in benzene addn. of stoichiometric amt. of tetraryltin to dithiophosphoric acid soln.; refluxing, 4h; keeping at room temp., overnight; crystn.; filtration; drying (vac.); elem. anal.;

in benzene byproducts: NH4Cl; addn. of Sn compd. soln. to dithiophosphate suspension; refluxing, 4h; filtration of pptd. NH4Cl; evapn.; washing (n-hexane); recrystn. (toluene); elem. anal.;