Abstract: | Structural Chemistry of Phosphorus Containing Chains and Rings. 16. Molecular and Crystal Structure of the Triisopropylundecaphosphane P11(i-Pr)3 The compound 4,7,11-triisopropyl-pentacyclo6.3.0.02.6.03.10.05.9]undecaphosphane, C9H21P11, crystallizes triclinically in the space group P1 with a = 1 045.3 pm, b = 1 057.2 pm, c = 1 075,0 pm, α = 101.00°, β = 98.89°, γ = 112.27° and Z = 2. The main structural feature is a phosphorus skeleton with approximate symmetry D3 composed of six five-membered rings which are asymmetrically substituted by the isopropyl groups. The (average) bond lengths are d(P? P) = 221.6 pm, d(P? C) = 187.5 pm, d(C? C) = 151.4 pm, d(C? H) = 108 pm with 217.6 ≤ d(P? P) ≤ 226.4 pm. The geometry of the substituents is quite normal. |