In:
Acta Crystallographica Section B Structural Science, International Union of Crystallography (IUCr), Vol. 65, No. 3 ( 2009-06-01), p. 249-268
Abstract:
The X-ray analysis of (6 R ,7a S )-6-( tert -butyl-dimethylsilanyloxy)-1-hydroxy-2-phenyl-5,6,7,7a-tetrahydropyrrolizin-3-one, C 19 H 27 NO 3 Si, revealed a diffraction pattern which is typical for modulated structures: strong Bragg peaks surrounded by weaker reflections which cannot be indexed with the same three reciprocal lattice vectors that are used to describe the strong peaks. For this class of crystal structures the concept of superspace has been developed which, however, for many crystallographers still constitutes a Gordian Knot. As a possible tool to cut this knot the crystal structure of the above-mentioned tetrahydropyrrolizinone derivative is presented as an illustrative example for handling and describing the modulated structure of a typical pharmaceutical ( i.e. molecular) compound. Having established a working knowledge of the concepts and terminology of the superspace approach a concise and detailed description of the complete process of peak indexing, data processing, structure solution and structure interpretation is presented for the incommensurately modulated crystal structure of the above-mentioned compound. The superspace symmetry applied is P 2 1 (α0γ)0; the (incommensurate) q vector components at 100 K are α = 0.1422 (2) and γ = 0.3839 (8).
Type of Medium:
Online Resource
ISSN:
0108-7681
DOI:
10.1107/S0108768109015614
DOI:
10.1107/S0108768109015614/bk5084sup1.cif
DOI:
10.1107/S0108768109015614/bk5084Isup2.hkl
DOI:
10.1107/S0108768109015614/bk5084sup3.pdf
DOI:
10.1107/S0108768109015614/bk5084sup4.gif
DOI:
10.1107/S0108768109015614/bk5084sup5.gif
Language:
Unknown
Publisher:
International Union of Crystallography (IUCr)
Publication Date:
2009
detail.hit.zdb_id:
2020841-8
SSG:
13
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