Phosphoryl- and thiophosphoryl-dithioformates. Part IV. Electrochemical reduction and EPR study of the radical anions

The reduction of a number of phosphoryl- and thiophosphoryl formates, monot hioformates and dithioformates has been studied by means of cyclic voltamme try and EPR spectroscopy. The reduction potentials of all dithioformates ar e close to -1 V vs. SCE, and increase for S-alkyl monothioformates and even more for O-alkyl monothioformates. The radical anions of the compounds bea ring the thiocarbonyl function have been characterised by means of EPR spec troscopy, whereas those of the compounds having the carbonyl function under went decomposition before detection. Reduction at higher potentials led in most cases to the detection of paramagnetic dianions derived from fragmenta tion of the initially formed radical anions.