HYBRIDIZATION EFFECTS IN FLUOROCARBONS

Hybridization calculations based on experimental bond-angle data show that the carbon hybrid atomic orbitals in double bonds, carbonyls, and cyclopropyl groups containing a gem-difluoro group are not sp2 hybridized as formerly thought, but are sp3 hybridized. This is also true of the trifluoromethyl free radical. This new understanding of the hybridization in fluorocarbons makes possible an explanation of the unusual chemical reactivity of perfluoroolefins and perfluorocyclopropanes. While the carbon HAOs used in forming the C-F bonds in these compounds are sp3 hybridized as in saturated fluorocarbons, with the C-F bonds having approximately the same bond energies, those used in forming the C-C bonds have less p character than in the corresponding hydrocarbons. © 1969, American Chemical Society. All rights reserved.