Synthesis and spectral studies of some metal complexes derived from 1, 3, 4-oxadiazole and evaluated of biological activity

Abstract

The percent work describes the synthesis and characterization of Ligand [L1] 2, 5-bis(4-butoxy phenyl) -1,3,4- oxadiazole in several steps, one is the treating of 4-hydroxy benzoic acid with alkyl bromide, (RBr) R=[(CH3(CH2)3] in alkaline medium of KOH to give the precursor[ S1] 4-(butyloxy) benzoic acid. The second step have been prepared the precursor [S2]4-(butyloxy) benzoate from compound [S1] in methanolic acidic solution. The third step prepared the precursor [S3] 4-(n-butoxy) benzohydrazide by the reaction [S2] and hydrazine hydrate(90%). The last step reaction between precursor [S1] and [S3] in present of POCls to obtained ligand [L1]. The primary ligand [L1] was characterized by Fourier transform infrared spectraFT-IR,1H-NMR,13C-NMR,ThermalGravimetric analysis, (UV-Vis) spectrophotometer, Mass spectroscopy and elemental microanalysis (C.H.N) and melting point. The compound benzyl (propane-2-yl) carbamodithioate (S-bpth) was used as co- ligand to synthesis the metal complexes. The Ag(L1) complex was prepared from two moles of L1 and one mole of AgNO3 in dichloromethane solvent at inert condition. The complexes Ni(II), Pd(II), Pt(II), Cu(II) and Zn(II) were synthesized from the two mole of primary ligand(L1 ) and one mole secondary ligand (S-bpth) with one m mole of metal chloride in ethanol medium and characterized comprehensively by Fourier transform infrared spectra(FT-IR), (UV-Vis) spectrophotometer, elemental microanalysis (C.H.N) metal analysis, Atomic absorption spectrophotometer (F.A.A), Magnetic moment, Conductivity measurement and some of complexes by Thermal analysis. The results obtained from elemental analyses and spectroscopic measurements have suggested that the Ag(I)-L1 complex is linear geometry. The mixed ligand complexes of palladium(II), platinum(II) and copper(II) have square planar geometry exceptnickel(II) and Zn(II) complex which is tetrahedral geometry. The second part of the work involved the study of biological activity of the primary 1,3,4-oxadiazole ligand and its metal complexes in DMSO as control against some bacteria strains (Staphylococcus aureus, Bacillus subtilis, Escherichia Coli and Eterobactern) with respect to Ampicillin and Ciproflixine as standard drugs. The observed results from inhibition zone values investigated that most metal complexes exhibited greater inhibition against the all kinds of bacteri zone values that most metal complexes exhibited greater inhibition against the all kinds of bacteria.