Browsing by Author "Fendler, Janos H."

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    Proton Magnetic Resonance Investigations of Alkylammonium Carboxylate Micelles in Non-aqueous Solvents: Part 4.—Effects of Dimethyl Sulphoxide, Imidazole, Methanol, Pyrazole, 2-Pyridone, and Tetrabutylammonium Perchlorate on Dodecylammonium Propionate in Benzene, Deuterochloroform and Dichloromethane
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) El Seoud, Omar A.; Fendler, Eleanor J.; Fendler, Janos H.
    Addition of dimethyl sulphoxide (DMSO), imidazole, methanol, pyrazole, 2-pyridone, and tetra-butylammonium perchlorate, in the concentration range of 0.02 to 0.10 mol dm–3, to 0.50 mol dm–3 dodecylammonium propionate (DAP) in benzene, deuterochloroform or dichloromethane results in large shifts of the NH+3 proton resonances of DAP. Less pronounced shifts occur also for the protons immediately adjacent to the functional head groups of DAP (i.e. CH2NH+3 and CH2CO–2) while protons further removed are unaffected. Plots of the observed shift of the NH+3 of DAP against solubilizate concentration are linear and the shifts decrease in the order pyrazole ≳2-pyridone ≳imidazole > tetrabutylammonium perchlorate > DMSO > methanol in benzene, pyrazole∼2-pyridone∼imidazol > methanol in CDCl3, and pyrazole∼imidazole > methanol in CH2Cl2. The data are interpreted in terms of the interactions among the solubilizate, the solvent, and the surfactant. Solubilization sites as well as specific interactions in the reversed micellar pseudo-phase are discussed.
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    Proton Magnetic Resonance Investigations of Alkylammonium Carboxylate Micelles in Non-aqueous Solvents: Part 5.1—Effects of Dodecylammonium Propionate on Solubilizates in Benzene and in Deuterochloroform
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) El Seoud, Omar A.; Fendler, Eleanor J.; Fendler, Janos H.
    Chemical shifts, at constant concentration, of the solubilizate protons of dimethyl sulphoxide, imidazole, methanol, pyrazole, and 2-pyridone have been determined as functions of dodecylammonium propionate (DAP) concentrations in benzene, in deuterobenzene, and in deuterochloroform. Equilibrium constants between solubilizates and micellar DAP have been obtained from these data and are discussed. Determined line broadening of both the solubilizate and the DAP protons are discussed in terms of the average lifetime of the solubilizate in the micellar environment.
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    Pulse Radiolysis Study of the Reactions of Hydrated Electrons with Naphthalene, Phenanthrene, Biphenyl and Fluorene in Aqueous Micellar Solutions
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (1-6), 1974) Fendler, Janos H.; Gillis, Hugh A.; Klassen, Norman V.
    The reaction of hydrated electrons with naphthalene, phenanthrene, biphenyl and fluorene to form the respective aromatic radical anions has been studied in aqueous solutions (1 % methanol, pH 12.1) in the presence and absence of micellar hexadecyltrimethylammonium bromide (CTAB). The reaction rates are 3-9 times faster in the presence of micellar CTAB suggesting that CTAB will, in general, enhance this type of reaction. An absorption spectrum of the free fluorene radical anion was obtained. In the presence of CTAB the aromatic radical anions decay to second transients which are probably the hydrogen adducts of the aromatic molecules.
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    Radiolysis of Pyrimidines in Aqueous Solutions: Part 2.—Product Formation in the Interaction of ea~, -H, -OH and C17- with
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (07), 1974) Infante, Gabriel A.; Jirathana, Poonsri; Fendler, Eleanor J.; Fendler, Janos H.
    Product yields in the reaction of e~, -H, -OH and Cl/ with uracil and uracil- have been determined quantitatively in 60Co y-irradiated aqueous uracil solutions in the presence of suitable scavengers. Good material balances between G(—uracil) and G(total products) have been obtained in all cases. The products determined were: uracil dimer, alloxan, alloxantin, uracil czj-glycol, uracil /ra/u-glycol, dialuric acid, isobarbituric acid, 5-hydroxydihydrouraciI, 6-hydroxydihydrouraciI, dihydrouracil, formylurea, 5-hydroxyhydantoin, parabanic acid, urea and alcohol adducts. Based on the yields of these products and the available literature, mechanisms are proposed and discussed.
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    Radiolysis of Pyrimidines in Aqueous Solutions: Part 3.’—Micellar Effects on Product Yields Formed in the Interaction of ea~, •H, -OH and Cl? with Thymine and Uracil
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1974, 70 (07), 1974) Fendler, Janos H.; Infante, A.; Jirathana, Poonsri; Fendler, Eleanor J.
    Micellar surfactants decrease the yield of products formed in the interaction of ea"q, -H, -OH and Cl2 with uracil and thymine far in excess of the decrease expected on the basis of simple competition of these species for the pyrimidines and the surfactants. Additionally, in the presence of micelles percentages of some of the radiolytic products of thymine, particularly the dimers, decrease at the expense of the glycols. Effects on uracil are smaller than those on thymine. These results are explicable in terms of interactions between the product-forming intermediate species with the micelles and the significance of this behaviour is discussed.