الفهرس 
COVEROnly 14 pages are availabe for public view
 |  | from | 271 |  |  |
| | | from | 271 | | |
Abstract
This thesis comprises six chapters as follows :
Chapter 1 includes a literature survey on metal complexes of the quinolyl and pyridyl hydrazones till recent years.
Chapter 2 gives the experimental part which deals with the reagents, materials, preparation of the ligands and their complexes, solutions as well as instrumentation and working procedures.
Chapters 3 – 6 cover the discussion of the results of this study as follows:
Chapter 3 relates the structure elucidation of three series of quinolyl hydrazones via elemental analysis and the spectral studies (electronic, IR, 1H NMR and mass spectra). Also, it relates a theoretical study of the structural parameters of the studied hydrazones as well as the effect of several solvents (polar or non-polar; protic or aprotic) on their electronic spectra. It was found that λmax correlates linearly with the structural parameters and Hammett,s constant.
Chapters 4 – 6 give the physico-chemical studies on the isolated solid complexes. These chapters were classified according to the type of the chelating agent [Isatin HQ (Ch. 4), Oxime HQ (Ch. 5) and 2,4-OH BzHQ (Ch. 6)]. The structure elucidation of the quinolyl hydrazone complexes was achieved via elemental and thermal analysis and the spectral studies (electronic, IR, ESR and mass spectra) as well as conductance and magnetic measurements. This study reflects the following remarks:
(i) Mono-, binuclear and dimeric complexes as well as homoleptic (5, 7 – 10, 15 – 17, 22 & 37) and heteroleptic complexes (the others) were obtained.
(ii) The structural diversity for the obtained complexes e.g. different geometries such as Oh, Td, square pyramid and square planar were suggested.
(iii) The ligands showed a variety of modes of bonding depending on the nature of the metal ions and their counter ions as well as the experimental conditions.
(iv) The strong coordinating ability of the halide anions (Cl‾ & Br‾), the oxo-anions (NO3‾ & SO42–) and the carboxylate anion (AcO‾) in comparison to non / weakly coordinating ability of the oxo-anion (ClO4‾).
(v) The binuclear and dimeric complexes were formed via Lactim, oximate or phenoxy bridges. There is no evidence for the formation of such bridging via the anions, especially Cl‾, Br‾ or SO42–.
(vi) Also, there is no evidence in this study for the formation of any oxidized species especially in case of cobalt (II) - and oxovanadium (IV) - complexes.
(vii) All the binuclear complexes have the ratio 2 : 2; L : M, except the phenolic complex (24) which has the ratio 3 : 2; L : CuII.
(viii) The more rigid ligands (Isatin HQ & 2,4-OH BzHQ; containing condensed aromatic moiety) behave towards the studied metal ions as bidentate donors, whereas, the flexible oximic hydrazone (Oxime HQ, aliphatic condensed moiety) behaves either tridentate or bidentate donor.
(ix) The effect of 8- position14 in case of Isatinic complexes (1-11) is more obvious, where the N- atom of the quinoline ring does not participate in the chelation. Therefore, the color of most complexes (orange → red) is dominated by a CT transition in the indole ring. To our knowledge, the indole ring occurs in Orange Blossoms and Jasmine Flowers.
(x) The Oxinato - (37) and Phen - (38) complexes reflect the strong competency of 8-hydroxy-quinoline (Oxine) and 1,10-phenanthroline (Phen) towards oxovanadium (IV) - ion as compared to the phenolic hydrazone (H2Lc). This may be due to the bulkiness of the latter (Scheme 6.3).
(xi) Finally, some of the current isatinic and oximic complexes were screened for both anti-bacterial and anti-fungal activities and the obtained results revealed some activity especially towards the bacteria.