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Trommer C, Kuhlemann E, Engesser TA, Walter M, Thakur S, Kuch W, Tuczek F. Spin crossover in dinuclear iron(II) complexes bridged by bis-bipyridine ligands: dimer effects on electronic structure, spectroscopic properties and spin-state switching. Dalton Trans 2024; 53:9909-9920. [PMID: 38808483 DOI: 10.1039/d4dt00707g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Inspired by the well-studied mononuclear spin crossover compound [Fe(H2B(pz)2)2(bipy)], the bipyridine-based bisbidentate ligands 1,2-di(2,2'-bipyridin-5-yl)ethyne (ac(bipy)2) and 1,4-di(2,2'-bipyridine-5-yl)-3,5-dimethoxybenzene (Ph(OMe)2(bipy)2) are used to bridge two [Fe(H2B(pz)2)2] units, leading to the charge-neutral dinuclear iron(II) compounds [{Fe(H2B(pz)2)2}2 μ-(ac(bipy)2)] (1) and [{Fe(H2B(pz)2)2}2 μ-(Ph(OMe)2(bipy)2)] (2), respectively. The spin-crossover properties of these molecules are investigated by temperature-dependent PPMS measurements, Mössbauer, vibrational and UV/Vis spectroscopy as well as X-ray absorption spectroscopy. While compound 1 undergoes complete SCO with T1/2 = 125 K, an incomplete spin transition is observed for 2 with an inflection point at 152 K and a remaining high-spin fraction of 40% below 65 K. The spin transitions of the dinuclear compounds are also more gradual than for the parent compound [Fe(H2B(pz)2)2(bipy)]. This is attributed to steric hindrance between the molecules, limiting intermolecular interactions such as π-π-stacking.
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Affiliation(s)
- Clara Trommer
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Eike Kuhlemann
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Tobias A Engesser
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Marcel Walter
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Sangeeta Thakur
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Wolfgang Kuch
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Felix Tuczek
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
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2
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Paliwoda D, Vendier L, Nicolazzi W, Molnár G, Bousseksou A. Pressure Tuning of Coupled Structural and Spin State Transitions in the Molecular Complex [Fe(H 2B(pz) 2) 2(phen)]. Inorg Chem 2022; 61:15991-16002. [PMID: 36162137 DOI: 10.1021/acs.inorgchem.2c02286] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The large volume change, which accompanies the molecular spin crossover (SCO) phenomenon in some transition metal complexes, prompts frequently the coupling of the SCO with other instabilities. Understanding the driving mechanism(s) of such coupled phase transitions is not only important for fundamental reasons but also provides scope for the development of multifunctional materials. The general theoretical expectation is that the coupling has elastic origin, and the sequence of transitions can be tuned by an externally applied pressure, but dedicated experiments remain scarce. Here, we used high-pressure and low-temperature single-crystal X-ray diffraction to investigate the high-spin (HS) to low-spin (LS) transitions in the molecular complexes [FeII(H2B(pz)2)2(bipy)] and [FeII(H2B(pz)2)2(phen)]. In the bipyridine complex, the SCO is continuous and isostructural over the whole T, P-range (100-300 K, 0-2 GPa). In the phenanthroline derivative, however, the SCO is concomitant with a symmetry-breaking transition (C2/c to P1̅). Structural analysis reveals that the coupling between the two phenomena can be tuned by external pressure from a virtually simultaneous HSC2/c-LSP1̅ transition to the sequence of HSC2/c-LSC2/c-LSP1̅ transitions. The correlation of spontaneous strain and order parameter behaviors highlights that the "separated" transitions remain still connected via strain coupling, whereas the "simultaneous" transitions are partially split.
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Affiliation(s)
- Damian Paliwoda
- LCC, CNRS & Université de Toulouse (UPS, INP), 31077 Toulouse, France
| | - Laure Vendier
- LCC, CNRS & Université de Toulouse (UPS, INP), 31077 Toulouse, France
| | - William Nicolazzi
- LCC, CNRS & Université de Toulouse (UPS, INP), 31077 Toulouse, France
| | - Gábor Molnár
- LCC, CNRS & Université de Toulouse (UPS, INP), 31077 Toulouse, France
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3
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Cini A, Poggini L, Chumakov AI, Rüffer R, Spina G, Wattiaux A, Duttine M, Gonidec M, Fittipaldi M, Rosa P, Mannini M. Synchrotron-based Mössbauer spectroscopy characterization of sublimated spin crossover molecules. Phys Chem Chem Phys 2020; 22:6626-6637. [PMID: 32159166 DOI: 10.1039/c9cp04464g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The spin crossover (SCO) efficiency of [57Fe(bpz)2(phen)] (where bpz = bis(pyrazol-1-yl)borohydride and phen = 9,10-phenantroline) molecules deposited on gold substrates was investigated by means of synchrotron Mössbauer spectroscopy. The spin transition was driven thermally, or light induced via the LIESST (light induced excited spin-state trapping) effect. Both sets of measurements show that, once deposited on a gold substrate, the efficiency of the SCO mechanism is modified with respect to molecules in the bulk phase. A correlation in the distribution of hyperfine parameters in the sublimated films, not evidenced so far in the bulk phase, is reported. This translates into geometrical distortions of the first coordination sphere of the iron atom that seem to correlate with the decreased spin conversion. The work reported clearly shows the potentiality of synchrotron Mössbauer spectroscopy for the characterization of nanostructured Fe-based SCO systems, thus resulting as a key tool in view of their applications in innovative nanoscale devices.
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Affiliation(s)
- Alberto Cini
- Department of Physics and Astronomy, University of Florence and INSTM Research Unit of Florence, via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy.
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Ossinger S, Naggert H, Bill E, Näther C, Tuczek F. Electronic Structure, Vibrational Spectra, and Spin-Crossover Properties of Vacuum-Evaporable Iron(II) Bis(dihydrobis(pyrazolyl)borate) Complexes with Diimine Coligands. Origin of Giant Raman Features. Inorg Chem 2019; 58:12873-12887. [DOI: 10.1021/acs.inorgchem.9b01813] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sascha Ossinger
- Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
| | - Holger Naggert
- Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Christian Näther
- Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
| | - Felix Tuczek
- Institute of Inorganic Chemistry, Christian-Albrechts-University Kiel, Max-Eyth-Strasse 2, 24118 Kiel, Germany
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Piedrahita-Bello M, Ridier K, Mikolasek M, Molnár G, Nicolazzi W, Salmon L, Bousseksou A. Drastic lattice softening in mixed triazole ligand iron(ii) spin crossover nanoparticles. Chem Commun (Camb) 2019; 55:4769-4772. [PMID: 30924832 DOI: 10.1039/c9cc01619h] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A series of spin-crossover (SCO) coordination nanoparticles (ca. 60 nm) with the general formulae [Fe(Htrz)1+y-x(trz)2-y(NH2trz)x](BF4)y·nH2O (x = 0, 0.1, 0.2 and 0.3) were synthesized in concentrated solutions without using any surfactant or polymer. The nanoparticle powders were investigated by transmission electron microscopy, powder X-ray diffraction, magnetometry, calorimetry, Raman/IR spectroscopies, elemental analysis and 57Fe Mössbauer spectrometry. Remarkably, the latter revealed a large decrease of the lattice stiffness when incorporating a small amount of amino-triazole ligand, reflected by the drop of the Debye temperature from 285 K (x = 0) to 205 K (x = 0.3). This collapse of the lattice cohesion was attributed to a reorganization of the supramolecular interactions between the Fe-triazole chains. This effect on the SCO properties is also discussed.
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Mikolasek M, Manrique-Juarez MD, Shepherd HJ, Ridier K, Rat S, Shalabaeva V, Bas AC, Collings IE, Mathieu F, Cacheux J, Leichle T, Nicu L, Nicolazzi W, Salmon L, Molnár G, Bousseksou A. Complete Set of Elastic Moduli of a Spin-Crossover Solid: Spin-State Dependence and Mechanical Actuation. J Am Chem Soc 2018; 140:8970-8979. [DOI: 10.1021/jacs.8b05347] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Mirko Mikolasek
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Maria D. Manrique-Juarez
- LCC-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
- LAAS-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Helena J. Shepherd
- School of Physical Sciences, University of Kent, Canterbury, CT2 7NH, United Kingdom
| | - Karl Ridier
- LCC-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Sylvain Rat
- LCC-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | | | | | - Ines E. Collings
- ESRF-The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Fabrice Mathieu
- LAAS-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Jean Cacheux
- LAAS-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Thierry Leichle
- LAAS-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Liviu Nicu
- LAAS-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | | | - Lionel Salmon
- LCC-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
| | - Gábor Molnár
- LCC-CNRS, Université de Toulouse, CNRS, 31077 Toulouse, France
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Ould‐Hamouda A, Viquerat B, Degert J, Matar SF, Létard JF, Guillaume F, Freysz E. Impact of Spin State Transition on Vibrations of [Fe–(PM–BiA)
2
(NCS)
2
] and [Fe–(PM–PEA)
2
(NCS)
2
] Spin Crossover Compounds: Experimental and Theoretical Far IR and Raman Study. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201700979] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Amine Ould‐Hamouda
- Université Bordeaux CNRS, UMR 5798, LOMA 358 cours de la libération 33405 Talence Cedex France
| | - Benjamin Viquerat
- Université Bordeaux CNRS, UMR 5798, LOMA 358 cours de la libération 33405 Talence Cedex France
| | - Jérôme Degert
- Université Bordeaux CNRS, UMR 5798, LOMA 358 cours de la libération 33405 Talence Cedex France
| | - Samir F. Matar
- Université Bordeaux, CNRS, ICMCB 33400 Talence France
- Lebanese German University (LGU) Sahel‐Alma Campus, P.O. Box 206 Jounieh Lebanon
| | | | | | - Eric Freysz
- Université Bordeaux CNRS, UMR 5798, LOMA 358 cours de la libération 33405 Talence Cedex France
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Rat S, Ridier K, Vendier L, Molnár G, Salmon L, Bousseksou A. Solvatomorphism and structural-spin crossover property relationship in bis[hydrotris(1,2,4-triazol-1-yl)borate]iron(ii). CrystEngComm 2017. [DOI: 10.1039/c7ce00741h] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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