Crystals at a Carrefour on the Way through the Phase Space: A Middle Path

• Main Authors: Yury V. Torubaev, Ivan V. Skabitsky
• Format: Article
• Language: English
• Published: MDPI AG 2021-03-01
• Series: Molecules
• Subjects: non-covalent interactions; chalcogen bonding; polymorphism; supramolecular synthons; synthons evolution; synthon crossover
• Online Access: https://www.mdpi.com/1420-3049/26/6/1583

Multiple supramolecular functionalities of cyclic α-alkoxy tellurium-trihalides (including Te---O, Te---X (X = Br, I) and Te---π(C=C) supramolecular synthons) afford rich crystal packing possibilities, which consequently results in polymorphism or Z’ > 1 crystal structures. Example of three crystal forms of cyclohexyl-ethoxy-tellurium-trihalides, one of which combines the packing of two others, affords a unique model to observe the <i>supramolecular synthon evolution</i> at the early stages of crystallization, when <i>crystals on the way</i> find themself at a carrefour between the evolutionally close routes, but fail to choose between two energetically close packing patterns, so taking the “middle path”, which incorporates both of them (and results in two crystallographically independent molecules). In general, this allows a better understanding of the existing structures, and an instrument to search for the new polymorphic forms.