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A list of organic kryptoracemates
László Fábián1, Carolyn Pratt Brock
1Pfizer Institute for Pharmaceutical Materials Science, Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, England.
Acta Crystallographica. Section B, Structural Science
|January 27, 2010
Summary
Researchers compiled 181 organic kryptoracemates, which are racemic compounds crystallizing in Sohnke space groups. Most of these structures could have formed ordered crystals in non-Sohnke groups, highlighting unusual crystallographic behavior.
Area of Science:
- Crystallography
- Solid-state chemistry
- Organic chemistry
Background:
- Kryptoracemates are racemic compounds that crystallize in Sohnke space groups, containing only proper symmetry operations.
- These structures represent a crystallographic curiosity, challenging typical crystallization expectations.
- Understanding their formation is key to advancing crystal engineering and materials science.
Purpose of the Study:
- To compile and analyze a comprehensive list of organic kryptoracemates.
- To investigate the crystallographic properties and conformational characteristics of these compounds.
- To determine the prevalence of kryptoracemates within the broader context of organic crystal structures.
Main Methods:
- Utilized software to search the Cambridge Structural Database.
- Employed InChI string generation and comparison for structural validation.
- Analyzed crystal structures for symmetry, conformation, and centroid positioning.
Main Results:
- A list of 181 organic kryptoracemates was compiled.
- 151 out of 181 structures could have crystallized in non-Sohnke groups.
- Kryptoracemates constitute 0.1% of relevant organic structures, with enantiomers often exhibiting near-perfect conformational similarity and pseudosymmetry in 60% of cases.
Conclusions:
- Kryptoracemates are rare but systematically identifiable crystallographic phenomena.
- The study provides a detailed analysis of their structural features and prevalence.
- Findings contribute to a deeper understanding of crystal packing and symmetry in organic solids.
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