CONFORMATIONAL ISOMERISM OF PHOSPHORUS-CONTAINING FULLERENYL RADICALS

ESR spectra of phosphorus-containing fullerenyl radicals C-.(60)-P(O)( OPri)(2) and C-.(60)-P(O)(OEt)Ph were studied at low temperatures (193 -273 K). A decrease in the rate of rotation of organophosphorus group around the C-P bond results first in line broadening and then in the a ppearance of two doublets due to two ''extreme'' conformations, which have different g-factors and hyperfine coupling constants (HCC) of the unpaired electron with the P-31 nucleus. The kinetic and thermodynami c parameters of the conformational isomerism were calculated.