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Item Reaction of Cob(i)alamin with Nitrous Oxide and Cob(in)alamin(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1977, 73 (2), 1977) Blackburn, Robert; Kyaw, Maung; Swallow, A. JohnCob(I)alamin (vitamin B12s) has been generated by pulse radiolysis of N2O-saturated solutions of cob(II)alamin (vitamin B12r) containing sodium formate. It reacts with N2O with rate constants in the range 200–1200 dm3 mol–1 s–1, depending on pH and buffer concentration. The final product is cob(II)alamin, formed in 100 % yield. The initial product is thought to be cob(III)alamin (vitamin B12a or B12h) but this does not build up to significant concentrations. Cob(III)alamin (vitamin B12a or B12h) reacts with cob(I)alamin with a rate constant of 3.2 × 107 dm3 mol–1 s–1 independent of pH in the range 5.8–11.0. Cyanocobalamin (vitamin B12) does not react with cob(I)alamin.Item Negative Ion Reactions in Nitrous Oxide-I-Carbon Dioxide Mixtures(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (11), 1972) Parkes, David A.The rate constants have been measured for the following reactions in N2O + CO2 mixtures at pressures in the Torr region, using a drift tube and mass filter: NO–+ 2CO2→ CO2·NO–+ CO2, k9= 7.5 × 10–29 cm6 molecule–2 s–1, NO–+ CO2→ NO + CO2+ e, k10= 1.0 × 10–11 cm3 molecule–1 s–1, NO–+ CO2+ N2O → CO–3+ N2+ NO, k12= 1.0 × 10–27 cm6 molecule–2 s–1, → N3O–2+ CO2, or → CO2·NO–+ NO2O, k13= 1.5 × 10–28 cm6 molecule–2 s–1. The results obtained here confirm the importance of collisional detachment from NO– in N2O negative ion chemistry.Item Electron Attachment and Negative Ion-Molecule Reactions in Nitrous Oxide(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (11), 1972) Parkes, David A.The negative ions formed in N2O and N2O and N2O + O2 mixtures have been studied in the gas phase using a drift tube and mass filter. Gas pressures were in the Torr range, and reduced fields were varied between 10–17 and 10–15 V cm2 molecule–1. The observed ion spectrum was found to be governed by the following reaction, with their associated thermal rate constants: e + N2O → N2+ O–, k1= 4 × 10–15 cm3 molecule–1 s–1, O–+ N2O → NO–+ NO, k3=(1.95 ± 0.06)× 10–10 cm3 molecule–1 s–1, NO–+ N2O → NO–2+ N2, k4=(2.8 ± 0.2)× 10–14 cm3 molecule–1 s–1, NO–+ 2N2O → N3O–2+ N2O, k5=(8.5 ± 1.5)× 10–30 cm6 molecule–2 s–1, O–+ 2N2O → N2O–2+ N2O, k6=(4.2 ± 0.5)× 10–29 cm6 molecule–2 s–1, NO–+ N2O → N2O + NO + e, k11=(6.0 ± 1.0)× 10–12 cm3 molecule–1 s–1, O–2+ N2O → O–3+ N2, k10 < 10–12 cm3 molecule–1 s–1. The rates of reaction, (5), (6) and (11) were weak functions of reduced field. In no experiment was any evidence found for the existence of a long-lived N2O– ion.Item Oxidation of Aluminium by Nitrous Oxide in the Temperature Range 323-683 K(Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (8), 1972) Hunt, G L; Ritchie, I MThis paper describes experiments on the oxidation of evaporated aluminium films by nitrous oxide in the temperature range 323-683 K. The kinetics of the reaction were followed by measuring the rate of increase in resistance of the film as it was consumed by oxidation. Experiments in which an electric field was applied across the growing oxide layer were carried out. The pressure dependence of the reaction was studied by investigating the change in oxidation rate accompanying an abrupt pressure change. The results of all these experiments indicate that the aluminium/nitrous oxide system is very complex, and no single rate determining step is operative over the whole temperature range. Four different regions of growth were identified, and possible reaction mechanisms are considered