METASTABLE ION STUDY OF FLUORINATED ORGANIC-COMPOUNDS .3. ALPHA,ALPHA,ALPHA-TRIFLUOROANISOLE AND ALPHA,ALPHA,ALPHA-TRIFLUOROCRESOLS

The spontaneous unimolecular dissociation reactions of the molecular i ons of the C7H5F30 positional isomers alpha, alpha, alpha-trifluoroani sole (1), o-alpha. alpha, alpha-trifluorocresol (2) and m-alpha, alpha , alpha-trifluorocresol (3), have been investigated by mass-analyzed i on kinetic energy (MIKE) spectrometry and deuterium-labelling. The res ults are compared with those of the non-fluorinated analogues anisole (4), o-cresol (5) and m-cresol (6). Ions 1.+ and 4.+ fragment in an an alogous fashion yielding MIKE spectra which are characteristically dif ferent from those of the isomers 2.+, 3.+, 5.+ and 6.+. Unlike ions 5. + and 6.+ whose MIKE spectra are closely similar, the fluorinated anal ogues 2.+ and 3.+ have different dissociation characteristics. This is because a pronounced ortho-effect is operative in 2.+.