1
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Dürrmann A, Hörner G, Baabe D, Heinemann FW, de Melo MAC, Weber B. Cooperative spin crossover leading to bistable and multi-inert system states in an iron(III) complex. Nat Commun 2024; 15:7321. [PMID: 39183211 PMCID: PMC11345420 DOI: 10.1038/s41467-024-51675-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Accepted: 08/12/2024] [Indexed: 08/27/2024] Open
Abstract
Cooperativity among spin centres has long been the royal road in spin crossover (SCO) research to impose magnetic bistability in terms of thermal hysteresis. In this work we access magnetic multi-inert states of the iron(III) compound {FeL2[B(Ph)4]} ≡ FeB at low temperature, in addition to thermal bistability. The packing of the low-spin and high-spin forms of crystalline FeB differs only marginally what ultimately leads to structural conservatism. This indicates that the SCO-immanent breathing of the complex cation is almost fully compensated by the anion matrix. The unique cooling rate dependence of the residual low-temperature magnetisation in FeB unveils continuous switching between the trapped high-spin (ON) and the relaxed low-spin state (OFF). The macroscopic ratio of the spin states (ON:OFF) can be adjusted as a simple function of the cooling rate. That is, cooperative spin crossover can be the source of bistable and multi-inert system states in the very same material.
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Affiliation(s)
- Andreas Dürrmann
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, Jena, Germany
- Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, Bayreuth, Germany
| | - Gerald Hörner
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, Jena, Germany
- Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, Bayreuth, Germany
| | - Dirk Baabe
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, Braunschweig, Germany
| | - Frank W Heinemann
- Lehrstuhl für Anorganische und Allgemeine Chemie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstr. 1, Erlangen, Germany
| | | | - Birgit Weber
- Institute for Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, Jena, Germany.
- Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, Bayreuth, Germany.
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2
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Zakrzewski J, Liberka M, Wang J, Chorazy S, Ohkoshi SI. Optical Phenomena in Molecule-Based Magnetic Materials. Chem Rev 2024; 124:5930-6050. [PMID: 38687182 PMCID: PMC11082909 DOI: 10.1021/acs.chemrev.3c00840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Since the last century, we have witnessed the development of molecular magnetism which deals with magnetic materials based on molecular species, i.e., organic radicals and metal complexes. Among them, the broadest attention was devoted to molecule-based ferro-/ferrimagnets, spin transition materials, including those exploring electron transfer, molecular nanomagnets, such as single-molecule magnets (SMMs), molecular qubits, and stimuli-responsive magnetic materials. Their physical properties open the application horizons in sensors, data storage, spintronics, and quantum computation. It was found that various optical phenomena, such as thermochromism, photoswitching of magnetic and optical characteristics, luminescence, nonlinear optical and chiroptical effects, as well as optical responsivity to external stimuli, can be implemented into molecule-based magnetic materials. Moreover, the fruitful interactions of these optical effects with magnetism in molecule-based materials can provide new physical cross-effects and multifunctionality, enriching the applications in optical, electronic, and magnetic devices. This Review aims to show the scope of optical phenomena generated in molecule-based magnetic materials, including the recent advances in such areas as high-temperature photomagnetism, optical thermometry utilizing SMMs, optical addressability of molecular qubits, magneto-chiral dichroism, and opto-magneto-electric multifunctionality. These findings are discussed in the context of the types of optical phenomena accessible for various classes of molecule-based magnetic materials.
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Affiliation(s)
- Jakub
J. Zakrzewski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Michal Liberka
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
- Doctoral
School of Exact and Natural Sciences, Jagiellonian
University, Lojasiewicza
11, 30-348 Krakow, Poland
| | - Junhao Wang
- Department
of Materials Science, Faculty of Pure and Applied Science, University of Tsukuba, 1-1-1 Tonnodai, Tsukuba, Ibaraki 305-8573, Japan
| | - Szymon Chorazy
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Shin-ichi Ohkoshi
- Department
of Chemistry, School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
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3
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Seredyuk M, Znovjyak K, Valverde-Muñoz FJ, Muñoz MC, Fritsky IO, Real JA. Rotational order-disorder and spin crossover behaviour in a neutral iron(II) complex based on asymmetrically substituted large planar ionogenic ligand. Dalton Trans 2024; 53:8041-8049. [PMID: 38652019 DOI: 10.1039/d4dt00368c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Octahedrally coordinated spin crossover (SCO) FeII complexes represent an important class of switchable molecular materials. This study presents the synthesis and characterisation of a novel complex, [FeII(ppt-2Fph)2]0·2MeOH, where ppt-2Fph is a new asymmetric ionogenic tridentate planar ligand 2-(5-(2-fluorophenyl)-4H-1,2,4-triazol-3-yl)-6-(1H-pyrazol-1-yl)pyridine. The complex exhibits a hysteretic thermally induced SCO transition at 285 K on cooling and at 293 K on heating, as well as light induced excited spin state trapping (LIESST) at lower temperatures with a relaxation T(LIESST) temperature of 73 K. Single crystal analysis in both spin states shows that the compound undergoes an unusual partial (25%) reversible order-disorder of the asymmetrically substituted phenyl group coupled to the thermal SCO. The highly cooperative SCO transition, analysed by structural energy framework analysis at the B3LYP/6-31G(d,p) theory level, revealed the co-existence of stabilising and destabilising energy variations in the lattice. The observed antagonism of intermolecular interactions and synchronous rotational disorder, which contributes to the overall entropy change, is suggested to be at the origin of the cooperative SCO transition.
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Affiliation(s)
- Maksym Seredyuk
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
- Instituto de Ciencia Molecular, Departamento de Química Inorgánica, Universidad de Valencia, 46980 Paterna, Valencia, Spain.
- Enamine Ltd., Winston Churchill Str. 78, 02094 Kyiv, Ukraine
| | - Kateryna Znovjyak
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
| | - Francisco Javier Valverde-Muñoz
- Instituto de Ciencia Molecular, Departamento de Química Inorgánica, Universidad de Valencia, 46980 Paterna, Valencia, Spain.
| | - M Carmen Muñoz
- Departamento de Física Aplicada, Universitat Politècnica de València, Camino de Vera s/n, E-46022, Valencia, Spain
| | - Igor O Fritsky
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601 Kyiv, Ukraine.
| | - José Antonio Real
- Instituto de Ciencia Molecular, Departamento de Química Inorgánica, Universidad de Valencia, 46980 Paterna, Valencia, Spain.
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4
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Jornet-Mollá V, Rodríguez-Tarrazó MI, Dolz-Lozano MJ, Giménez-Saiz C, Romero FM. Hydrogen-bonded assemblies of iron(II) spin crossover complexes. Dalton Trans 2024; 53:7848-7856. [PMID: 38625687 DOI: 10.1039/d4dt00579a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The paper reports on the synthesis, crystal structure, thermal and magnetic properties of spin crossover (SCO) salts containing the [Fe(bpp)2]2+ cation (bpp = 2,6-bis(pyrazol-3-yl)pyridine) and different rigid polycarboxylate anions, such as anthracene-9,10-dicarboxylate (ADC), benzene-1,3,5-tricarboxylate (BTC) and biphenyl-4,4'-dicarboxylate (BPDC). Compound [Fe(bpp)2](ADC)·9H2O (1) shows a porous hydrogen-bonded structure with water molecules sitting in the channels. It contains low-spin (LS) Fe2+ cations that undergo crossover to the high-spin (HS) state upon dehydration. Anhydrous 1 remains HS on cooling at low temperatures. A similar magnetic behaviour is obtained for the partially protonated BTC salt [Fe(bpp)2](HBTC)·5H2O (2), showing a spin change concomitant with dehydration to a HS phase that undergoes gradual and partial SCO on cooling, affecting 25% of the Fe2+ cations. Instead, the BPDC salt [Fe(bpp)2](BPDC)·5H2O (3) has a ground HS state in its fully hydrated form.
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Affiliation(s)
- Verónica Jornet-Mollá
- Departament de Química Inorgànica, Universitat de València, C/Dr. Moliner, 50, E-46100 Burjassot, Spain.
| | - Marina I Rodríguez-Tarrazó
- Departament de Química Inorgànica, Universitat de València, C/Dr. Moliner, 50, E-46100 Burjassot, Spain.
| | - Miquel J Dolz-Lozano
- Departament de Química Inorgànica, Universitat de València, C/Dr. Moliner, 50, E-46100 Burjassot, Spain.
| | - Carlos Giménez-Saiz
- Departament de Química Inorgànica, Universitat de València, C/Dr. Moliner, 50, E-46100 Burjassot, Spain.
| | - Francisco M Romero
- Departament de Química Inorgànica, Universitat de València, C/Dr. Moliner, 50, E-46100 Burjassot, Spain.
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5
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Hagiwara H, Sonoda K. Impact of flexible hexyl chain ordering in a mononuclear spin crossover iron(III) complex. Dalton Trans 2024; 53:5851-5860. [PMID: 38477362 DOI: 10.1039/d4dt00425f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
A novel FeIII complex [Fe(Hex-tnal)2]BPh4 (1) with a tridentate N2O ligand having an n-hexyl chain, Hex-Htnal (=1-((((1-hexyl-1H-1,2,3-triazol-4-yl)methyl)imino)methyl)naphthalen-2-ol), is reported. Temperature-dependent magnetic susceptibility measurements revealed that 1 exhibits a two-step spin crossover (SCO) transition in the 400-10 K temperature range, including an unusual gradual χMT change above RT (300-345 K) and a hysteretic χMT jump in a narrow temperature range of 345-357 K. These behaviors were also characterized by differential scanning calorimetry. Variable-temperature single-crystal X-ray diffraction studies revealed that the order-disorder transition and conformational change of the hexyl chains and the symmetry change associated with the re-entrant structural phase transition, namely triclinic P1̄ (100-275 K) ↔ monoclinic C2/c (296-340 K) ↔ triclinic P1̄ (360 K), are coupled to variations in intermolecular interactions and the N4O2 coordination environment, resulting in the occurrence of the unusual two-step SCO transition of 1. This study demonstrates that the flexible motion of alkyl substituents in the supramolecular lattice influences the occurrence of anomalous magnetic switching properties.
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Affiliation(s)
- Hiroaki Hagiwara
- Department of Chemistry, Faculty of Education, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
| | - Kento Sonoda
- Department of Chemistry, Faculty of Education, Gifu University, Yanagido 1-1, Gifu 501-1193, Japan.
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Roseiro P, Yalouz S, Brook DJR, Ben Amor N, Robert V. Modifications of Tanabe-Sugano d6 Diagram Induced by Radical Ligand Field: Ab Initio Inspection of a Fe(II)-Verdazyl Molecular Complex. Inorg Chem 2023; 62:5737-5743. [PMID: 36971364 DOI: 10.1021/acs.inorgchem.3c00275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Quantum entanglement between the spin states of a metal center and radical ligands is suggested in an iron(II) [Fe(dipyvd)2]2+ compound (dipyvd = 1-isopropyl-3,5-dipyridil-6-oxoverdazyl). Wave function ab initio (Difference Dedicated Configuration Interaction, DDCI) inspections were carried out to stress the versatility of local spin states. We named this phenomenon excited state spinmerism, in reference to our previous work (see Roseiro et al., ChemPhysChem 2022, e202200478) where we introduced the concept of spinmerism as an extension of mesomerism to spin degrees of freedom. The construction of localized molecular orbitals allows for a reading of the wave functions and projections onto the local spin states. The low-energy spectrum is well-depicted by a Heisenberg picture. A 60 cm-1 ferromagnetic interaction is calculated between the radical ligands with the Stotal = 0 and 1 states largely dominated by a local low-spin SFe = 0. In contrast, the higher-lying Stotal = 2 states are superpositions of the local SFe = 1 (17%, 62%) and SFe = 2 (72%, 21%) spin states. Such mixing extends the traditional picture of a high-field d6 Tanabe-Sugano diagram. Even in the absence of spin-orbit coupling, the avoided crossing between different local spin states is triggered by the field generated by radical ligands. This puzzling scenario emerges from versatile local spin states in compounds which extend the traditional views in molecular magnetism.
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7
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Gong Y, Chen X, Zhao B, Wang J, Zhang W, Chen X. Ferroelastic phase transitions in three new layered perovskites: (3-XC6H5CH2CH2NH3)2[CdCl4] (X = F, Cl, and Br). CHINESE CHEM LETT 2023. [DOI: 10.1016/j.cclet.2023.108282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
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8
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Su S, Wu S, Huang Y, Xu W, Gao K, Okazawa A, Okajima H, Sakamoto A, Kanegawa S, Sato O. Photoinduced Persistent Polarization Change in a Spin Transition Crystal. Angew Chem Int Ed Engl 2022; 61:e202208771. [DOI: 10.1002/anie.202208771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Sheng‐Qun Su
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Shu‐Qi Wu
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Yu‐Bo Huang
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Wen‐Huang Xu
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Kai‐Ge Gao
- College of Physical Science and Technology Yangzhou University Jiangsu 225009 P. R. China
| | - Atsushi Okazawa
- Department of Electrical Engineering and Bioscience Waseda University Okubo 3-4-1, Shinjuku-ku Tokyo 169-8555 Japan
| | - Hajime Okajima
- Faculty of Science and Engineering Chuo University 1-13-27 Kasuga, Bunkyo-ku Tokyo 112-8551 Japan
| | - Akira Sakamoto
- Graduate School of Science and Engineering Aoyama Gakuin University 5-10-1 Fuchinobe, Chuo-ku Sagamihara 252-5258 Japan
| | - Shinji Kanegawa
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering and IRCCS Kyushu University 744 Motooka, Nishi-ku Fukuoka 819-0395 Japan
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9
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Su SQ, Wu SQ, Huang YB, Xu WH, Gao KG, Okazawa A, Okajima H, Sakamoto A, Kanegawa S, Sato O. Photoinduced Persistent Polarization Change in a Spin Transition Crystal. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202208771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Sheng-Qun Su
- Kyushu University: Kyushu Daigaku Institute for Materials Chemistry and Engineering 819-0395 Fukuoka JAPAN
| | - Shu-Qi Wu
- Kyushu University: Kyushu Daigaku Institute for Materials Chemistry and Engineering 819-0395 Fukuoka JAPAN
| | - Yu-Bo Huang
- Kyushu University: Kyushu Daigaku Institute for Materials Chemistry and Engineering 819-0395 Fukuoka JAPAN
| | - Wen-Huang Xu
- Kyushu University: Kyushu Daigaku Institute for Materials Chemistry and Engineering 819-0395 Fukuoka JAPAN
| | - Kai-Ge Gao
- Yangzhou University College of Physical Science and Technology 225009 Jiangsu CHINA
| | - Atsushi Okazawa
- Waseda University: Waseda Daigaku Department of Electrical Engineering and Bioscience 169-8555 Tokyo JAPAN
| | - Hajime Okajima
- Chuo University: Chuo Daigaku Faculty of Science and Engineering 112-8551 Tokyo JAPAN
| | - Akira Sakamoto
- Aoyama Gakuin University: Aoyama Gakuin Daigaku Graduate School of Science and Engineering 252-5258 sagamihara JAPAN
| | - Shinji Kanegawa
- Kyushu University: Kyushu Daigaku Institute for Materials Chemistry and Engineering and IRCCS 819-0395 Fukuoka JAPAN
| | - Osamu Sato
- Kyushu University Institute for Materials Chemistry and Engineering 744, Motooka, Nishi-ku 819-0395 Fukuoka JAPAN
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Sheng HJ, Xia CC, Zhang XY, Zhang CC, Ji WJ, Zhao Y, Wang XY. Anion Modified Spin Crossover in [Fe(qsal-4-F)] + Complexes with a 4-Position Substituted Qsal Ligand. Inorg Chem 2022; 61:12726-12735. [PMID: 35905478 DOI: 10.1021/acs.inorgchem.2c01795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Four iron(III) complexes, [Fe(qsal-4-F)2]Y·sol (Hqsal-4-F = 4-fluoro-N-(8-quinolyl)salicylaldimine; Y = NO3-, sol = 0.91MeOH·0.57H2O (1NO3); Y = PF6- (2PF6); Y = BF4- (3BF4); Y = OTf-, sol =1.5MeOH (4OTf)), with a new 4-position substituted qsal type ligand Hqsal-4-F have been synthesized and structurally and magnetically characterized. Complexes 1NO3-3BF4 consist of 1D chains formed by the [Fe(qsal-4-F)2]+ cations connected by π-π and C-H···O interactions, which are further linked by more weak interactions to form 2D layers and 3D networks. On the other hand, complex 4OTf has a structure of nearly isolated 1D column where the [Fe(qsal-4-F)2]+ cations are connected by π-π, C-H···π, and C-F···π interactions. Magnetic studies revealed the occurrence of two-step symmetry-breaking SCO in 1NO3 and two-step gradual SCO in 2PF6. Complex 3BF4 undergoes a gradual SCO, whereas 4OTf remains almost high-spin. The smaller anions tend to stabilize the low-spin state, while larger anions tend to stabilize the high-spin state. In addition, the intermediate spin state of 1NO3 could be thermally trapped by quenching from the high temperature, thereby kinetically suppressing the spin transition to the full low-spin state. This work represents a good example that the position of the substituent and the anions plays critical roles in the preparation of SCO materials with tunable properties.
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Affiliation(s)
- Hui-Juan Sheng
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Cheng-Cai Xia
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xin-Yu Zhang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Cheng-Cheng Zhang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Wen-Jie Ji
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xin-Yi Wang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
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11
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Chakraborty P, Sy M, Fourati H, Delgado T, Dutta M, Das C, Besnard C, Hauser A, Enachescu C, Boukheddaden K. Optical microscopy imaging of the thermally-induced spin transition and isothermal multi-stepped relaxation in a low-spin stabilized spin-crossover material. Phys Chem Chem Phys 2022; 24:982-994. [PMID: 34918013 DOI: 10.1039/d1cp04321h] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The thermal spin transition and the photo-induced high-spin → low-spin relaxation of the prototypical [Fe(ptz)6](BF4)2 spin-crossover compound (ptz = 1-propyltetrazole) diluted in the isostructural ruthenium host lattice [Ru(ptz)6](BF4)2, which stabilizes the Fe(II) low-spin state, have been investigated. We demonstrate the presence of a crystallographic phase transition around 145 K (i.e. from the high-temperature ordered high-spin phase to a low-temperature disordered low-spin phase) upon slow cooling from room temperature. This crystallographic phase transition is decoupled from the thermal spin transition. A supercooled ordered low-spin phase is observed as in the pure Fe(II) analogue upon fast cooling. A similar order-disorder phase transition is also observed for pure [Ru(ptz)6](BF4)2 but at relatively higher temperature (i.e. at around 150 K) without involving any spin transition. For Ru-diluted [Fe(ptz)6]2+, the crystallographic phase transition as well as strong cooperative effects involving various degrees of elastic frustration are at the origin of stepped sigmoidal high-spin → low-spin relaxation curves, which are modelled in the framework of a classical mean field model, considering both the tunnelling and thermally activated regimes. Optical microscopy studies performed on two different single crystals showed the existence of hysteretic thermal transitions with slight domain formation, hardly visible in the static crystal images. This behavior is attributed to the double effect upon Ru dilution, which decreases the cooperative character of the transition and simultaneously reduces the optical contrast between the LS and HS states. Moreover, the transition temperature revealed to be slightly crystal dependent, highlighting the crucial role of the spatial distribution of Ru from one crystal to another, in addition to the well-known effects of crystal shape and size.
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Affiliation(s)
- Pradip Chakraborty
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Mouhamadou Sy
- Université Assane Seck de Ziguinchor, Département de Physique, LCPM, BP 523 Diabir, Ziguinchor 27000, Sénégal
| | - Houcem Fourati
- Université Paris-Saclay, UVSQ, CNRS, GEMAC, 45 Avenue des Etats Unis 78035, Versailles, France.
| | - Teresa Delgado
- Département de Chimie Physique, Université de Genève, 30, Quai Ernest-Ansermet, CH-1211, Genève 4, Switzerland.,Chimie ParisTech-CNRS, IRCP (PSL), 11 rue P. et M. Curie, 75005 Paris, France
| | - Mousumi Dutta
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Chinmoy Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur-721302, India.
| | - Céline Besnard
- Laboratoire de Cristallographie, Université de Genève, 24, Quai Ernest-Ansermet, CH-1211, Genève 4, Switzerland
| | - Andreas Hauser
- Département de Chimie Physique, Université de Genève, 30, Quai Ernest-Ansermet, CH-1211, Genève 4, Switzerland
| | | | - Kamel Boukheddaden
- Université Paris-Saclay, UVSQ, CNRS, GEMAC, 45 Avenue des Etats Unis 78035, Versailles, France.
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12
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Seredyuk M, Znovjyak K, Valverde-Muñoz FJ, Muñoz MC, Fritsky IO, Amirkhanov VM, Real JA. Spin transition and symmetry-breaking in new mononuclear FeII tren-complexes with up to 38 K hysteresis around room temperature. Inorg Chem Front 2022. [DOI: 10.1039/d1qi00941a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
New FeII complexes based on the well-known tripodand ligand type undergo abrupt hysteretic spin transition due to the symmetry-breaking in the room temperature region.
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Affiliation(s)
- Maksym Seredyuk
- Departament de Quimica Inorgànica, Institut de Ciencia Molecular (ICMol), Universitat de València, Valencia, Spain
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601, Kyiv, Ukraine
| | - Kateryna Znovjyak
- Departament de Quimica Inorgànica, Institut de Ciencia Molecular (ICMol), Universitat de València, Valencia, Spain
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601, Kyiv, Ukraine
| | | | - M. Carmen Muñoz
- Departamento de Fisica Aplicada, Universitat Politècnica de València, Camino de Vera s/n, 46022, Valencia, Spain
| | - Igor O. Fritsky
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601, Kyiv, Ukraine
| | - Volodymyr M. Amirkhanov
- Department of Chemistry, Taras Shevchenko National University of Kyiv, 64/13, Volodymyrska Street, 01601, Kyiv, Ukraine
| | - Jose A. Real
- Departament de Quimica Inorgànica, Institut de Ciencia Molecular (ICMol), Universitat de València, Valencia, Spain
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13
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Qiu YR, Cui L, Ge JY, Kurmoo M, Ma G, Su J. Iron(II) Spin Crossover Coordination Polymers Derived From a Redox Active Equatorial Tetrathiafulvalene Schiff-Base Ligand. Front Chem 2021; 9:692939. [PMID: 34409015 PMCID: PMC8365465 DOI: 10.3389/fchem.2021.692939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/19/2021] [Indexed: 11/13/2022] Open
Abstract
Two polymorphic FeII coordination polymers [FeIIL (TPPE)0.5] 1) and [(FeII3L3 (TPPE)1.5)] 2), were obtained from a redox-active tetrathiafulvalene (TTF) functionalized ligand [H2L = 2,2’-(((2-(4,5-bis-(methylthio)-1,3-dithiol-2-ylidene)benzo(d) (1,3) dithiole-5,6-diyl)bis-(azanediyl))bis-(meth anylylidene)) (2E,2E')-bis(3-oxobutanoate)] and a highly luminescent connector {TPPE = 1,1,2,2-tetrakis[4-(pyridine-4-yl)phenyl]-ethene}. Complex 1 has a layered structure where the TPPE uses its four diverging pyridines from the TPPE ligand are coordinated by the trans positions to the flat TTF Schiff-base ligand, and complex 2 has an unprecedented catenation of layers within two interpenetrated frameworks. These coordination polymers reserved the redox activity of the TTF unit. Complex 1 shows gradual spin transition behavior without hysteresis. And the fluorescence intensity of TPPE in 1 changes in tandem with the spin crossover (SCO) transition indicating a possible interplay between fluorescence and SCO behavior.
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Affiliation(s)
- Ya-Ru Qiu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China.,State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, China
| | - Long Cui
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, China
| | - Jing-Yuan Ge
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, China
| | - Mohamedally Kurmoo
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, China.,Institut de Chimie de Strasbourg, CNRS-UMR 7177 Université de Strasbourg, Strasbourg, France
| | - Guijun Ma
- School of Physical Science and Technology, ShanghaiTech University, Shanghai, China
| | - Jian Su
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing National Laboratory of Microstructures, Nanjing University, Nanjing, China
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14
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Galadzhun I, Kulmaczewski R, Cespedes O, Halcrow MA. Iron/2,6‐Di(pyrazol‐1‐yl)pyridine Complexes with a Discotic Pattern of Alkyl or Alkynyl Substituents. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Iurii Galadzhun
- School of Chemistry University of Leeds Woodhouse Lane Leeds LS2 9JT UK
| | | | - Oscar Cespedes
- School of Physics and Astronomy University of Leeds EC Stoner Building Leeds LS2 9JT UK
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15
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Zhao Q, Xue JP, Liu ZK, Yao ZS, Tao J. Spin-crossover iron(ii) long-chain complex with slow spin equilibrium at low temperatures. Dalton Trans 2021; 50:11106-11112. [PMID: 34318840 DOI: 10.1039/d1dt01378e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A mononuclear complex with long alkyl chains, [FeII(H2Bpz2)2(C9bpy)] (1; H2Bpz2 = dihydrobis(1-pyrazolyl)borate, C9bpy = 4,4'-dinonyl-2,2'-bipyridine), was synthesized. Single-crystal X-ray crystallographic studies revealed that the Δ- and Λ-forms of the complex co-crystallized in the lattice asymmetric unit, while magnetic measurements unveiled that this complex underwent incomplete one-step spin crossover (SCO) with the transition completeness and temperature depending on the measurement velocity because of slow spin equilibrium. Multivariable approaches such as varying scan rate, annealing the sample, light irradiation and pressure have been adopted to effectively overcome the slow spin equilibrium and thus improve the SCO completeness.
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Affiliation(s)
- Qi Zhao
- Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Liangxiang Campus, Beijing Institute of Technology, Beijing 102488, People's Republic of China.
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16
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Kitase K, Akahoshi D, Kitazawa T. Effects of Both Methyl and Pyrimidine Groups in Fe-Ag Spin-Crossover Hofmann-Type Complex {Fe(4-Methylpyrimidine) 2[Ag(CN) 2] 2}. Inorg Chem 2021; 60:4717-4722. [PMID: 33691406 DOI: 10.1021/acs.inorgchem.0c03655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The spin-crossover (SCO) phenomenon is an active area of research. This paper describes the synthesis of an Fe-Ag Hofmann-type complex, {Fe(4-methylpyrimidine)2[Ag(CN)2]2}, which demonstrates a one-step SCO and single-layer Hofmann-type structure with Ag-N interactions and no Ag-Ag interactions, which is strikingly different from the previously synthesized complex {Fe(4-methylpyrimidine)2[Au(CN)2]2} that contains Au-Au interactions and no Au-N interactions. This difference can be explained in terms of the lack of relativistic effect in the Ag atoms and the different cooperative effects caused by their different structures. A scan-rate-dependent hysteresis is observed using magnetic measurement whereas not using 57Fe Mössbauer spectroscopy, suggesting that the spin transition is relatively slow.
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Affiliation(s)
- Kosuke Kitase
- Department of Chemistry, Toho University, Chiba 274-8510, Japan
| | | | - Takafumi Kitazawa
- Department of Chemistry, Toho University, Chiba 274-8510, Japan.,Research Centre for Materials with Integrated Properties, Toho University, Chiba 274-8510, Japan
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17
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Jornet-Mollá V, Giménez-Saiz C, Vieira BJC, Waerenborgh JC, Romero FM. Temperature dependence of desolvation effects in hydrogen-bonded spin crossover complexes. Dalton Trans 2021; 50:2536-2544. [PMID: 33522546 DOI: 10.1039/d0dt03986a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The synthesis, crystal structure and (photo)magnetic properties of the anhydrous spin crossover salt of formula [Fe(bpp)2](C6H8O4) (1) (bpp = 2,6-bis(pyrazol-3-yl)pyridine; C6H8O4 = adipate dianion), obtained by desolvation at 400 K of the original tetrahydrate in a single-crystal-to-single-crystal (SC-SC) transformation, are reported. This work offers a comparison between this compound and the previously reported hydrated material ([Fe(bpp)2](C6H8O4)·4H2O, 1·4H2O), highlighting the significance of the thermal conditions used in the dehydration-rehydration processes. In both compounds, a hydrogen-bonded network between iron(ii) complexes and adipate anions is observed. The original tetrahydrate (1·4H2O) is low-spin and desolvation at 450 K triggers a low-spin (LS) to high-spin (HS) transition to an amorphous phase that remains stable over the whole temperature range of study. Surprisingly, the dehydrated compound at 400 K (1) keeps the crystallinity, undergoes a partial spin crossover (T1/2 = 180 K) and a quantitative LS to HS photomagnetic conversion at low temperatures, with a T(LIESST) value of 61 K.
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Affiliation(s)
- Verónica Jornet-Mollá
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán 2, 46980 Paterna, Spain.
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18
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Kulmaczewski R, Bamiduro F, Shahid N, Cespedes O, Halcrow MA. Structural Transformations and Spin-Crossover in [FeL 2 ] 2+ Salts (L=4-{tert-Butylsulfanyl}-2,6-di{pyrazol-1-yl}pyridine): The Influence of Bulky Ligand Substituents. Chemistry 2021; 27:2082-2092. [PMID: 33073890 DOI: 10.1002/chem.202004072] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Revised: 10/16/2020] [Indexed: 11/06/2022]
Abstract
4-(tert-Butylsulfanyl)-2,6-di(pyrazol-1-yl)pyridine (L) was obtained in low yield from a one-pot reaction of 2,4,6-trifluoropyridine with 2-methylpropane-2-thiolate and sodium pyrazolate in a 1:1:2 ratio. The materials [FeL2 ][BF4 ]2 ⋅solv (1[BF4 ]2 ⋅solv) and [FeL2 ][ClO4 ]2 ⋅solv (1[ClO4 ]2 ⋅solv; solv=MeNO2 , MeCN or Me2 CO) exhibit a variety of structures and spin-state behaviors including thermal spin-crossover (SCO). Solvent loss on heating 1[BF4 ]2 ⋅x MeNO2 (x≈2.3) occurs in two steps. The intermediate phase exhibits hysteretic SCO around 250 K, involving a "reverse-SCO" step in its warming cycle at a scan rate of 5 K min-1 . The reverse-SCO is not observed in a slower 1 K min-1 measurement, however, confirming its kinetic nature. The final product [FeL2 ][BF4 ]2 ⋅0.75 MeNO2 was crystallographically characterized, and shows abrupt but incomplete SCO at 172 K which correlates with disorder of an L ligand. The asymmetric unit of 1[BF4 ]2 ⋅y Me2 CO (y≈1.6) contains five unique complex molecules, four of which undergo gradual SCO in at least two discrete steps. Low-spin 1[ClO4 ]2 ⋅0.5 Me2 CO is not isostructural with its BF4 - congener, and undergoes single-crystal-to-single-crystal solvent loss with a tripling of the crystallographic unit cell volume, while retaining the P 1 ‾ space group. Three other solvate salts undergo gradual thermal SCO. Two of these are isomorphous at room temperature, but transform to different low-temperature phases when the materials are fully low-spin.
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Affiliation(s)
- Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Faith Bamiduro
- School of Chemical and Process Engineering, University of Leeds, Leeds, LS2 9JT, UK
| | - Namrah Shahid
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, E. C. Stoner Building, Leeds, LS2 9JT, UK
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK
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19
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Jornet-Mollá V, Giménez-Saiz C, Yufit DS, Howard JAK, Romero FM. A Reversible Hydrogen-Bond Isomerization Triggered by an Abrupt Spin Crossover near Room Temperature. Chemistry 2021; 27:740-750. [PMID: 32812653 DOI: 10.1002/chem.202003654] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Indexed: 11/10/2022]
Abstract
The spin crossover salt [Fe(bpp)2 ](isonicNO)2 ⋅ 2.4 H2 O (1⋅2.4 H2 O) (bpp=2,6-bis(pyrazol-3-yl)pyridine; isonicNO=isonicotinate N-oxide anion) exhibits a very abrupt spin crossover at T1/2 =274.4 K. This triggers a supramolecular linkage (H-bond) isomerization that responds reversibly towards light irradiation or temperature change. Isotopic effects in the thermomagnetic behavior reveal the importance of hydrogen bonds in defining the magnetic state. Further, the title compound can be reversibly dehydrated to afford 1, a material that also exhibits spin crossover coupled to H-bond isomerization, leading to strong kinetic effects in the thermomagnetic properties.
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Affiliation(s)
- Verónica Jornet-Mollá
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
| | - Carlos Giménez-Saiz
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
| | - Dmitry S Yufit
- Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | | | - Francisco M Romero
- Instituto de Ciencia Molecular, Universitat de València, P. O. Box 22085, 46071, Valencia, Spain
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20
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Galadzhun I, Kulmaczewski R, Shahid N, Cespedes O, Howard MJ, Halcrow MA. The flexibility of long chain substituents influences spin-crossover in isomorphous lipid bilayer crystals. Chem Commun (Camb) 2021; 57:4039-4042. [DOI: 10.1039/d1cc01073e] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
These two compounds are isomorphous but show different spin-state behaviour on cooling. This may be influenced by the packing of alkyl vs. alkynyl chains in the solid state.
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Affiliation(s)
| | | | - Namrah Shahid
- School of Chemistry
- University of Leeds
- Woodhouse Lane
- Leeds
- UK
| | - Oscar Cespedes
- School of Physics and Astronomy
- University of Leeds
- Leeds LS2 9JT
- UK
| | - Mark J. Howard
- School of Chemistry
- University of Leeds
- Woodhouse Lane
- Leeds
- UK
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21
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Guo W, Daro N, Pillet S, Marchivie M, Bendeif EE, Tailleur E, Chainok K, Denux D, Chastanet G, Guionneau P. Unprecedented Reverse Volume Expansion in Spin-Transition Crystals. Chemistry 2020; 26:12927-12930. [PMID: 32428382 DOI: 10.1002/chem.202001821] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/04/2020] [Indexed: 11/09/2022]
Abstract
The current craze for research around the spin crossover phenomenon can be justified to some extent by the mechanical properties due to the decrease of volume associated with the transition of the metal ion from the HS state to the LS state. As demonstrated here, the molecular complex [Fe(PM-pBrA)2 (NCS)2 ] exhibits, on the contrary, an increase of the unit-cell volume from HS to LS. This counter-intuitive and unprecedented behavior that concerns both the thermal and the photoexcited spin conversions is revealed by a combination of single-crystal and powder X-ray diffraction complemented by magnetic measurements. Interestingly, this abnormal volume change appears concomitant with the wide rotation of a phenyl ring which induces a drastic modification, though reversible, of the structural packing within the crystal. In addition, the light-induced HS state obtained through the Light-Induced Excited Spin-State Trapping shows a remarkably high relaxation temperature, namely T(LIESST), of 109 K, one of the highest so far reported. The above set of quite unusual characteristics opens up new fields of possibilities within the development of spin crossover materials.
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Affiliation(s)
- Wenbin Guo
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
| | - Nathalie Daro
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
| | - Sébastien Pillet
- Université de Lorraine, CNRS, CRM2, Nancy, 254506, Vandoeuvre-les-Nancy, France
| | - Mathieu Marchivie
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
| | - El-Eulmi Bendeif
- Université de Lorraine, CNRS, CRM2, Nancy, 254506, Vandoeuvre-les-Nancy, France
| | - Elodie Tailleur
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
| | - Kittipong Chainok
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France.,Materials and Textiles Technology, Faculty of Science and Technology, Thammasat University, Khlong Luang, Pathum Thani, 12121, Thailand
| | - Dominique Denux
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
| | | | - Philippe Guionneau
- CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, 33600, Pessac, France
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22
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Kashiro A, Kohno W, Ishida T. Odd–Even Effect on the Spin-Crossover Temperature in Iron(II) Complex Series Involving an Alkylated or Acyloxylated Tripodal Ligand. Inorg Chem 2020; 59:10163-10171. [DOI: 10.1021/acs.inorgchem.0c01296] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Atsushi Kashiro
- Department of Engineering Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
| | - Wakana Kohno
- Department of Engineering Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
| | - Takayuki Ishida
- Department of Engineering Science, The University of Electro-Communications, Chofu, Tokyo 182-8585, Japan
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23
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Structural Evidence of Spin State Selection and Spin Crossover Behavior of Tripodal Schiff Base Complexes of tris(2-aminoethyl)amine and Related Tripodal Amines. MAGNETOCHEMISTRY 2020. [DOI: 10.3390/magnetochemistry6020028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
A review of the tripodal Schiff base (SB) complexes of tris(2-aminoethyl)amine, Nap(CH2CH 2NH2)3 (tren), and a few closely related tripodal amines with Cr(II), Mn(III) (d4), Mn(II), Fe(III) (d5), Fe(II) (d6), and Co(II) (d7) is provided. Attention is focused on examination of key structural features, the M-Nimine, M-Namine, or M-O and M-Nap bond distances and Nimine-M-N(O) bite and C-Nap-C angles and how these values correlate with spin state selection and spin crossover (SCO) behavior. A comparison of these experimental values with density functional theory calculated values is also given. The greatest number, 132, of complexes is observed with cationic mononuclear iron(II) in a N6 donor set, Fe(II)N6. The dominance of two spin states, high spin (HS) and low spin (LS), in these systems is indicated by the bimodal distribution of histogram plots of Fe(II)-Nimine and Fe(II)-Nazole/pyridine bond distances and of Nimine–Fe(II)-Nazole/pyridine and C-Nap-C bond angles. The values of the two maxima, corresponding to LS and HS states, in each of these histograms agree closely with the theoretical values. The iron(II)-Nimine and iron(II)-Nazole/pyridine bond distances correlate well for these complexes. Examples of SCO complexes of this type are tabulated and a few of the 20 examples are discussed that exhibit interesting features. There are only a few mononuclear iron(III) cationic complexes and one is SCO. In addition, a significant number of supramolecular complexes of these ligands that exhibit SCO, intervalence, and chiral recognition are discussed. A summary is made regarding the current state of this area of research and possible new avenues to explore based on analysis of the present data.
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24
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Alkan M, Rogachev AY. Coupling of two curved polyaromatic radical-anions: stabilization of dimers by counterions. Phys Chem Chem Phys 2020; 22:6716-6726. [PMID: 32163075 DOI: 10.1039/c9cp06935f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this study, a comprehensive theoretical investigation of both kinetic and thermodynamic stabilities was performed for dimeric dianionic systems (C20H10)22- and (C28H14)22-, neutralized by two alkali metal cations. The influence of the counterions was of primary interest. The impact of the additional/spectator ligand(s) was elucidated by considering adducts with four molecules of diglyme or two molecules of 18-crown-6 ether. Importantly, both types of systems - in the form of contact-ion pair (CIP) and solvent-separated ion pair (SSIP) - were considered. The SSIP set was augmented by the adduct, in which the dimeric dianionic species were neutralized with purely organic cations N(CH3)4+ and P(CH3)4+. Detailed analysis of the bonding revealed that the presence of the counterions made these systems thermodynamically stable. This finding is in sharp contrast with results obtained for isolated (PAH)22- systems, which were previously found to be thermodynamically unstable, but kinetically persistent. The introduction of the alkali metal cations to the system significantly increases the ionic term (ΔEelstat), whereas the repulsive ΔEPauli one was found to be substantially reduced. Considering that the orbital component (ΔEorb) exhibited only a moderate decrease and the preparation energy (ΔEprep) showed no changes, the above-mentioned changes in ΔEelstat and ΔEPauli provided a clear explanation for the increase of the thermodynamic stability of the target species. Importantly, a clear correlation between the size of the alkali metal cation and stability of the target dimeric product was established. Thermodynamic stability of the system rises with a decrease in the size of M+ due to enlargement of the ΔEorb. Evaluated energy barriers (as spin-crossing points between singlet and triplet energy surfaces) were found to be equal to +15.85 kcal mol-1 and +18.5 kcal mol-1 for [(Cs+)2{(C20H10)22-}] and [(Cs+)2{(C28H14)22-}], respectively, which is substantially higher than those calculated for isolated (PAH)22- systems (+10.00 kcal mol-1 for (C20H10)22- and +12.35 kcal mol-1 for (C28H14)22-). Thus, this study identified the presence of counterions as the key factor, which have a dramatic influence on the thermodynamic and kinetic stabilities of the aimed dianionic dimeric systems, which are formed by two curved polyaromatic monoanion-radicals.
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Affiliation(s)
- Melisa Alkan
- Department of Chemistry, Illinois Institute of Technology, Chicago, IL 60616, USA.
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25
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Zhang HY, Hu CL, Hu ZB, Mao JG, Song Y, Xiong RG. Narrow Band Gap Observed in a Molecular Ferroelastic: Ferrocenium Tetrachloroferrate. J Am Chem Soc 2020; 142:3240-3245. [DOI: 10.1021/jacs.9b13446] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Han-Yue Zhang
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People’s Republic of China
| | - Chun-Li Hu
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, People’s Republic of China
| | - Zhao-Bo Hu
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Jiang-Gao Mao
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, P. R. China
- Graduate School of the Chinese Academy of Sciences, Beijing 100039, People’s Republic of China
| | - You Song
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Ren-Gen Xiong
- Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, People’s Republic of China
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26
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Ma TT, Sun XP, Yao ZS, Tao J. Homochiral versus racemic polymorphs of spin-crossover iron(ii) complexes with reversible LIESST effect. Inorg Chem Front 2020. [DOI: 10.1039/c9qi01590f] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Homochiral and racemic polymorphs show different spin-crossover behaviours due to different intermolecular interactions, and reversible LIESST effects can be realized on homochiral complexes.
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Affiliation(s)
- Ting-Ting Ma
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Liangxiang Campus
- Beijing Institute of Technology
- Beijing 102488
| | - Xiao-Peng Sun
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Liangxiang Campus
- Beijing Institute of Technology
- Beijing 102488
| | - Zi-Shuo Yao
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Liangxiang Campus
- Beijing Institute of Technology
- Beijing 102488
| | - Jun Tao
- Key Laboratory of Cluster Science of Ministry of Education
- School of Chemistry and Chemical Engineering
- Liangxiang Campus
- Beijing Institute of Technology
- Beijing 102488
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27
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Singh MK, Shukla P, Khatua M, Rajaraman G. A Design Criteria to Achieve Giant Ising-Type Anisotropy in Co II -Encapsulated Metallofullerenes. Chemistry 2019; 26:464-477. [PMID: 31506987 DOI: 10.1002/chem.201903618] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/05/2019] [Indexed: 11/10/2022]
Abstract
Discovery of permanent magnetisation in molecules just like in hard magnets decades ago led to the proposal of utilising these molecules for information storage devices and also as Q-bits in quantum computing. A significant breakthrough with a blocking temperature as high as 80 K has been recently reported for lanthanocene complexes. While enhancing the blocking temperature further remains one of the primary challenges, obtaining molecules that are suitable for the fabrication of the devices sets the bar very high in this area. Encouraged by the fact that our earlier predictions of potential single-molecule magnets (SMMs) in lanthanide-containing endohedral fullerenes have been verified, here we set out to undertake a comprehensive study on CoII -ion-encapsulated fullerene as potential SMMs. To study this class of molecules, we have utilised an array of theoretical methods ranging from density functional to ab initio CASSCF/NEVPT2 methods for obtaining reliable estimate of zero-field splitting parameters D and E. Additionally, we have also employed, for the first time a combination of molecular dynamics based on DFT methods coupled with CASSCF/NEVPT2 methods to seek the role of conformational isomers in the relaxation of magnetisation. Particularly, we have studied, Co@C28 , Co@C38 and Co@C48 cages and their isomers as potential target molecules that could yield substantial magnetic anisotropy. Our calculations categorically reveal a very large Ising anisotropy in this class of molecules, with Co@C48 cages predicted to yield D values as high as -127 cm-1 . Our calculations on the smaller cages reveal the free movement of CoII ion inside the cage, leading to the likely scenario of faster relaxation of magnetisation. However, larger fullerene cages were found to solve this issue. Further models with incorporating units such as {CoOZn}, {CoScZnN} inside larger fullerenes yield axial zero-field splitting values as high as -200 cm-1 with negligible E/D values. As these units represent a strong axiality coupled with a viable way to obtain air-stable low-coordinate CoII complexes, this opens up a new paradigm in the search of SMMs in this class of molecules.
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Affiliation(s)
- Mukesh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Pratima Shukla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Munmun Khatua
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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28
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Arczyński M, Stanek J, Sieklucka B, Dunbar KR, Pinkowicz D. Site-Selective Photoswitching of Two Distinct Magnetic Chromophores in a Propeller-Like Molecule To Achieve Four Different Magnetic States. J Am Chem Soc 2019; 141:19067-19077. [PMID: 31747269 DOI: 10.1021/jacs.9b09576] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Magnetic photoswitching is a highly important but relatively rare phenomenon for enabling optical writing/reading of the magnetic state of a molecule. In this work, an unprecedented site-selective double photoswitching is reported from the assembly of two different "photomagnetic chromophores" into a single hexanuclear molecule: namely, a spin-crossover Fe(II) center exhibiting light-induced excited spin state trapping (LIESST) and a photochemically active octacyanometalate(IV) unit. Four different magnetization levels are accessible through the appropriate combination of violet/red light and temperature, results that highlight the potential of photomagnetic molecules as future molecular memory cells.
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Affiliation(s)
- Mirosław Arczyński
- Jagiellonian University , Faculty of Chemistry , Gronostajowa 2 , 30-387 Kraków , Poland
| | - Jan Stanek
- Marian Smoluchowski Institute of Physics , Jagiellonian University , Łojasiewicza 11 , 30-348 Kraków , Poland
| | - Barbara Sieklucka
- Jagiellonian University , Faculty of Chemistry , Gronostajowa 2 , 30-387 Kraków , Poland
| | - Kim R Dunbar
- Department of Chemistry , Texas A&M University , College Station , Texas 77842-3012 , United States
| | - Dawid Pinkowicz
- Jagiellonian University , Faculty of Chemistry , Gronostajowa 2 , 30-387 Kraków , Poland
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29
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Ye YS, Chen XQ, De Cai Y, Fei B, Dechambenoit P, Rouzières M, Mathonière C, Clérac R, Bao X. Slow Dynamics of the Spin‐Crossover Process in an Apparent High‐Spin Mononuclear Fe
II
Complex. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201911538] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Yi Shan Ye
- School of Chemical EngineeringNanjing University of Science and Technology 210094 Nanjing P. R. China
| | - Xiu Qin Chen
- School of Chemical EngineeringNanjing University of Science and Technology 210094 Nanjing P. R. China
| | - You De Cai
- School of Chemical EngineeringNanjing University of Science and Technology 210094 Nanjing P. R. China
| | - Bin Fei
- School of Chemical EngineeringNanjing University of Science and Technology 210094 Nanjing P. R. China
| | - Pierre Dechambenoit
- Univ. BordeauxCNRS, Centre de Recherche Paul Pascal—CRPP, UMR 5031 33600 Pessac France
| | - Mathieu Rouzières
- Univ. BordeauxCNRS, Centre de Recherche Paul Pascal—CRPP, UMR 5031 33600 Pessac France
| | - Corine Mathonière
- Univ. BordeauxCNRS, Institut de Chimie de la Matière Condensée de Bordeaux—ICMCB, UMR 5026 33600 Pessac France
| | - Rodolphe Clérac
- Univ. BordeauxCNRS, Centre de Recherche Paul Pascal—CRPP, UMR 5031 33600 Pessac France
| | - Xin Bao
- School of Chemical EngineeringNanjing University of Science and Technology 210094 Nanjing P. R. China
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30
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Ye YS, Chen XQ, De Cai Y, Fei B, Dechambenoit P, Rouzières M, Mathonière C, Clérac R, Bao X. Slow Dynamics of the Spin-Crossover Process in an Apparent High-Spin Mononuclear Fe II Complex. Angew Chem Int Ed Engl 2019; 58:18888-18891. [PMID: 31633857 DOI: 10.1002/anie.201911538] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 10/18/2019] [Indexed: 11/09/2022]
Abstract
A mononuclear FeII complex that shows a high-spin (S=2) paramagnetic behavior at all temperatures (with standard temperature-scan rates, ≈1 K min-1 ) has, in fact, a low-spin (S=0) ground state below 100 K. This low-spin state is not easily accessible due to the extremely slow dynamics of the spin-crossover process-a full relaxation from the metastable high-spin state to the low-spin ground state takes more than 5 h below 80 K. Bidirectional photo-switching of the FeII state is achieved reproducibly by two selective irradiations (at 530-590 and 830-850 nm). The slow dynamics of the spin-crossover and the strong structural cooperativity result in a remarkably wide 95-K hysteresis loop induced by both temperature and selected light stimuli.
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Affiliation(s)
- Yi Shan Ye
- School of Chemical Engineering, Nanjing University of Science and Technology, 210094, Nanjing, P. R. China
| | - Xiu Qin Chen
- School of Chemical Engineering, Nanjing University of Science and Technology, 210094, Nanjing, P. R. China
| | - You De Cai
- School of Chemical Engineering, Nanjing University of Science and Technology, 210094, Nanjing, P. R. China
| | - Bin Fei
- School of Chemical Engineering, Nanjing University of Science and Technology, 210094, Nanjing, P. R. China
| | - Pierre Dechambenoit
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal-CRPP, UMR 5031, 33600, Pessac, France
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal-CRPP, UMR 5031, 33600, Pessac, France
| | - Corine Mathonière
- Univ. Bordeaux, CNRS, Institut de Chimie de la Matière Condensée de Bordeaux-ICMCB, UMR 5026, 33600, Pessac, France
| | - Rodolphe Clérac
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal-CRPP, UMR 5031, 33600, Pessac, France
| | - Xin Bao
- School of Chemical Engineering, Nanjing University of Science and Technology, 210094, Nanjing, P. R. China
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31
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Dragulescu-Andrasi A, Filatov AS, Oakley RT, Li X, Lekin K, Huq A, Pak C, Greer SM, McKay J, Jo M, Lengyel J, Hung I, Maradzike E, DePrince AE, Stoian SA, Hill S, Hu YY, Shatruk M. Radical Dimerization in a Plastic Organic Crystal Leads to Structural and Magnetic Bistability with Wide Thermal Hysteresis. J Am Chem Soc 2019; 141:17989-17994. [DOI: 10.1021/jacs.9b09533] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Alina Dragulescu-Andrasi
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Alexander S. Filatov
- Department of Chemistry, University of Chicago, Chicago, Illinois 32306, United States
| | - Richard T. Oakley
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Xiang Li
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Kristina Lekin
- Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Ashfia Huq
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Chongin Pak
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Samuel M. Greer
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Johannes McKay
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Minyoung Jo
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Jeff Lengyel
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Ivan Hung
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Elvis Maradzike
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - A. Eugene DePrince
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
| | - Sebastian A. Stoian
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Stephen Hill
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University, Tallahassee, Florida 32306, United States
| | - Yan-Yan Hu
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Michael Shatruk
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, United States
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
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32
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Ozumerzifon TJ, Higgins RF, Joyce JP, Kolanowski JL, Rappé AK, Shores MP. Evidence for Reagent-Induced Spin-State Switching in Tripodal Fe(II) Iminopyridine Complexes. Inorg Chem 2019; 58:7785-7793. [DOI: 10.1021/acs.inorgchem.9b00340] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tarik J. Ozumerzifon
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Robert F. Higgins
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Justin P. Joyce
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Jacek L. Kolanowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Anthony K. Rappé
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P. Shores
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
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33
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Valverde-Muñoz FJ, Seredyuk M, Meneses-Sánchez M, Muñoz MC, Bartual-Murgui C, Real JA. Discrimination between two memory channels by molecular alloying in a doubly bistable spin crossover material. Chem Sci 2019; 10:3807-3816. [PMID: 31015922 PMCID: PMC6457193 DOI: 10.1039/c8sc05256e] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 02/20/2019] [Indexed: 11/21/2022] Open
Abstract
A multistable spin crossover (SCO) molecular alloy system [Fe1-x M x (nBu-im)3(tren)](P1-y As y F6)2 (M = ZnII, NiII; (nBu-im)3(tren) = tris(n-butyl-imidazol(2-ethylamino))amine) has been synthesized and characterized. By controlling the composition of this isomorphous series, two cooperative thermally induced SCO events featuring distinct critical temperatures (T c) and hysteresis widths (ΔT c, memory) can be selected at will. The pristine derivative 100As (x = 0, y = 1) displays a strong cooperative two-step SCO and two reversible structural phase transitions (PTs). The low temperature PTLT and the SCO occur synchronously involving conformational changes of the ligand's n-butyl arms and two different arrangements of the AsF6 - anions [T1c = 174 K (ΔT1c = 17 K), T2c = 191 K (ΔT2c = 23 K) (scan rate 2 K min-1)]. The high-temperature PTHT takes place in the high-spin state domain and essentially involves rearrangement of the AsF6 - anions [TPTc = 275 K (ΔTPTc = 16 K)]. This behavior strongly contrasts with that of the homologous 100P [x = 0, y = 0] derivative where two separate cooperative one-step SCO can be selected by controlling the kinetics of the coupled PTLT at ambient pressure: (i) one at low temperatures, T c = 122 K (ΔT c = 9 K), for temperature scan rates (>1 K min-1) (memory channel A) where the structural modifications associated with PTLS are inhibited; (ii) the other centered at T c = 155 K (ΔT c = 41 K) for slower temperature scan rates ≤0.1 K min-1 (memory channel B). These two SCO regimes of the 100P derivative transform reversibly into the two-step SCO of 100As upon application of hydrostatic pressure (ca. 0.1 GPa) denoting the subtle effect of internal chemical pressure on the SCO behavior. Precise control of AsF6 - ↔ PF6 - substitution, and hence of the PTLT kinetics, selectively selects the memory channel B of 100P when x = 0 and y ≈ 0.7. Meanwhile, substitution of FeII with ZnII or NiII [x ≈ 0.2, y = 0] favors the low temperature memory channel A at any scan rate. This intriguing interplay between PT, SCO and isomorphous substitution was monitored by single crystal and powder X-ray diffractometries, and magnetic and calorimetric measurements.
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Affiliation(s)
| | - Maksym Seredyuk
- Departament de Química Inorgànica , Institut de Ciència Molecular (ICMol) , Universitat de València , Valencia , Spain .
- On leave from Department of Chemistry , Taras Shevchenko National University of Kyiv , 64/13, Volodymyrska Street , 01601 , Kyiv , Ukraine . ;
| | - Manuel Meneses-Sánchez
- Departament de Química Inorgànica , Institut de Ciència Molecular (ICMol) , Universitat de València , Valencia , Spain .
| | - M Carmen Muñoz
- Departament de Física Aplicada , Universitat Politècnica de València , Camino de Vera s/n , E-46022 , Valencia , Spain
| | - Carlos Bartual-Murgui
- Departament de Química Inorgànica , Institut de Ciència Molecular (ICMol) , Universitat de València , Valencia , Spain .
| | - José A Real
- Departament de Química Inorgànica , Institut de Ciència Molecular (ICMol) , Universitat de València , Valencia , Spain .
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34
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Solvent Effects on the Spin Crossover Properties of Iron(II) Imidazolylimine Complexes. CRYSTALS 2019. [DOI: 10.3390/cryst9020116] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A series of Fe(II) complexes, fac-[Fe(4-ima-Bp)3](Y)2⋅sol (Y = ClO4; sol = 3EtOH 1, 3MeOH 2; Y= BF4; sol = EtOH⋅4H2O 3, 4H2O 4 and 3.5MeCN 5) have been prepared and structurally and magnetically characterized. The low temperature structures of 1, 2 and 5 have been determined by X-ray crystallography with LS Fe(II) centres found in all cases. Extensive C–H···π interactions between the cations form 2D layers, which are linked to one another through N-H···O and O-H···O hydrogen bonds, resulting in high cooperativity. Despite 5 containing MeCN, N-H···O/F hydrogen bonds, and C–H···π and π-π interactions combine to give similar 2D layers. Magnetic measurements reveal moderately abrupt spin crossover for 1-4; becoming more gradual and only 50% complete in 1 due to solvent loss. The MeCN solvate shows more gradual SCO and reinforces how subtle changes in packing can significantly influence SCO behaviour.
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