الفهرس 
acknowledgmentOnly 14 pages are availabe for public view
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Abstract
The thesis comprises three chapters. The first concerns with the literature survey on the structural chemistry of some azo, thiobarbituric acid compounds and the complexes of both.
The second chapter is related to the experimental part. The synthesis of both the ligands and their complexes are described. The analytical data depict the formation of different complexes with the stoichiometries 1:1, 1:2, 1:3 and 2:3 (M:L) depending on the transition metal salt and the ligand. The standardization of the instruments used for the measurements (H-NMR, IR, UV-Vis, ESR, pH and magnetic susceptibility) are described. The preparations of the solutions (ligands, buffer, synthetic sea water and purifica- tion of solvents) are explained.
The third chapter is concerned to the results and discussion. The 1H-NMR spectra of the ligands proved that 5-(phenylazo) thiobar- bituric acid exists mainly in the thione form with the possible existence of the phenomena of tautomerism between the CH group in the 5 position with the adjacent carbonyl group. This leads to form the C-C-OH system that favours to form an intramolecular hydrogen bond with the azo group. The strength of this bond is greatly influenced by the nature of the substituents attached to the phenyl ring. The electron withdrawing substituents decrease the intramolecular hydrogen bond to a great extent as indicated.