الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
1- In the first chapter, the literature survey of the previous studies on the complexes of different
metals specially lanthanides and actinides ions
wi th the different azo compounds is given. The previous
studies including also potentiometric, conductometric,
spectrophotometric and polarographic studies on the metal complexes.
2- The experimental part includes the preparation of arsenazo dyes under investigation, the stock
solutions together with their standardization. It comprises also an outline about the equipments used for conductometric, spectrophotometric, potentiometric, polarographic, IR, TGA and DTA measurements.
3- Chapter III includes the results and discussion
of the studies on the solutions of complexes formed
between arsenazo dyes under investigation with the
ions (SC3+, y3+, La3+) and actinide
and U02+) and its stability cons-
2
lanthanide metal
metal ions (Th4+
tanto from the potentiometric measurement studies
the proton-reagent stability constants
are evaluated. The results give the metal-reagent
stability constant of the complex log k1 and log k2
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for 1:1 and 1:2 complexes formed between arsenazo
dyes and metal ions. Comparison of the stability
constants of the chelates under investigation it
was found that the log k value is depend on the
ionic size and oxidation state of the ions. The
results of the pk values obtained are supported
by its determination using different spectrophotometric
methods namely the molar ratio, continuous
variation and corresponding solution methods. The
stability constants obtained by using the polarographic
measurements for the different chelates
are slightly different than that obtaind potentiometrically
or spectrophotometrically which may be
due to the reduction behaviour of the chelate on
the DME.
The stoichiometry of metal complexes in solution
is also studies by different spectrophotometric
methods namely the molar ratio, straight line and
continuous vibration methods. The resul ts reveal tha t the
complexes of 1:1 and 1:2 (M:L) types are formed
for ligands I, II, III and IV. Stoichiometry of
metal complexes in solution are also studies by
conductometric titration method giving a ratio not
much different from that obtained spectrophotometrically
except for ligand IV which form 2: 1 (M:L)
complex with different metal ions.
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The infrared absorption spectra of ligands
and their metal chelates give an indication that
the coordination and covalent bond for ligands I
and II occur through the azo group and the hydroxyl
group of naphthol part with the different metal
ions whereas for ligands III and IV the bonds of
the metal ions with it occur through carboxylic
group and the hydroxyl one of the naphthoic part.
For chela tes of the type 2: 1 of ligand IV, the coordination
and covalent bonds occur to the second
metal ion was through the azo group and one hydroxyl
of the arsenate group. The molar conductance of
the chelates are determined indicating that the
chelates are non electrolyte in nature. The solid
complexes are also analysed by the thermal methods
viz. TGA to confirm the stoichiometry which indicate
that the most chelate compounds are mononuclear
but in case of 2_hydroxy-1-(1-phenylazo-2-arsonic
acid) -3-naphthoic acid it form three types of complexes
namely (1: 1) t (1 :2) and (2: 1) (M:L). The number
of water molecules of crystallization are determined
by dehydration method which supported by the TGA
whereas, the number of water molecules coordinated
to the metal ion are determined by TGA only. The latter
is confirmed by endothermic peaks observed in the
curves of TDA which exhibit also the positions of
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the phase transformation of the chelates under studies.
The electronic absorption spectra of the solid
metal chela tes of the ligands I-IV with Sc 3+, y3+,
La 3+, Th4+ and uo~+ ions in DMF and nuj 01 mull show a red
or blue shift for the CT band of the free ligand. Which
confirmed generally that such ligands coordinated
with the metal ions in some sort of chelation leading
to the formation of the various types of chelates.
4- Chapter IV, includes the analytical determination
of lanthanide metal ions (Sc3+, y3+, La
3
+)
and actinide ions (Th4+ and uo~+) with arsenazo
dyes under investigation using the spectrophotometric
methods. The optimum blank solutions for the spectrophotometric
determination of metal ions can be observed
for the limiting value for the determination
of all metal ions. Ligand III is the most sui table
one to determine the metal ions under investigation.
This due to that chelation of the metal ion wi t.hligand ill
occurs through a chelating centre far from arsenic
acid group of henderence effect .i . e through hydroxy
and carboxy groups of naphthoic acid. Sc
3
+ is the
most suitable metal ion can be determined by ligand
III because of the high molar absorptivity of its
chelates. These results are also confirmed by the
polarographic method for determining metal ions