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Gavara-Edo M, Valverde-Muñoz FJ, Muñoz MC, Elidrissi Moubtassim S, Marques-Moros F, Herrero-Martín J, Znovjyak K, Seredyuk M, Real JA, Coronado E. Design and Processing as Ultrathin Films of a Sublimable Iron(II) Spin Crossover Material Exhibiting Efficient and Fast Light-Induced Spin Transition. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:9591-9602. [PMID: 38047182 PMCID: PMC10687866 DOI: 10.1021/acs.chemmater.3c01704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 12/05/2023]
Abstract
Materials based on spin crossover (SCO) molecules have centered the attention in molecular magnetism for more than 40 years as they provide unique examples of multifunctional and stimuli-responsive materials, which can be then integrated into electronic devices to exploit their molecular bistability. This process often requires the preparation of thermally stable SCO molecules that can sublime and remain intact in contact with surfaces. However, the number of robust sublimable SCO molecules is still very scarce. Here, we report a novel example of this kind. It is based on a neutral iron(II) coordination complex formulated as [Fe(neoim)2], where neoimH is the ionogenic ligand 2-(1H-imidazol-2-yl)-9-methyl-1,10-phenanthroline. In the first part, a comprehensive study, which covers the synthesis and magnetostructural characterization of the [Fe(neoim)2] complex as a bulk microcrystalline material, is reported. Then, in the second part, we investigate the suitability of this material to form thin films through high-vacuum sublimation. Finally, the retainment of all present SCO capabilities in the bulk when the material is processed is thoroughly studied by means of X-ray absorption spectroscopy. In particular, a very efficient and fast light-induced spin transition (LIESST effect) has been observed, even for ultrathin films of 15 nm.
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Affiliation(s)
- Miguel Gavara-Edo
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
| | | | - M. Carmen Muñoz
- Departamento
de Fisica Aplicada, Universitat Politècnica
de València, Camino de Vera s/n, Valencia 46022, Spain
| | - Safaa Elidrissi Moubtassim
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
| | - Francisco Marques-Moros
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
| | | | - Kateryna Znovjyak
- Department
of Chemistry, Taras Shevchenko National
University of Kyiv, 64/13,
Volodymyrska Street, Kyiv 01601, Ukraine
| | - Maksym Seredyuk
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
- Department
of Chemistry, Taras Shevchenko National
University of Kyiv, 64/13,
Volodymyrska Street, Kyiv 01601, Ukraine
| | - José Antonio Real
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
| | - Eugenio Coronado
- Instituto
de Ciencia Molecular, Universidad de Valencia, Catedrático José Beltrán
2, Paterna 46980, Spain
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2
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Yazdani S, Phillips J, Ekanayaka TK, Cheng R, Dowben PA. The Influence of the Substrate on the Functionality of Spin Crossover Molecular Materials. Molecules 2023; 28:molecules28093735. [PMID: 37175145 PMCID: PMC10180229 DOI: 10.3390/molecules28093735] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 04/18/2023] [Accepted: 04/18/2023] [Indexed: 05/15/2023] Open
Abstract
Spin crossover complexes are a route toward designing molecular devices with a facile readout due to the change in conductance that accompanies the change in spin state. Because substrate effects are important for any molecular device, there are increased efforts to characterize the influence of the substrate on the spin state transition. Several classes of spin crossover molecules deposited on different types of surface, including metallic and non-metallic substrates, are comprehensively reviewed here. While some non-metallic substrates like graphite seem to be promising from experimental measurements, theoretical and experimental studies indicate that 2D semiconductor surfaces will have minimum interaction with spin crossover molecules. Most metallic substrates, such as Au and Cu, tend to suppress changes in spin state and affect the spin state switching process due to the interaction at the molecule-substrate interface that lock spin crossover molecules in a particular spin state or mixed spin state. Of course, the influence of the substrate on a spin crossover thin film depends on the molecular film thickness and perhaps the method used to deposit the molecular film.
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Affiliation(s)
- Saeed Yazdani
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Jared Phillips
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Thilini K Ekanayaka
- Department of Physics and Astronomy, Jorgensen Hall, University of Nebraska, Lincoln, NE 68588-0299, USA
| | - Ruihua Cheng
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, IN 46202, USA
| | - Peter A Dowben
- Department of Physics and Astronomy, Jorgensen Hall, University of Nebraska, Lincoln, NE 68588-0299, USA
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Kumar KS, Ruben M. Sublimable Spin-Crossover Complexes: From Spin-State Switching to Molecular Devices. Angew Chem Int Ed Engl 2021; 60:7502-7521. [PMID: 31769131 PMCID: PMC8048919 DOI: 10.1002/anie.201911256] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Indexed: 11/10/2022]
Abstract
Spin-crossover (SCO) active transition metal complexes are an important class of switchable molecular materials due to their bistable spin-state switching characteristics at or around room temperature. Vacuum-sublimable SCO complexes are a subclass of SCO complexes suitable for fabricating ultraclean spin-switchable films desirable for applications, especially in molecular electronics/spintronics. Consequently, on-surface SCO of thin-films of sublimable SCO complexes have been studied employing spectroscopy and microscopy techniques, and results of fundamental and technological importance have been obtained. This Review provides complete coverage of advances made in the field of vacuum-sublimable SCO complexes: progress made in the design and synthesis of sublimable functional SCO complexes, on-surface SCO of molecular and multilayer thick films, and various molecular and thin-film device architectures based on the sublimable SCO complexes.
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Affiliation(s)
- Kuppusamy Senthil Kumar
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS)CNRS-Université de Strasbourg23, rue du Loess, BP 4367034Strasbourg cedex 2France
| | - Mario Ruben
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS)CNRS-Université de Strasbourg23, rue du Loess, BP 4367034Strasbourg cedex 2France
- Institute of NanotechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institute of Quantum Materials and -TechnologyKarlsruhe Institute of Technology (KIT)Hermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
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4
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Nonvolatile Voltage Controlled Molecular Spin-State Switching for Memory Applications. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry7030037] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Nonvolatile, molecular multiferroic devices have now been demonstrated, but it is worth giving some consideration to the issue of whether such devices could be a competitive alternative for solid-state nonvolatile memory. For the Fe (II) spin crossover complex [Fe{H2B(pz)2}2(bipy)], where pz = tris(pyrazol-1-yl)-borohydride and bipy = 2,2′-bipyridine, voltage-controlled isothermal changes in the electronic structure and spin state have been demonstrated and are accompanied by changes in conductance. Higher conductance is seen with [Fe{H2B(pz)2}2(bipy)] in the high spin state, while lower conductance occurs for the low spin state. Plausibly, there is the potential here for low-cost molecular solid-state memory because the essential molecular thin films are easily fabricated. However, successful device fabrication does not mean a device that has a practical value. Here, we discuss the progress and challenges yet facing the fabrication of molecular multiferroic devices, which could be considered competitive to silicon.
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Kumar KS, Ruben M. Sublimierbare Spin‐Crossover‐Komplexe: Vom Schalten des Spinzustands zu molekularen Bauelementen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201911256] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Kuppusamy Senthil Kumar
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) CNRS-Université de Strasbourg 23, rue du Loess, BP 43 67034 Strasbourg cedex 2 Frankreich
| | - Mario Ruben
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) CNRS-Université de Strasbourg 23, rue du Loess, BP 43 67034 Strasbourg cedex 2 Frankreich
- Institut für Nanotechnologie Karlsruher Institut für Technologie (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Deutschland
- Institut für Quantenmaterialien und -technologien Karlsruher Institut für Technologie (KIT) Hermann-von-Helmholtz-Platz 1 76344 Eggenstein-Leopoldshafen Deutschland
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6
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Mosey A, Dale AS, Hao G, N'Diaye A, Dowben PA, Cheng R. Quantitative Study of the Energy Changes in Voltage-Controlled Spin Crossover Molecular Thin Films. J Phys Chem Lett 2020; 11:8231-8237. [PMID: 32878433 DOI: 10.1021/acs.jpclett.0c02209] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Voltage-controlled nonvolatile isothermal spin state switching of a [Fe{H2B(pz)2}2(bipy)] (pz = tris(pyrazol-1-1y)-borohydride, bipy = 2,2'-bipyridine) film, more than 40 to 50 molecular layers thick, is possible when it is adsorbed onto a molecular ferroelectric substrate. Accompanying this high-spin and low-spin state switching, at room temperature, we observe a remarkable change in conductance, thereby allowing not only nonvolatile voltage control of the spin state ("write") but also current sensing of the molecular spin state ("read"). Monte Carlo Ising model simulations of the high-spin state occupancy, extracted from X-ray absorption spectroscopy, indicate that the energy difference between the low-spin and high-spin state is modified by 110 meV. Transport measurements demonstrate that four terminal voltage-controlled devices can be realized using this system.
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Affiliation(s)
- Aaron Mosey
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
| | - Ashley S Dale
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
| | - Guanhua Hao
- Department of Physics and Astronomy, University of Nebraska Lincoln, Lincoln, Nebraska 68588, United States
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Alpha N'Diaye
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Peter A Dowben
- Department of Physics and Astronomy, University of Nebraska Lincoln, Lincoln, Nebraska 68588, United States
| | - Ruihua Cheng
- Department of Physics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States
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7
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Abstract
The transfer of the inherent bistability of spin crossover compounds to surfaces has attracted considerable interest in recent years. The deposition of the complexes on surfaces allows investigating them individually and to further understand the microscopic mechanisms at play. Moreover, it offers the prospect of engineering switchable functional surfaces. We review recent progress in the field with a particular focus on the challenges and limits associated with the dominant experimental techniques used, namely near-edge X-ray absorption fine structure (NEXAFS) spectroscopy and scanning tunneling microscopy (STM). One of the main difficulties in NEXAFS-based experiments is to ascertain that the complexes are in direct contact with the surfaces. We show that molecular coverage determination based on the amplitude of the edge-jump of interest is challenging because the latter quantity depends on the substrate. Furthermore, NEXAFS averages the signals of a large number of molecules, which may be in different states. In particular, we highlight that the signal of fragmented molecules is difficult to distinguish from that of intact and functional ones. In contrast, STM allows investigating individual complexes, but the identification of the spin states is at best done indirectly. As quite some of the limits of the techniques are becoming apparent as the field is gaining maturity, their detailed descriptions will be useful for future investigations and for taking a fresh look at earlier reports.
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8
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Anomalous Pressure Effects on the Electrical Conductivity of the Spin Crossover Complex [Fe(pyrazine){Au(CN)2}2]. MAGNETOCHEMISTRY 2020. [DOI: 10.3390/magnetochemistry6030031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
We studied the spin-state dependence of the electrical conductivity of two nanocrystalline powder samples of the spin crossover complex [Fe(pyrazine){Au(CN)2}2]. By applying an external pressure (up to 3 kbar), we were able to tune the charge transport properties of the material from a more conductive low spin state to a crossover point toward a more conductive high spin state. We rationalize these results by taking into account the spin-state dependence of the activation parameters of the conductivity.
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9
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Zhang L, Tong Y, Kelai M, Bellec A, Lagoute J, Chacon C, Girard Y, Rousset S, Boillot M, Rivière E, Mallah T, Otero E, Arrio M, Sainctavit P, Repain V. Anomalous Light‐Induced Spin‐State Switching for Iron(II) Spin‐Crossover Molecules in Direct Contact with Metal Surfaces. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Luqiong Zhang
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
| | - Yongfeng Tong
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Massine Kelai
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Amandine Bellec
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Jérôme Lagoute
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Cyril Chacon
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Yann Girard
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Sylvie Rousset
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Marie‐Laure Boillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Eric Rivière
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Edwige Otero
- Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin 91192 Gif sur Yvette France
| | - Marie‐Anne Arrio
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
| | - Philippe Sainctavit
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
- Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin 91192 Gif sur Yvette France
| | - Vincent Repain
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
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10
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Zhang L, Tong Y, Kelai M, Bellec A, Lagoute J, Chacon C, Girard Y, Rousset S, Boillot M, Rivière E, Mallah T, Otero E, Arrio M, Sainctavit P, Repain V. Anomalous Light‐Induced Spin‐State Switching for Iron(II) Spin‐Crossover Molecules in Direct Contact with Metal Surfaces. Angew Chem Int Ed Engl 2020; 59:13341-13346. [DOI: 10.1002/anie.202003896] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 04/22/2020] [Indexed: 01/11/2023]
Affiliation(s)
- Luqiong Zhang
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
| | - Yongfeng Tong
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Massine Kelai
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Amandine Bellec
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Jérôme Lagoute
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Cyril Chacon
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Yann Girard
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Sylvie Rousset
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
| | - Marie‐Laure Boillot
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Eric Rivière
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Talal Mallah
- Institut de Chimie Moléculaire et des Matériaux d'Orsay Univ Paris Sud Université Paris-Saclay CNRS, UMR 8182 91405 Orsay Cedex France
| | - Edwige Otero
- Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin 91192 Gif sur Yvette France
| | - Marie‐Anne Arrio
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
| | - Philippe Sainctavit
- Institut de Minéralogie, de Physique des Matériaux et, de Cosmochimie, CNRS UMR7590 Sorbonne Université, MNHN 75252 Paris Cedex 5 France
- Synchrotron SOLEIL L'Orme des Merisiers Saint-Aubin 91192 Gif sur Yvette France
| | - Vincent Repain
- Université de Paris Laboratoire Matériaux et Phénomènes Quantiques, CNRS 75013 Paris France
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11
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Zhang Y, Séguy I, Ridier K, Shalabaeva V, Piedrahita-Bello M, Rotaru A, Salmon L, Molnár G, Bousseksou A. Resistance switching in large-area vertical junctions of the molecular spin crossover complex [Fe(HB(tz) 3) 2]: ON/OFF ratios and device stability. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:214010. [PMID: 32032965 DOI: 10.1088/1361-648x/ab741e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Multilayer crossbar junctions composed of ITO/[Fe(HB(1,2,4-triazol-1-yl)3)2]/M (with M = Al or Ca) were fabricated and investigated for their resistance switching properties. Current-voltage-temperature maps revealed ON/OFF resistance ratios as high as 400, with the ON and OFF states defined, respectively, as the low-resistance, low spin state and the high-resistance, high spin state of the spin crossover layer. Similar results were obtained with Al and Ca cathodes indicating that the charge transport in the insulating spin crossover film is at the origin of the resistance switching instead of electron injection at the electrodes. The reproducibility and stability of the device properties were also studied.
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Affiliation(s)
- Yuteng Zhang
- LCC, CNRS and Université de Toulouse, Toulouse, France. LAAS, CNRS and Université de Toulouse, INSA, UPS, F-31077 Toulouse, France
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12
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Senthil Kumar K, Šalitroš I, Heinrich B, Moldovan S, Mauro M, Ruben M. Spin-crossover in iron(II)-phenylene ethynylene-2,6-di(pyrazol-1-yl) pyridine hybrids: toward switchable molecular wire-like architectures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:204002. [PMID: 31945748 DOI: 10.1088/1361-648x/ab6cc2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Luminescent oligo(p-phenylene ethynylene) (OPE) and spin-crossover (SCO) active Fe(II)-2,6-di(pyrazol-1-yl) pyridine (BPP) systems are prominent examples proposed to develop functional materials such as molecular wires/memories. A marriage between OPE and Fe(II)-BPP systems is a strategy to obtain supramolecular luminescent ligands capable of metal coordination useful to produce novel spin-switchable hybrids with synergistic coupling between spin-state of Fe(II) and a physical property associated with the OPE skeleton, for example, electronic conductivity or luminescence. To begin in this direction, two novel ditopic ligands, namely L1 and L2, featuring OPE-type backbone end-capped with metal coordinating BPP were designed and synthetized. The ligand L2 tailored with 2-ethylhexyloxy chains at the 2 and 5 positions of the OPE skeleton shows modulated optical properties and improved solubility in common organic solvents relative to the parent ligand L1. Solution phase complexation of L1 and L2 with Fe(BF4)2·6H2O resulted in the formation of insoluble materials of the composition [Fe(L1)] n (BF4)2n and [Fe(L2)] n (BF4)2n as inferred from elemental analyses. Complex [Fe(L1)] n (BF4)2n underwent thermal SCO centred at T 1/2 = 275 K as well as photoinduced low-spin to high-spin transition with the existence of the metastable high-spin state up to 52 K. On the other hand, complex [Fe(L2)] n (BF4)2n , tethered with 2-ethylhexyloxy groups, showed gradual and half-complete SCO with 50% of the Fe(II)-centres permanently blocked in the high-spin state due to intermolecular steric interactions. The small angle x-ray scattering (SAXS) pattern of the as-prepared solid complex [Fe(L1)] n (BF4)2n revealed the presence of nm-sized crystallites implying a possible methodology towards the template-free synthesis of functional-SCO nanostructures.
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Affiliation(s)
- Kuppusamy Senthil Kumar
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034 Strasbourg cedex 2, France
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13
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Poggini L, Londi G, Milek M, Naim A, Lanzilotto V, Cortigiani B, Bondino F, Magnano E, Otero E, Sainctavit P, Arrio MA, Juhin A, Marchivie M, Khusniyarov MM, Totti F, Rosa P, Mannini M. Surface effects on a photochromic spin-crossover iron(ii) molecular switch adsorbed on highly oriented pyrolytic graphite. NANOSCALE 2019; 11:20006-20014. [PMID: 31603165 DOI: 10.1039/c9nr05947d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Thin films of an iron(ii) complex with a photochromic diarylethene-based ligand and featuring a spin-crossover behaviour have been grown by sublimation in ultra-high vacuum on highly oriented pyrolytic graphite and spectroscopically characterized through high-resolution X-ray and ultraviolet photoemission, as well as via X-ray absorption. Temperature-dependent studies demonstrated that the thermally induced spin-crossover is preserved at a sub-monolayer (0.7 ML) coverage. Although the photochromic ligand ad hoc integrated into the complex allows the photo-switching of the spin state of the complex at room temperature both in bulk and for a thick film on highly oriented pyrolytic graphite, this photomagnetic effect is not observed in sub-monolayer deposits. Ab initio calculations justify this behaviour as the result of specific adsorbate-substrate interactions leading to the stabilization of the photoinactive form of the diarylethene ligand over photoactive one on the surface.
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Affiliation(s)
- Lorenzo Poggini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
| | - Giacomo Londi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
| | - Magdalena Milek
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstr. 1, 91058, Erlangen, Germany
| | - Ahmad Naim
- CNRS, Univ. Bordeaux, ICMCB, UMR5026, F-33600 Pessac, France
| | - Valeria Lanzilotto
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
| | - Brunetto Cortigiani
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
| | - Federica Bondino
- CNR-IOM, Laboratorio TASC, Basovizza SS-14, Km 163.5, 34149 Trieste, Italy
| | - Elena Magnano
- CNR-IOM, Laboratorio TASC, Basovizza SS-14, Km 163.5, 34149 Trieste, Italy
| | - Edwige Otero
- Synchrotron SOLEIL L'Orme des Merisiers Saint Aubin, BP 48 91192, Gif sur Yvette, France
| | - Philippe Sainctavit
- Synchrotron SOLEIL L'Orme des Merisiers Saint Aubin, BP 48 91192, Gif sur Yvette, France and IMPMC-UMR7590, CNRS, Sorbonne université, MNHN 4 place Jussieu, 75005 Paris, France
| | - Marie-Anne Arrio
- IMPMC-UMR7590, CNRS, Sorbonne université, MNHN 4 place Jussieu, 75005 Paris, France
| | - Amélie Juhin
- IMPMC-UMR7590, CNRS, Sorbonne université, MNHN 4 place Jussieu, 75005 Paris, France
| | | | - Marat M Khusniyarov
- Department of Chemistry and Pharmacy, Friedrich-Alexander University Erlangen-Nürnberg (FAU), Egerlandstr. 1, 91058, Erlangen, Germany
| | - Federico Totti
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
| | - Patrick Rosa
- CNRS, Univ. Bordeaux, ICMCB, UMR5026, F-33600 Pessac, France
| | - Matteo Mannini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit of Firenze, University of Firenze, I-50019 Sesto Fiorentino, Italy.
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14
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Barker A, Kelly CT, Kühne IA, Hill S, Krzystek J, Wix P, Esien K, Felton S, Müller-Bunz H, Morgan GG. Spin state solvomorphism in a series of rare S = 1 manganese(iii) complexes. Dalton Trans 2019; 48:15560-15566. [PMID: 31342029 DOI: 10.1039/c9dt02476j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Structural, magnetic and spectroscopic data of four complex salts, [Mn(napsal2323)]NTf2, 1,[Mn(napsal2323)]ClO4, 2, [Mn(napsal2323)]BF4, 3 and [Mn(napsal2323)]NO3, 4, of the [Mn(napsal2323)]+ complex cation indicate that the Mn3+ ion is stabilized in the rare S = 1 spin triplet form in this ligand sphere. Zero-field splitting values of D = +19.6 cm-1 and |E| = 2.02 cm-1 for complex 1 were obtained by High Field Electron Paramagnetic Resonance (HFEPR) measurements conducted over a range of frequencies. Structural and magnetic data also indicate that co-crystallization of complexes 2 and 3 with 0.5 equivalents of ethanol yields the high spin S = 2 forms of the perchlorate and tetrafluoroborate solvates [Mn(napsal2323)]ClO4·0.5(C2H5OH), 2·0.5EtOH and [Mn(napsal2323)]BF4·0.5(C2H5OH), 3·0.5EtOH.
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Affiliation(s)
- Andrew Barker
- School of Chemistry, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
| | - Conor T Kelly
- School of Chemistry, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
| | - Irina A Kühne
- School of Chemistry, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
| | - Stephen Hill
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA and Department of Physics, Florida State University, Tallahassee, FL 32306, USA
| | - J Krzystek
- National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310, USA
| | - Paul Wix
- School of Chemistry & CRANN Institute, Trinity College Dublin, University of Dublin, College Green, Dublin 2, Ireland
| | - Kane Esien
- Centre for Nanostructured Media (CNM), School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Solveig Felton
- Centre for Nanostructured Media (CNM), School of Mathematics and Physics, Queen's University Belfast, Belfast, BT7 1NN, UK
| | - Helge Müller-Bunz
- School of Chemistry, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
| | - Grace G Morgan
- School of Chemistry, University College Dublin (UCD), Belfield, Dublin 4, Ireland.
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