Enantiomeric resolution and X-ray optical activity of a tricobalt extended metal atom chain

Autor: Anandi Srinivasan, Philippe Sainctavit, Vladimir Bulicanu, Andrei Rogalev, Fabrice Wilhelm, Ahmad Naim, Elizabeth A. Hillard, Miguel Cortijo, Patrick Rosa, Rodolphe Clérac
Přispěvatelé: Centre de Recherche Paul Pascal (CRPP), Université de Bordeaux (UB)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB), Université de Bordeaux (UB)-Institut Polytechnique de Bordeaux-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), the CNRS, the University of Bordeaux, the Conseil Régional de la Nouvelle Aquitaine, the France Canada Research fund (PhD fellowship for AS), the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 706556 CHIMMM (Postdoctoral fellowship for MC), the Erasmus Mundus European program (PhD fellowship for VB), the ANR project CHIROTS ANR-11-JS07-013-01 (PR, PhD fellowship for AN), the European Synchrotron Radiation Facility (beamtimes CH-4171, CH-4457 and CH-5009), the GDR MCM-2 and the MOLSPIN COST action CA15128., Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
Zdroj: Chemical Science
Chemical Science, 2018, 9 (5), pp.1136-1143. ⟨10.1039/c7sc04131d⟩
Chemical Science, The Royal Society of Chemistry, 2018, 9 (5), pp.1136-1143. ⟨10.1039/c7sc04131d⟩
'Chemical Science ', vol: 9, pages: 1136-1143 (2018)
ISSN: 2041-6520
2041-6539
DOI: 10.1039/c7sc04131d⟩
Popis: Enantiopure single crystals of extended metal atom chains display exceptionally large optical X-ray dichroisms at the Co K-edge.
A simple procedure based on anion exchange was employed for the enantiomeric resolution of the extended metal atom chain (EMAC) [Co3(dpa)4(MeCN)2]2+. Use of the chiral salt (NBu4)2[As2(tartrate)2], (Λ-1 or Δ-1), resulted in the selective crystallization of the EMAC enantiomers as [Δ-Co3(dpa)4(MeCN)2](NBu4)2[Λ-As2(tartarte)2]2, (Δ-2) and [Λ-Co3(dpa)4(MeCN)2](NBu4)2[Δ-As2(tartrate)2]2 (Λ-2), respectively, in the P4212 space group, whereas a racemic mixture of 1 yielded [Co3(dpa)4(MeCN)2][As2(tartrate)2]·2MeCN (rac-3), which crystallized in the C2/c space group. The local electronic and magnetic structure of the EMAC enantiomers was studied, exploiting a variety of dichroisms in single crystals. A strong linear dichroism at the Co K-edge was observed in the orthoaxial configuration, whereas it vanished in the axial orientation, thus spectroscopically confirming the D4 crystal symmetry. Compounds Δ-2 and Λ-2 are shown to be enantiopure materials as evidenced by mirror-image natural circular dichroism spectra in the UV/vis in solution and in the X-ray range at the Co K-edge in single crystals. The surprising absence of detectable X-ray magnetic circular dichroism or X-ray magnetochiral dichroism signals at the Co K-edge, even at low temperature (3 K) and a high magnetic field (17 T), is ascribed to a strongly delocalized spin density on the tricobalt core.
Databáze: OpenAIRE
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