RADIOLYSIS OF SODIUM AND POTASSIUM TETRAPHENYLBORATE IN AQUEOUS SYSTEMS

The Co-60 gamma-radiolysis of soluble and insoluble tetraphenylborate (TPB) salts in aqueous solution was studied at 25-degrees-C. In the radiolysis of air-saturated 0.05 M sodium tetraphenylborate (NaTPB) solution the products and their G values are hydrogen, 0.46; biphenyl, 1.9; benzene, 1.3; and phenol, 0.41. Deposition of 4.4 Mrad caused the pH to increase from 8.2 to 9.8. Radiolysis of NaTPB solution produced hydrogen at the same rate as radiolysis of water. In the radiolysis of 10 wt % solid potassium tetraphenylborate (KTPB) aqueous slurries, the radiolysis products were analyzed from the aqueous layer and also after dissolving the solid in acetone so as to release trapped products into solution. Benzene was the major product along with trace amounts of biphenyl and phenol. Only 10% of the benzene (G = 0.71) was released during radiolysis; 90% (G = 7.1) was released when the solid was dissolved in acetone. The radiolysis mechanism is discussed in terms of two alternate pathways for the reaction of OH. radical with TPB- ion, involving electron transfer or OH. addition to the aromatic ring.