Spin-crossover nanoparticles and nanocomposite materials
TL;DR: In this article, the state of the art of the elaboration and the application of nanoparticles and nanohybrid/nanocomposite materials based on spin-crossover (SCO) complexes is reported.
About: This article is published in Comptes Rendus Chimie.The article was published on 2018-12-01 and is currently open access. It has received 76 citations till now. The article focuses on the topics: Nanocomposite.
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TL;DR: OctaDist computes the octahedral distortion parameters initially designed in the context of the spin-crossover phenomenon and denoted ζ, Σ, and Θ from standard structural files.
Abstract: OctaDist is an interactive and visual program for determination of structural distortion in octahedral coordination complexes such as spin crossover complexes, single-ion magnets, perovskites or metal–organic frameworks. OctaDist computes the octahedral distortion parameters initially designed in the context of the spin-crossover phenomenon and denoted ζ, Σ, and Θ from standard structural files. The program also provides additional tools for molecular analyses and visualization. It emphasizes performance, flexibility, ease of use, application programming interface (API) consistency, and clear documentation. The modules and classes in OctaDist can be easily customized to include new algorithms or analytical tools. OctaDist is cross-platform supported for modern operating systems and is available as open-source distributed under the GNU General Public License version 3.
108 citations
TL;DR: This review aims to summarise the chemical strategies that have guided the design of conductive metal-organic frameworks and the identified opportunities for further development and showcase relevant examples of functional devices that have received increasing attention from researchers.
Abstract: Materials scientists are currently shifting from purely inorganic, organic and silicon-based materials towards hybrid organic-inorganic materials to develop increasingly complex and powerful electronic devices. In this context, it is undeniable that conductive metal-organic frameworks (MOFs) and bistable coordination polymers (CPs) are carving a niche for themselves in the electronics world. The tunability and processability of these materials alongside the combination of electrical conductivity with porosity or spin transition offers unprecedented technological opportunities for their integration into functional devices. This review aims to summarise the chemical strategies that have guided the design of this type of materials and the identified opportunities for further development. We also examine the strategies to process them as thin films and stress the importance of analysing the effects of nanostructuration on their physical properties that might be crucial for device performance. Finally, we showcase relevant examples of functional devices that have received increasing attention from researchers and highlight the opportunities available for more sophisticated applications that could take full advantage of the combination of electrical conductivity and magnetic bistability.
101 citations
TL;DR: In this article, the synthesis, properties and applications of spin crossover polymer composites, polymers and some related soft materials are reviewed, with a particular attention paid on the influence of the polymer matrix on the spin crossover properties and on the use of active polymers for development of synergies between the properties of the matrix and the load.
52 citations
Cites methods from "Spin-crossover nanoparticles and na..."
...This conjuncture has motivated considerable research for the incorporation of SCO materials and nanomaterials [18] into malleable and processable polymer matrices using increasingly sophisticated methods, such as spray coating, matrix-assisted pulsed laser evaporation, electrospinning or 3D printing....
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TL;DR: In this paper, the authors present the recent progress on spin crossover and valence tautomerism conductors, focusing on syntheses, strategies, crystal structures, magnetic properties, and conductivities of such materials as well as synergistic and cooperative properties of bistability and conductivity.
33 citations
TL;DR: Nanoparticles of the spin‐crossover coordination polymer [FeL(bipy)]n were synthesized by confined crystallization within the core of polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP) diblock copolymer micelles allowing thermal treatment without disintegration of their structure.
Abstract: Nanoparticles of the spin-crossover coordination polymer [FeL(bipy)]n were synthesized by confined crystallization within the core of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) diblock copolymer micelles. The 4VP units in the micellar core act as coordination sites for the Fe complex. In the bulk material, the spin-crossover nanoparticles in the core are well isolated from each other allowing thermal treatment without disintegration of their structure. During annealing above the glass transition temperature of the PS block, the transition temperature is shifted gradually to higher temperatures from the as-synthesized product (T1/2 ↓=163 K and T1/2 ↑=170 K) to the annealed product (T1/2 ↓=203 K and T1/2 ↑=217 K) along with an increase in hysteresis width from 6 K to 14 K. Thus, the spin-crossover properties can be shifted towards the properties of the related bulk material. The stability of the nanocomposite allows further processing, such as electrospinning from solution.
19 citations
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3,136 citations
TL;DR: In this article, the transition temperature of transition metal compounds can be fine tuned using an approach based on the concept of a molecular alloy, and it is possible to design a compound for which room temperature falls in the middle of the thermal hysteresis loop.
Abstract: Some 3dn (4 ≤ n ≤ 7) transition metal compounds exhibit a cooperative transition between a low-spin (LS) and a high-spin (HS) state. This transition is abrupt and occurs with a thermal hysteresis, which confers a memory effect on the system. The intersite interactions and thus the cooperativity are magnified in polymeric compounds such as [Fe(Rtrz)3]A2·nH2O in which the Fe2+ ions are triply bridged by 4-R-substituted-1,2,4-triazole molecules. Moreover, in these compounds, the spin transition is accompanied by a well-pronounced change of color between violet in the LS state and white in the HS state. The transition temperatures of these materials can be fine tuned, using an approach based on the concept of a molecular alloy. In particular, it is possible to design a compound for which room temperature falls in the middle of the thermal hysteresis loop. These materials have many potential applications, for example, as temperature sensors, as active elements of various types of displays, and in information storage and retrieval.
1,934 citations
TL;DR: The magnetization in the ferrimagnetic region below 16 kelvin was substantially increased after illumination and could be restored almost to its original level by thermal treatment and these effects are thought to be caused by an internal photochemical redox reaction.
Abstract: Photoinduced magnetization was observed in a Prussian blue analog, K0.2Co1.4- [Fe(CN)6]·6.9H2O. An increase in the critical temperature from 16 to 19 kelvin was observed as a result of red light illumination. Moreover, the magnetization in the ferrimagnetic region below 16 kelvin was substantially increased after illumination and could be restored almost to its original level by thermal treatment. These effects are thought to be caused by an internal photochemical redox reaction. Furthermore, blue light illumination could be used to partly remove the enhancement of the magnetization. Such control over magnetic properties by optical stimuli may have application in magneto-optical devices.
1,537 citations
TL;DR: Amphiphilic block copolymers (ABCs) represent a new class of functional polymers that are unique building blocks serving a number of applications mainly related to the energetic and structural control of materials interfaces as discussed by the authors.
Abstract: Amphiphilic block copolymers (ABCs) represent a new class of functional polymers that are unique building blocks serving a number of applications mainly related to the energetic and structural control of materials interfaces. The chemical structure of ABCs can be programmed such that interfaces between materials with very different chemical nature, polarity, and cohesion energy can be controlled to a much broader extent than currently possible with low molecular weight surfactants. This is the physical basis for the construction of thermodynamically stable materials hybrids with nanoscale structure and order that consist of a polymer on one side and metal or ceramic nanoparticles or nanophases on the other. These hybrids are particularly interesting since they inherit some of the properties of both the polymer and the inorganic materials, such as mechanical performance and magnetic and optical characteristics.
1,174 citations
TL;DR: This critical review discusses recent work in the field of molecule-based spin crossover materials with a special focus on these emerging issues, including chemical synthesis, physical properties and theoretical aspects as well (223 references).
Abstract: Recently we assisted a strong renewed interest in the fascinating field of molecular spin crossover complexes by (1) the emergence of nanosized spin crossover materials through direct synthesis of coordination nanoparticles and nanopatterned thin films as well as by (2) the use of novel sophisticated high spatial and temporal resolution experimental techniques and theoretical approaches for the study of spatiotemporal phenomena in cooperative spin crossover systems. Besides generating new fundamental knowledge on size-reduction effects and the dynamics of the spin crossover phenomenon, this research aims also at the development of practical applications such as sensor, display, information storage and nanophotonic devices. In this critical review, we discuss recent work in the field of molecule-based spin crossover materials with a special focus on these emerging issues, including chemical synthesis, physical properties and theoretical aspects as well (223 references).
1,084 citations