DiThiophosphate, barium

Shopov and his co-workers have recently published two papers on hydroperoxide decomposition by barium dialkyl dithiophosphates. The decomposition rate of cumene hydroperoxide at 140 °C. in the presence of barium dibenzyl dithiophosphate was found (20) not to be described by Equation H. A mechanism, similar to that of Kennerly and Patterson (13) but slightly more detailed was proposed as follows ... 

By studying the reaction in the presence and absence of a radical acceptor, 2,6-di-terf-butyl-4-methylphenol, radical-induced decomposition was selectively eliminated and the separate terms in Equation K were evaluated. Using barium dibenzyl dithiophosphate the following ratio was obtained ... 

C. Kubierschky 6 prepared a series of oxythiophosphates with only part of the oxygen of the normal phosphates replaced by sulphur. He said that acids decompose all thiophosphates hydrogen sulphide is evolved, and, in some cases, sulphur separates. Monothiophosphates give white precipitates with calcium, barium, and strontium salts, the dithiophosphates with barium and strontium salts, and the trithiophosphates with barium salts only. All thiophosphates yield precipitates with cadmium, copper, silver, and mercurous salts, which decompose after a time,... 

Thiophosphates, Detection.—Many of the reactions already described, such as the production of H2S and phosphoric acid when these salts are treated with acids, will serve to detect the thiophosphates. The alkali and ammonium salts are soluble, the others mostly insoluble. Calcium, barium and strontium monotbiophosphates, barium and strontium dithiophosphates and barium trithiophosphate are insoluble, the other alkaline earth salts soluble. Thiophosphate solutions mixed with alkali sulphides give a green colour with ferric chloride. Monothiophosphates give a blue precipitate with cobalt sulphate soluble in excess of the cobalt salt, dithiophosphates a green precipitate soluble in excess of dithiophosphate, and trithiophosphates a brown solution. Several other tests have been described.3... 

Of the four acids, however, monothiophosphoric acid is sufficiently stable that Klement obtained an 83% solution by reacting barium dithiophosphate with the stoichiometric quantity of H3SO4, followed by hydrolysis of the resulting dithiophosphoric acid to monothiophosphoric acid. 

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