الفهرس 
General DiscussionOnly 14 pages are availabe for public view
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Abstract
SUMMMARY
1-In the first chapter, the literature survey on the studies of the organic compounds similar to those under investigation and its complexes with some transition and actinide metal ions is given. The literature includes potentiometric, spectrophotometric and conductometric studies on the metal-complexes.
2-The experimental part comprises the preparation of the organic ligands and their stock solutions of the azo and azo-azomethine derivatives together with their standardization. It also comprises an outline about the equipments used for the potentiometric, spectrophotometric, conductometric, TGA and DTA measurements.
3-Chapter III includes the studies of the spectra of the compounds under investigation in uv and visible region. The bands exhibited in the uv spectra of the compounds in ethanol solution are assigned according to the nature of the band and spectral behaviour in different organic solvents. The A band (at 202-217 nm) is due to (1La C____ lA ) transition of phenyl ring and the shoulder at 230-235 nm range is
(181)
due to (1Ba < 1A) transition of naphthyl
ring. The B band at 270-276 nm is due to tran-sition of (1Lb <---- 1A) state of phenyl ring and C band at 312-335 nm is due to (1Bb < 1A)
transition of naphthyl ring. The band D at 400-500 nm range represents a charge transfer transitions from the aromatic moieties through the azo and azomethine groups. The mesomeric shifts representing the CT interaction can be represented as follow:
IV
The variation in the position of the CT band in different organic solvents is interpreted and related to the microscopic and macroscopic solvent polarity parameters. The values of Amax of CT band in different solvents are plotted against the micros-copic solvent polarity parameters B, ET and
(182) Z-values. A linear relation is obtained for the
solvents of the same character, but deviation of some other solvents takes place’from the linearity suppor-ting that their is a slight contribution of the micros-. copic parameters in the electronic transition energies. The macroscopic parameters such as D-1/D+1, F2(n),
F(n), .(D) and F(D) of the framework of the solvent molecules are also plotted with sa2Smax and ”max of the CT band. The plots given are nonlinearity indicating that such parameters are not the predominant factors. The shift of the CT band is consequently a resultant of the effect of microcscopic and macros-copic solvent polarity leading to shift and hypso-chromic one due to the solute-solvent association.
The ir and 1Hnmr spectra of the compounds under investigation are studied and the different function groups are assigned. The ir spectra of the compounds are divided into four regions, namely:
(a) 4000-1800cm-1, (b) 1800-1500cm -1
- 1
(c) 1500-1000 cm -1 and 1000-650 cm ranges. In case
of the first region (a) the.POH and J)CH bands were appeared. As for region (b) the J)CH=N, e1C=O and A)N=N are assigned. On the other hand, the SOH and ))C-0 are appeared in region (c). At the last region the band due to $CH are also assigned.
(183)
The 1Hnmr spectra due to the different types of hydrogen protons which expected for the compounds under study (I-IX) can be numerate, determined and correlated to the molecular structure of the compounds. Generally, from the results of the electronic, IR and 1Hnmr spectra and elemental analysis the
structural formula of some representative compounds
are as follows:
VIII
The spectral behaviour of the compounds under investigation in universal buffer solutions containing 40% (by volume) ethanol are studied. The pKa values of the azo and azo-azomethine compounds (I-IX) are determined using three different methods viz (i) half
(184)
height method (ii) the modified limiting absorbance method and (iii) the colleter method. The ionisation constant of the compounds obtained are attributed to the ionisation of OH and COON groups. The pKa values of the OH group are correlated to the molecular structure of the compounds. The free energy change
AG* values of the ionisation process is calculated and give a general behaviour as that of pKa values.
4- Chapter IV includes the studies of the chelation between some azo and azo-azomethine ligands with
2
U0+2 , Th4+, Ni2+, C 2Fe3+ and Cu2+ ions. The
stoichiometry of the chelates of the mentioned metal ions with different ligands are studied by conducto-metric titration. Some mononuclear ligands form chelates of the type 1:1, 1:2 and others of binuclear type form chelates of the type 1:1 and 2:1. The molar conductance of the chelates are determined indicating that the chelates are electrolytic in nature and also the number of ions present in each type of complex. The composition of the solid complexes of the ratios 1:1 and 2:1 are confirmed by the chemical
_
analysis of Mn+, and NO ions. The number of
water molecules of crystallization are determined
by dehydration method whereas, the number of water
(185)
molecules coordinated to the metal ion are determined by TGA. The latter is confirmed by the endothermic peak observed in the results of DTA.
The ir-spectra of the metal chelates are discussed and compared with those of the free ligands.
The main bands are assigned using the comparison method. It was found that the bands corresponding
to C=O, OH, CH=N and N=N in the free ligand are
I I
to tower WAIM number
of the chelates. These such groups in the
chelation with the metal ions.
The electronic spectra of the different metal chelates as mujol mull and DMF are studied. The types of the transitions are determined and the different absorption bands are assigned as M > L or L ----> M charge transfer transitions or to the ligand field spectra as d ----> d transitions. The latter bands are assigned according to the suggested geochemistry of the chelates.
The potentiometric titration measurements are used to calculate the proton-ligand stability constant (log KH) for the free ligands and the stepwise formation constant (log KH) of several metal ions chelates. The log KH values obtained are coincide
display a shit
1
broadened or
or disappear
in the spectra
support the
contribution of
(186) with that given spectrophotometrically (pka). The log K values obtained are interpreted according to the oxidation number of the metal ion, its ionic size and the electronic energy levels of the metal ion that ligand was coordinated.