EPR STUDIES OF THE X-RAY-IRRADIATED DITHIOPHOSPHATE SALTS

The powder EPR spectra of some ammonium and potassium salts of dithiop hosphoric acid, (RO)(2)P(S)SH, irradiated with X-rays at 77 K have bee n recorded and analyzed in respect to their distinguishable EPR-active components. In general each EPR spectrum is a superposition of isotro pic and anisotropic features from a number of carbon- and phosphorus-c entered radicals. Whereas carbon-centered radicals are practically iso tropic the phosphorus-centered species exhibit threefold anisotropy wi th a large (700-800 G) isotropic P-31 hyperfine splitting. The identif ication of the latter is based on the magnitudes of the P-31 Splitting as well as on the phosphorous 3p/3s spin densities ratio. The experim entally obtained EPR parameters of the studied radicals are refined us ing computer simulation procedure.