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Crystals of Benzamide, the First Polymorphous Molecular Compound, Are Helicoidal
Author(s) -
Shtukenberg Alexander G.,
Drori Ran,
Sturm Elena V.,
Vidavsky Netta,
Haddad Asaf,
Zheng Jason,
Estroff Lara A.,
Weissman Haim,
Wolf Sharon G.,
Shimoni Eyal,
Li Chao,
Fellah Noalle,
Efrati Efi,
Kahr Bart
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.202005738
Subject(s) - benzamide , crystallography , lamellar structure , metastability , crystallization , materials science , polymorphism (computer science) , crystal (programming language) , supersaturation , crystal structure , chemistry , stereochemistry , organic chemistry , biochemistry , computer science , genotype , programming language , gene
The growth of spontaneously twisted crystals is a common but poorly understood phenomenon. An analysis of the formation of twisted crystals of a metastable benzamide polymorph (form II ) crystallizing from highly supersaturated aqueous and ethanol solutions is given here. Benzamide, the first polymorphic molecular crystal reported (1832), would have been the first helicoidal crystal observed had the original authors undertaken an analysis by light microscopy. Polymorphism and twisting frequently concur as they are both associated with high thermodynamic driving forces for crystallization. Optical and electron microscopies as well as electron and powder X‐ray diffraction reveal a complex lamellar structure of benzamide form II needle‐like crystals. The internal stress produced by the overgrowth of lamellae is shown to be able to create a twist moment that is responsible for the observed non‐classical morphologies.