Li+ and Ca2+ derivatives of the isonicotinate-n-oxide ion including single crystal-to-single crystal transformations
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Date
2014-07-29
Journal Title
Journal ISSN
Volume Title
Publisher
Americal Chemical Society
Abstract
Crystals of [Li(inox)(H2O)] (where inox– = the isonicotinate-N-oxide ion) are obtained from aqueous solution. The Li+ cations and the carboxylate anions form a two-dimensional (2D) sheet containing four-membered (−Li–O–Li–O−) rings and 16-membered (−Li–O–C–O−)4 rings; the sheets are linked to adjacent parallel sheets through hydrogen bonds. Crystals of solvent-free [Li(inox)], obtained from t-butanol, consist of a three-dimensional network which can also be prepared in microcrystalline form by dehydration of [Li(inox)(H2O)] at 200 °C. Crystals of [Ca(inox)2(H2O)2] contain 2D sheets with 4,4 topology in which Ca2+ ions, bound by trans water molecules, provide the 4-connecting nodes. The Ca(H2O)22+ units are linked by carboxylate groups to generate 16-membered (−Ca–O–C–O−)4 rings. Sheets are bound together by hydrogen bonds between the pyridine-N-oxide units and coordinated water molecules. [Ca(inox)2(H2O)2] can be dehydrated at 190 °C in a single crystal-to-single crystal transformation to give [Ca(inox)2] whose structure is related to that of the hydrated precursor. A proposed solid-state mechanism for this single crystal-to-single crystal transformation, in which the N-oxide takes up the site on calcium vacated by water is proposed © 2014 American Chemical Society.
Description
Keywords
Crystals, Aqueous solutions, Anions, Hydrogen, Topology, Carboxylic acids
Citation
White, K. F., Abrahams, B. F., Maynard-Casely, H., & Robson, R. (2014). Li+ and Ca2+ derivatives of the isonicotinate-n-oxide ion including single crystal-to-single crystal transformations. Crystal Growth & Design, 14(9), 4602-4609. doi:10.1021/cg500710t