Reactions with Silanes and Alkali Aluminiumhydrides

Evidence for the existence of trisilylphosphine was found for the first time by Aylett, Emeleus and Maddock in the reactions between silyl iodide, HsSil, and phosphine or between silyltrialkylammonium iodide and phosphine. According to Amberger the reaction of potassium dihydrogenphosphide with silyl bromide is suitable for the preparation of trisilylphosphine. The reaction. 

Glidewell and Sheldrick found that the formation of trisilylphosphine occurs according to the scheme  

The intermediate mono- and disilylphosphines can be isolated using suitable conditions. The preferential formation of trisilylphosphine is a result of the increasing acidity of the compounds in the following order, PH3  

H3SiPH2 (H3Si 2PH. Trisilylphosphine reacts with water or hydrogen chloride to form disiloxane or silyl chloride, respectively. It has a much smaller nucleophilic character than trimethylphosphine.  

Lithium aluminiumhydride reacts with phosphine in diglyme ortetrahydro-furan to give LiAl(PH2)4 with evolution of hydrogen 

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