In this article, a synthesized ligand [(1-phenyl-2-pyrazolin-5-one) azo (6-bromo-2-hydroxynaphthalen-1-yl)] has employed for preparing three new complexes of Co(II), Ni(II) and Cu(II). The new azo ligand (PABH) has analyzed by Micro Elemental Analysis (CHNO), UV-visible, Fourier Transform infrared (FTIR) approaches, 1 H, 13 C-NMR spectroscopy and mass spectroscopy. The consequence has specified that the ligand was represented as N,N,O-tridentate. The preparing of complexes has accomplished after fixing the finest concentration and pH values. UV-Vis spectra of these complexes solutions have been examined for a range of pH (5-9) and concentration (1×10 -4 -5×10 -4 ) Molar that comply with Lambert-Beers law. A stoichiometry of the complexes has comprehended in relation to mole ratio which has investigated from a spectroscopic technique. The ratio of metal: ligand was achieved with (1:2) for all complexes. The metal ions complexes were characterized by FTIR, UV-Visible, molar conductance, atomic absorption, magnetic susceptibility and elemental analysis CHNO techniques. From the results of physico-chemical and spectral techniques, octahedral geometry has been proposed for these metal complexes. All these compounds were evaluated against two kinds of human pathogenic bacteria such as Staphylococcus aureus (Gram Positive) and Escherichia coli (Gram negative).

In this article, a synthesized ligand [5-amino 2-phenyl.4H-pyrazol-3-one ] and it was used to prepare new complexes of Mn (II),Co(II), Ni(II), Cu(II), Zn(II), Pd(II) and Ag(I). The new ligand (HMABP) has categorized by Micro Elemental Analysis (C.H.N.S), UV-visible, Fourier Transform infrared (FTIR) approaches, 1H,13C-NMR spectroscopy and mass spectroscopy. The consequence has specified that the ligand was represented as N,N,O-tetradentate. The preparing of complexes has accomplished after fixing the finest concentration and pH. UV-Vis spectra of these complexes solutions have been examined for a range of pH (3-10) and concentration (1x10-4-5.5x10-4) Molar that comply with Lambert-Beers Law. A stoichiometry of the complexes has comprehended in relation to mole ratio which has gotten from spectroscopic investigations of the complex  has solutions. The ratio of metal: ligand was achieved with (1:1) for all complexes. The metal ions complexes were characterized by FTIR, UV-Visible, molar conductance, atomic absorption, magnetic susceptibility, elemental analysis C.H.N.S techniques. From the results of physico-chemical and spectral techniques, octahedral geometry except with Pd2+ was square planar and tetrahedral shape with Ag+ have been proposed for these metal complexes.

In this research the ligand 5-((3-(1-((5-bromopyridin-2yl)imino)ethyl)-2-hydroxyphenyl)diazenyl)-2-phenyl-2,4-dihydro-3H-pyrazol-3-one (BHAP)was used to prepare new complexes with elements Cu(II) ,Ni(II), Pt(II),Co(II) ,Cr(III). The new ligand was analyzed by partial analysis of the elements (C.H.N). UV- visible and infrared rays(FTIR), spectroscopy H1NMR, C13NMR and mass spectrometry. The complexes were prepared after determining the optimum pH and concentration values ​​by examining the spectra (UV - Vis) of the solutions of these complexes to find out the pH (3-10), concentration (1*10 -4-5.5*10-4) and molar ratios that agree with Beer-Lambert's law. The chemical measurement of the complexes was known with respect to the ligand ratio, which was verified by spectroscopy technique, after choosing the maximum absorption of the solutions of those complexes, where the ligand ratio (1:1) was achieved for all complexes. The properties of the prepared complexes were identified by (FTIR), ultraviolet and visible rays, molar conduction, atomic absorption, magnetic sensitivity and elemental analysis techniques (C.H.N. Through the results obtained from physical, chemical and spectroscopic techniques, the geometrical shape of these complexes was suggested as octahedral. All these complexes were evaluated against two types of pathogenic bacteria (positive and negative).

Reacting [O, O-2, 3-(chloro(carboxylic)methylidene)]-5, 6-isopropylidene-L-ascorbic acid with the L-proline gave new product "[O, O-2, 3-(N-carboxylic methylidene)-N-proline-5, 6-isopropylidene]-L-ascorbic acid (NCNPA)", that has been isolated and categorized through "1H, 13C-NMR, elemental analysis (C.H.N), mass spectroscopy, UV-Visible in addition to Fourier Transform infrared (FTIR) approaches". The complexes of (NCNPA) with metal ions, M2+ (Mn, Co, Ni, Cu, Zn, Cd, Hg) and Cr3+ have been produced and characterized through FTIR, UV-Vis., molar conductance, atomic absorption, magnetic susceptibility, elemental analysis (C.H.N) methods. The ratio of metal: ligand have been obtained was (1:1) for every complex. Studying thermodynamic functions (G, H, S) for the complexes at dissimilar temperatures the data indicated, that the reaction between metals ions and (NCNPA) was exothermic, spontaneous, and more random. The complexes have been proven stable and follow the Irving-Williams series that refers to an octahedral, and their stability decreases with increasing the temperature. The TLC for L(NCNPA) and complexes depicted one spot for each, indicating the purity of these compounds. All these compounds have been evaluated against dual kinds of humanoid pathogenic bacteria gram +ve and gram -ve.

The paper reports the study of the complex formation of cobalt (II) with diethylenetriaminepentaacetic acid (DTPA, H5L) based on spectrophotometric (SF) and potentiometric data (pH). Complexes of different compositions were found, and equilibrium constants, as well as the stability constants of these complexes, were determined. Accumulation of complexes in proportion is calculated based on the acidity of the medium. The experimental data have been carried out by using mathematical models to assess the solution's possible existence with a wide spectrum of complex particles and to point out those which are quite sufficient to copy the experimental data. In addition, thermodynamic parameters (ΔG°, ΔH°, and ΔS°) for the studying complexes were calculated according to the values of stability constant (KST) at 25 °C obtained from the temperature dependence of stability constant by using van’t Hoff equation.