1
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Trommer C, Kuhlemann E, Engesser TA, Walter M, Thakur S, Kuch W, Tuczek F. Spin crossover in dinuclear iron(II) complexes bridged by bis-bipyridine ligands: dimer effects on electronic structure, spectroscopic properties and spin-state switching. Dalton Trans 2024; 53:9909-9920. [PMID: 38808483 DOI: 10.1039/d4dt00707g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Inspired by the well-studied mononuclear spin crossover compound [Fe(H2B(pz)2)2(bipy)], the bipyridine-based bisbidentate ligands 1,2-di(2,2'-bipyridin-5-yl)ethyne (ac(bipy)2) and 1,4-di(2,2'-bipyridine-5-yl)-3,5-dimethoxybenzene (Ph(OMe)2(bipy)2) are used to bridge two [Fe(H2B(pz)2)2] units, leading to the charge-neutral dinuclear iron(II) compounds [{Fe(H2B(pz)2)2}2 μ-(ac(bipy)2)] (1) and [{Fe(H2B(pz)2)2}2 μ-(Ph(OMe)2(bipy)2)] (2), respectively. The spin-crossover properties of these molecules are investigated by temperature-dependent PPMS measurements, Mössbauer, vibrational and UV/Vis spectroscopy as well as X-ray absorption spectroscopy. While compound 1 undergoes complete SCO with T1/2 = 125 K, an incomplete spin transition is observed for 2 with an inflection point at 152 K and a remaining high-spin fraction of 40% below 65 K. The spin transitions of the dinuclear compounds are also more gradual than for the parent compound [Fe(H2B(pz)2)2(bipy)]. This is attributed to steric hindrance between the molecules, limiting intermolecular interactions such as π-π-stacking.
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Affiliation(s)
- Clara Trommer
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Eike Kuhlemann
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Tobias A Engesser
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
| | - Marcel Walter
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Sangeeta Thakur
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Wolfgang Kuch
- Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany.
| | - Felix Tuczek
- Institut für Anorganische Chemie, Christian-Albrechts-Universität zu Kiel, Max-Eyth-Straße 2, D-24118 Kiel, Germany.
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2
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Bagchi S, Kamilya S, Mehta S, Mandal S, Bandyopadhyay A, Narayan A, Ghosh S, Mondal A. Spin-state switching: chemical modulation and the impact of intermolecular interactions in manganese(III) complexes. Dalton Trans 2023; 52:11335-11348. [PMID: 37530419 DOI: 10.1039/d3dt01707a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
A series of mononuclear manganese(III) complexes [Mn(X-sal2-323)](ReO4) (X = 5 Cl, 1; X = 5 Br, 2; X = 3,5 Cl, 3; X = 3,5 Br, 4; and X = 5 NO2, 5), containing hexadentate ligands prepared using the condensation of N,N'-bis(3-aminopropyl)ethylenediamine and 5- or 3,5-substituted salicylaldehyde, has been synthesized. Variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, electrochemical, and spectroelectrochemical analyses, and theoretical calculations have been used to explore the role of various ligand substituents in the spin-state switching behavior of the prepared manganese(III) complexes. All five complexes consist of an analogous distorted octahedral monocationic MnN4O2 surrounding offered by the flexible hexadentate ligand and ReO4- as the counter anion. However, a disordered water molecule was detected in complex 4. Complexes 1 (X = 5 Cl) and 5 (X = 5 NO2) show gradual and complete spin-state switching between the high-spin (HS) (S = 2) and the low-spin (LS) (S = 1) state with T1/2 values of 146 and 115 K respectively, while an abrupt and complete transition at 95 K was observed for complex 2 (X = 5 Br). Alternatively, complex 3 (X = 3, 5 Cl) exhibits an incomplete and sharp transition between the HS and LS states at 104 K, while complex 4 (X = 3, 5 Br) (desolvated) remains almost LS up to 300 K and then displays gradual and incomplete SCO at a higher temperature. The nature of the spin-state switch and transition temperature suggest that the structural effect (cooperativity) plays a more significant role in comparison with the electronic effect coming from various substituents (Cl, Br, and NO2), which is further supported by the detailed structural, electrochemical, and theoretical studies.
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Affiliation(s)
- Sukanya Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Subhankar Mandal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Arka Bandyopadhyay
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Awadhesh Narayan
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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3
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Ostrovsky S, Klokishner S. Modeling of Spin Crossover in Linear Trinuclear Complexes: Effects of External Pressure. J Phys Chem A 2022; 126:8348-8357. [DOI: 10.1021/acs.jpca.2c04820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Serghei Ostrovsky
- Institute of Applied Physics, Academy Street 5, MD-2028Chisinau, Moldova
| | - Sophia Klokishner
- Institute of Applied Physics, Academy Street 5, MD-2028Chisinau, Moldova
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4
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Investigation of Solutions of Iron(II) Complexes with Tris(pyrazol-1-yl)methane, Possessing the Spin-Crossover Phenomenon. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.110112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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Ghosh S, Bagchi S, Kamilya S, Mehta S, Sarkar D, Herchel R, Mondal A. Impact of counter anions on spin-state switching of manganese(III) complexes containing an azobenzene ligand. Dalton Trans 2022; 51:7681-7694. [PMID: 35521740 DOI: 10.1039/d2dt00660j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Four mononuclear manganese(III) complexes coordinated with photo-active hexadentate azobenzene ligands, [Mn(5azo-sal2-323)](X) (X = Cl, 1; X = BF4, 2; X = ClO4, 3; X = PF6, 4), were prepared. The impact of various counter anions on the stabilization and switching of the spin state of the manganese(III) center was explored through detailed magneto-structural investigation using variable temperature single-crystal X-ray diffraction, magnetic, spectroscopic, and spectroelectrochemical studies, along with theoretical calculations. All four complexes consisted of an isostructural monocationic distorted octahedral MnN4O2 coordination environment offered by the hexadentate ligand and Cl-, BF4-, ClO4-, and PF6- as counter anions respectively. Complex 1 with a spherical Cl- counter anion showed a reversible and gradual spin-state switching between low-spin (LS) (S = 1) and high-spin (HS) (S = 2) states above 400 K, where non-covalent cation-anion interactions played a significant role in stabilizing the LS state. While, irrespective of the shape of the counter anion, complexes 2-4 remained in the HS state throughout the measured temperature range of 300-2 K, where strong π-π interaction between the azobenzene motifs among cationic units played a substantial role in stabilizing the HS state. Furthermore, magnetic data analyses revealed significantly large zero-field splitting in the S = 1 state for 1 (D = 19.4 cm-1, E/D = 0.008) in comparison with that in the S = 2 state for 2-4 (D = 3.99-4.97 cm-1, E/D = 0.002-0.195). Spectroelectrochemical investigations revealed the quasi-reversible reduction and oxidation of the manganese(III) center to manganese(II) and manganese(IV), respectively. A detailed theoretical calculation at the DFT and CASSCF level of theory was carried out to better understand the magneto-structural correlation.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sukanya Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Debopam Sarkar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, CZ-771 46 Olomouc, Czech Republic
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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Orellana-Silla A, Valverde-Muñoz FJ, Muñoz MC, Bartual-Murgui C, Ferrer S, Real JA. Halobenzene Clathrates of the Porous Metal-Organic Spin-Crossover Framework [Fe(tvp) 2(NCS) 2] n. Stabilization of a Four-Step Transition. Inorg Chem 2022; 61:4484-4493. [PMID: 35235314 PMCID: PMC8924922 DOI: 10.1021/acs.inorgchem.2c00014] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Here we show that
the porous metal–organic spin crossover
(SCO) framework [Fe(tvp)2(NCS)2]@4(CH3CN·H2O) [1@4(CH3CN·H2O)] is
an excellent precursor material for the systematic synthesis, via
single-crystal to single-crystal transformation, of a series of halobenzene
clathrates. Immersion of samples constituted of single crystals of 1@4(CH3CN·H2O) in the liquid halobenzenes PhXn, X = F (n = 1–6),
X = Cl (n = 1, 2), and X = Br (n = 1) at room temperature induces complete replacement of the guest
molecules by PhXn to afford 1@2PhXn. Single-crystal analyses
of the new clathrates confirm the integrity of the porous framework
with the PhXn guests being organized by
pairs via π-stacking filling the nanochannels. The magnetic
and calorimetric data confirm the occurrence of practically complete
SCO behavior in all of the clathrates. The characteristic SCO equilibrium
temperatures, T1/2, seem to be the result
of a subtle balance in the host–guest interactions, which are
temperature- and spin-state-dependent. The radically distinct supramolecular
organization of the PhCl2 guests in 1@2PhCl2 affords a rare example of four-step SCO
behavior following the sequence [HS1:LS0] ↔
[HS2/3:LS1/3] ↔ [HS1/2:LS1/2] ↔ [HS1/4:LS3/4] ↔ [HS0:LS1], which
has been structurally characterized. Guest exchange
via single-crystal to single-crystal transformation
has been revealed to be an excellent approach to systematically stow
halobenzene molecules in the nanochannels of the porous spin-crossover
(SCO) metal−organic framework [FeII(tvp)2(NCS)2]n. This has enabled
the unveiling of key structural factors leading to a four-step SCO
behavior.
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Affiliation(s)
- Alejandro Orellana-Silla
- 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, 46022 Valencia, Spain
| | - Carlos Bartual-Murgui
- Instituto de Ciencia Molecular/Departamento de Química Inorgánica, Universidad de Valencia, 46980 Paterna, Valencia, Spain
| | - Sacramento Ferrer
- Departamento de Química Inorgánica, Universidad de Valencia, 46100 Burjassot, Valencia,Spain
| | - José Antonio Real
- Instituto de Ciencia Molecular/Departamento de Química Inorgánica, Universidad de Valencia, 46980 Paterna, Valencia, Spain
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7
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Kaushik K, Ghosh S, Kamilya S, Rouzières M, Mehta S, Mondal A. Reversible Photo- and Thermo-Induced Spin-State Switching in a Heterometallic { 5d-3d} W 2Fe 2 Molecular Square Complex. Inorg Chem 2021; 60:7545-7552. [PMID: 33929177 DOI: 10.1021/acs.inorgchem.1c01014] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Following the complex-as-a-ligand strategy, self-assembly of [W(CN)8]3- and iron(II) with bidentate nitrogen donor ligand bik (bik = bis(1-methyl-1H-imidazol-2-yl)ketone) ligand affords a cyanide-bridged [W2Fe2] molecular square complex [HNBu3]2{[W(CN)8]2[Fe(bik)2]2}·6H2O·CH3OH (1). The complex was characterized by single-crystal X-ray diffraction analyses, (photo)magnetic studies, optical reflectivity, electrochemical studies, and spectroscopic studies. Structural analyses revealed that in the [W2Fe2] square motif tungsten(V) and iron(II) centers reside in an alternate corner of the square and are bridged by the cyanide ligands. Complex 1 exhibits thermo-induced spin crossover (SCO) between {WV (S = 1/2) - FeIILS (S = 0)} and {WV (S = 1/2) - FeIIHS (S = 2)} pairs near room temperature and photoinduced spin-state switching with TLIESST = 70 K under light irradiation at low temperature. To the best of our knowledge, 1 represents the first complex containing iron(II) and [WV(CN)8]3- units exhibiting both SCO and photomagnetic effect.
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Affiliation(s)
- Krishna Kaushik
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C. V. Raman Road, Bangalore 560012, India
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8
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Balić T, Jagličić Z, Sadrollah E, Jochen Litterst F, Počkaj M, Baabe D, Kovač-Andrić E, Bijelić J, Gašo-Sokač D, Djerdj I. Single crystal growth, structural characterization and magnetic properties study of an antiferromagnetic trinuclear iron(III) acetate complex with uncoordinated hexamine. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120292] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Ghosh S, Bagchi S, Kamilya S, Mondal A. Effect of ligand substituents and tuning the spin-state switching in manganese(iii) complexes. Dalton Trans 2021; 50:4634-4642. [PMID: 33720257 DOI: 10.1039/d1dt00284h] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Three mononuclear manganese(iii) complexes based on flexible hexadentate ligands obtained from the condensation of N,N'-bis(3-aminopropyl)ethylenediamine and salicylaldehyde or salicylaldehyde with substitutions at the 5 or 3,5 positions, namely [Mn(X-sal2-323)](BPh4) (X = 5 H, 1; X = 5 Br, 2, and X = 3,5 Br, 3) have been synthesized. The impact of ligand substituents has been studied by variable temperature single-crystal X-ray diffraction analyses, and magnetic, spectroscopic and electrochemical investigations. The complexes have an analogous monocationic MnN4O2 surrounding offered by the flexible hexadentate ligand in a distorted octahedral geometry. Complex 1 remains in the high spin state over the entire temperature range, while complex 2 shows a reversible and complete two-step thermo-induced spin-state switching. An incomplete spin-state switching from a high spin to an intermediate high-spin low-spin (1 : 1) state was observed for complex 3. Single-crystal X-ray structural studies show the presence of three different spin states in 2 during the occurrence of the spin-state switching process. Electrochemical investigations showed that the reduced state of manganese(iii) centers in 3 is easily accessible in comparison to complexes 1 and 2.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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10
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Co-Processing of [Fe(NH2trz)3](2ns)2 and UHMWPE into Materials Combining Spin Crossover and High Mechanical Strength. SCI 2021. [DOI: 10.3390/sci3010007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
The coordination polymer [Fe(NH2trz)3](2ns)2 (NH2trz = 4-amino-1,2,4-triazole and 2ns− = counterion 2-naphthalene sulfonate) exhibits the rare phenomenon of spin crossover in an attractive temperature range, i.e., somewhat above room temperature. Spin crossover in [Fe(NH2trz)3](2ns)2 is manifested by thermochromism, which is accompanied by a magnetic transition from diamagnetism to paramagnetism. However, [Fe(NH2trz)3](2ns)2 is brittle and difficult to process, which limits its use. In this study, we show that [Fe(NH2trz)3](2ns)2 can be co-processed with ultrahigh molecular weight polyethylene (UHMWPE), which possesses outstanding mechanical properties, particularly when tensile-drawn. Therefore, [Fe(NH2trz)3](2ns)2–UHMWPE blends were gel-processed by extrusion, employing a relatively poor solvent, which has recently been shown to offer advantages compared to good solvents. Uniform and flexible films, ribbons and fibers with [Fe(NH2trz)3](2ns)2 fractions as high as 33.3% m/m were obtained that could be readily drawn. Spin crossover in the coordination polymer is retained in these materials, as evident from their thermochromism. The tensile strength and Young’s modulus of the blends exceed those of typical commodity polymers. Thus, the films, ribbons and fibers constitute a special class of multifunctional materials that combine the flexibility and excellent mechanical properties of drawn UHMWPE with the spin crossover behavior of [Fe(NH2trz)3](2ns)2.
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Ghosh S, Kamilya S, Rouzières M, Herchel R, Mehta S, Mondal A. Reversible Spin-State Switching and Tuning of Nuclearity and Dimensionality via Nonlinear Pseudohalides in Cobalt(II) Complexes. Inorg Chem 2020; 59:17638-17649. [PMID: 33174721 DOI: 10.1021/acs.inorgchem.0c02887] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The self-assembly of a macrocyclic tetradentate ligand, cobalt(II) tetrafluoroborate, and nonlinear pseudohalides (dicyanamide and tricyanomethanide) has led to two cobalt(II) complexes, {[Co(L)(μ1,5-dca)](BF4)·MeOH}n (1) and [Co2(L)2(μ1,5-tcm)2](BF4)2 (2) (L = N,N'-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane; dca- = dicyanamido; tcm- = tricyanomethanido). Both complexes were characterized by single-crystal X-ray diffraction, spectroscopic, magnetic, and electrochemical studies. Structural analyses revealed that 1 displays a one-dimensional (1D) coordination polymer containing [Co(L)]2+ repeating units bridged by μ1,5-dicyanamido groups in cis positions, while 2 represents a discreate dinuclear cobalt(II) molecule bridged by two μ1,5-tricyanomethanido groups in a cis conformation. Both complexes have a CoN6 coordination environment around each cobalt center offered by the tetradentate ligand and cis coordinating bridging ligands. Complex 1 exhibits a high-spin (S = 3/2) state of cobalt(II) in the temperature range of 2-300 K with a weak ferromagnetic coupling between two dicyanamido-bridged cobalt(II) centers. Interestingly, complex 2 exhibits reversible spin-state switching associated with spin-spin coupling. Complexes 1 and 2 also exhibit interesting redox-stimuli-based reversible paramagnetic high-spin cobalt(II) to diamagnetic low-spin cobalt(III) conversion, offering an additional way to switch magnetic properties. A detailed theoretical calculation was consistent with the stated results.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Sujit Kamilya
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Mathieu Rouzières
- Univ. Bordeaux, CNRS, Centre de Recherche Paul Pascal, CRPP, UMR 5031, 33600 Pessac, France
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, CZ-771 46 Olomouc, Czech Republic
| | - Sakshi Mehta
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
| | - Abhishake Mondal
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India
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12
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Ghosh S, Bagchi S, Das M, Kamilya S, Mondal A. Stepwise spin-state switching in a manganese(III) complex. Dalton Trans 2020; 49:14776-14780. [PMID: 33078798 DOI: 10.1039/d0dt02746d] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A mononuclear manganese(iii) complex containing a flexible hexadentate chelating ligand has been prepared and characterized by performing, at various temperatures, single-crystal X-ray diffraction analyses and magnetic, spectroscopic, and electrochemical studies. The complex was shown to consist of an MnN4O2 octahedral coordination environment, and to exhibit reversible two-step thermally induced spin-state switching, a gradual one at 168 K and an abrupt one at 103 K. Structural analyses revealed the existence of three spin-states, namely high-spin, low-spin, and intermediate states, during the spin-state switching process. Electrochemistry studies showed the quasi-reversible reduction and oxidation of the manganese(iii) center with a comparatively easily accessible reduced state.
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Affiliation(s)
- Subrata Ghosh
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Sir C V Raman Road, Bangalore 560012, India.
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13
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Kupko N, Meehan KL, Witkos FE, Hutcheson H, Monroe JC, Landee CP, Dickie DA, Turnbull MM, Xiao F. Cobalt halide complexes of 2-, 3- and 4-methoxyaniline: Syntheses, structures and magnetic behavior. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114680] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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14
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Co-Processing of [Fe(NH2trz)3](2ns)2 and UHMWPE into Materials Combining (Spin Crossover and High Mechanical Strength. SCI 2020. [DOI: 10.3390/sci2030066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The coordination polymer [Fe(NH2trz)3](2ns)2 exhibits the rare phenomenon of spin crossover in an attractive temperature range, i.e., somewhat above room temperature. Spin crossover in [Fe(NH2trz)3](2ns)2 is manifest by thermochromism, which is accompanied by a magnetic transition from diamagnetism to paramagnetism. However, [Fe(NH2trz)3](2ns)2 is brittle and difficult to process, which limits its use. In this study, we show that [Fe(NH2trz)3](2ns)2 can be co-processed with ultrahigh molecular weight polyethylene (UHMWPE), which possesses outstanding mechanical properties, particularly when tensile drawn. Therefore, [Fe(NH2trz)3](2ns)2–UHMWPE blends were gel-processed by extrusion, employing a relatively poor solvent, which has recently been shown to offer advantages compared to good solvents. Uniform and flexible films, ribbons and fibers with [Fe(NH2trz)3](2ns)2 fractions as high as 33.3% m/m were obtained that could be readily drawn. Spin crossover in the coordination polymer is retained in these materials, as evident from their thermochromism. The tensile strength and Young’s modulus of the blends exceed those of typical commodity polymers. Thus, the films, ribbons and fibers constitute a special class of multifunctional materials that combine the flexibility and excellent mechanical properties of drawn UHMWPE with the spin crossover behavior of [Fe(NH2trz)3](2ns)2.
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Avila Y, Crespo P, Plasencia Y, Mojica H, Rodríguez-Hernández J, Reguera E. Intercalation of 3X-pyridine with X = F, Cl, Br, I, in 2D ferrous nitroprusside. Thermal induced spin transition in Fe(3F-pyridine)2[Fe(CN)5NO]. J SOLID STATE CHEM 2020. [DOI: 10.1016/j.jssc.2020.121293] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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16
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Ghosh S, Selvamani S, Kamilya S, Mehta S, Mondal A. Tuning of Spin Crossover Properties in a Series of Mononuclear Cobalt(II) Complexes Based on Macrocyclic Tetradentate Ligand and Pseudohalide Coligands. Dalton Trans 2020; 51:9642-9652. [DOI: 10.1039/d0dt02546a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The three mononuclear cobalt(II) complexes, [Co(L)(NCX)2] (L = N,N'-di-tert-butyl-2,11-diaza[3,3](2,6)pyridinophane, and X = S (1), Se (2), and [C(CN)2] (3)), have been synthesized and characterized using variable temperature single-crystal X-ray crystallography,...
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Dragulescu-Andrasi A, Hietsoi O, Üngör Ö, Dunk PW, Stubbs V, Arroyave A, Kovnir K, Shatruk M. Dicyanometalates as Building Blocks for Multinuclear Iron(II) Spin-Crossover Complexes. Inorg Chem 2019; 58:11920-11926. [PMID: 31136155 DOI: 10.1021/acs.inorgchem.9b01121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A synthetic strategy featuring dicyanometalates [M(CN)2]- (M = Ag, Au) as N-coordinating ditopic linkers connecting partially blocked FeII centers has been employed to produce heterometallic hexanuclear complexes, which exhibit spin-crossover (SCO) behavior at the FeII sites. The reaction between tris(2-pyridylmethyl)amine (tpma)-capped FeII ions and [Ag(CN)2]- proceeded with partial decomposition of the dicyanoargentate and led to the formation of {[Fe(tpma)]4(μ-CN)2[μ-Ag(CN)2]2}(ClO4)4·3H2O (1), in which both [Ag(CN)2]- and CN- act as bridging ligands, and the opposite [Ag(CN)2]- bridges are engaged in a pronounced argentophilic d10-d10 interaction. In an analogous synthesis, the more stable [Au(CN)2]- species remained intact and furnished the complex {[Fe(tpma)]2[μ-Au2(CN)4]2} (2), which features two FeII centers bridged by two [Au2(CN)4]2- dimers. The use of S,S'-bis(2-pyridylmethyl)-1,2-thioethane (bpte) as a mixed-donor, N2S2-coordinating capping ligand yielded {[Fe(bpte)]2[μ-Au2(CN)4]2} (3), with a structure analogous to that of 2. Variable-temperature magnetic susceptibility measurements revealed that complexes 1-3 exhibit an onset of SCO above 350 K. Measurements above 400 K further confirmed the occurrence of a gradual spin-state conversion for complex 2.
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Affiliation(s)
- Alina Dragulescu-Andrasi
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Oleksandr Hietsoi
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Ökten Üngör
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Paul W Dunk
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Victoria Stubbs
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Alejandra Arroyave
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Kirill Kovnir
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
| | - Michael Shatruk
- Department of Chemistry and Biochemistry , Florida State University , 95 Chieftan Way , Tallahassee , Florida 32306 , United States
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Lan W, Valverde-Muñoz FJ, Hao X, Dou Y, Muñoz MC, Zhou Z, Liu H, Liu Q, Real JA, Zhang D. An unprecedented hetero-bimetallic three-dimensional spin crossover coordination polymer based on the tetrahedral [Hg(SeCN)4]2− building block. Chem Commun (Camb) 2019; 55:4607-4610. [DOI: 10.1039/c9cc01291e] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
A new non-Hoffmann type of hetero-bimetallic HgII–FeII spin-crossover coordination polymer has been structurally and magnetically investigated.
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Affiliation(s)
- Wenlong Lan
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
| | | | - Xiaoyun Hao
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
| | - Yong Dou
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
| | - M. Carmen Muñoz
- Departamento de Física Aplicada
- Universitat Politècnica de València
- E-46022 Valencia
- Spain
| | - Zhen Zhou
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
| | - Hui Liu
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
| | - Qingyun Liu
- College of Chemical and Environmental Engineering
- Shandong University of Science and Technology
- Qingdao 266510
- P. R. China
| | - José Antonio Real
- Instituto de Ciencia Molecular (ICMol)
- Universitat de València
- 46980 Paterna
- Spain
| | - Daopeng Zhang
- College of Chemical and Chemical Engineering
- Shandong University of Technology
- Zibo 255049
- P. R. China
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