الفهرس 
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Abstract
preparation, characterization and biological activity study on polydentate Schiff base ligands and their chelates with some transition metals and their applications in the determination of Fe(III) in the natural water samples.”
(1)Chapter (I) includes the literature survey on the synthesis of the Schiff bases as well as their complexes with transition metals from the stability and structure point of view and the disadvantages of the previous studied in the determination of Fe(III) e.g. the methods and the different factors affecting in it.
(2) Chapter (II) includes the experimental part, involving materials, solutions, preparation of the Schiff bases as well as the metal chelates of the parent Schiff bases with Ni(II), Co(II), Cu(II) Zn(II), Cr(III) and Fe(III) metal ions and the steps of the recovery test.
(3) Chapter (III) includes the results and discussion:-
a) The preparation and characterization of the organic ligand, 2-[2-(2-formylphenoxy)ethoxy]benzaldehyde (L1) and the Schiff bases of 7, 8, 16, 17-tetrahydrodibenzo [e,m] [1,4,8,11]dioxadiazacyclotetradecine (L2), 7,8,9,10,11,12,13,14,21,22,23,24-dodecahydrodibenzo[a,g][20] annulene (H2L3) and 3-{(1E)-2-[3-(2-{3-[(1E)-2-aza-2-(3-carboxyphenyl)vinyl]phenoxy}ethoxy)phenyl]-1-azavinyl}benzoic acid (H2L4) were reported and discussed in terms of their structures using elemental analyses, IR,1H NMR, mass spectra, thermal analyses, molecular modeling, X-ray powder diffraction and spectrophotometric studies.
b)The ionization constants (pKa) of the Schiff bases as well as the stability constants of their metal chelates with Ni(II), Co(II), Cu(II) Zn(II), Cr(III) and Fe(III) ions were calculated spectrophotometrically. The Schiff bases investigated form 1:1 complexes with the above mentioned metal ions.
c)The solid complexes of the bisaldehyde ligand (L1) and Schiff bases (L2, H2L3 and H2L4) with the above mentioned metal ions were prepared and characterized using different tools of analyses such as, elemental analyses (C, H, N and metal content), IR, solid reflectance, molar conductance, magnetic susceptibility, 1H NMR and thermal analyses to identify their tentative formulae in a trial to elucidate their molecular structure.
d)Coats-Redfern equation was used to calculate the different thermodynamic parameters of decomposition processes of these chelates, namely activation energy (E*), entropy (ΔS*), enthalpy (ΔH*) and the free energy change of activation (ΔG*). The high values of the activation energies reflect the thermal stability of the complexes. The entropy was found to have negative values in all the complexes, which indicates that the decomposition reactions proceed with lower rate than normal ones.
e)Based on the results of magnetic susceptibility and solid reflectance spectra, octahedral geometries are suggested for the investigated complexes.
f)from the IR spectral studies, it is concluded that:
(i) L1 ligand behaves as a neutral tetradentate with 4 O donor sites.
(ii) L2 ligand behaves as a neutral tetradentate with 2 O and 2 N donor sites.
(iii) H2L3 ligand behaves as a neutral hexadentate with 2 O and 4 N donor sites.
(iv) H2L4 ligand behaves as binegative hexadentate with 4 O and 2 N donor sites.
g) from X-ray diffraction, it is concluded that:
(i) L1 ligand and its chelates behaves as a crystalline structure except its Fe(III) and Co(II) chelates are in a mourphus phase.
(ii) L2 ligand and its chelates behaves as a crystalline structure except its Fe(III) and Co(II) chelates are in a mourphus phase.
(iii) H2L3 ligand and its chelates behaves as a mourphus structure except its Cr(III) chelate is in a crystalline phase.
(iv) H2L4 ligand and its chelates behaves as a mourphs structure except its Cr(III) and Cu(II) chelates are in a crystalline phase.
h) The Schiff bases and their metal complexes under study showed a remarkable biological activity against Aspergillus flavus and Canidia albicans fungi and, Staphylococcus (G+) and E. coli (G−) bacteria. The biological activity of the organic Schiff bases increases in the order H2L4 > H2L3 >L1 > L2 for E. coli (G−) bacteria and H2L4 > L1 > H2L3 > L2 for Staphylococcus (G+) bacteria. Also the complexes showed a remarkable biological activity. Therefore, it is claimed here that the synthesis of these complexes might be recommended and /or established as new line for search to new antitumour particularly when one knows that many workers studied the possible antitumour action of many synthetic and semisynthetic compounds.
4) Chapter (IV) includes evaluating the capability of the results of the recovery procedures from the spectrophotometric determination of Fe(III) to different water samples under effect of different parameters e.g. effect of pH, effect of ligands concentration, effect of iron concentration, effect of temperature, effect of time and effect of foreign ions are studied.
(5) An arabic summary is given in addition to the english one and the thesis ends with the list of references which were of help to the author carrying out the present work.