Conformational dimorphism of isochroman-1-ones in the solid state



Druh Článek v odborném periodiku
Časopis / Zdroj Journal of Molecular Structure
Fakulta / Pracoviště MU

Přírodovědecká fakulta

Obor Organická chemie
Klíčová slova Adamantane; Isochroman-1-one derivatives; Conformational polymorph
Popis Isochroman-1-one derivatives, which are relatives of coumarins, display a broad spectrum of biological activity; therefore, these derivatives attract the attention of chemists. A series of new isochroman-1-ones were prepared by the reaction of benzyl-derived Grignard reagents with acyl chlorides. All of the prepared compounds were characterized using single-crystal X-ray diffraction as well as FT-IR, NMR and MS techniques. Single crystal X-ray diffraction analysis revealed that the isochromanones can adopt two distinct conformations in the solid state. For one of the compounds, two polymorphs with unique forms crystallized separately under different temperatures. The packing of all of the examined crystals is stabilized via weak intramolecular C-H center dot center dot center dot pi and/or C-H center dot center dot center dot O interactions. Although the closed conformer was predominantly found in the actual crystals, the open conformer is thermochemically more stable for all of the examined compounds according to DFT calculations. (C) 2014 Elsevier B.V. All rights reserved.
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