الفهرس 
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Abstract
Since the 50s of last century, many thiosemicarbazides have
provoked wide interest for their significant biological and
pharmaceutical activities, such as antibacterial, antiviral,
antimalarial, antileprotic and antineoplastic as well as anticancer
activity. The current interest in thiosemicarbazides is due to the
presence of various donor atoms (O, N and S-donors), which
exhibit diverse bonding modes leading to different structural
motifs.
The main aim of the present thesis is focused on the
preparation and characterization, elemental analyses, thermal
(TGA and DTGA), spectral (IR, UV-Visible, EI-mass, NMR and
ESR), XRD and magnetic measurements of new complexes of
(Z)-N-benzoyl-N’-(1H-1,2,4-triazol-3-yl)carbamimidothioic acid
(H2L1) and N-(benzo[d]thiazol-2-ylcarbamothioyl)benzamide
(H2L2) with Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II),
Cd(II), Hg(II) and U(VI)O2
2+ metal ions. Also, molecular
computational calculation and biological activity studies were
carried out.
A brief description of the overall work in this thesis can be
summarized as follow:
Chapter one displays different publications concerning the
complexation of thiosemicarbazides with a great attention to
the compounds similar to that investigated and their
biological activities.
The second chapter covers the experimental part and
illustrates the experiments used in this work. It includes a list
of reagents, stock solutions along with the physical
measurements and instrumentation, as well as the working
procedures and a description for the preparation of ligands
and its metal complexes. In addition, this chapter includes the
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Summary
recommended procedures for the antioxidant, antitumor and
the anti-microbial activity of the prepared metal complexes.
Chapter three deals with the results and discussion which are
summarized to give the following information:
1- The proposed chemical formulae of the ligands and their
metal complexes are in good agreement with the
stoichiometries concluded from their analytical data of
carbon, hydrogen, nitrogen, chloride and metal contents.
2- Most of complexes have high melting points (>300˚C) and
insoluble in most organic solvents.
3- The coordination sites of the ligand, the nature of metalligand bonds and the nature of the acetate groups and the
existence of the solvated molecules have been elucidated
using IR spectra. Different modes of chelation for the
investigated ligands are suggested based on careful
comparison between the spectra of the ligands and their
corresponding complexes. The data obtained are
summarized as:
H2L1 acts as:
i. NN neutral bidentate via (C=N)*
and (C=N) of
hetero ring moiety in Cr(III) and Co(II) complexes.
ii. NO uni-negative bidentate via the enolized (C-O)
with deprotonation and (C=N) in the complexes of
Cu(II) and Fe(III) chlorides in addition to complexes
of Zn(II) and UO2
2+ acetate.
iii. OS mono-negative bidentate in Cd(II) and Hg(II)
complexes via (C=O) and the deprotonated thiol
groups.
iv. NOS mono-negative tridentate via the deprotonated
-SH, (C=O) and (C=N) ring groups in Zn(II)
chloride complex.
v. Binegative tridentate and tetradentate in Mn(II) and
the binuclear Ni(II) complexes, respectively.
H2L2 acts as:
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Summary
i. NSO neutral tridentate in Cu(II) complex.
ii. NSO mononegative tridentate in Co(II) complex.
iii.NSO binegative tridentate in Fe(III) complex.
iv. OS mononegative bidentate in Mn(II) complex.
v. NO mononegative bidentate in Ni(II), Cr(III) and
Zn(II) complexes.
vi. NS mononegative bidentate in Cd(II) and Hg(II)
complexes.
4- The 1H NMR spectra of the diamagnetic Zn(II), Cd(II) and
Hg(II) complexes of H2L2 are used to detect the potential
coordination sites.
5- The geometries are suggested of the prepared complexes
based on the data evaluated from spectral and magnetic
measurements; [Zn(HL1)(OAc)(H2O)], [Cd(HL1)Cl(H2O)],
[Hg(HL1)Cl(H2O)], [Zn(HL1)Cl].0.5H2O,
[Cd(HL2)Cl(H2O)], [Hg(HL2)Cl(H2O)] and
[Zn(HL2)2].2H2O are quite near to a tetrahedral geometry
predicting sp3
hybridization. On the other hand,
[Ni2(HL1)Cl2(H2O)2].4H2O complex showed mixed
geometries (tetrahedral and square planar) with sp3
and
dsp2 hybridization. On the other hand, all other complexes
afforded an octahedral geometry with d
2
sp3
or sp3
d
2
hybridization.
6- The geometries of both Cu(II) complexes were elucidated
using ESR spectra confirming an octahedral geometry for
both complexes
7- Good information about the geometry and crystal lattice
system, lattice parameters for Co(II) and Ni(II) complexes
using the powder X-ray diffraction pattern confirming the
proposed geometry for complexes.
8- Detailed thermal analysis for the prepared complexes was
performed in the temperature range 20-800 ˚C. The
thermograms show the decomposition steps after which a
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Summary
constant weight is observed corresponding to the remaining
part of the complex.
9- In order to assess the influence of the structural properties
of the ligands and the type of the metal on thermal
behaviour of the complexes, the order (n) and the heat of
activation (Ea) of the various decomposition stages are
determined from the TGA and DTGA using HorowitzMetzger and Coats-Redfern methods. This section includes
also the determination of the thermodynamic parameters of
activation (ΔH*
, ΔS*
and ΔG*
) which can be calculated by
Erying equation.
10-The final part in this chapter deals with the antimicrobial
activity, antitumor and antioxidant activity for both ligands
and their metal complexes.