On the abundance of chiral crystals

Abstract

A common perception of many chemists is that non-biological chiral crystals comprise a small fraction of all crystals, as is the case of chiral non-biological molecules (~10%). We show that the proportion of non-biological chiral crystals is as high as 23%; and only ~6% of these are labelled as chiral.

Double Chiral Hybrid Materials: Formation of Chiral Phenolic Resins on Polyamine-associated Chiral Silica

“…8,9 However, in the past two decades, the research on the chiral transfer between organics and inorganics has gained increasing attention, and a series of synthetic inorganics have been endowed with chirality by molecular imprinting from small chiral organic molecules (on the molecular scale) or by copying the helical shapes (with helical pitch sizes over tens of nanometers) of organic templates.…”

“…8,9 However, in the past two decades, the research on the chiral transfer between organics and inorganics has gained increasing attention, and a series of synthetic inorganics have been endowed with chirality by molecular imprinting from small chiral organic molecules (on the molecular scale) or by copying the helical shapes (with helical pitch sizes over tens of nanometers) of organic templates. 10,11 Interestingly, without the combination of external chiral components, it has been demonstrated that some natural and synthetic chiral inorganics could be directly applied to the enantioselective separation and synthesis of chiral organic small molecules (e.g., amino acids, glucoses).…”

Generation of Supramolecular Chirality around Twofold Rotational or Helical Axes in Crystalline Assemblies of Achiral Components

“…In fact, the Cambridge Structural Database (CSD) includes about seven hundred thousand of crystal data, and remarkably over 70% of organic crystals involve the 21 operations [41]. Moreover, about 10% belong to chiral crystals composed of achiral molecules [36][37][38][39]. These facts indicate that it still remains open to interpret a mechanism for generating supramolecular chirality through the 21 operation.…”

“…Sixty-five among 230 groups are known as the chiral Sohncke symmetry space groups [39]. When symmetry operations are discriminable in chirality by themselves, they hold a pair of notations.…”

“…Consequently, the 21 assembly of achiral molecules does not exhibit supramolecular chirality, while that of chiral molecules exhibit it. As a result, supramolecular chirality of 21 assemblies composed of achiral molecules has been overlooked since the establishment of the crystallography in the first half of the last century [36][37][38][39].…”