During the early stages of ESR investigation of free radicals, the number of fluorine containing species was limited to a few ?r-type species, the fluoranil.
1980
P. H. H. FISCHER A N D J. P. COLPA
Fluorine Hyperfine Interaction in Aromatic Anion Radicals P . H . H . FISCHER Max-Planck-Institut für Medizinische Forschung, Heidelberg, Germany and J. P. COLPA Department of Theoretical Chemistry, University of Amsterdam, The Netherlands * ( Z . Naturforsch. 24 a, 1980—1988 [1969] ; received 5 August 1969)
The relation between the fluorine hyperfine splittings in about 20 fluorine substituted aromatic radicals and the zi spin densities calculated according to McLachlans method is analysed with an expression of the type aF
+Qcc
=QIfQfF
Qcc
+
{QcF
+ ( ? F C ) Q CF .
For the Q factors the following values are obtained:
