Racemic Triarylmethanol Derivative Crystallizes as a Chiral Crystal Structure with Enantiomeric Disorder, in the Sohncke Space Group P21

Abstract

[EN] The X-ray crystal structure of a racemic triarylcarbinol derivate ((±)-1) was determined. Compound (±)-1 crystallizes as a chiral structure in the noncentrosymmetric Sohncke space group P21 and the crystals show a special case of enantiomeric disorder with two molecules of opposite handedness sharing many of the atomic positions in the asymmetric unit. The corresponding (R)- and (S)-enantiomers of 1 were separated by chiral HPLC, and crystallized independently yielding single crystals of both of them. The X-ray diffraction analysis of the crystals allowed the determination of the absolute configuration of both enantiomers (R)-1 and (S)-1. Both enantiomers establish intermolecular hydrogen bonds in the solid state, which induce significant differences in their molecular arrangement when compared to racemic crystal (±)-1.