Electronegativity of Radicals. A Method of Calculation

Gordy's expression, relating the electronegativity of an atom with the number of electrons in the valence shell and the covalent bond radius, has been extended to the calculation of the group electronegativity of a radical. Both the state of hybridization and the effect of the electronegativity property of other atoms on the bonding atom in the radical have been accounted for. The group electronegativities calculated by this expression are in agreement with those obtained from the ``sensitive'' CH bending vibrational frequencies, but disagree with group electronegativities obtained from other spectroscopic data. The causes of these differences have been discussed.