الفهرس 
ِAcknowledgementOnly 14 pages are availabe for public view
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Abstract
The present work comprise a study of electron transfer reaction of chromium (III)-Anti Parkinson drugs (Levodopa and Carbidopa) ternary complexes involving some Nucleosides by N-bromosuccinimid. CHAPTER I, Introduction. The electron transfer, outer- sphere and inner- sphere mechanisms have been discussed. Catalytic Reactions especially, Micellar catalyzed reactions and its characteristics have been reported. The beneficial actions of chromium (III) were summarized and Oxidation of chromium from trivalent (CrIII) to hexavalent (CrVI) was discussed with description of toxicity of CrVI inside the cell. The uses of NBS as brominating agent, oxidizing agent for organic and miscellaneous inorganic compound s were reported with concerning on the oxidation of CrIII - complexes by NBS. The biological important of Levodopa and Carbidopa as Anti-Parkinson drugs were illustrated. The nucleosides as a common glycosylamine compounds were reported with concentration on Uridine and Inosine as famous types of purine and pyrimidine nitrogenous base, respectively. CHAPTER II, Experimental. Chemicals, Solutions and Preparation of the mixed ligand CrIII - complexes were illustrated. The different instruments were used in this study were described. Kinetics procedures for the kinetic studies and method for the data were determined. CHAPTER III, Results and discussion. This part includes the layout of the results obtained and their discussion. The effects of various parameters on the rate of the reaction have been discussed. This chapter consists of three parts as follows; Part (I) The ternary complex, [CrIII(LD)(Urd)(H2O)4](NO3)2.3H2O (LD = Levodopa, Urd = Uridine) was prepared and characterized. The product of the oxidation reaction was examined using High Performance Liquid chromatography (HPLC) technique. Kinetics of oxidation of [CrIII(LD)(Urd)(H2O)4+2] with N-bromosuccinimide (NBS) in an aqueous solution was studied spectrophotometrically, over (1.0 - 5.0) × 10-4 mol dm-3 complex, (0.5- 5.0) ×10-2 mol dm-3 NBS, (0.2- 0.3) mol dm-3 Ionic strength (I) and (30- 50)oC. The reaction is first order with respect to [CrIII] and [NBS], decreases as pH increases in range (5.46- 6.54) and increases with adding Sodium Dodecyl Sulphate (SDS) in range (0.0-1.0)×10-3 mol dm-3. Thermodynamic activation parameters including enthalpy; ΔH*, and entropy, ΔS*, were calculated. The experimental rate law is consistent with a mechanism in which the protonated species is considered to be the most reactive species compared to its conjugate base. It is assumed that two steps one-electron transfer takes place via an inner-sphere mechanism. Part (II) Preparation and characterization of the mixed ligand complex of CrIII with CD and Urd, [CrIII(CD)(Urd)(H2O)4](NO3)2.5H2O has been performed. Using HPLC technique, the product of the oxidation reaction was examined. In an aqueous solution, Kinetics of oxidation of [CrIII(CD)(Urd)(H2O)4]2+ with NBS was studied over a ranges of complex and NBS concentrations of (1.0 - 5.0) × 10-4 mol dm-3and (0.5 - 5.0) × 10-2 mol dm-3, respectively, (0.2- 0.3) mol dm-3 Ionic strength (I) and (30-50)oC. The rate shows first-order dependence on both [CrIII(CD)(Urd)(H2O)4+2] and [NBS]. It is decreases as pH increases over the range studied whereas increases with adding Sodium Dodecyl Sulphate (SDS) in range (0.0-1.0) × 10-3 mol dm-3. Thermodynamic activation parameters including enthalpy; ΔH*, and entropy, ΔS*, were calculated. The oxidation found to obeys the rate law d[CrVI]/dt = {k3 + k2[H+]}[NBS][CrIII(CD)(Urd)(H2O)4+2]. It is assumed that two step one - electron transfer takes place via an inner-sphere mechanism. Part (III) The ternary CrIII-complex, [CrIII(LD)(Ino)(H2O)4]2+ (LD = levodopa, Ino = Inosine), respectively, were prepared and characterized. The product of the each oxidation reaction was examined using HPLC technique. Kinetics of oxidation of [CrIII(LD)(Ino)(H2O)4]2+ by NBS in an aqueous solution to CrVI have been studied spectrophotometrically over the (1.0- 5.0) × 10-4 mol dm-3 complex, (0.5- 5.0) ×10-2 mol dm-3 NBS, (0.2- 0.3) mol dm-3 Ionic strength (I) and (30-50)oC range. The reaction was first order with respect to both [NBS] and [CrIII] and increases with pH and SDS over the used ranges. Thermodynamic activation parameters including enthalpy; ΔH*, and entropy, ΔS*, were calculated. The oxidation of [CrIII(LD)(Ino)(H2O)4+2] with[NBS] follows the rate equation d[CrVI]/dt ={k3+ k 2/[H+])}[NBS][CrIII (LD)(Ino)(H2O)4+2]. It is assumed that, two step one - electron transfer take place via an inner-sphere mechanism. Part (IV) The ternary complex [CrIII(CD)(Ino)(H2O)4](NO3)2.H2O (CD = Carbidopa, Ino = Inosine) was prepared and identified. The product of the oxidation was examined using HPLC technique. Oxidation of [CrIII(CD)(Ino)(H2O)4]2+ with NBS was studied kinetically in an aqueous solution over ranges of complex and NBS; (1.0-5.0 )×10-4 and (0.5-5.0)×10-2 mol dm-3, respectively using varied ranges of pH, ionic strength and temperatures. The reaction is first order with respect to [CrIII] and [NBS]. The rate of reaction increases with increasing pH values over the range (6.76 - 7.84). The anionic surfactant, Sodium Dodecyl Sulphate (SDS) was found to increase the rate of the oxidation in the range (0.0 - 1.0) ×10-3 mol dm-3. Thermodynamic activation parameters were calculated. The rate of oxidation obeys the equation d[CrVI]/dt = {k3 + k2(1/[H+])}[CrIII(CD)(Ino)(H2O)4+2] × [NBS].The experimental rate law is consistent with a mechanism in which, the protonated and deprotonated species are involved in the rate determing step. It is assumed that, two steps one - electron transfer takes place via an inner - sphere mechanism.