Browsing by Author "El Seoud, Omar A."

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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.
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.