Krivoshein, Arcadius2020-05-262020-05-262014Khrustalev, V. N., Sandhu, B., Bentum, S., Fonari, A., Krivoshein, A. V., and Timofeeva, T. V. (2014) Absolute configuration and polymorphism of 2-phenylbutyramide and a-methyl-a-phenylsuccinimide, Crystal Growth & Design 14, 3360-3369.https://hdl.handle.net/10657.1/2349Crystal structures of racemic and homochiral forms of 2-phenylbutyramide (1) and 3-methyl-3-phenylpyrrolidine-2,5-dione (2) were investigated in detail by a single crystal X-ray diffraction study. Absolute configurations of the homochiral forms of 1 and 2, obtained by chromatographic separation of racemates, were determined. It was revealed that racemate and homochiral forms of 1 are very similar in terms of supramolecular organization (H-bonded ribbons) in crystal, infrared (IR) spectral characteristics, and melting points. The presence of two different molecular conformations in homochiral forms of 1 allowed mimicking of crystal packing of the H-bonded ribbons in racemate 1. Two polymorph modifications (monoclinic and orthorhombic) comprising very similar H-bonded zigzag-like chains were found for the homochiral forms of compound 2 that were significantly different in terms of crystal structure, IR spectra, and melting points from the racemic form of 2. Unlike compound 1, homochiral forms of compound 2 have a higher density than the corresponding racemate which contradicts the Wallach rule and indicates that, in this case, homochiral forms are more stable than racemate forms.Amides,Inhibitors,Inhibition,Screening assays,ReceptorsCrystals, Noncovalent interactions, Molecular structure, Crystal structure, MoleculesArticle