ESR STUDY OF CARBORANE-CONTAINING ORGANOFLUORINE RADICALS

It has been shown by ESR that the addition of photochemically generate d boron-centered carboranyl radicals to branched fluoroalkenes affords stable spin-adducts. It has been found that the addition of boron-cen tered radicals with 1-substituted 2-fluoroalkenyl-o-carborane gives st able alpha-carboranyl radicals. Negligible variations in the values of the constants of hyperfine coupling of the unpaired electron with the nucleus of the beta-B-11 atom in radicals of various structures imply the stability of the carborane conformation with respect to the 2p(z) -orbital of the unpaired electron. This may be caused by hyperconjugat ion between the boron atom and the unpaired clectron as well as steric interaction.