Negative chemical ionization mass spectrometric study on the electron-attachment process of nitric carbons

The formation of negative ions from halogenated acetonitriles XCH2CN (X = F , Cl, Br, I) and C6F4(CN)(2) was studied using negative chemical ionization mass spectrometry. The halide ion was observed for XCH2CN (X = Cl, Br, I). While the intensity of the ion increased with increasing temperature for I CH2CN, the temperature dependence for the production of ions was only sligh tly observed over the temperature range of 393-537 K for ClCH2CN and BrCH2C N. The parent anions were observed for C6F4(CN)(2). The intensity of the pa rent anions increased in the order 1,3-C6F4(CN)(2)(-) < 1,2-C6F4(CN)(2)(-) < 1,4-C6F4(CN)(2)(-). A temperature dependence for the parent anions was no t observed. The difference in the intensity can be explained by a recombina tion reaction with the positive ions.