Browsing by Author "Eley, D. D."

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Polymerization of Ethylene on Chromium Oxide Catalysts: Part 4.—Infra-red Study of the Adsorption of Nitric Oxide and Ammonia on Active Catalyst
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (3), 1973) Eley, D. D.; Rochester, C. H.; Scurrell, M. S.
Nitric oxide adsorbs on reduced supported chromium(VI) oxide catalyst to give infra-red bands at 1740, ca. 1800, and ca. 1860 cm-1. The band at ca. 1800 cm1 has been assigned to nitric oxide molecules coordinatively chemisorbed on Cr4i ions in the surface. The band at 1740 cm-1 is considered to result from a combination of separate bands at 1743 and 1738 cm-1 due to nitric oxide covalently bound to Cr3+ and Cr5+ sites respectively. The band at ca. 1860 cm 1 is similarly assigned to nitric oxide chemisorbed on two types of site. The adsorption of ammonia gave infra-red bands due to coordinatively bound ammonia at 3400 and 3300 cm-1 which were insensitive to the extent of reduction of the catalyst. Correlations between the intensities of the bands due to adsorbed nitric oxide and the activities of catalyst samples for the polymerization of ethylene support the conclusion that Cr5i ions are the active sites in the polymerization process. The polymerization reaction was poisoned by the pre-adsorption of nitric oxide or ammonia.
Protolysis Kinetics of some Amino-acids Studied by the Nuclear Magnetic Resonance Spin Echo Technique
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (2), 1973) Eley, D. D.; Fawcett, A. S.; Hey, M. J.
Proton magnetic relaxation times have been measured as a function of pH and temperature for aqueous solutions of amino-acids in the series H3[graphic omitted]—[CH2]n—CO2 where n= 1, 2, 3, 5 and 7 and also for solutions of α-alanine, sarcosine, L-proline, picolinic acid and 2-pyrrolidone. The T1 values were independent of pH but T2 had a minimum value near to pH 6 at room temperature for most of the solutions studied. In many cases, a second minimum occurred close to pKal for the amino-acid. The data are analysed in terms of proton exchanges between amino groups and sites which are oxygen attached. Kinetic parameters are derived for some exchange reactions which have not previously been considered in connection with amino-acid solutions.
Temperature Effect on Stearic Acid Monolayers on Water
(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1973, 69 (2), 1973) Casilla, R.; Cooper, W. D.; Eley, D. D.
Measurements are described for the force-area curve of stearic acid on pure water at temperatures of 1.6, 3.0, 5.0, 10.0 and 20.0°C. The Ao values for both solid and liquid films increase with tempera ture at the same rate, which is greater than for the corresponding cross-sectional areas in the B and C states of solid stearic acid. There are minima in the compressibilities of both solid and liquid films around 5°C. Taken together, these data point to an interaction between water molecules and the stearic acid head groups, related to the water structure as manifested in the temperature of maximum density of 4°C.