Synthesis, Characterization and Anti-Bacterial Activities of Zn2+, Cu2+ and Fe2+ Complexes of Asparagine

There is need for more research on complexes and their bioactivities. Complexes of copper (II), iron (II) and zinc (II) where synthesized with asparagine in the ratio of 1:2 and characterized. The melting point, colour and solubility in water, ethanol, diethyl ether, acetone, chloroform, DMSO and methanol were studied at 25oC. The characterization of the prepared complexes was done using FT-IR, UV-VIS, XRD, and crystallography methods. The percentage yield obtained were 60.3%, 44.2% and 26.12% for Cu (II), Fe(II) and Zn (II) complexes respectively. The complexes were found to be soluble only in methanol and slightly in ethanol amongst other solvents studied at room temperature. The melting points of the complexes ranged between 230-234OC, 292- 298oC and 285-288oC for Cu(II), Fe(II) and Zn(II) complexes respectively while that of the ligand (asparagine) used was found to be 240-250oC, an indication that the prepared complexes have higher melting point compared to the ligand possibly due to strong coordination. The FT-IR spectra shows that the prepared Cu(II), Fe(II) and Zn(II) complexes have tentative coordinate points at O and N atoms with confirmed UV-VIS wavelengths of 386nm, 290nm and 370nm respectively. The complexes were found to be crystalline as confirmed by the sharp peaks of their X-ray diffraction results. The crystalline size for zinc and copper complexes are 44.22 nm and 30.89 nm respectively. The crystallographic indicate that the complexes exhibit an octahedral structure for Cu(II) and Zn(II) complexes respectively. Anti-bacterial study of the synthesized complexes indicated that these complexes have antibacterial activity against Staphylococcus aureus, and Escherichia coli.