Kulmaczewski, R orcid.org/0000-0002-3855-4530, Armstrong, IT, Catchpole, P orcid.org/0000-0003-3048-060X et al. (5 more authors) (2023) Di-Iron(II) [2+2] Helicates of Bis-(Dipyrazolylpyridine) Ligands – the Influence of the Ligand Linker Group on Spin State Properties. Chemistry: A European Journal, 29 (9). e202202578. ISSN 0947-6539
Abstract
Four bis [2-{pyrazol-1-yl}-6-{pyrazol-3-yl}pyridine] ligands have been synthesized, with butane-1,4-diyl ( L 1 ), pyrid-2,6-diyl ( L 2 ), benzene-1,2-dimethylenyl ( L 3 ) and propane-1,3-diyl ( L 4 ) linkers between the tridentate metal-binding domains. L 1 and L 2 form [Fe 2 ( μ - L ) 2 ]X 4 (X ‒ = BF 4 ‒ or ClO 4 ‒ ) helicate complexes when treated with the appropriate iron(II) precursor. Solvate crystals of [Fe 2 ( μ - L 1 ) 2 ][BF 4 ] 4 exhibit three different helicate conformations, which differ in the torsions of their butanediyl linker groups. The solvates exhibit gradual thermal spin-crossover, with examples of stepwise switching and partial spin-crossover to a low temperature mixed-spin form. Salts of [Fe 2 ( μ - L 2 ) 2 ] 4+ are high-spin, which reflects their highly twisted iron coordination geometry. The composition and dynamics of assembly structures formed by iron(II) with L 1 - L 3 vary with the ligand linker group, by mass spectrometry and 1 H NMR. Gas phase DFT calculations imply the butanediyl linker conformation in [Fe 2 ( μ - L 1 ) 2 ] 4+ influences its spin state properties, but show anomalies attributed to intramolecular electrostatic repulsion between the iron atoms.
Metadata
Item Type: | Article |
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Copyright, Publisher and Additional Information: | © 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Inorganic Chemistry (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) > Organic Chemistry (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Condensed Matter (Leeds) |
Funding Information: | Funder Grant number EPSRC (Engineering and Physical Sciences Research Council) EP/K012568/1 EPSRC (Engineering and Physical Sciences Research Council) EP/K00512X/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 05 Dec 2022 17:04 |
Last Modified: | 16 Jan 2025 10:47 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/chem.202202578 |
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Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:193454 |