ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Structural Chemistry of Phosphorus Containing Chains and Rings. 11. Crystal and Molecular Structures of the Two Stereoisomers of Tetraphospha-silaspiro[2.2]pentane (PBut)2Si(PBut)2The spirocyclic compound 1,2,4,5-tetra-tert-butyl-1,2,4,5-tetraphospha-3-silaspiro[2.2]pentane exists in tow diastereomers of point symmetry 4 and 2. The isomer with symmetry 4 even in the solid crystallizes tetragonally in I41/a with a = 1247.0, c = 1505.5 pm and Z = 4. The isomer of fairly exact symmetry 2 crystallizes triclinically in P1 with a = 612.8, b = 996.3, c = 1017.2 pm, α = 75.63, β = 72.38, γ = 88.71° and Z = 1. In this disordered structure the surroundings of Si is slightly distorted due to the influence of the substituents. The (average) bond lengths are (4, 2): d(Si—P) = 220.09(9), 221.5(5); d(P—P) = 225.5(2), 224.2(5); d(P—C) = 189.4(3), 190(2); d(C—C) = 151.4(4), 152(3) pm. The geometry of the substituents in both isomers is quite normal.
Notes:
Die Spiroverbindung 1,2,4,5-Tetra-tert-butyl-1,2,4,5-tetraphospha-3-silaspiro[2.2]pentan liegt in zwei Diastereomeren der Punktsymmetrie 4 und 2 vor. Das Isomer der auch im Festkörper exakten Symmetrie 4 kristallisiert tetragonal in der Raumgruppe I41/a mit a = 1247,0, c = 1505,5 pm und Z = 4. Das sterisch weniger günstige Isomer der im Festkörper nicht streng erfüllten Symmetrie 2 kristallisiert triklin in der Raumgruppe P1 mit a = 612,8, b = 996,3, c = 1017,2 pm, α = 75.63, β = 72,38, γ = 88,71° und Z = 1. In dieser nur fehlgeordnet beschreibbaren Struktur wird die Umgebung des Si durch Substituenteneinflüsse etwas verzerrt. Die (mittleren) Bindungslängen betragen (4, 2): d(Si—P) = 220,09(9), 221,5(5); d(P—P) = 225,5(2), 224,2(5); d(P—C) = 189,4(3), 190(2); d(C—C) = 151,4(4), 152(3) pm. Die Geometrie der Substituenten ist in beiden Isomeren normal.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19845150802
