In the present communication a synthesized ligand 4- [2-(1-methyl benzimidazolyl) azo] proline (MBP) was used to prepare three new complexes of Cu(II), Ag(I) and Au(III). The ligand and its complexes were characterized by elemental analysis (CHN), A.A, UV-Vis, FTIR and HNMR spectroscopy, magnetic susceptibility measurement, thermal analysis and molar conductivity measurement. Chloride ion content was also evaluated by Mohr method. The result was showed that the ligand was acted as N,N-bidentate. The preparation of the complexes was conducted after fixing the optimum concentration and pH. UV-Vis spectra of these complex solutions were investigated studied for a range of pH (5-9) and concentration (1×10 -5 -3×10 -5 ) which obey Lampert-Beers Law. The stoichiometry of the complexes was deduced according to mole ratio and Job methods which were obtained from spectroscopic studies of the complex hassolutions. The ratio of metal: ligand have been obtained was (1:2) for Cu(II) and Ag(I) complexes while Au(III) complex has (1:1)mole ratio. The antibacterial activates and dyeing achievement for the ligand and its complexes were test.

The synthesis, structural spectroscopic properties of 4-(2-benzimidazolylazo)proline (BMP) and its complexes derived from [Cu(II), Ag(I) and Au(III)] salts were done. The mode of bonding for the complexes were accomplished based on elemental analysis, FTIR, UV-Vis and HNMR spectroscopy, magnetic measurement and molar conductivity. It has been found that the ligand (BMP) behaves as N,N-neutral bidentate which was forming chelates with molar ratio (1:2) (M:L) stoichiometry for [Cu(II) and Ag(I)] while Au(III) complex form molar ratio (1:1) at optimum concentration and pH as well as (l max ). The stability constant and Gibbs free energy for the prepared complexes are evaluated by spectroscopic methods. The prepared ligand (BMP) in comparison to its metal complexes, were screened for their antibacterial activity against two bacterial species, Escherichia coli and Staphylococcus. Dying performance was also studied.