الفهرس | Only 14 pages are availabe for public view |
Abstract The present thesis comprises three main chapters in addition to Arabic and English summaries as well as the relevant references. The First Chapter: - Introduction This chapter includes a scientific literature survey related to nitrogen containing ligands and their metal complexes, regarding design, synthesis, characterization and different biological applications as anticancer, antibacterial and antifungal. Also, the previous studies carried out on the effect of gamma irradiation on some different compounds especially metal complexes. The Second Chapter: - Experimental This chapter includes a detailed account about the method of synthesis of the current nitrogen containing ligand and its metal complexes by reacting the ligand under study with different metal salts as: manganese(II), cobalt(II) nickel(II), copper(II), thorium(IV) and uranyl(II). Different standardized instruments as spectral (UV-Vis; IR) methods, elemental analyses, magnetic moment, molar conductivity measurements, thermal (TG/DTG) technique, electron paramagnetic resonance (EPR) spectra and X-ray diffraction (XRD) patterns were used for characterization of the structure of the synthesized ligand as well as its corresponding metal complexes. The ligand and its metal complexes have also been screened for their antibacterial and antifungal activities against pathogenic bacteria and fungal strains. Some selected complexes (2B,4B,6B) were subjected to gamma irradiation to a dose of 100 kGy and at a dose rate of 2.2 kGy h-1. The FT-IR, UV–Visible absorption spectra, molar conductivity, magnetic susceptibilities and thermal analysis (TG/DTG) for the irradiated samples were obtained. X-ray powder diffraction technique of the unirradiated and irradiated samples of complexes were carried out. Electron paramagnetic resonance (EPR) spectra were carried out for one of the copper(II) complexes before and after irradiation. The third Chapter: - Results and discussion This chapter includes the results obtained and their discussion and includes the following: - (i) Synthesis and characterization of ligand (L): N,N-((Z)-ethane-1,2- diylidine)bis(2-aminobenzohydrazide) and its Mn(II), Co(II), Ni(II), Cu(II), Th(IV) and UO2(II) metal complexes. (ii) characterization of the obtained compounds was achieved by using different analytical and spectroscopic tools such as {IR; UV/ Vis}, molar conductance, magnetic moment measurements and thermal analysis (TG/DTG) technique. X-ray diffraction (XRD) patterns and electron paramagnetic resonance (EPR) spectra have also been carried out for some selected complexes to substantiate the proposed structure. Also, selected complexes (2B,4B,6B) indicated after irradiation as (2A,4A,6A) were irradiated by γ-rays at a dose of 100 kGy and at a dose rate of 2.2 kGy h-1 by using Indian 60Co γ-ray cell type GE-4000 A under room temperature. from the obtained results we have reported the following remarks: 1. The complexes are air stable, non-hygroscopic and are slightly soluble in alcohols, insoluble in most common organic solvents. but, they are soluble in DMF or DMSO solvents. 2. The results of elemental analyses showed that all complexes are formed in molar ratio (1M:1L) except for complex (4) that is 2M:1L and complex (8) that is 1M:2L. 3. The molar conductivity values for metal complexes show that all complexes are non-electrolytes except complex (7) that is 1:1 electrolyte and complex (8) is 1:2 electrolyte. 4. IR spectral studies of ligand (L) showed that the ligand exhibits interesting coordinating ability to the different metal ions and behave as a neutral tetradentate or bidentate one or as dibasic tetradentate. 5. The electronic absorption spectra and magnetic susceptibility measurements proved that all metal complexes have distorted octahedral geometry except complex (4) that adopt tetrahedral geometry. 6. The EPR spectrum of Cu(II) complex (6B) in powdered form indicated axial spectrum with dx2- y2 ground state of Cu(II) ion. 7. The thermal behavior of metal complexes shows good agreement with the formula suggested from the analytical, spectral and magnetic data. The decomposition temperature lies in the range (136-235 °C) for metal complexes. 8. X-ray powder diffraction (XRD) patterns of complexes (2B,4B,6B) showed that these complexes are amorphous. By comparing the results of molar conductivity, FT-IR, UV-Vis. absorption spectra, TGA, XRD and EPR studies of unirradiated and irradiated we can outline the following remarks: 1- Molar conductivity of iradiated complexes slightly changed after irradiation. 2- Position, shape and intensities of IR peaks of some functional groups as (C=N), (C=O) in irradiated complexes slightly changed after irradiation. 3- No new peaks were observed in UV–Visible spectra after irradiation, but a slightly change in the intensity as well as position of d-d bands were observed. Also, magnetic moments of irradiated complexes showed slight changes after irradiation. Thus, there was no change in the geometry complexes after irradiation. 4- UV–Vis spectra, magnetic moments and Electron paramagnetic resonance (EPR) spectrum of Cu(II) complex (6A) after irradiation indicated its octahedral geometry with dx2- y2 ground state. 5- TGA results indicated slightly change in dehydration temperature and thermal decomposition of irradiated complexes. 6- X-ray diffraction (XRD) patterns studies indicated no change in the XRD patterns of complexes after irradiation and that the unirradiated and irradiated complexes are amorphous. (iii) The ligand and its all metal complexes have been screened against pathogenic bacteria and fungal strains for testing their antimicrobial activity, The antimicrobial studies results showed that these compounds exhibit a moderate antibacterial and antifungal activity, and that: 1. Mn(II) complex was the most potent one, it showed higher antibacterial activity than the free ligand with respect to gram positive (Staphylococcus aureus) at both concentration (20, 10 mg/ml). Also, Ni(II) complex showed higher antibacterial activity than the free ligand with respect to gram positive at both concentration. 2. Although the ligand has no antifungal activity, complexes (2A,3) exhibited moderate activity at low concentration (10 mg/ml) and complex (7) exhibited activity at high concentration. 3. Antimicrobial activity of tested complexes is higher than that of the free ligand, which implies an increase in the antimicrobial activity with chelation/coordination. |