الفهرس 
Chapter IOnly 14 pages are availabe for public view
Abstract
In this work, 5 Quinolyl hydrazones and their transition metal complexes were isolated and characterized via extensive spectroscopic and analytical studies. Also, this work concerned with the AlloxHQ- complexes rather than the others. The AlloxHQa,b hydrazones bear two different heterocyclic rings (Quinoline + Pyrimidine). The AlloxHQ- complexes were isolated to investigate the following effects:
i) Effect of Anions
In this study, the isolated AlloxHQa - complexes revealed that the bonding mode and the basicity of the hydrazone as well as the formed chelates are highly affected by the type of the metal ion and its counter anion as shown in the following Schemes as an example:
Scheme 4.1 Copper(II)- AlloxHQa complexes.
Scheme 4.2 Nickel(II)- AlloxHQa complexes.
ii) Effect of Basic medium
Also, in this study, the isolated AlloxHQa - complexes in absence and in presence of KOH as a basic medium are highly different and the ligand shows a variety of modes of bonding. However, there is no evidence for the formation of hydroxo- complexes as shown in the following Scheme;
Scheme 4.8 AlloxHQa complexes in absence and in presence of KOH
iii) Effect of Auxiliary ligands
This study is a competency one and afforded mixed ligand complexes including Phen and Oxine as auxiliary ligands;
Scheme 5.3 AlloxHQa (Phen / Oxine) mixed ligand complexes.
iv) Stereochemical Effect
This study revealed that the presence of the Me- group in 8- position of the quinoline ring may cause some steric hindrance and / or change the mode of bonding as well as the basicity of the hydrazone i.e. the pathway of the reaction. Therefore, the metal complexes of both AlloxHQa,b are very different as shown in the following Schemes;
Scheme 4.9 AlloxHQb- complexes.
Scheme 4.10 AlloxHQa- complexes.
On the other hand, the reaction of the other hydrazones with Cu(II), Ni(II) and Co(II)- chlorides afforded mono-, bi- and trinuclear complexes (c.f. Schemes 4.11-4.13). However, in this work the following remarks can be concluded in the following points:
(i)The hydrazones showed a variety of modes of bonding and have a reformed character i.e. can change their modes of bonding.
(ii) The AlloxHQa hydrazones showed a unique unusual mode of bonding (c.f. complexes 4, 8, 12, 26).
(iii)The more flexible BHQ hydrazone afforded bi- and trinuclear complexes;
Scheme 4.13 BHQ complexes.
By contrast, the more rigid NaphHQ hydrazone afforded mononuclear square planar complexes;
Scheme 4.11 NaphHQ complexes.
On the other hand, the reaction of the BzHQ hydrazone with Co(II), Ni(II) and Cu(II)- chlorides in presence of KOH afforded mononuclear and binuclear complexes. There is no evidence for the formation of hydroxo- complexes and the presence of KOH in the reaction mixture enhances the phenoxy bridging leading to the formation of binuclear complexes (36, 38). For cobalt(II)- complex (38), the hydrazone produces ligand field strong enough to cause spin pairing.
Finally, all the isolated complexes in this work were characterized via elemental and thermal analyses, conductivity and magnetic susceptibility measurements as well as electronic, vibration, mass and ESR spectra.