Reaction of nitrosomethane and of trifluoronitrosomethane with nitric oxide

Abstract

The kinetics of the reaction of trifluoronitrosomethane with nitric oxide to form nitrogen dioxide have been followed in the temperature range 298–333 K. The third order rate constant for the reaction CF₃NO + 2NO → CF₃+ N₂+ NO₃, is given by k/dm⁶ mol^–2 s^–1= 17.4 exp (–1 110 K/T). The Arrhenius parameters are compared with those for the corresponding reaction of nitrosomethane which is about one hundred times faster at room temperature.

In the absence of nitric oxide, monomeric trifluoronitrosomethane is stable at room temperature whereas monomeric nitrosomethane undergoes dimerisation. Under the experimental conditions used, where nitrosomethane is prepared from the photolysis of iodomethane in presence of nitric oxide, it also disappears in a slow reaction first order in nitrosomethane. It has been confirmed that this reaction is the isomerisation to formaldoxime. No evidence for the reaction CH₃NO + NO → CH₃O + N₂O has been found.