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

Alkyl dinitrites have at-tracted attention as an im-portant type of nitrosating agent and a pollution source in atmosphere.The reac-tivity 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 twoαC-βC bonds.For 1,4-cyclohexane dinitrite,in addition to the decomposition via intermediate(M-NO)^(+),cleavage ofβC-βC 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.