Diphosphine disulfides phosphinic acids

Reactions with diphosphine disulfides Phosphinic acids and sec. phosphines... 

The metal and ammonium salts of dithiophosphinic acids tend to exhibit far greater stability with respect to this thermal decomposition reaction, and consequently these acids are often prepared directly in their salt form for convenience and ease of handling. Alkali-metal dithiophosphinates are accessible from the reaction of diphosphine disulfides with alkali-metal sulfides (Equation 22) or from the reaction of alkali-metal diorganophosphides with two equivalents of elemental sulfur (Equation 23). Alternatively, they can be prepared directly from the parent dithiophosphinic acid on treatment with an alkali-metal hydroxide or alkali-metal organo reagent. Reaction of secondary phosphines with elemental sulfur in dilute ammonia solution gives the dithiophosphinic acid ammonium salts (Equation 24). 

Thionyl chloride Phosphinic acid chlorides from diphosphine disulfides... 

Without additional reagents Thiophosphinic acid bromides from diphosphine disulfides s. 19, 590 Thionyl chloride Phosphinic acid chlorides from diphosphine disulfides s. 19, 591... 

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