Structural Effect on Electron Impact Decomposition of 1, 3- and 1, 4-Cyclohexane Dinitrites

Alkyl dinitrites have attracted attention as an important type of nitrosating agent and a pollution source in atmosphere. The reactivity and chemistry of alkyl dinitrites induced by the two ONO functional groups are relatively unknown. In this work, decompositions of 1, 3-cyclohexane dinitrite and 1, 4-cyclohexane dinitrite are studied by electron impact ionization mass spectroscopy (EI-MS). Apart from NO⁺ (m/z=30), fragment ions m/z=43 and 71 are the most abundant for the 1, 3-isomer. On the other hand, fragments m/z=29, 57, 85, and 97 stand out in the EI-MS spectrum of 1, 4-isomer. Possible dissociation mechanisms of the two dinitrites are proposed by theoretical calculations. The results reveal that the ring-opening of 1, 3-cyclohexane dinitrite mainly starts from the intermediate ion (M-NO)⁺ by cleavage of two \alphaC-\betaC bonds. For 1, 4-cyclohexane dinitrite, in addition to the decomposition via intermediate (M-NO)⁺, cleavage of \betaC-\betaC bonds can occur directly from the parent cation M⁺. The results will help to understand the structural related chemistry of alkyl dinitrites in atmosphere and in NO transfer process.