The mass spectra of some substituted polyfluoroaromatic compounds

The application of mass spectrometry, including precise mass measurements of molecular ions and selected fragment peaks, in determining the structure of twenty-nine substituted polyfluorobenzenes and two polyfluoropyridines is discussed. These compounds are divided into five categories: (a) fluorinated benzenes; (b) alkyl substituted polyfluorobenzenes; (c) halogen substituted polyfluorobenzenes; (d) oxygen containing substituents in polyfluorobenzenes and (e) nitrogen and sulfur containing polyfluoroaromatics. It is shown that the nature of substituents, their size, position on the ring and the completeness of fluorination are all vitally important in determining the fragmentation processes. The rupture of the various carbon to halogen and carbon to hydrogen bonds are discussed. Metastable peaks were found in some cases and their precursors were traced.