الفهرس 
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Abstract
Semicarbazone ligands can be used to synthesise metal
complexes with a wide range of structures and applications due to
their ability to coordinate in either neutral or anionic state. In order
to create novel molecules with interesting pharmacological
properties, some metal complexes based on semicarbazone ligands
can exhibit anticancer, antibacterial, and other biological activities.
There is not any previous work described the metal
complexes with semicarbazone of pyrano[3,2-c]quinolines
moieties, therefore, the object of the present Thesis is to synthesis
semicarbazone of 6-ethyl-4-hydroxy-2,5-dioxo-5,6-dihydro-2Hpyrano[
3,2-c]quinoline-3-carboxaldehyde, H2L, ligand and study
its chelating behavior towards copper(II), manganese(II), cobalt(II),
nickel(II), zinc(II), cadmium(II), chromium(III), iron(III),
oxovanadium(IV) and dioxouranium(VI) ions in a molar ratio (1:1,
ligand: metal ion).
The H2L ligand was prepared and elucidated by elemental
analysis, IR, 1H-NMR, 13C-NMR, mass and electronic spectra.
The newly prepared metal complexes of the present ligand
were identified by elemental analyses, infrared, electronic, mass,
1H-NMR, 13C-NMR and ESR spectra as well as magnetic
susceptibility measurements, molar conductance and thermal
gravimetric analysis (TGA).
The obtained results showed that the ligand behaves as
dianionic O2N tridentate forming chelates with molar ratio 1:1,
Summary
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(M:L) in all complexes and coordinates through enolate oxygen,
azomethine nitrogen and deprotonated OH group.
The absorption and fluorescence characteristics of the H2L
and some of its metal complexes were recorded in nine different
solvents with gradual increasing polarities at room temperature. The
solvent effects on the fluorescence spectra of the prepared
compounds showed solvatochromic behavior.
The ground and excited state dipole moments of the H2L and
some of its metal complexes were determined experimentally by
solvatochromic shift method using Bilot–Kawski, Lippert–Mataga,
Bakhshiev, Kawski–Chamma–Viallet and Reichardt’s microscopic
solvent polarity functions and compared with those values obtained
by TD-DFT (B3LYP/ GENECP) method. The large difference in
dipole moments between electronically ground and excited states
were found. Hence, the singlet excited state of the present molecules
in polar solvent was more stabilized than the ground state.
All complexes exhibited octahedral geometry except
UO2(VI) complex exhibited pentagonal bipyramidal geometry.
In the infrared spectra, it was found that the stretching
frequency of C=Nazomethine, in all complexes was shifted to lower
values in the range 1582-1571 cm-1.
Also, the 1H-NMR spectra of diamagnetic Zn(II), Cd(II) and
UO2(VI) complexes showed the disappearance of OH and NH
protons which observed in the free ligand, indicating the presence of
the ligand in the enol form during chelation, as well as the
Summary
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participation of the ligand to metal ion through the phenolic and
amidic oxygen atoms.
To understand the nature of bonding of H2L ligand to metal
ions; DFT calculations were performed using Gaussian 09 program.
All theoretically probable structures of the free ligand (H2L) and its
complexes have been calculated using B3LYP/GENECP basis set
for C, H, N and O atoms and SDD basis set for the metal atom in
gas phase to search for the most probable model building stable
structure.
Investigation of the structural parameters data and their
correlations refers the following points:
1. The calculated dipole moment, EHOMO, ELUMO and Egap of the
free ligand conformers, predicted the more favorable tautomeric
form of the ligand.
2. ΔEgap of all complexes are smaller than that of their free ligand,
indicates that the reactivity of complexes is higher than free
ligand.
3. Generally, bond lengths of coordinating centers are longer than
the corresponding in the free ligand (C=Nazomethine, C-Ophenolic
and C-Oquinoline).
Summary
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The H2L ligand and its metal complexes were screened for
their antimicrobial activity against Staphylococcus aureus and
Bacillus subtilis as Gram-positive bacteria, Escherichia coli and
Salmonella typhimurium as Gram-negative bacteria, Candida
albicans as yeast and Aspergillus fumigatus as fungal strains.
The antitumor activity of the H2L ligand and its metal
complexes were investigated against hepatocellular carcinoma cell
line (HepG-2) in comparison with the standard antitumor drug Cisplatin.
The tested complexes revealed variable activity towards the
used cell.
Docking investigations on the H2L ligand and current
complexes revealed that they all significantly inhibited the VEGFR-
2 enzyme.
The geometrical structures of the current complexes are
shown below.