FORMATION OF HYPOPHOSPHATE IN THE RADIOLYSIS OF PHOSPHITE SOLUTION.

The formation of hypophosphate and phosphate in the radiolysis of a phosphite solution was established by the anion-exchange chromatographic technique. The quantitative determination of their yields was made by colorimetry of the phosphate and hypophosphate with the Mo(V)+Mo(VI) reagent, which develops molybdenum-blue colors in two steps at different temperatures. The G values in an aerated condition are 0.01 molecules/100 eV in acid and 0.1 molecule/100 eV in neutral pH with respect to the hypophosphate formation, independent of the phosphite concentration. In a deaerated system much higher values are obtained, amounting to around 0.5 molecules/100 eV at a phosphite concentration of 10−3 M. The G values of hypophosphate plus phosphate are around 3.0; this is in agreement with the half-value of the primary radical yields, 1/2·(gred+gOH), reported in the data derived from the radiation-chemical studies in the aqueous system. The hypothesis that the hypophosphate (IV) ion radical is a transient species in t...