Success or Failure of Chiral Crystallization of Similar Heterocyclic Compounds

Abstract

Single crystals of two achiral and planar heterocyclic compounds, C9H8H3O(CA1) and C8H5NO2 (CA4), recrystallized from ethanol, were characterized by single crystal X-ray analysis, respectively, and chiral crystallization was observed only for CA1 as P212121 (# 19), whereas it was not observed for CA4 P21/c (# 14). In CA1, as a monohydrate, the hydrogen bonds were pronounced around the water of crystallization (O4), and the planar cyclic sites were arranged in parallel to slightly tilted positions. On the other hand, an anhydride CA4 formed a dimer by hydrogen bonds between adjacent molecules in the crystal, which were aggregated by van der Waals forces and placed in parallel planar cyclic sites.

High Proportion of Chiral Crystallization of Achiral Indolyl Sulfonamides: Effect of Intermolecular Interactions

“…The construction of polar crystals that show the chiral property by an assembly of achiral molecules generally occurs infrequently because molecules usually assemble to cancel out their polarity and asymmetric property. , In this context, it is important to understand the circumstances, frequency, and chances of an achiral molecule crystallizing in a homochiral manner . While the ability to control chiral crystallization of achiral molecules is intriguing, a rational explanation of this phenomenon has not been reported as yet. ,− Nevertheless, the significance of molecular interactions within the crystal has been acknowledged …”