ISSN:
0044-2313
Keywords:
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Description / Table of Contents:
On the Polymorphism of 1,5-Diphosphabicyclo[3.3.0]octane-1,5-disulfide. Crystal and Molecular Structure of Orthorhombic Modification1,5-Diphosphabicyclo[3.3.0]octane-1,5-disulfide 2 has been found to crystallize in two modifications. The results of an x-ray structure analysis performed on the orthorhombic modification are as follows. The dimensions of the unit cell containing 4 molecules are a = 1370(1) pm, b = 1120(1) pm, c = 646(1) pm, the space group is Pnma. The molecules of 2 exhibit C2v symmetry (within the experimental error) and an eclipsed endo-endo-conformation, the diphospholane ring as a part of the bicyclic structure has an envelope conformation. The molecular structure of 2 is exactly the same for the orthorhombic as well as for the monoclinic modification, the polymorphism is caused by slight differences of molecular packing in the crystal lattice (packing polymorphism).
Notes:
1,5-Diphosphabicyclo[3.3.0]octan-1,5-disulfid 2 kristallisiert in zwei Modifikationen. Eine Röntgenkristallstrukturanalyse der orthorhombischen Modifikation ergab: Die Raumgruppe ist Pnma, die Elementarzelle mit den Abmessungen a = 1370(1) pm, b = 1120(1) pm, c = 646(1) pm enthält 4 Moleküle. 2 besitzt die Molekülsymmetrie C2v (im Rahmen der experimentellen Genauigkeit) und liegt in einer cis-endo-endo-Konformation vor, die beiden Diphospholanringe weisen eine „envelope“-Konformation auf. 2 hat in der orthorhombischen und in der monoklinen Form die gleiche Molekülstruktur, die Polymorphie beruht auf geringen Unterschieden in der Anordnung der Moleküle im Kristallgitter (Packungspolymorphie).
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/zaac.19794580119
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