Synthesis, Structures and Various Biological Applications of New Zn(II) Complexes Having Different Coordination Modes Controlled by the Drug Furosemide in Presence of Bioactive Nitrogen Based Ligands.

Abstract

Novel Zn(II) complexes with the general formula: [Zn(furo)2(L)n], n = 1 or 2, (furo = furosemide = (4‐chloro‐2‐(furan‐2‐ylmethylamino)‐5‐sulfamoylbenzoic acid) were prepared. The complexes [Zn(furo)2(MeOH)2] (1; MeOH = methanol), [Zn(furo)2(2‐ampy)2] (2; 2‐ampy = 2‐aminopyridine), [Zn(furo)2(2‐ammepy)2] (3; 2‐ammepy = 2‐aminomethylpyridine), [Zn(furo)2(H2O)(2,2‐bipy)] (4; 2,2′‐ bipy = 2,2′‐bipyridine), [Zn(furo)2(H2O)(4,4′‐bipy)] (5; 4,4′‐bipy = 4,4′‐ bipyridine), [Zn(furo)2(1,10‐phen)] (6; 1,10‐phen = 1,10‐phenanthroline), [Zn(furo)2(2,9‐dmp)] (7; 2,9‐dmp = 2,9‐dimethyl‐1,10‐phenanthroline), and [Zn (furo)2(quin)2] (8; quin = quinoline) were synthesized and characterized using different techniques such as IR, UV–Vis, 1 H NMR, 13C NMR, LC/MS and others. The crystal structure of complex (4) was determined using single‐ crystal X‐ray diffraction. The anti‐bacterial activity of complexes (1–8) was tested using agar diffusion method against three gram‐positive (Staphylococcus aureus, Bacillus subtilis and Staphylococcus epidermidis) and three gram‐negative bacteria (Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa). The obtained results showed different Inhibition Zone Diameters (IZD) with various anti‐bacterial activities against the selected gram‐positive and gram‐negative bacteria. In addition, the rate of bis‐(4‐nitrophenyl) phosphate hydrolysis was measured at different temperatures, different pH values and different concentrations. The rates for the eight complexes were in the following order: complex 4>2>5>8 > 7 > 6 > 3 > 1.