The Chemical Ionization Mass Spectra of Fluorotoluenes

Abstract

The methane and hydrogen chemical ionization mass spectra of benzyl fluoride, the isomeric fluorotoluenes, and fluorobenzene have been determined. Reaction mechanisms have been elucidated by using CD4 and D2 as reagent gases. Both the CH4 and H2 spectra of benzyl fluoride show C7H7+ as the major ion. In the CH4 spectra of the fluorotoluenes MH+ is the only abundant ion resulting from protonation while in the H2 chemical ionization spectra considerable loss of HF and H2 occurs from MH+. There is no evidence for ring expansion to form tropylium type ions. The novel reactions[Formula: see text]are important reaction modes for R = CH3 or H and indicate that a long-lived collision complex is formed between CH5+ or H3+ and the aromatic neutral.