Metal distribution and disorder in the crystal structure of [NH2Et2][Cr7MF8(tBuCO2)16] wheel molecules for M = Mn, Fe, Co, Ni, Cu, Zn and Cd. Issue 6 (7th November 2014)

• Record Type: Journal Article
• Authors: Larsen, Finn Krebs; Overgaard, Jacob; Christensen, Mogens; McIntyre, Garry James; Timco, Grigore; Winpenny, Richard E. P.
• Is Part Of: Acta crystallographica. Volume 70:Issue 6(2014:Dec.)
• Page Start: 932
• Page End: 941
• Publication Date: 2014-11-07
• DOI: 10.1107/S2052520614019179
• Languages: English
• ISSNs: 2052-5206

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>The homometallic wheel compound [Cr<sub>8</sub>F<sub>8</sub>(O<sub>2</sub>CCMe<sub>3</sub>)<sub>16</sub>] formed with fluorine and pivalic acid ligands can be modified by introducing in the synthesis process a divalent cation <italic>M</italic> capable of octahedral coordination instead of one of the trivalent Cr centres in the ring. Heterometallic mono‐anionic species [Cr<sub>7</sub><italic>M</italic>F<sub>8</sub>(O<sub>2</sub>CCMe<sub>3</sub>)<sub>16</sub>]<sup>−</sup> can form diethylammonium salts and be crystallized from ethylacetate solution as compounds with the general formula [NH<sub>2</sub>Et<sub>2</sub>][Cr<sub>7</sub><italic>M</italic>F<sub>8</sub>(<sup><italic>t</italic></sup>BuCO<sub>2</sub>)<sub>16</sub>][C<sub>4</sub>H<sub>8</sub>O<sub>2</sub>]<sub>0.5</sub> for <italic>M</italic> = Mn, Fe, Co, Ni, Cu, Zn and Cd. Their structures are isomorphous, belonging to the space group <italic>P</italic>2<sub>1</sub>/<italic>c</italic>. The study has determined the degree of order for the individual <italic>M</italic> heterometal over the possible metal positions of the ring in the crystal structure by modelling based on X‐ray diffraction data. The model took into account disorder in <italic>tert</italic>‐butyl groups of the pivalate ligands and in the position and orientation of the ethylacetate solvent molecule. The heterometal turned out to be partly ordered in the crystal structure.</p> </abstract>