ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
Formation of Organosilicon Compounds. LXVI. Crystal and Molecular Structure of Hexamethyl-heptasilahexacyclo-heptadecane Si7C16H361,3,7,9,11,13-Hexamethyl-1,3,5,7,9,11,13-heptasilahexacyclo-heptadecane Si7C16H36 crystallizes in the triclinic space group P1 with a = 11.393 Å, b = 11.819 Å, c = 10.583 Å, α = 83.73°, β = 67.42°, γ = 62.19° and Z = 2 formula units. The average bond lengths are CH—Si= 1.886, CH2—Si = 1.870 and CH3—Si = 1.883 Å. The steric interactions of CH2-groups and CH3-groups in the range of the eight-membered ring (1,14,13,12,11,10,9,15) lead to an increase of the bond angles Si—CH—Si within this ring (117.4°) and to a small but significant lowering of the symmetry from C2v to C2.
Notes:
1,3,7,9,11,13-Hexamethyl-1,3,5,7,9,11,13-heptasilahexacyclo-heptadecan Si7C16H36 kristallisiert triklin in der Raumgruppe P1 mit a = 11,393 Å, b = 11,819 Å, c = 10,583 Å, α = 83,73°, β = 67,42°, γ = 62,19° und Z = 2 Formeleinheiten. Die mittleren Bindungslängen sind CH—Si = 1,886, CH2—Si = 1,870 und CH3—Si = 1,883 Å. Die sterischen Wechselwirkungen der CH3- und CH2-Gruppen im Bereich des Achtrings (1,14,13,12,11,10,9,15) führen dort zu einer Aufweitung der Bindungswinkel Si—CH—Si auf 117,4° und zu einer geringen, aber signifikanten Symmetrieerniedrigung von C2v auf C2.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19764250102
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