الفهرس 
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Abstract
ENGLISH SUMMARY
The present thesis comprises of three main chapters in addition to Arabic and English summaries as well as relevant references.
The First Chapter: Introduction
This chapter concerned with a scientific literature survey related to Schiff base ligands and their metal complexes especially those of biological active and structural viewpoints related to 2-benzoylpyridine, 5-aminouracil and 4,4`-methylenedianiline.
The Second Chapter: Experimental
This part describes the preparation of Schiff base ligands; (N,N’)-4,4’-methylenebis(N-(phenyl(pyridin-2-yl)methylene)aniline) (L1) and ((E)-5-((phenyl(pyridin-2-yl)methylene)amino)pyrimidine-2,4(1H,3H)-dione) (H2L2) resulted from the reaction of 2-benzoylpyridine with 4,4`-methylenedianiline or 5-aminouracil with (2:1) and (1:1) molar ratio, respectively. Also, the methods used to prepare the metal complexes of these ligands with Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Fe(III), Cr(III), Ru(III), Zr(IV) and Hf(IV) were described. Different instrumental methods were utilized for elucidation the structure of ligands and their metal complexes as elemental analyses, spectral techniques (IR, UV–Vis, 1H NMR, X-ray diffraction, ESR and mass spectra for the ligands), magnetic susceptibility, molar conductivity and thermogravimetric studies. Finally, the biological activity of the prepared ligands and some of their metal complexes has been screened against the human hepatic cell line Hep-
G2 to establish their potential as anticancer agents.
The Third Chapter: Results and Discussion
This chapter is divided into two parts:
Part I
An extraordinary range of properties for L1 ligand are exhibited by the prepared complexes. The structure of L1 ligand and its metal complexes was investigated using analytical and spectral methods. The obtained data depict that:
1. The elemental analyses and spectral methods (IR, UV–Vis, 1H NMR and mass spectra) support the formation of Schiff base ligand (L1).
2. The results show that the 2:1 (M:L) molar ratio reaction of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), and Cr(III) chloride, CuBr2, and Cu(NO3)2 with the ligand produced complexes with 4:1, 3:1, 1:1, and 1:2 (M:L) molar ratio.
3. The molar conductivity values reveal that all complexes are characteristic for the non-electrolyte nature and the anions are directly attached to the metal ions.
4. The IR results reveal that the ligand behaves as a neutral tetradentate moiety in all metal complexes {except Zn(II) complex}, it binds with the ion via four nitrogen atoms of azomethine groups and pyridine rings, respectively. While, the ligand acts as a neutral bidentate fashion in Zn(II) and coordinates through two nitrogen atoms of (C═N) group and pyridine ring to form mononuclear complex with 1:2 (M:L) molar ratio.
5. The electronic spectra and magnetic moment measurements proved that Mn(II), Cu(II) chloride, Zn(II) and Cr(III) chelates have octahedral geometry, while Co(II), Ni(II) complexes (2, 3) and Cu(II), Pd(II) complexes (5, 6, 7) have triagonal bipyramidal, square pyramidal and square planar structure, respectively.
6. The ESR spectra of Schiff base copper(II) complexes are axial in nature for complexes (5) and (6), where g|| > g ┴ indicates a (dx2-y2)1 ground state, which is a typical occurrence for tetragonal copper(II) complexes. The geometric parameter G for the complexes (5) and (6) was calculated to be 2.94 and 2.61, respectively, pointing to the presence strong antiferromagnetic interaction between copper(II) ions. Also, the Cu(II) ESR spectrum (4) exhibits rhombic symmetry.
7. The thermal decomposition behavior of the ligand and its metal complexes was discussed based on thermogravimetric analyses. The follow-up of the pathway of the thermal decomposition and final residues confirmed the chemical formula and geometrical structure of the prepared metal complexes. The thermal decomposition reactions ended with the formation of metal or metal oxide contaminated with carbon sometimes. The end products (cobalt, Mn3O4 and Cr2O3) isolated from the thermal decomposition of Co(II), Mn(II) and Cr(III) chelates were confirmed using IR and XRD spectra.
8. The activation thermodynamic parameters, such as activation energy (E*), enthalpy of activation (ΔH*), entropy of activation (ΔS*) and Gibbs free energy (ΔG*) have been calculated using DTG curves. The data showed that he higher thermal stability of Mn(II) complex than Cr(III) may be related to the smaller electronegativity and higher ionic radius of manganese than chromium. Also, the higher thermal stability of the Ni(II) complex than the Co(II) complex is related to the number of solvent molecules of crystallization, which decreases the flexibility of the structure due to the formation of inter and intramolecular hydrogen bonds
9. The results obtained from the pharmacological studies of the ligand and some of its metal complexes (4-7,9) against the human hepatic cell line Hep-
G2 reveal that the copper(II) bromide complex (5) exhibits high inhibition on the cell line than the ligand and the other metal complexes.
Part II
This part includes synthesis of Schiff base ligand (H2L2) from the condensation reaction of MDA with 5-aminouracil as well as its metal complexes. The structure of ligand and its complexes was investigated by different analytical and spectral techniques. The data refer to the following results:
1. The elemental analyses and spectral methods (IR, UV–Vis, 1H NMR and mass spectra) support the formation of Schiff base ligand (H2L1).
2. The data display that the 1:1 (M:L) molar ratio reaction of Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Fe(III), Cr(III), Ru(III), Zr(IV) and Hf(IV) chloride with the ligand produced complexes with 1:1 and 2:1 (M:L) molar ratio.
3. The molar conductivity values point to the non-electrolytic nature for all complexes except CuCl2 (4) and PdCl2 (6) complexes which were typified (1:1) electrolyte.
4. The IR results reveal that the ligand behaves as a neutral pentadentate; tetradentate; tridentate and bidentate moiety (in keto form) in complexes (2’); (1’), (3’); (6’-8’) and (4’), (5’), (9’-11’), respectively.
5. The electronic spectra and magnetic moment measurements demonstrated that Cu(II), Cr(III), Fe(III), Cr(III), Ru(III), Zr(IV), Hf(IV) chelates possess octahedral geometry, while Mn(II), Ni(II) and Zn(II) complexes display a tetrahedral structure. Also, the spectra of Co(II) and Pd(II) compounds suggested that they possess trigonal bipyramidal and square planar geometrical structures, respectively.
6. The thermal decomposition behavior pathways of the ligand and its metal complexes have been studied by (TG/DTG) analyses. The final thermal decomposition products are (metal or metal + C). The thermodynamic and kinetic parameters of the thermal decomposition were evaluated and discussed. The change of entropy values (ΔS*) for the thermal decomposition steps showed that the transition states are more ordered, i.e. in a less random molecular configuration than the reacting complexes. Also, the fraction appeared in the calculated order of the thermal reactions (n), confirmed that the reactions proceeded in complicated mechanisms.
7. The biological activity of the ligand as well as its metal complexes has been tested in vitro against liver tissue as anticancer activity. The results show that the coordination compounds exhibit increased cytotoxic activity when compared to its free ligand.
The data in this thesis are collected in (17 Tables) and represented in (23 Figures), (38 Schemes), Also, a list of references is given and containing.