A list of organo­metallic krypto­racemates

The vast majority of racemic solutions of chiral compounds apparently crystallize at room temperature in non-Sohncke space groups as racemic crystals. However, krypto­racemic crystals composed of nearly enantio­meric pairs occasionally crystallize at room temperature, or appear as low-temperature phases, in Sohncke space groups. As a complement to the previously published catalog of organic krypto­racemates [Fábián & Brock (2010). Acta Cryst. B66, 94-103], 1412 chiral organo­metallic crystal structures have now been extracted from the Cambridge Structural Database and analyzed. 26 are listed herein as credible krypto­racemates. The possible influence of temperature is discussed, together with some problems in characterizing and classifying these structures.