Radiation-induced chain reactions in alkaline solutions of nitrous oxide in aliphatic alcohols

1966 ◽  
pp. 250
Author(s):  
Warren V. Sherman
1978 ◽  
Vol 82 (1) ◽  
pp. 26-29 ◽  
Author(s):  
T. G. Ryan ◽  
T. E. M. Sambrook ◽  
G. R. Freeman

In the region of pressure 0 to 500 mrn approximately to the equation the thermal decomposition of nitrous oxide conforms approximately to the equation k = an /1 + a'n + bn , where k is the form al first-order rate constant, — (1/n) d n /d t , n the initial concentration and a, a' and b are nearly constant. Above about 100 m m this expression approximates to k = A + bn , which holds up to several atmospheres. Fresh and more detailed experiments have once again disproved the suggestion that the first term in these expressions is due to a surface reaction. (In certain states of reaction vessels, made of a particular brand of silica, a surface reaction may appear but is immediately recognizable by special criteria, and can be eliminated.) Detailed study of the formation of nitric oxide in the course of the decomposition, and of the effect of inert gas upon this process, shows that side reactions involving oxygen atoms, chain reactions and catalysis by nitric oxide play only minor parts in determining the shape of the k-n curve. The form of this curve, which is an inherent character of the reaction N 2 O = N 2 + O, raises theoretical questions of considerable interest.


1967 ◽  
Vol 45 (14) ◽  
pp. 1661-1668 ◽  
Author(s):  
W. J. Holtslander ◽  
G. R. Freeman

There is a radiation-induced chain reaction in methylcyclohexane (MCH) – CCl4 mixtures in the vapor phase at 110° and 380 Torr. The chain-propagation products are chloroform and methylcyclohexylchloride (Gmax ≈ 40) and the chain-termination products are mainly methylcyclohexene (MC), bimethylcyclohexyl (C14), and hexachloroethane, depending on the composition of the mixture. At CCl4 concentrations < 1 mole%, HCl is formed mainly by reaction of Cl− with positive ions, e.g. Cl− + C7H14+ → HCl + C7H13. The value of the ratio G(MC)/G(C14) is 8 ± 1 in pure MCH and in the mixtures up to 44 mole% CCl4.There is a radiation-induced chain reaction in MCH–N2O mixtures in the vapor phase. At 110° and 380 Torr, G(N2) = 22, G(MC) = 16, and G(C14) = 1.6, independent of N2O concentration between 2 and 10 mole%. The G-values are independent of MCH pressure between 50 and 520 Torr. Product formation is inhibited by the addition of SF6 or DI. The half-life of the ion N2O− with respect to decomposition to N2 + O− is 10−4–10−3 s under these conditions. It is suggested that the mechanism contains the reactions [Formula: see text] [Formula: see text]Reaction [24] is slightly exothermic. Reaction [25] is exothermic if the electron affinity of N2O is greater than that of C7H13.


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