Synthese,Charakterisierung und Struktur von P7(t-Bu3Si)3 („Tris(supersilyl)heptaphosphan(3)”︁)

Synthesis, Characterization, and Structure of P₇(t-Bu₃Si)₃ (?Tris(supersilyl)heptaphosphane(3)”? Tris(tri-tert-butylsilyl)heptaphosphanortricyclane P₇(t-Bu₃Si)₃ 1 is obtained from the reaction of (t-Bu)₃Si? Si(t-Bu)₃ with white phosphorus and forms colorless to pale yellow thermostable crystals. 1 is identified by the complete analysis of its ³¹P{¹H} NMR spectrum (A[MX]₃ spin system) as well as by a single crystal structure determination (space group Pca2₁, a = 170.76(2)pm, b = 131.14(3)pm, c = 426.61(5)pm, α = β = γ= 90°, Z = 8 formula units in the elementary cell). The steric demand of the (t-Bu)₃Si-Groups causes an increase of the exocyclic bond angles at the equatorial phosphorus atoms P^e, while it does not particularly influence the P₇-skeleton. Chlorine (r.t.) and bromine (70°C) degrade the P₇-cage of 1 with formation of PX₃ and (t-Bu)₃SiX (X = Cl, Br).