الفهرس 
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Abstract
The present thesis comprises of (171 pages), the data are collected in (30 Tables) and represented in (72 Figures). Also, a list of references is given (125 references). This thesis involves three main chapters:
I- The first chapter is related to the literature survey of thiosemicarbazone derivatives and their metal complexes especially those of biological, pharmacological, industrial activity and structural viewpoints. Also, a literature survey of Eobania vermiculata and its mucous secretion was reported.
II- The second chapter is concerned with the experimental part of; (E)-N’-(1-(4-aminophenyl)ethylidene)morpholine-4-carbothiohydrazide (L1), (E)-N’-(furan-2-ylmethylene)morpholine-4-carbothiohydrazide (L2) and (E)‐N’‐(1‐(4‐((E)‐2‐hydroxybenzylideneamino)phenyl)ethylidene)morpholine-4‐carbothiohydrazide (HL3) thiosemicarbazone ligands derived from 4-morpholinethiosemicarbazide moiety along with their metal complexes. The obtained compounds were investigated by elemental analyses, molar conductivity, magnetic susceptibility measurements, molecular modeling, spectral techniques (mass, IR, UV-Vis., 1H NMR and ESR), X-ray diffraction and thermogravimetric analyses. The prepared compounds were screened in vitro for their anti-molluscicidal and antibacterial activity.
III- The third chapter involves the discussion of the results concerned with:
(1) characterization of thiosemicarbazone ligand (L1) as well as its metal complexes. The data prove that the isolated metal complexes possess different stoichiometry; 1:1 and 1:2 (M:L). The ligand coordinates with metal ions in a neutral bidentate fashion through the thione sulfur and azomethine nitrogen atoms (NS type). The molar conductance values point to non-electrolytic nature of complexes (1, 6-10) and 1:1 electrolyte for complexes (2, 3, 5). Whereas, complex (4) possesses 1:2 electrolytic behavior.
(2) Discussion of the results related to thiosemicarbazone ligand (L2) along with its metal complexes shows that the obtained metal complexes are formed with 1:1 and 2:1 (L:M) stoichiometry. The ligand reacts with all metal ions in a neutral thione form. The electrolytic Cu(II); Zn(II) complexes (5, 6; 10) bind with the ligand through the thione sulfur, furfural oxygen and azomethine nitrogen atoms (NSO type) to construct fused five membered rings. While, the rest non-electrolyte complexes chelate via the furfural oxygen and azomethine nitrogen atoms of the ligand (NO type).
(3) Investigation of asymmetric Schiff base ligand (HL3) as well as its metal complexes. Analytical data reveal that the separated metal complexes have different stoichiometry; 2:2 and 2:1 (M:L). The ligand behaves as a monobasic tetradentate donor and binds with metal ions via the deprotonated phenolic oxygen, imine nitrogen, thione sulfur and azo-methine nitrogen atoms (ONNS chromophore). Powder X-ray diffraction analysis for Co(II), Cu(II) and Ru(III) complexes (1, 3, 7) reveal that cobalt and ruthenium complexes have amorphous nature, while, copper complex is crystalline. All metal complexes have non-electrolyte nature.
Generally, electronic spectral data prove that all metal complexes possess octahedral geometry, except square planar Cu(II) complexes; (3, 6, 7), (5, 6) and (3) derived from (L1), (L2) and (HL3) ligands, respectively, as well as tetrahedral Zn(II) and Ni(II) complexes; (10) and (2) originated from (L2) and (HL3) ligands, respectively. Thermogravimetric analyses and mass spectra of metal complexes confirm the number of solvents in their inner and outer spheres. The thermal stability of metal complexes varies according to the number of solvents of crystallization, ionic radii and steric effect of anions. The activation thermodynamic parameters along with the order of reaction (n) were estimated from DTG curves by using Piloyan method. Molecular modeling data are used to demonstrate the thermal decomposition
pathways of ligands and their metal complexes, confirming their chemical structures. The thermal decomposition reactions run out with the formation of (metal, metal oxide, metal + carbon or metal oxide + carbon). The ESR spectra of Cu(II) complexes indicate that the unpaired electron is localized mainly in the d(x2-y2) orbital with axial symmetry and covalence character of metal–ligand bonds. The investigated compounds exhibit a remarkable activity on some biochemical targets in Eobania vermiculata, leading to excess mucous secretion, causing dryness and death for the snails. Thus, these compounds can be used to combat the proliferation of Eobania vermiculata. Additional studies are still necessary to supply the most prospective mode of action of these compounds on Eobania vermiculata. Also, the in vitro antibacterial screening of asymmetric Schiff base ligand and its metal complexes establish that these compounds have a considerable activity against the representative Gram-positive bacteria; Staphylococcus aureus and Gram-negative bacteria; Escherichia coli with different inhibition degrees.