REACTIONS OF SILICON-SILICON BONDS .6. REDUCTIVE TRICHLOROSILYLATION REACTIONS LEADING TO ALKYLAMINOBIS(TRICHLOROSILYL)PHOSPHANES AND DIALKYLAMINOBIS(TRICHLOROSILYL)PHOSPHANES

Reactions of hexachlorodisilane aid of trichlorosilane/triethylamine w ith alkyl- and dialkylaminodichlorophosphanes RPCl(2) 1a-f [R = iPr: a ; (Me(3)Si)(2)CH: b; R = 1-adamantyl: c: R = tBu: d; R = Et(2)N: e; R = iPr(2)N: f] furnish bis(trichlorosilyl)phosphanes RP(SiCl3)(2) 3a-f. However, when less bulky substituents are attached to the phosphorus atom, so that there is little steric crowding, the double reductive si lylations leading from 1 to 3 are accompanied by side reactions and de composition of 3. Therefore, only 3b, 3c, 3d and 3f were isolated in a pure state. These compounds are more readily prepared by the trichlor osilane/triethylamine method. H-1-, P-31- and Si-29-NMR spectra confir m their constitution. The structure of solid 3f, the first aminobis(tr ichlorosilyl)phosphane, was determined by X-ray crystallography. 3f co ntains a phosphorus atom in a pyramidal environment surrounded by two silicon atoms and a planar nitrogen atom of the diisopropylamino group .