1
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Nielsen HH, Vilariño P, Rodríguez G, Trepard F, Roubeau O, Aromí G, Aguilà D. Self-assembly of a supramolecular spin-crossover tetrahedron. Dalton Trans 2024; 53:9792-9797. [PMID: 38787740 DOI: 10.1039/d4dt00578c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
A new mononuclear iron(II) SCO compound featuring H-bonding donor and acceptor units has been synthesized and exploited to produce a purely supramolecular switchable [Fe4] tetrahedron. Magnetic and crystallographic measurements evidence a singular magnetic behavior for each of the four Fe(II) centers of the generated architecture and underscore the potential of this strategy to develop novel SCO materials.
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Affiliation(s)
- Hannah H Nielsen
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
- Department of Chemistry, Aarhus University, DK-8000 Aarhus, Denmark
| | - Pol Vilariño
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
| | - Gemma Rodríguez
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
| | - Florian Trepard
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
| | - Olivier Roubeau
- Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC and Universidad de Zaragoza, Plaza San Francisco s/n, 50009, Zaragoza, Spain.
| | - Guillem Aromí
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
- Institute of Nanoscience and Nanotechnology, University of Barcelona (IN2UB), 08007 Barcelona, Spain
| | - David Aguilà
- Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
- Institute of Nanoscience and Nanotechnology, University of Barcelona (IN2UB), 08007 Barcelona, Spain
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2
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Chen FL, Sun YC, Liu XL, Li G, Zhang CC, Gao BH, Zhao Y, Wang XY. Spin Crossover in [Fe(qsal-5-Br q) 2] + Complexes with a Quinoline-Substituted Qsal Ligand. Inorg Chem 2024; 63:8750-8763. [PMID: 38693869 DOI: 10.1021/acs.inorgchem.4c00354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2024]
Abstract
Using a quinoline substituted Qsal ligand, Hqsal-5-Brq (Hqsal-5-Brq = N-(5-bromo-8-quinolyl)salicylaldimine), four FeIII complexes, [Fe(qsal-5-Brq)2]A·CH3OH (Y = NO3- (1NO3), BF4- (2BF4), PF6- (3PF6), OTf- (4OTf), were prepared and characterized. Structure analysis revealed that complex 2BF4 contained two species (2BF4(P1̅) and 2BF4(C2/c)). In these compounds except 3PF6, the [Fe(qsal-5-Brq)2]+ cations form 1D chains through π-π interactions and other weak interactions. Adjacent chains are connected to form the 2D "Chain Layer" structures and 3D structures through various supramolecular interactions. For 3PF6, a "Dimer Chain" structure is formed from the loosely connected dimers. Magnetic studies revealed that compounds 1NO3 and 2BF4(P1̅) displayed abrupt hysteretic SCO with the transition temperature T1/2↓ = 235 K, T1/2↑ = 240 K for 1NO3 and T1/2↓ = 230 K, T1/2↑ = 235 K for 2BF4(P1̅), while compounds 3PF6 and 4OTf are in the HS state. Desolvation of the complexes significantly modifies their SCO properties: the desolvated 1NO3 and 2BF4 show a gradual SCO, desolvated 3PF6 undergoes a two-step SCO, and desolvated 4OTf exhibits a hysteretic transition. Overall, this work reported the FeIII-SCO complexes of the quinoline-substituted Hqsal ligand and highlighted the potential of these ligands for the development of interesting FeIII-SCO materials.
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Affiliation(s)
- Feng-Li Chen
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Yu-Chen Sun
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Xin-Li Liu
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China
| | - Gang Li
- 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
| | - Bo-Hong Gao
- 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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3
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Halcrow MA, Vasili HB, Pask CM, Kulak AN, Cespedes O. Activating a high-spin iron(II) complex to thermal spin-crossover with an inert non-isomorphous molecular dopant. Dalton Trans 2024; 53:6983-6992. [PMID: 38563124 DOI: 10.1039/d4dt00443d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
[Fe(bpp)2][ClO4]2 (bpp = 2,6-bis{pyrazol-1-yl}pyridine; monoclinic, C2/c) is high-spin between 5-300 K, and crystallises with a highly distorted molecular geometry that lies along the octahedral-trigonal prismatic distortion pathway. In contrast, [Ni(bpp)2][ClO4]2 (monoclinic, P21) adopts a more regular, near-octahedral coordination geometry. Gas phase DFT minimisations (ω-B97X-D/6-311G**) of [M(bpp)2]2+ complexes show the energy penalty associated with that coordination geometry distortion runs as M2+ = Fe2+ (HS) ≈ Mn2+ (HS) < Zn2+ ≈ Co2+ (HS) ≲ Cu2+ ≪ Ni2+ ≪ Ru2+ (LS; HS = high-spin, LS = low-spin). Slowly crystallised solid solutions [FexNi1-x(bpp)2][ClO4]2 with x = 0.53 (1a) and 0.74 (2a) adopt the P21 lattice, while x = 0.87 (3a) and 0.94 (4a) are mixed-phase materials with the high-spin C2/c phase as the major component. These materials exhibit thermal spin-transitions at T½ = 250 ± 1 K which occurs gradually in 1a, and abruptly and with narrow thermal hysteresis in 2a-4a. The transition proceeds to 100% completeness in 1a and 2a; that is, the 26% Ni doping in 2a is enough to convert high-spin [Fe(bpp)2][ClO4]2 into a cooperative, fully SCO-active material. These results were confirmed crystallographically for 1a and 2a, which revealed similarities and differences between these materials and the previously published [FexNi1-x(bpp)2][BF4]2 series. Rapidly precipitated powders with the same compositions (1b-4b) mostly resemble 1a-4a, except that 2b is a mixed-phase material; 2b-4b also contain a fraction of amorphous solid in addition to the two crystal phases. The largest iron fraction that can be accommodated by the P21 phase in this system is 0.7 ± 0.1.
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Affiliation(s)
- Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Hari Babu Vasili
- School of Physics and Astronomy, University of Leeds, W. H. Bragg Building, Leeds, LS2 9JT, UK
| | - Christopher M Pask
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Alexander N Kulak
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, W. H. Bragg Building, Leeds, LS2 9JT, UK
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4
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Jeong AR, Park SR, Shin JW, Kim J, Tokunaga R, Hayami S, Min KS. Mononuclear Fe(III) complexes with 2,4-dichloro-6-((quinoline-8-ylimino)methyl)phenolate: synthesis, structure, and magnetic behavior. Dalton Trans 2024; 53:6809-6817. [PMID: 38545959 DOI: 10.1039/d3dt04385a] [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
Three Fe(III)-based coordination complexes [Fe(dqmp)2](NO3)·H2O (1), [Fe(dqmp)2](BF4)·2CH3COCH3 (2), and [Fe(dqmp)2](ClO4) (3) were synthesized from Fe(NO3)3·9H2O/Fe(ClO4)3·xH2O, NaBF4, and 2,4-dichloro-6-((quinoline-8-ylimino)methyl)phenol (Hdqmp) in methanol/acetone and characterized. The structures of complexes 1-3 were determined via single-crystal X-ray crystallography at 100 K and room temperature, and their magnetic properties in the solid and solution forms were investigated. All complexes showed meridional structures with two tridentate dqmp- ligands coordinated with Fe(III) cations. In the solid state, complex 1 showed an abrupt and complete spin crossover at 225 K, whereas complexes 2 and 3 exhibited an incomplete spin crossover at 135 and 150 K, respectively. In a dimethylformamide solution, the complexes showed counterion-dependent spin transitions. In contrast to the solid state, in solution, complex 1 did not exhibit complete spin crossover. However, complexes 2 and 3 showed more complete spin transitions in solutions than in the solid state. The relaxation times, T1 and T2, for 1 and 2 were determined and both increased with temperature from 220 to 380 K. The T1 of 1 was larger than that of 2 at 380 K, and the T1 values were larger than the T2 values.
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Affiliation(s)
- Ah Rim Jeong
- Department of Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea.
| | - Si Ra Park
- Department of Chemistry Education, Kyungpook National University, Daegu 41566, Republic of Korea.
| | - Jong Won Shin
- Department of Chemistry, Kyungpook National University, Daegu 41566, Republic of Korea.
| | - Jihyun Kim
- Department of Chemistry Education, Kyungpook National University, Daegu 41566, Republic of Korea.
| | - Ryuya Tokunaga
- Department of Chemistry, Kumamoto University, Kumamoto 860-8555, Japan
| | - Shinya Hayami
- Department of Chemistry, Kumamoto University, Kumamoto 860-8555, Japan
| | - Kil Sik Min
- Department of Chemistry Education, Kyungpook National University, Daegu 41566, Republic of Korea.
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5
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Díaz-Torres R, Gómez-Coca S, Ruiz E, Harding P, Harding DJ. Improving spin crossover characteristics in heteroleptic [Fe III(qsal-5-I)(qsal-5-OMe)]A complexes. Dalton Trans 2023. [PMID: 37908189 DOI: 10.1039/d3dt02503a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
A family of heteroleptic spin crossover (SCO) [FeIII(qsal-5-I)(qsal-5-OMe)]A·sol (qsal-5-X = 5-X-2-[(8-quinolylimino)methyl]phenolate; A = NO3-1 sol = 2MeOH, NCS-2 sol = 0.75MeOH·1.3H2O, BF4-3 sol = MeOH, OTf-4, sol = MeOH) complexes have been synthesized. Most of the complexes exhibit gradual SCO, with the exception of NCS, which is principally high spin. In contrast, the OTf complex shows an abrupt hysteretic SCO (35 K) after solvent loss. The magnetic properties of this complex are significantly improved in comparison to the related homoleptics, [Fe(qsal-I)2]OTf 5 (hysteresis, 8 K) and [Fe(qsal-5-OMe)2]OTf·CH2Cl26 (gradual SCO). Structural studies reveal that slight changes in the crystal packing cause stronger interactions improving the cooperativity. These findings are supported by DFT calculations using the r2SCAN functional in which the calculated structures show that SCO from the LS to the HS state causes pronounced scissoring of the 1D π-π chains and substantial changes in their relative orientation following loss of MeOH.
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Affiliation(s)
- Raúl Díaz-Torres
- Thammasat University Research Unit in Multifunctional Crystalline Materials and Applications (TU-MCMA), Faculty of Science and Technology, Thammasat University, Pathum Thani 12121, Thailand
| | - Silvia Gómez-Coca
- Departament de Química Inorgànica i Orgànica, Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica, Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Phimphaka Harding
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand.
| | - David J Harding
- School of Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima, 30000, Thailand.
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6
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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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7
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Kulmaczewski R, Kershaw Cook LJ, Pask CM, Cespedes O, Halcrow MA. Iron(II) Complexes of 4-(Alkyldisulfanyl)-2,6-di(pyrazolyl)pyridine Derivatives. Correlation of Spin-Crossover Cooperativity with Molecular Structure Following Single-Crystal-to-Single-Crystal Desolvation. CRYSTAL GROWTH & DESIGN 2022; 22:1960-1971. [PMID: 35431660 PMCID: PMC9007408 DOI: 10.1021/acs.cgd.2c00005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2022] [Revised: 01/24/2022] [Indexed: 06/14/2023]
Abstract
The complex salts [Fe(L 1)2]X2 (1X 2 ; L 1 = 4-(isopropyldisulfanyl)-2,6-bis(pyrazolyl)pyridine; X- = BF4 -, ClO4 -) form solvated crystals from common organic solvents. Crystals of 1X 2 ·Me2CO show abrupt spin transitions near 160 K, with up to 22 K thermal hysteresis. 1X 2 ·Me2CO cocrystallizes with other, less cooperative acetone solvates, which all transform into the same solvent-free materials 1X 2 ·sf upon exposure to air, or mild heating. Conversion of 1X 2 ·Me2CO to 1X 2 ·sf proceeds in a single-crystal to single-crystal fashion. 1X 2 ·sf are not isomorphous with the acetone solvates, and exhibit abrupt spin transitions at low temperature with hysteresis loops of 30-38 K (X- = BF4 -) and 10-20 K (X- = ClO4 -), depending on the measurement method. Interestingly, the desolvation has an opposite effect on the SCO temperature and hysteresis in the two salts. The hysteretic spin transitions in 1X 2 ·Me2CO and 1X 2 ·sf do not involve a crystallographic phase change but are accompanied by a significant rearrangement of the metal coordination sphere. Other solvates 1X 2 ·MeNO2, 1X 2 ·MeCN, and 1X 2 ·H2O are mostly isomorphous with each other and show more gradual spin-crossover equilibria near room temperature. All three of these lattice types have similar unit cell dimensions and contain cations associated into chains through pairwise, intermolecular S···π interactions. Polycrystalline [Fe(L 2)2][BF4]2·MeNO2 (2[BF 4 ] 2 ·MeNO2; L 2 = 4-(methyldisulfanyl)-2,6-bis(pyrazolyl)pyridine) shows an abrupt spin transition just above room temperature, with an unsymmetrical and structured hysteresis loop, whose main features are reversible upon repeated thermal scanning.
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Affiliation(s)
- Rafal Kulmaczewski
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | | | - Christopher M. Pask
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
| | - Oscar Cespedes
- School
of Physics and Astronomy, University of
Leeds, E. C. Stoner
Building, Leeds LS2 9JT, U.K.
| | - Malcolm A. Halcrow
- School
of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, U.K.
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8
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Liu JH, Guo XQ, Wang ZC, Cai LX, Zhou LP, Tian CB, Sun QF. Cation modulated spin state and near room temperature transition within a family of compounds containing the same [FeL 2] 2- center. Dalton Trans 2022; 51:3894-3901. [PMID: 35167636 DOI: 10.1039/d1dt04254h] [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
Spin-crossover (SCO) active compounds have received much attention due to their potential application in molecular devices. Herein, a family of solvent-free FeII compounds, formulated as (A)2[FeL2], (H2L = pyridine-2,6-bi-tetrazolate, A = (Me)4N+1, Et2NH2+2, iPr2NH2+3 and iPrNH3+4), were synthesized and characterized. Single-crystal X-ray diffraction studies reveal that 1-4 are all supramolecular frameworks containing the same [FeL2]2- center, which is arranged into two packing modes via inter-molecular interactions, that is, a 3D architecture in 1 and 1D chain in 2-4. The spin states of 1-4 at different temperatures are assigned on the basis of the single-crystal X-ray diffraction data. Solid state magnetic investigations indicate that 1 and 4 exhibit a low spin state (below 350 K) and high spin state (2-400 K), respectively. 2 and 3 display clear SCO behavior in the measured temperature, but with different profiles and critical temperatures. 2 undergoes a complete gradual SCO with a critical temperature of T1/2 = 260 K. 3 has an abrupt near room temperature transition between T1/2 cooling = 278 K and T1/2 warming = 286, centered at 282 K (9 °C). This study reveals the importance of organic cations in the modulation of SCO behavior and offers a new insight for the design of SCO compounds with near room temperature spin transitions.
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Affiliation(s)
- Jia-Hui Liu
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China. .,State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Xiao-Qing Guo
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Zi-Cheng Wang
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China. .,State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Li-Xuan Cai
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Li-Peng Zhou
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Chong-Bin Tian
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China. .,State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
| | - Qing-Fu Sun
- College of Chemistry and Materials Science, Fujian Normal University, Fuzhou 350007, China. .,State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
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9
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Kiehl J, Hochdörffer T, Carrella LM, Schünemann V, Nygaard MH, Overgaard J, Rentschler E. Pronounced Magnetic Bistability in Highly Cooperative Mononuclear [Fe(L npdtz) 2(NCX) 2] Complexes. Inorg Chem 2022; 61:3141-3151. [PMID: 35142508 DOI: 10.1021/acs.inorgchem.1c03491] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular materials that exhibit stimuli-responsive bistability are promising candidates for the development of molecular switches and sensors. We herein report on the coexistence of a wide thermal hysteretic spin crossover (SCO) effect and a thermally inducible metastable high-spin state at low temperatures achieved with the two new complexes [FeII(Lnpdtz)2(NCX)2] (X = S; Se), with Lnpdtz being (2-naphthyl-5-pyridyl-1,2,4-thiadiazole) and X = S (1) and Se (2). Pronounced π-π-stacking of the aromatic side residues of the ligands enables strong intermolecular interactions, leading to abrupt SCO properties and broad magnetic hysteresis of 10 K for X = S and 58 K for X = Se. In this paper, we also present the pressure-induced spin-state switching around 0.8 GPa. A pronounced thermally induced excited spin state trapping (TIESST effect) is observed for the highly cooperative SCO compounds, which was experimentally followed by low-temperature single crystal structure analysis (20 K) and temperature-dependent Mössbauer spectroscopy.
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Affiliation(s)
- Jonathan Kiehl
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Tim Hochdörffer
- Department of Physics, Technische Universität Kaiserslautern, Erwin-Schroedinger-Str. 46, D-67663 Kaiserslautern, Germany
| | - Luca M Carrella
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
| | - Volker Schünemann
- Department of Physics, Technische Universität Kaiserslautern, Erwin-Schroedinger-Str. 46, D-67663 Kaiserslautern, Germany
| | - Mathilde H Nygaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
| | - Jacob Overgaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, DK-8000 Aarhus, Denmark
| | - Eva Rentschler
- Department of Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10-14, D-55128 Mainz, Germany
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10
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Jia S, Fan L, Zheng CY, Jin S, Li D. Mixed-valence {FeII2FeIII4} hexanuclear complexes with thermally induced Fe(III) spin crossover behavior. Dalton Trans 2022; 51:12968-12974. [DOI: 10.1039/d2dt02041f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cyano-bridged mixed-valence {Fe6} hexanuclear complexes {[Tp4-MeFeII(CN)3]2[FeIII(Tpa)]2[FeIII(OR)(Tpa)]2}·6ClO4·S {Tp4-Me = tri(4-methyl-pyrazol-1-yl)borate, Tpa = Tris(2-pyridylmethyl)amine; R = -CH3 S = 8MeOH 1, R = -C2H5 S = 6EtOH 2 } have been obtained...
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11
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Díaz-Torres R, Boonprab T, Gómez-Coca S, Ruiz E, Chastanet G, Harding P, Harding DJ. Structural and theoretical insights into solvent effects in an iron(III) SCO complex. Inorg Chem Front 2022. [DOI: 10.1039/d2qi01159j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alcohol effects in a series of iron(III) spin crossover complexes [Fe(qsal-Cl)2]NO3·ROH (R = Me 1, Et 2, 1-Pr 3) are explored. Despite the solvents differing from each other by only...
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Correlation between Supramolecular Connectivity and Magnetic Behaviour of [FeIII(5-X-qsal)2]+-Based Salts Prone to Exhibit SCO Transition. MAGNETOCHEMISTRY 2021. [DOI: 10.3390/magnetochemistry8010001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We present an extensive study to determine the relationship between structural features of spin crossover (SCO) systems based on N-(8-quinolyl)salicylaldimine (qsal) ligand derivatives and their magnetic properties. Thirteen new compounds with general formula [FeIII(5-X-qsal)2]+ (X = H, F, Cl, Br and I) coupled to Cl−, ClO4−, SCN−, PF6−, BF4− and BPh4− anions were prepared and magnetically characterized. The structure/properties correlations observed in these compounds were compared to those of salts with the same [FeIII(qsal-X)2]+ cations previously reported in the literature. These cations favour the LS configuration in compounds with the weakest connectivity. As connectivity increases most of them present HS states at room temperature and structures may be described as arrangements of parallel layers of interacting cation dimers. All the compounds based on these cations undergoing complete SCO transitions within the 4–300 K temperature range have high intralayer connectivity. If, however, the interlayer connectivity becomes very strong they remain blocked in the HS or in the LS state. The SCO transition may be affected by the slightest change of solvent molecules content, disorder or even crystallinity of the sample and it remain difficult to predict which kind of ligand substituent should be selected to obtain compounds with the desired connectivity.
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13
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Spitsyna NG, Blagov MA, Lazarenko VA, Svetogorov RD, Zubavichus YV, Zorina LV, Maximova O, Yaroslavtsev SA, Rusakov VS, Raganyan GV, Yagubskii EB, Vasiliev AN. Peculiar Spin-Crossover Behavior in the 2D Polymer K[Fe III(5Cl-thsa) 2]. Inorg Chem 2021; 60:17462-17479. [PMID: 34757728 DOI: 10.1021/acs.inorgchem.1c01821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A potassium salt of the N2S2O2-coordination Fe(III) anion K[Fe(5Cl-thsa)2] (1) (5Cl-thsa - 5-chlorosalicylaldehyde thiosemicarbazone) is synthesized and characterized structurally and magnetically over a wide temperature range. Two polymorphs of salt 1 characterized by the common 2D polymer nature and assigned to the same orthorhombic Pbcn space group have been identified. The molecular structure of the minor polymorph of 1 was solved and refined at 100, 250, and 300 K is shown to correspond to the LS configuration. The dominant polymorph of 1 features K+ cations disordered over a few crystallographic sites, while the minor polymorph includes fully ordered K+ cations. The major polymorph exhibits a complete three-step cooperative spin-crossover transition both in the heating and cooling modes: The first step occurs in a temperature range from 2 to 50 K; the second abrupt hysteretic step occurs from 200 to 250 K with T1/2 = 230 K and a 6 K hysteresis loop. The third gradual step occurs from 250 to 440 K. According to 57Fe Mössbauer, XRPD, and EXAFS data, the spin-crossover transition for the dominant polymorph is quite peculiar. Indeed, the increase in the HS concentration by 57% at the second step does not result in the expected significant increase in the iron(III)-ligand bond lengths. In addition, the final step of the spin conversion (ΔγHS = 26%) is associated with a structural phase transition with a symmetry lowering from the orthorhombic (Pbcn) to the monoclinic (P21/n) space group. This nontrivial phenomenon was investigated in detail by applying magnetization measurements, electron spin resonance, 57Fe Mössbauer spectroscopy, and DFT calculations. These results provide a new platform for understanding the multistep spin-crossover character in the Fe(III) thsa-complexes and related compounds.
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Affiliation(s)
- Nataliya G Spitsyna
- Institute of Problems of Chemical Physics, RAS, Chernogolovka, 142432, Russia
| | - Maxim A Blagov
- Institute of Problems of Chemical Physics, RAS, Chernogolovka, 142432, Russia
| | | | | | - Yan V Zubavichus
- Synchrotron Radiation Facility SKIF, Boreskov Institute of Catalysis, SB RAS, Koltsovo 630559, Russia
| | | | - Olga Maximova
- Lomonosov Moscow State University, Moscow 119991, Russia
| | | | | | | | - Eduard B Yagubskii
- Institute of Problems of Chemical Physics, RAS, Chernogolovka, 142432, Russia
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Yu ZM, Zhao SZ, Wang YT, Xu PY, Qin CY, Li YH, Zhou XH, Wang S. Anion-driven supramolecular modulation of spin-crossover properties in mononuclear iron(III) Schiff-base complexes. Dalton Trans 2021; 50:15210-15223. [PMID: 34622889 DOI: 10.1039/d1dt02394b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Fe(III) complexes [Fe(5-F-sal-N-1,4,7,10)]Y (Y = PF6- for 1, Y = ClO4- for 2, Y = I- for 3 and Y = NO3- for 4) have been prepared. Single-crystal X-ray crystallographic studies show that complex 1 crystallizes in the orthorhombic Pna21 space group and complexes 2-4 have an isomorphous structure and crystallize in the same monoclinic space group, P21/n. Complexes 2-4 have two independent molecules (Fe1 and Fe2) in the unit cell. Magnetic susceptibility measurements demonstrated that complexes 1 and 3 showed a gradual one-step SCO behavior (T1/2 for 1 = 177 K and for 3 = 227 K) without thermal hysteresis. The magnetic behavior of 2 shows an incomplete two-step SCO process at T1/2 = 114 K and 170 K, respectively, while 4 is in a high-spin state at all measured temperatures. A careful evaluation of the supramolecular structures of these complexes revealed correlation between the supramolecular packing forces and their SCO behavior. The crystal structure of 1 consists of a three-dimensional (3D) extended network constructed from N-H⋯F and C-H⋯F hydrogen bonds, and C-H⋯π and C⋯C short contacts. In compounds 2-4, the crystal packing is governed by C⋯C, C-H⋯π and p-π interactions for the Fe1 centers and by C-H⋯π/O interactions for the Fe2 centers, which form 1D chains. Additional interactions (C-H⋯F and N-H⋯O/I) connect the neighboring chains and planes to form a complex supramolecular network. The anion⋯π interactions in 4 provide a means for preventing SCO occurring at low temperatures. This suggests that the supramolecular connectivity of the anions influences the magnetic properties.
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Affiliation(s)
- Zong-Mei Yu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Sheng-Ze Zhao
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Yu-Ting Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Peng-Yu Xu
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Chun-Yan Qin
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Yong-Hua Li
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Xin-Hui Zhou
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
| | - Shi Wang
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China.
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Berdiell IC, Kulmaczewski R, Shahid N, Cespedes O, Halcrow MA. The number and shape of lattice solvent molecules controls spin-crossover in an isomorphous series of crystalline solvate salts. Chem Commun (Camb) 2021; 57:6566-6569. [PMID: 34113938 DOI: 10.1039/d1cc02624k] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Crystals of [FeL2][BF4]2·nMeCN (L = N-(2,6-di{pyrazol-1-yl}pyrid-4-yl)acetamide; n = 1 or 2) and [FeL2][ClO4]2·MeCN are isomorphous. When n = 1 the compounds exhibit an abrupt, hysteretic spin-transition below 200 K, but when n = 2 the material remains high-spin on cooling. [FeL2]X2·EtCN (X- = BF4- or ClO4-) are isomorphous with the MeCN solvates and undergo their spin-transition at almost the same temperature. However this now occurs in two-steps via a re-entrant mixed-spin intermediate phase, which correlates with crystallographic ordering of the bent propionitrile molecule.
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Affiliation(s)
- Izar Capel Berdiell
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK. and Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas, P.O. Box 1527, Heraklion GR-711 10, Greece
| | - Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, 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, EC 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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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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Ouyang ZJ, Mo XY, Ye JQ, Yu XX, Huang SY, Liu XL, Chen WB, Gao S, Dong W. High temperature anionic Fe(III) spin crossover behavior in a mixed-valence Fe(II)/Fe(III) complex. Dalton Trans 2021; 50:5960-5967. [PMID: 33949504 DOI: 10.1039/d1dt00111f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two ion-pair Fe(iii) complexes (PPh4)[FeIII(HATD)2]·2H2O (1, H3ATD = azotetrazolyl-2,7-dihydroxynaphthalene) and [FeII(phen)3][FeIII(HATD)2]2·3DMA·3.5H2O (2, phen = 1,10-phenanthroline, DMA = N,N-dimethylformamide) were synthesized by employing the tridentate ligand H3ATD. Crystal structure analyses reveal that complexes 1 and 2 consist of FeIII ions in an octahedral environment where a FeIII ion is coordinated by two HATD2- ligands forming the [FeIII(HATD)2]- core. The shortest cationanion distance between the phosphorus ion of the (PPh4)+ cation and the ferric ion of the [FeIII(HATD)2]- anion is 13.190 Å in complex 1, whereas that between the ferrous ion of the [FeII(Phen)3]2+ cation and the ferric ion of the [FeIII(HATD)2]- anion is 7.821 Å in complex 2. C-HC and C-HO hydrogen interactions between the [FeII(phen)3]2+ cation and the [FeIII(HATD)2]- anion are observed in 2. Face-to-face π-π stacking interactions between naphthalene rings with the separated interplanar center to center distances of 3.421-3.680 Å were observed, which result in a one-dimensional supramolecular chain in complexes 1 and 2. Magnetic measurements show that complex 1 is in the low-spin (LS) state below 500 K, whereas 2 undergoes a high temperature spin crossover (SCO) between 360 and 500 K. Magneto-structural relationship studies reveal that π-stacking, hydrogen interactions and Coulomb interactions between the [FeIII(HATD)2]- anion and the [FeII(phen)3]2+ cation play a crucial role in the high temperature Fe(iii) SCO behaviour of complex 2.
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Affiliation(s)
- Zhi-Jian Ouyang
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Xiao-Ying Mo
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Jia-Qi Ye
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Xiao-Xuan Yu
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Shu-Yuan Huang
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Xiao-Ling Liu
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Wen-Bin Chen
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
| | - Song Gao
- School of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510641, P. R. China
| | - Wen Dong
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology, School of Chemistry and Chemical Engineering, Guangzhou University, Guangzhou 510006, P. R. China.
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18
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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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