الفهرس 
The formation of imidazole complexesOnly 14 pages are availabe for public view
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Abstract
The thesis contains five main chapters: Chapter 1: The introduction is concerned with: General informations about pyrimidines, their important roles in the formation of the nucleic acids, its complexes and chemistry of 99mTc are given. Chapter 2:
Physicochemical studies of the reaction of 99mTc with 5, 5´-diethyl barbituric acid, adenine, d-glucose and thiobarbituric acid at different temperatures
The reaction of 99mTc with d-glucose, thibarbituric acid, adenine and 5, 5´-diethyl barbituric at different temperatures were studied by using TLC with radio detector and solvent effects on the electronic absorption spectra of reaction mixtures were studied. characterization of the 99mTc complexes as well as the determination of the extent of radiolabeling was done by thin layer chromatography using 0.9 % NaCl solution as a solvent where the Rf value of 99mTc O4- is (≈1). The solvatochromism for the reaction of 99mTc with d-glucose was mainly affected by solute permanent dipole-solvent permanent dipole interaction, the dipolar interaction for the reaction of 99mTc with of 5, 5´-diethyl barbituric acid and for the reaction of 99mTc with adenine and thiobarbituric was solute-solvent hydrogen bonding.Chapter 3: Spectral,thermal studies of d-glucose, 5,5’ diethyl Barbituric, thiobarbituric acid and adenine with Mn(II),Mo(VI) and Cr(III) complexes. Preparation of d-glucose, thibarbituric acid, adenine and 5, 5´-diethyl barbituric acid complexes with Mo(VI), Cr(III) and Mn(II), elemental analyses, IR, nujol mull electronic spectra, DTA, TGA and DSC studies of the prepared complexes were carried out. The elemental analysis give the stoichiometry of complexes to be MoO2 (HL1)2, Mn 3(L1)2 (OH)(H2O)6Cl, Mo2[(L2)5(HL2)2], Mn (H2L2)3Cl2, Cr (H L2)(L2) (H2O)3, Mo2 (L3)5(OH)2 (H2O)3, Cr2 (HL3)2(HL1) (SO4) 2(H2O)7 and Cr (HL4)2 ( (H2O)(OH). IR spectra of: 1- D-glucose complexes show different modes of vibrations for (C=O) confirm the involvement of the – C=O group in complexation. The appearance of new broad bands at 901 cm-1 for Mo complex and 597 cm-1 for Mn complex indicating the presence of the cis-MoO22+ moiety and MnO. 2- Thibarbituric acid complexes shows different modes of vibrations for (C=O, C=S, O-H, N-H and C-N) and the contribution of the NH and C=O groups in complexation of the complexes and the contribution of C=S groups in complexation in case of Cr(III)complex. 3- The adenine complexes depicted different modes of vibrations for (C=C, N-H, NH2and C-N) and the contribution of the NH2 group and the heterocyclic nitrogen atom group on complexation.4- 5,5’ diethyl barbituric acid complex shows different modes of vibrations for (C=O, O-H, N-H and C-N), indicate the participation of both C=O and C=N in complixation. Electronic nujol mull spectra 1- Molybdenum complexes: The electronic spectrum of MoO2 (HL1)2, Mo2(L2)5(HL2)2and Mo2 (L3)5(OH)2 (H2O)5 complexes has been assigned to be an octahedral geometry of molybdenum centers . 2- Manganese complexes: These are of a tetrahedral geometry of manganese in the complex [ Mn 3(L1)2 (OH)(H2O)6Cl] and an octahedral manganese (II) in Mn (H2L2)3Cl2 complex. 3- chromium complexes:
The electronic spectra of Cr (H L2)(L2) (H2O)3, Cr2 (L3)3 (SO4) 2(H2O)7 and Cr (HL4)2 ( (H2O)(OH) confirmed the octahedral geometry of the complexes. Thermal analysis: The thermal behavior of the complexes has been studied by applying TG, DTA, and DSC techniques, and the thermodynamic parameters and mechanisms of the decompositions were evaluated. The thermal processes proceeded in complicated mechanisms where the bond between the central metal ion and the ligands dissociates after losing small molecules such as H2O, HCl or C=O, for example the molybdenum d-glucose complex is ended with dioxo molybdenum O-O-methane as a final product. However, the thermal reaction of the manganese d-glucose is ended with a mixture of manganese oxide and manganese hydroxyl O-ethylene.DTA thermal analysis were studied for the prepared complexes. The ln
T versus 103/T plots for the complexes gave best fit straight lines from
which the activation energies (Ea) were calculated . The order of chemical
reactions (n) were calculated. The reaction orders are 1, 1.5 and 2. The
fractions appeared in the calculated order of the thermal reactions, (n) that the
reactions proceeded in complicated mechanisms.
The calculated values of the collisions number, Z, let to suggest
different mechanisms.
The change of entropy values, S#, for all complexes, are nearly of the
same magnitude and all are with –ve signs, so, the transition states are more
ordered.
The heat of transformation, H were calculated.
DSC thermal analysis studies for complexes gave the following:
The glass transition, crystallization and melting temperatures were
determined from DSC graphs for the complexes.
Debye model was applied to describe capacity change over a large
temperature range. The Cp can be represented as follows:
Cp = aT + b
By plotting Cp versus T, a straight line is obtained, thus, ”a” and ”b”
parameters can be determined from the slope and intercept of the line,
respectively.
Further applications based on Debye model on the complexes are given
from the scope of the following equations:
Cp Cv = T3 + γT, 2 T
T
Cp
Plots of Cp / T versus T2 gave straight lines with slopes α and intercepts γ.Thermodynamic and Kinetic Studies:
The influences of the structural properties of the chelating agent and the type of the metal on the thermal behavior of the complexes, the order (n) and the heat of activation (E) of the various decomposition stages were determined from the TG and DTA.
The evaluated kinetic parameters gave the following observations:
All decomposition stages showed a best fit for n = 1, while the other values have no better correlation.
The negative values of the entropy of activation, ΔS* of the decomposition steps of the metal complexes indicate that the activated fragments have more ordered structure than the undecomposed complexes and/or the decomposition reactions are slow .
The positive sign of the enthalpy of activation, ΔH* of the decomposition stages reveals that the decomposition stages are endothermic processes.
The positive sign of free energy of activation, ΔG*, indicates higher values of the final residue than that of the initial compound, all the decomposition steps are non-spontaneous processes.
Chapter 4: The reaction of d-glucose, 5,5’ diethyl barbituric, thiobarbituric acid and adenine with Mn(II),Mo(VI) and Cr(III) complexe with 18F- in different media . Preparation of 18F- and its reactions with Mn (H2L2)3Cl2, Mo2 (L3)5(OH)2 (H2O)3, MoO2 (HL)2, Cr (H L2)(L2) (H2O)3, Cr (HL4)2 ( (H2O)(OH) and Cr2 (HL3)2(H2L3) (SO4) 2(H2O)7 complexes were studied in neutral, acidic and basic media. The reaction mixtures have been analyzed by TLC. A nuclciophilic substitution happened and 18F- replace.
OH-> Cl-> SO4-2 according to the electro negativity order.Chapter 5: Comparison between different techniques in purification of O18 enriched water after cyclotron irradiation.
The high cost of virgin 18O-H2O enriched water pointed to recycle process after the first irradiation for the production of radiopharmaceuticals. The irradiated 18O-H2O was contaminated by both organic substances (ethanol, acetonitrile,etc.) and inorganic ions (Cd2+, Na+, K+, Cl-, etc). In our study different techniques (ozonolysis, UV, distillation and resin) were used to minimize the concentration of both organic substances and inorganic ions.The results were compared. Ozonolysis and distillation gave the best results in minimizing both organic substances and inorganic ions respectively