial species, three Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis and Candida albicans) and two Gram negative bacteria (Escherichia coli and Pseudomonas aeruginosa) were studied and compared to the activities of free ligands by using the microdilution method.