Electron-donating substituent influence on the spin-crossover phenomenon in iron(III) bis-o-iminobenzosemiquinonates

Ershova, Irina V.; Bogomyakov, A. S.; Кубрин, С. П.; Fukin, Georgy K.; Пискунов, А. В.

doi:10.1016/j.ica.2019.119402

Cited by 9 publications

(14 citation statements)

References 39 publications

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“…The values of FeÀ N, FeÀ O, and FeÀ Br bond distances obtained from EXAFS data at various temperatures are in good agreement with the data of XRD analysis for ( Me imSQ) 2 FeBr. [44,45] Although the distances from XRD were obtained only at three temperatures of 100, 240, and 293 K, an increase in the FeÀ O distances in the coordination center from 1.9009 (19) (Figure 6 open circles). The values of FeÀ Br obtained from XRD of the distances of 2.3816(6) Å (100 K) and 2.3755(7) Å (293 K) also confirm our conclusion, obtained from the EXAFS analysis, that they remain constant over the entire temperature range.…”

Section: Resultsmentioning

confidence: 98%

“…c) Temperature dependence of the effective magnetic moment of the complex. [44] continuously changes and temperature T 1/2 is about 110 K. The spectra of pure components are further compared with theoretical spectra for DFT-optimized structural models.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 4 shows the thermal dependence of the parameters of the ( Me imSQ) 2 FeBr Mössbauer spectrum. [44] The Mössbauer spectrum of ( Me imSQ) 2 FeBr at 14 K has the form of a doublet with isomer shift parameters δ = 0.25 mm/s and quadrupole splitting ΔE Q = 2.56 mm/s, characteristic of the intermediate spin (S Fe = 3/2) of Fe(III) ions, [19] the values of which gradually change upon heating to room temperature and reach δ = 0.33 mm/s and ΔE Q = 1.12 mm/s. The latter are characteristic for Fe(III) ions with larger distances in the first coordination shell, e. g. for HS state S Fe = 5/2.…”

Section: Resultsmentioning

confidence: 99%

“…Complex of iron(III) ( Me imSQ) 2 FeBr based on 4,6-di-tert-butyl-N-(2,6-dimethyl-phenyl)-o-aminophenol has been prepared as described previously. [20,44] Figure 1a shows the schematic structure of the complex.…”

Section: Resultsmentioning

confidence: 99%

“…This complex was recently synthesized in the series of ( Me imSQ) 2 FeX (X=Cl, Br, I, N 3 , NCO) and was discussed as having a spin-crossover behavior. [44] However unusual behaviour of magnetization upon cooling could be alternatively described within the model of exchange coupled trimer (S 1 = 3/2 -spin of Fe(III) ion and S 2 = S 3 = 1/2 -spins of radical anion ligands) i. e. when metal is always in intermediate spin state. Mössbauer analysis could not resolve transition between two isolated HS and IS phase in contrast to the related ( MeO imSQ) 2 FeCl [20] but demonstrated a continuous variation of isomeric shift and quadrupole splitting across all temperature range.…”

Section: Introductionmentioning

confidence: 99%

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Structural Changes in Five‐Coordinate Bromido‐bis(o‐iminobenzo‐semiquinonato)iron(III) Complex: Spin‐Crossover or Ligand‐Metal Antiferromagnetic Interactions?

et al. 2021

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Spin-crossover metal complexes represent important building blocks for a future generation of electronic and optical devices. Pentacoordinated o-iminosemiquinonate iron(III) complexes are able to demonstrate spin transitions between high spin (HS) and intermediate spin (IS) states under the influence of temperature or irradiation. Studied (Me imSQ) 2 FeBr sample showed a broad magnetic transition in the temperature region from 30 K to 300 K. Remarkably that observed behavior of magnetization can be interpreted with two controversial models. In the first model, the values of the effective magnetic moment at low temperature and high temperature can be assigned to the IS and HS magnetic moment of ferric ion coupled antiferromagnetically to radical anion ligands. In the second model, the metal spin on metal center remains IS in the whole temperature interval, while the mutual orientation of three magnetic moments in the molecule undergo changes due to exchange interactions. In this work we apply density functional theory and X-ray absorption spectroscopy to unravel the origin of magnetic properties of the complex. Temperature-induced changes of interatomic distances in the first coordination sphere support the second model. Such comprehensive analysis of the magnetic properties makes it possible to shed light on the nature of spin transitions in complexes of transition metals with open-shell ligands, which are often complicated by strong exchange interactions.

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Section: Resultsmentioning

confidence: 98%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Structural Changes in Five‐Coordinate Bromido‐bis(o‐iminobenzo‐semiquinonato)iron(III) Complex: Spin‐Crossover or Ligand‐Metal Antiferromagnetic Interactions?

et al. 2021

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Electronic Lability of Quinonoid‐Bridged Dinuclear 3 d‐Metal Complexes with Tetradentate N‐Donor Bases

Chegerev

Старикова

2021

Eur J Inorg Chem

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Bimetallic coordination compounds prone to spin‐state‐switching rearrangements via spin‐crossover or valence tautomerism mechanisms are of ongoing interest due to their unique magnetic characteristics. Dinuclear transition metal (Cr, Mn, Fe, Co, Ni, Cu) complexes with redox‐active bridging ligands (tetraoxolenes and their imine derivatives, di‐o‐quinones bearing linker groups) and tetradentate nitrogen‐containing bases (tetraazacyclotetradecane, tris(2‐pyridylmethyl)amine and N,N′‐dialkyl‐2,11‐diaza[3.3]‐(2,6)pyridinophane derivatives) are described from the viewpoint of their electronic structure and magnetic properties. The present review summarizes data on comprehensive investigations of bi‐ and polystable species of such structural architectures, which might be valuable for the chemists and materials scientists involved in the creation of new promising magnetic materials − building blocks for electronic devices of future generations.

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Metal‐Coordinated Ligand Radical Species With Non‐innocent Ortho‐aminophenol Functionalities: Reactivity and Catalysis

Ali,

Arora,

Rajput

et al. 2024

ChemistrySelect

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This review article presents a comprehensive analysis of metal complexes featuring ortho‐aminophenol based non‐innocent ligands in various oxidation states, including dianion/o‐amidophenolate, monoanion/o‐iminosemiquinonato, and o‐iminoquinonato forms. We focus extensively on the reactivity and catalytic properties of these metal complexes, offering insights into their potential applications and behavior in different chemical environments. The ligands are meticulously categorized based on their denticity, providing a clear framework for understanding their coordination chemistry. Correspondingly, the metal complexes are systematically organized according to the sequence of ligands, ensuring a coherent and logical presentation of the data. The structural approach not only highlights the intricate relationships between ligands and metal centers but also facilitates a deeper understanding of their roles in various catalytic processes.

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Electron-donating substituent influence on the spin-crossover phenomenon in iron(III) bis-o-iminobenzosemiquinonates

Cited by 9 publications

References 39 publications

Structural Changes in Five‐Coordinate Bromido‐bis(o‐iminobenzo‐semiquinonato)iron(III) Complex: Spin‐Crossover or Ligand‐Metal Antiferromagnetic Interactions?

Structural Changes in Five‐Coordinate Bromido‐bis(o‐iminobenzo‐semiquinonato)iron(III) Complex: Spin‐Crossover or Ligand‐Metal Antiferromagnetic Interactions?

Electronic Lability of Quinonoid‐Bridged Dinuclear 3 d‐Metal Complexes with Tetradentate N‐Donor Bases

Metal‐Coordinated Ligand Radical Species With Non‐innocent Ortho‐aminophenol Functionalities: Reactivity and Catalysis

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