The consequences of cation radical fluorination theory—I : A comparison of various theoretical scenarios with experiment for carbocyclic-aromatics,using CNDO/2 and INDO calculations

Various of the possible scenarios (Table 1) derived from cation radical fluorination theory are examined critically in the light of experiment. The predictions of the theory are made using CNDO/2 and some INDO calculations, and these are compared with the known experimental results for benzene, benzotrifluoride, naphthalene, anthracene and phenanthrene. It is concluded that cation radical theory must be broadly correct; it works well for monocyclic hydrocarbon compounds, assuming product control to be via spin or charge density in the intermediates (cations, radicals, cation-radicals), with sequence 3 (Table 1) preferred. In the absence of any modifying hypothesis, however, control of products by spin or charge density alone cannot explain the experimental results for the polycyclic substrates. The most plausible modifications appear to be product control via Wheland intermediate stability (sequence 7, Table 1) and/or rapid rearrangements.