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Abstract The thesis entitled ” Physicochemical Studies on Some Complexes Containing Nitroso and Azo Groups” comprises three chapters. The first includes the literature survey on the structural chemistry of some nitroso , azo and azo - nitroso and their complexes , beside the biological importance and the mechanism of nitrosation . The experimental part is given in the second chapter. The synthesis of both four free ligands and twenty one complexes [ Cr’” , Fern, COil, Nill and CUll ] are described. The analytical data depict the formation of different complexes with stoichiometries 1: 1 , 1:2 , 2: 1 , 1:3 and 1:4 (M:L) depending on the transition metal salt and the ligand . Different standardizied instruments (uv - vis , ir) , magnetic susceptibil ity ,pH, conductivity and thermal analysis are used . The preparation of solutions (ligands , metals, buffers and the purification of solvent) are explained. The results and discussions are given in the third chapter. The effect of the pH on the electronic absorption spectra of the ligands are illustrated, where the spectra indicated that the intensity and the band positions are pH dependent with the presence of some isobestic points . The dissociation constants of the ligands are evaluated by different spectroscopic methods (half height , Colleter , isobestic and modefied limiting absorption ). The pK values for DNR are of lower values than the parent resorcinol, due to the electron attracting property of the nitroso group . The azo and the substituent groups are of minor importance to effect the ionization process and the spectra. |