1
|
Zhang K, Wallis MJ, Craze AR, Hayami S, Min H, Fanna DJ, Bhadbhade MM, Tian R, Marjo CE, Lindoy LF, Li F. Spin crossover of a Fe(II) mononuclear complex induced by intermolecular factors involving chloride and solvent ordering. Dalton Trans 2024; 53:14144-14152. [PMID: 38721861 DOI: 10.1039/d4dt00706a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Two new salts of a mononuclear tripodal Fe(II) complex were prepared, using ClO4- and Cl-. The ClO4- sample (1) remained HS at low temperatures, similar to the previously reported BF4- analogue. Crystallising with the Cl- anion (2) led to a markedly different crystal packing arrangement, and engendered SCO activity. This has been correlated to the lower crystal packing density in 2 and the coordination complex conformational differences arising due to the packing motifs of 1 and 2. Further, solvent ordering effects have been proposed to facilitate spin transition behaviour in 2.
Collapse
Affiliation(s)
- Kenneth Zhang
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia.
| | - Matthew J Wallis
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia.
| | | | - Shinya Hayami
- Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Japan
| | - Hyunsung Min
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia.
- Advanced Materials Characterisation Facility, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | - Daniel J Fanna
- Advanced Materials Characterisation Facility, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia
| | - Mohan M Bhadbhade
- Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW, Australia
| | - Ruoming Tian
- Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW, Australia
| | - Christopher E Marjo
- Mark Wainwright Analytical Centre, University of New South Wales, Kensington, NSW, Australia
| | - Leonard F Lindoy
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Feng Li
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW, Australia.
| |
Collapse
|
2
|
Nikovskiy I, Aleshin DY, Novikov VV, Polezhaev AV, Khakina EA, Melnikova EK, Nelyubina YV. Selective Pathway toward Heteroleptic Spin-Crossover Iron(II) Complexes with Pyridine-Based N-Donor Ligands. Inorg Chem 2022; 61:20866-20877. [PMID: 36511893 DOI: 10.1021/acs.inorgchem.2c03270] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A new synthetic pathway is devised to selectively produce previously elusive heteroleptic iron(II) complexes of terpyridine and N,N'-disubstituted bis(pyrazol-3-yl)pyridines that stabilize the opposite spin states of the metal ion. Such a combination of the ligands in a series of the heteroleptic complexes induces the spin-crossover (SCO) not experienced by the homoleptic complexes of these ligands or shifts it to lower/higher temperatures respective to the SCO-active homoleptic complex. The midpoint temperatures of the resulting SCO span from ca. 200 K to the ambient temperature and beyond the highest temperature accessible by NMR spectroscopy and SQUID magnetometry. The proposed "one-pot" approach is applicable to other N-donor ligands to selectively produce heteroleptic complexes─including those inaccessible by alternative synthetic pathways─with highly tunable SCO behaviors for practical applications in sensing, switching, and multifunctional devices.
Collapse
Affiliation(s)
- Igor Nikovskiy
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991Moscow, Russia.,Bauman Moscow State Technical University, 2nd Baumanskaya Str., 5, 105005Moscow, Russia
| | - Dmitry Yu Aleshin
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991Moscow, Russia
| | - Valentin V Novikov
- Bauman Moscow State Technical University, 2nd Baumanskaya Str., 5, 105005Moscow, Russia.,Moscow Institute of Physics and Technology, Institutskiy per., 9, 141700Dolgoprudny, Russia
| | - Alexander V Polezhaev
- Bauman Moscow State Technical University, 2nd Baumanskaya Str., 5, 105005Moscow, Russia
| | - Ekaterina A Khakina
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991Moscow, Russia.,HSE University, Miasnitskaya Str., 20, 101000Moscow, Russia
| | - Elizaveta K Melnikova
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991Moscow, Russia
| | - Yulia V Nelyubina
- Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991Moscow, Russia.,Bauman Moscow State Technical University, 2nd Baumanskaya Str., 5, 105005Moscow, Russia
| |
Collapse
|
3
|
Athira S, Mondal DJ, Shome S, Dey B, Konar S. Effect of intermolecular anionic interactions on spin crossover of two triple-stranded dinuclear Fe( ii) complexes showing above room temperature spin transition. Dalton Trans 2022; 51:16706-16713. [DOI: 10.1039/d2dt02115c] [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
Two new Fe(ii)-based dinuclear triple helicates [Fe2L3]4+, displaying near room temperature spin transition have been synthesized and the effect of intermolecular interactions and co-operativity between metal centers on the SCO has been studied.
Collapse
Affiliation(s)
- S. Athira
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India
| | - Dibya Jyoti Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India
| | - Shraoshee Shome
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India
| | - Bijoy Dey
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India
| | - Sanjit Konar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal (IISERB), Bhopal By-pass Road, Bhauri, Madhya Pradesh-462066, India
| |
Collapse
|
4
|
Livesay BN, Shores MP. Influence of Coordinated Triflate Anions on the Solution Magnetic Properties of a Neutral Iron(II) Complex. Inorg Chem 2021; 60:15445-15455. [PMID: 34596394 DOI: 10.1021/acs.inorgchem.1c02112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In an effort to probe the impacts of speciation on spin-state switching, the synthesis and unique solution-phase magnetic properties of [((TIPSC≡C)3tren)Fe(OTf)2] (1) are described. Analysis of the single-crystal X-ray diffraction data shows that the tris(iminoalkyne) ligand coordinates to the iron(II) center through all four nitrogen atoms, while the other two coordination sites are filled by the oxygen atoms from triflate anions. Solid-state variable-temperature (VT) magnetic studies show that 1 remains high-spin (HS) at all temperatures. In the presence of moderately strong coordinating solvents, solvent replaces the two bound triflate counteranions, as observed by 19F NMR spectroscopy and supported by conductivity measurements. VT solution measurements show 1 to be in the HS state when this solvent is oxygen-donating but low-spin (LS) with a nitrogen-donating solvent. In the noncoordinating solvent dichloromethane, both triflates are bound to the iron(II) center at room temperature, but upon cooling, 1 undergoes a coordination change, resulting in the loss of one triflate, as shown by 19F NMR. With the moderately coordinating solvent acetone, triflate dissociation upon cooling results in a spin-switching species with a T1/2 value of 171 K, characterized via 19F NMR, Evans' method, and solution magnetometry measurements. Solution magnetic measurements collected in structurally similar cyclopentanone suggest that the spin-state switching event is exclusive to the acetone environment, suggesting the influence of both the local coordination environment and aggregation. Additionally, a comparison of the solvodoynamic diameters via dynamic light scattering suggests that aggregation of 1 is significantly different in (CH3)2CO and (CD3)2CO, leading to the observation of spin-switching behavior in the former and fully HS behavior in the latter. This study highlights the sensitivity of solution magnetic properties to solvent choice.
Collapse
Affiliation(s)
- Brooke N Livesay
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P Shores
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| |
Collapse
|
5
|
Bhowmick I, Newell BS, Shores MP. A systematic study of the influence of ligand field on the slow magnetic dynamics of Co(ii)-diimine compounds. Dalton Trans 2021; 50:10737-10748. [PMID: 34269774 DOI: 10.1039/d0dt01597k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Herein we report heteroleptic Co(ii) diimine complexes [Co(H2bip)2Cl2] (1), [Co(H2bip)2Br2] (2), [Co(H2bip)3]Br2·1MeOH (3) and [Co(H2bip)2(Me2bpy)]Br2·(MeCN)0.5·(H2O)0.25 (4) (H2bip = 2,2'-bi-1,4,5,6-tetrahydropyrimidine, bpy = 2,2'-dipyridyl, Me2bpy = 4,4'-Me-2,2'-dipyridyl), purposefully prepared to enable a systematic study of magnetic property changes arising from the increase of overall ligand field from σ/π-donor chlorido (1) to π-acceptor 4,4'Me-2,2'bpy (4). The presence of axial and rhombic anisotropy (D and E) of these compounds is sufficient to allow 1-4 to show field-induced slow relaxation of magnetization. Interestingly, we found as the effective ligand field is increased in the series, rhombicity (E/D) decreases, and the magnetic relaxation profile changes significantly, where relaxation of magnetization at a specific temperature becomes gradually faster. We performed mechanistic analyses of the temperature dependence of magnetic relaxation times considering Orbach relaxation processes, Raman-like relaxation and quantum tunnelling of magnetization (QTM). The effective energy barrier of the Orbach relaxation process (Ueff) is largest in compound 1 (19.2 cm-1) and gradually decreases in the order 1 > 2 > 3 > 4 giving a minimum value in compound 4 (8.3 cm-1), where the Raman-like mechanism showed the possibility of different types of phonon activity below and above ∼2.5 K. As a precursor of 1, the tetrahedral complex [Co(H2bip)Cl2] (1a) was also synthesized and structurally and magnetically characterized: this compound exhibits slow relaxation of magnetization under an applied dc field (1800 Oe) with a record slow relaxation time of 3.39 s at 1.8 K.
Collapse
Affiliation(s)
- Indrani Bhowmick
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
| | - Brian S Newell
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA. and Analytical Resources Core, Center for Materials and Molecular Analysis, Colorado State University, Fort Collins, Colorado 80523, USA
| | - Matthew P Shores
- Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872, USA.
| |
Collapse
|
6
|
Craze AR, Zenno H, Pfrunder MC, McMurtrie JC, Hayami S, Clegg JK, Li F. Supramolecular Modulation of Spin Crossover in an Fe(II) Dinuclear Triple Helicate. Inorg Chem 2021; 60:6731-6738. [DOI: 10.1021/acs.inorgchem.1c00553] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Alexander R. Craze
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| | - Hikaru Zenno
- Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, Japan
| | - Michael C. Pfrunder
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, QLD 4001, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George St, Brisbane, QLD 4001, Australia
| | - John C. McMurtrie
- School of Chemistry and Physics, Queensland University of Technology, 2 George Street, Brisbane, QLD 4001, Australia
- Centre for Materials Science, Queensland University of Technology, 2 George St, Brisbane, QLD 4001, Australia
| | - Shinya Hayami
- Department of Chemistry, Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto, Japan
| | - Jack K. Clegg
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, QLD 4072, Australia
| | - Feng Li
- School of Science, Western Sydney University, Locked Bag 1797, Penrith, NSW 2751, Australia
| |
Collapse
|
7
|
Shao D, Shi L, Shen FX, Wei XQ, Sato O, Wang XY. Reversible On–Off Switching of the Hysteretic Spin Crossover in a Cobalt(II) Complex via Crystal to Crystal Transformation. Inorg Chem 2019; 58:11589-11598. [DOI: 10.1021/acs.inorgchem.9b01436] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Dong Shao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People’s Republic of China
| | - Le Shi
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People’s Republic of China
| | - Fu-Xing Shen
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People’s Republic of China
| | - Xiao-Qin Wei
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, People’s Republic of China
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering, Kyushu University, 744 Motooka Nishi-ku, 816-8580 Fukuoka, Japan
| | - 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, People’s Republic of China
| |
Collapse
|
8
|
Adhikary A, Ghosh K. Fine tuning of coordination environments by anions on a series of Cu(II) dihydrazide complexes: Syntheses, structures, magnetic properties and solution phase anion exchange. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.04.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
9
|
Vicente AI, Wu X, Ortin Y, Ferreira LP, Carvalho MDD, Realista S, Barker A, Morgan GG, Galamba N, Costa PJ, Calhorda MJ, Martinho PN. Directing self-assembly in solution towards improved cooperativity in Fe(iii) complexes with amphiphilic tridentate ligands. Dalton Trans 2019; 48:4239-4247. [PMID: 30843914 DOI: 10.1039/c9dt00032a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An amphiphilic iron(iii) complex with a tridentate Schiff-base ligand was prepared by condensation of a hexadecyloxy functionalised salycylaldehyde with a diamine followed by complexation with FeCl2 and anion methathesis with NaClO4. The complex shows spin crossover both in the solid state and solution. However in solution self-assembly and consequently aggregation of individual molecules form concentration dependent particles with sizes of 300 nm for higher concentrations, or 5 nm for lower concentrations. Aggregate formation was confirmed by NANO-flex 180° DLS Size, scan-rate dependent cyclic voltammetry and scanning electron microscopy. Molecular simulations were used to investigate the self-assembly of the complex in solution, including the role of residual water molecules. The simulations showed the self-assembly of reverse micelle-like structures when a small water cluster is inserted in solution, whereas no large aggregates formed in dehydrated environments. The perchlorate anions were found near the metal centres, stabilizing the aggregates around the water pool. Simulations of pre-assembled structures further showed the lack of stability of large aggregates in the absence of water. The larger aggregates promoted efficient communication between the iron(iii) centres and the compound displayed spin crossover in solution at around 220 K with a 10 K hysteresis window, as measured by NMR and SQUID magnetometry.
Collapse
Affiliation(s)
- Ana I Vicente
- Centro de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa Campo Grande, 1749-016 Lisboa, Portugal.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Shen FX, Pi Q, Shi L, Shao D, Li HQ, Sun YC, Wang XY. Spin crossover in hydrogen-bonded frameworks of FeII complexes with organodisulfonate anions. Dalton Trans 2019; 48:8815-8825. [DOI: 10.1039/c9dt01326a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Four spin crossover FeII complexes of hydrogen-bonded frameworks were constructed from the charge-assisted hydrogen bonds between the FeII complexes and organodisulfonate anions.
Collapse
Affiliation(s)
- Fu-Xing Shen
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Qian Pi
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Le Shi
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Dong Shao
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Hong-Qing Li
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Yu-Chen Sun
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| | - Xin-Yi Wang
- State Key Laboratory of Coordination Chemistry
- Collaborative Innovation Center of Advanced Microstructures
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing
| |
Collapse
|
11
|
Yang FL, Chen X, Wu WH, Zhang JH, Zhao XM, Shi YH, Shen F. Spin switching in tris(8-aminoquinoline)iron(ii)(BPh 4) 2: quantitative guest-losing dependent spin crossover properties and single-crystal-to-single-crystal transformation. Dalton Trans 2018; 48:231-241. [PMID: 30516211 DOI: 10.1039/c8dt03584a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As a derivative of 2-picolylamine, which contains rich protons favouring hydrogen bond formation to assemble a variety of valuable spin crossover (SCO) compounds, 8-aminoquinoline (aqin) will be a good candidate for constructing new mononuclear bistable state compounds. With the guidance of this view, two solvated compounds [Fe(aqin)3](BPh4)2·2(CH3CN) (1·2CH3CN) and [Fe(aqin)3](BPh4)2·1.5(CH3COCH3) (2·1.5CH3COCH3) were synthesized. The structural characterization and magnetic studies demonstrate that this strategy has been successful. Single-crystal diffraction reveals that both the mononuclear compounds have facial (fac-)-configuration cations, which form hydrogen bonds using -NH2 groups with solvent molecules (acetonitrile or acetone). Subsequent magnetic measurement shows the highly sensitive solvent-dependent occurrence of a spin transition above room temperature for both compounds. Interestingly, for compound 1·2CH3CN, in the successively repeated heating and cooling process, by monitoring the loss of solvent molecules by TGA, the shifting of the spin transition curve is found to be linearly dependent on the fraction of the residual solvent content. Additionally, the desolvated sample can re-solvate with CH3CN and recover the magnetic response reproducibly. Furthermore, after losing the acetonitrile molecules, the single-crystal-to-single-crystal transformation occurred to give 1.
Collapse
Affiliation(s)
- Feng-Lei Yang
- School of Chemistry and Material Science and Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China.
| | | | | | | | | | | | | |
Collapse
|
12
|
|
13
|
Lathion T, Guénée L, Besnard C, Bousseksou A, Piguet C. Deciphering the Influence of Meridional versus Facial Isomers in Spin Crossover Complexes. Chemistry 2018; 24:16873-16888. [PMID: 30171722 DOI: 10.1002/chem.201804161] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Indexed: 11/08/2022]
Abstract
Chelate coordination of non-symmetrical didentate pyrazine-benzimidazole (L1) or pyridine-benzimidazole (L2) N-donor ligands around divalent iron in acetonitrile produces stable homoleptic triple-helical spin crossover [Fe(Lk)3 ]2+ complexes existing as mixtures of meridional (C1 -symmetry) and facial (C3 -symmetry) isomers in slow exchange on the NMR timescale. The speciation deviates from the expected statistical ratio mer/fac=3:1, a trend assigned to the thermodynamic trans-influence, combined with solvation effects. Consequently, the observed spin state FeII low-spin ↔FeII high-spin equilibria occurring in [Fe(Lk)3 ]2+ refer to mixtures of complexes in solution, an issue usually not considered in this field, but which limits rational structure-properties correlations. Taking advantage of the selective and quantitative formation of isostructural facial isomers in non-constrained related spin crossover d-f helicates (HHH)-[LnFe(Lk)3 ]5+ (Ln is a trivalent lanthanide, Lk=L5, L6), we propose a novel strategy for assigning pertinent thermodynamic driving forces to each spin crossover triple-helical isomer. The different enthalpic contributions to the spin state equilibrium found in mer-[Fe(Lk)3 ]2+ and fac-[Fe(Lk)3 ]2+ reflect the Fe-N bond strengths dictated by the trans-influence, whereas a concomitant solvent-based entropic contribution reinforces the latter effect and results in systematic shifts of the spin crossover transitions toward higher temperature in the facial isomers.
Collapse
Affiliation(s)
- Timothée Lathion
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, 1211, Geneva 4, Switzerland
| | - Laure Guénée
- Laboratory of Crystallography, University of Geneva, 24 quai E. Ansermet, 1211, Geneva 4, Switzerland
| | - Céline Besnard
- Laboratory of Crystallography, University of Geneva, 24 quai E. Ansermet, 1211, Geneva 4, Switzerland
| | - Azzedine Bousseksou
- Laboratory of Coordination Chemistry (LCC), CNRS & Université de Toulouse (UPS, INP), 205 route de Narbonne, Toulouse, 31077 Cedex 4, France
| | - Claude Piguet
- Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, 1211, Geneva 4, Switzerland
| |
Collapse
|
14
|
Tuning the Spin States of Two Apical Iron(II) Ions in a Pentanuclear Iron(II) Cluster Helicate through the Choice of Anions. CRYSTALS 2018. [DOI: 10.3390/cryst8030119] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Spin-crossover clusters with iron(II) high nuclearity are rare. By using 3,5-bis(pyridin-2-yl)-1,2,4-triazole (bptH) as the ligand with two bidentate chelating sites, we successfully obtained three pentanuclear iron(II) cluster helicate compounds [{FeII(μ-bpt)3}2FeII3(μ3-O)][FeII2(μ-Br)(μ-bpt)(NCS)4(H2O)]·2H2O·C2H5OH (1), [{FeII(μ-bpt)3}2FeII3(μ3-O)][FeII2(μ-bpt)2(NCS)4] (2), and [{FeII(μ-bpt)3}2FeII3(μ3-O)]I2·2C2H5OH (3). Research on single-crystal structure and magnetism has indicated that tuning the spin state of two iron(II) ions in axial direction is successfully realized by regulating the different counter anions: one apical [FeII(bpt)3]− unit exhibits spin-crossover behavior while the other [FeII(bpt)3]− unit remains in low spin state in 1, both apical ions are of high spin states in 2, and are of low spin states in 3.
Collapse
|
15
|
Cook BJ, Chen CH, Pink M, Caulton KG. Dehydrohalogenation of proton responsive complexes: versatile aggregation via pyrazolate pincer ligand arms. Dalton Trans 2018; 47:2052-2060. [DOI: 10.1039/c7dt04253a] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The behavior of the complex (H2L)CoCl2, where H2L is a bis-(pyrazol-3-yl)pyridine, towards Brønsted bases is studied, to evaluate peripheral NH deprotonation as a route to a dianionic pincer ligand on a d7 center.
Collapse
Affiliation(s)
- Brian J. Cook
- Department of Chemistry
- Indiana University
- Bloomington
- USA
| | - Chun-Hsing Chen
- Department of Chemistry
- Indiana University
- Bloomington
- USA
- Indiana University Molecular Structure Center
| | - Maren Pink
- Department of Chemistry
- Indiana University
- Bloomington
- USA
- Indiana University Molecular Structure Center
| | | |
Collapse
|
16
|
Oxo- and hydroxo-bridged diiron(III) porphyrin dimers: Inorganic and bio-inorganic perspectives and effects of intermacrocyclic interactions. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2017.02.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
|
17
|
Recent advances in guest effects on spin-crossover behavior in Hofmann-type metal-organic frameworks. Coord Chem Rev 2017. [DOI: 10.1016/j.ccr.2016.12.002] [Citation(s) in RCA: 250] [Impact Index Per Article: 35.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
|
18
|
Luo YH, Wen GJ, Gu LS, Wang MN, Sun BW. Study of spin crossover in an iron(II) tris(diimine) system tuned by counter anions. Polyhedron 2017. [DOI: 10.1016/j.poly.2016.09.059] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
19
|
Khan FST, Guchhait T, Sasmal S, Rath SP. Hydroxo-bridged diiron(iii) and dimanganese(iii) bisporphyrins: modulation of metal spins by counter anions. Dalton Trans 2017; 46:1012-1037. [DOI: 10.1039/c6dt03829h] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
A brief account has been presented on how the inter-heme interactions in μ-hydroxo diiron(iii) bisporphyrins and counter anions can induce significant change in the structure and properties including the iron spin state without affecting the overall topology.
Collapse
Affiliation(s)
| | - Tapas Guchhait
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
| | - Sujit Sasmal
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
| | - Sankar Prasad Rath
- Department of Chemistry
- Indian Institute of Technology Kanpur
- Kanpur-208016
- India
| |
Collapse
|
20
|
Khan FST, Pandey AK, Rath SP. Remarkable Anion-Dependent Spin-State Switching in Diiron(III) μ-Hydroxo Bisporphyrins: What Role do Counterions Play? Chemistry 2016; 22:16124-16137. [PMID: 27682429 DOI: 10.1002/chem.201603163] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Indexed: 12/20/2022]
Abstract
Addition of 2,4,6-trinitrophenol (HTNP) to an ethene-bridged diiron(III) μ-oxo bisporphyrin (1) in CH2 Cl2 initially leads to the formation of diiron(III) μ-hydroxo bisporphyrin (2⋅TNP) with a phenolate counterion that, after further addition of HTNP or dissolution in a nonpolar solvent, converts to a diiron(III) complex with axial phenoxide coordination (3⋅(TNP)2 ). The progress of the reaction from μ-oxo to μ-hydroxo to axially ligated complex has been monitored in solution by using 1 H NMR spectroscopy because their signals appear in three different and distinct spectral regions. The X-ray structure of 2⋅TNP revealed that the nearly planar TNP counterion fits perfectly within the bisporphyrin cavity to form a strong hydrogen bond with the μ-hydroxo group, which thus stabilizes the two equivalent iron centers. In contrast, such counterions as I5 , I3 , BF4 , SbF6 , and PF6 are found to be tightly associated with one of the porphyrin rings and, therefore, stabilize two different spin states of iron in one molecule. A spectroscopic investigation of 2⋅TNP has revealed the presence of two equivalent iron centers with a high-spin state (S=5/2) in the solid state that converts to intermediate spin (S=3/2) in solution. An extensive computational study by using a range of DFT methods was performed on 2⋅TNP and 2+ , and clearly supports the experimentally observed spin flip triggered by hydrogen-bonding interactions. The counterion is shown to perturb the spin-state ordering through, for example, hydrogen-bonding interactions, switched positions between counterion and axial ligand, ion-pair interactions, and charge polarization. The present investigation thus provides a clear rationalization of the unusual counterion-specific spin states observed in the μ-hydroxo bisporphyrins that have so far remained the most outstanding issue.
Collapse
Affiliation(s)
| | - Anjani Kumar Pandey
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India
| | - Sankar Prasad Rath
- Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur, 208016, India.
| |
Collapse
|
21
|
Coordination and electronic characteristics of a nitrogen heterocycle pincer ligand. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.07.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
22
|
Petzold H, Djomgoue P, Hörner G, Speck JM, Rüffer T, Schaarschmidt D. (1)H NMR spectroscopic elucidation in solution of the kinetics and thermodynamics of spin crossover for an exceptionally robust Fe(2+) complex. Dalton Trans 2016; 45:13798-809. [PMID: 27506162 DOI: 10.1039/c6dt01895e] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Fe(2+) spin crossover (SCO) complexes [Fe(5/6)](2+) employing hexadentate ligands (5/6) with cis/trans-1,2-diamino cyclohexanes (4) as central building blocks were synthesised. The ligands were obtained by reductive amination of 4 with 2,2'-bipyridyl-6-carbaldehyde or 1,10-phenanthroline-2-carbaldehyde 3. The chelating effect and the rigid structure of the ligands 5/6 lead to exceptionally robust Fe(2+) and Zn(2+) complexes conserving their structure even in coordinating solvents like dmso at high temperatures. Their solution behavior was investigated using variable temperature (VT) (1)H NMR spectroscopy and VT Vis spectroscopy. SCO behavior was found for all Fe(2+) complexes in this series centred around and far above room temperature. For the first time we have demonstrated that the thermodynamics as well as kinetics for SCO can be deduced by using VT (1)H NMR spectroscopy. An alternative scheme using a linear correction term C(1) to model chemical shifts for Fe(2+) SCO complexes is presented. The rate constant for the SCO of [Fe(rac-trans-5)](2+) obtained by VT (1)H NMR was validated by Laser Flash Photolysis (LFP), with excellent agreement (1/(kHL + kLH) = 33.7/35.8 ns for NMR/LFP). The solvent dependence of the transition temperature T1/2 and the solvatochromism of complex [Fe(rac-trans-5)](2+) were ascribed to hydrogen bond formation of the secondary amine to the solvent. Enantiomerically pure complexes can be prepared starting with R,R- or S,S-1,2-diaminocyclohexane (R,R-trans-4 or S,S-trans-4). The high robustness of the complexes reduces a possible ligand scrambling and allows preparation of quasiracemic crystals of [Zn(R,R-5)][Fe(S,S-5)](ClO4)4·(CH3CN) composed of a 1 : 1 mixture of the Zn and Fe complexes with inverse chirality.
Collapse
Affiliation(s)
- Holm Petzold
- TU Chemnitz, Institut für Chemie, Anorganische Chemie, Straße der Nationen 62, 09111 Chemnitz, Germany.
| | | | | | | | | | | |
Collapse
|
23
|
Magnetic Bistability in Macrocycle‐Based Fe
II
Spin‐Crossover Complexes: Counter Ion and Solvent Effects. Eur J Inorg Chem 2016. [DOI: 10.1002/ejic.201600660] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
24
|
Luo YH, Nihei M, Wen GJ, Sun BW, Oshio H. Ambient-Temperature Spin-State Switching Achieved by Protonation of the Amino Group in [Fe(H2Bpz2)2(bipy-NH2)]. Inorg Chem 2016; 55:8147-52. [DOI: 10.1021/acs.inorgchem.6b01193] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yang-Hui. Luo
- School
of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, People’s Republic of China
| | - Masayuki Nihei
- Faculty
of Pure and Applied Science, University of Tsukuba, Tennodai
1-1-1, Tsukuba 305-8571, Japan
| | - Gao-Ju Wen
- School
of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, People’s Republic of China
| | - Bai-Wang Sun
- School
of Chemistry and Chemical Engineering, Southeast University, Nanjing, 211189, People’s Republic of China
| | - Hiroki Oshio
- Faculty
of Pure and Applied Science, University of Tsukuba, Tennodai
1-1-1, Tsukuba 305-8571, Japan
| |
Collapse
|
25
|
The Effect of Ligand Design on Metal Ion Spin State—Lessons from Spin Crossover Complexes. CRYSTALS 2016. [DOI: 10.3390/cryst6050058] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
|
26
|
|
27
|
Zhu YY, Li HQ, Ding ZY, Lü XJ, Zhao L, Meng YS, Liu T, Gao S. Spin transitions in a series of [Fe(pybox)2]2+ complexes modulated by ligand structures, counter anions, and solvents. Inorg Chem Front 2016. [DOI: 10.1039/c6qi00417b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new family of mononuclear Fe(ii) compounds is synthesized based on pybox ligands. Their spin-crossover behaviours can be effectively mediated by ligand structures, counter anions, and solvents.
Collapse
Affiliation(s)
- Yuan-Yuan Zhu
- School of Chemistry and Chemical Engineering
- Hefei University of Technology and Anhui Key Laboratory of Advanced Functional Materials and Devices
- Hefei 230009
- China
| | - Hong-Qing Li
- School of Chemistry and Chemical Engineering
- Hefei University of Technology and Anhui Key Laboratory of Advanced Functional Materials and Devices
- Hefei 230009
- China
| | - Zhong-Yu Ding
- School of Chemistry and Chemical Engineering
- Hefei University of Technology and Anhui Key Laboratory of Advanced Functional Materials and Devices
- Hefei 230009
- China
| | - Xiao-Jin Lü
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- China
| | - Liang Zhao
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- China
| | - Yin-Shan Meng
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Tao Liu
- State Key Laboratory of Fine Chemicals
- Dalian University of Technology
- Dalian 116024
- China
| | - Song Gao
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| |
Collapse
|
28
|
Zhao XH, Zhang SL, Shao D, Wang XY. Spin Crossover in [Fe(2-Picolylamine)3]2+ Adjusted by Organosulfonate Anions. Inorg Chem 2015. [DOI: 10.1021/acs.inorgchem.5b00870] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Xin-Hua Zhao
- State Key Laboratory of Coordination Chemistry, Collaborative
Innovation Center of Advanced Microstructures, School of Chemistry
and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Shao-Liang Zhang
- State Key Laboratory of Coordination Chemistry, Collaborative
Innovation Center of Advanced Microstructures, School of Chemistry
and Chemical Engineering, Nanjing University, Nanjing 210093, China
| | - Dong Shao
- State Key Laboratory of Coordination Chemistry, Collaborative
Innovation Center of Advanced Microstructures, School of Chemistry
and Chemical Engineering, Nanjing University, Nanjing 210093, 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 210093, China
| |
Collapse
|
29
|
Spin state behavior of iron(II)/dipyrazolylpyridine complexes. New insights from crystallographic and solution measurements. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.08.006] [Citation(s) in RCA: 152] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
30
|
Tian L, Pang CY, Zhang FL, Qin LF, Gu ZG, Li Z. Toward chiral iron(II) spin-crossover grafted resins with imidazole Schiff-base ligands. INORG CHEM COMMUN 2015. [DOI: 10.1016/j.inoche.2015.01.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
31
|
Zhou J, Zhu BW, Luan J, Liu Z, Fang JK, Bao X, Peng G, Tucek J, Bao SS, Zheng LM. In air a spin crossover active iron(ii) complex of amine/NCBH3− ligands is converted to a low spin complex of imine/CN− ligands. Dalton Trans 2015; 44:20551-61. [DOI: 10.1039/c5dt03464g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A spin crossover FeII complex is in situ converted to a low spin complex in the presence of air, induced by the oxidative dehydrogenation of the tetradentate ligand and the generation of CN− from NCBH3−.
Collapse
Affiliation(s)
- Jian Zhou
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Bo-Wen Zhu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Jie Luan
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Zhan Liu
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Jing-Kun Fang
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Xin Bao
- School of Chemical Engineering
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
- State Key Laboratory of Coordination Chemistry
| | - Guo Peng
- Herbert Gleiter Institute of Nanoscience
- Nanjing University of Science and Technology
- 210094 Nanjing
- P. R. China
| | - Jiri Tucek
- Regional Centre of Advanced Technologies and Materials
- Department of Experimental Physics
- Faculty of Science
- Palacky University
- 78371 Olomouc
| | - Song-Song Bao
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Li-Min Zheng
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| |
Collapse
|
32
|
Luo YH, Yang LJ, Liu QL, Ling Y, Wang W, Sun BW. Lattice water molecules tuned spin-crossover for an iron(ii) complex with thermal hysteresis. Dalton Trans 2014; 43:16937-42. [DOI: 10.1039/c4dt02587c] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
33
|
Craig GA, Roubeau O, Aromí G. Spin state switching in 2,6-bis(pyrazol-3-yl)pyridine (3-bpp) based Fe(II) complexes. Coord Chem Rev 2014. [DOI: 10.1016/j.ccr.2014.02.002] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
34
|
Barrett SA, Halcrow MA. Anion-dependent spin crossover in solution for an iron(ii) complex of a 1H-pyrazolyl ligand. RSC Adv 2014. [DOI: 10.1039/c4ra00230j] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
|
35
|
Schulte KA, Fiedler SR, Shores MP. Solvent Dependent Spin-State Behaviour via Hydrogen Bonding in Neutral FeII Diimine Complexes. Aust J Chem 2014. [DOI: 10.1071/ch14145] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We report the syntheses, structures, and magnetic properties of cis-[Fe(pizR)2(NCS)2] complexes based on the pyridyl imidazoline ligands 2-(2′-pyridinyl)-4,5-dihydroimidazole (pizH, 1) and 2-(2′-pyridinyl)-4,5-dihydro-1-methylimidazole (pizMe, 2). The ligands, complexes, and magnetic measurements are chosen to separate hydrogen-bonding and intrinsic ligand field properties, so as to improve our understanding of the effect of hydrogen-bonding interactions on spin-state switching. In the solid state, both complexes are high spin between 5 and 300 K. In deuterated methanol and acetonitrile solutions, both complexes show gradual thermal spin crossover. Complex 1, capable of hydrogen bonding, shows solvent-sensitive spin crossover, whereas spin crossover in the methylated analogue 2 is insensitive to solvent identity.
Collapse
|
36
|
McDaniel AM, Klug CM, Shores MP. Synthesis of Functionalized Hexadentate Iminopyridine FeIIComplexes - Toward Anion-Dependent Spin Switching in Polar Media. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201086] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
37
|
Wei RJ, Tao J, Huang RB, Zheng LS. Anion-Dependent Spin Crossover and Coordination Assembly Based on [Fe(tpa)]2+[tpa = tris(2-pyridylmethyl)amine] and [N(CN)2]-: Square, Zigzag, Dimeric, and [4+1]-Cocrystallized Complexes. Eur J Inorg Chem 2012. [DOI: 10.1002/ejic.201200541] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
38
|
Martinho PN, Ortin Y, Gildea B, Gandolfi C, McKerr G, O'Hagan B, Albrecht M, Morgan GG. Inducing hysteretic spin crossover in solution. Dalton Trans 2012; 41:7461-3. [DOI: 10.1039/c2dt12036d] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
39
|
Klug CM, McDaniel AM, Fiedler SR, Schulte KA, Newell BS, Shores MP. Anion dependence in the spin-crossover properties of a Fe(ii) podand complex. Dalton Trans 2012; 41:12577-85. [DOI: 10.1039/c2dt31213a] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
40
|
Li B, Zhang J, Yong X, Li W, Zheng Y. The low spin Co(II) fragment with homoleptic 1,10-phenanthroline ligands: synthesis, structures, DFT investigations, and magnetic properties. Dalton Trans 2011; 40:4459-64. [PMID: 21416105 DOI: 10.1039/c0dt01640c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two complexes {[Co(II)(phen)(3)][Co(III)(phen)(CN)(4)](2)}·phen·11H(2)O (1) and [Co(II)(μ-CN)(2)(Co(III))(2)(phen)(4)(CN)(6)]·C(2)H(5)OH·2H(2)O (2) were synthesized with identical starting materials but with a different order of addition. Their crystal structures, spectroscopic analysis, DFT calculations, and investigations of their magnetic properties are reported herein. The X-ray diffraction studies reveal that complex 1 mainly consists of discrete [Co(II)(phen)(3)](2+) cations and [Co(III)(phen)(CN)(4)](-) anions, while complex 2 is dominantly comprised of discrete neutral V-shaped trinuclear units [Co(II)(μ-CN)(2)(Co(III))(2)(phen)(4)(CN)(6)]. The first low-spin Co(II) fragment with homoleptic 1,10-phenanthroline ligands in 1 is observed at room temperature, owing to charge transfer from the neighboring anion via adventitious contacts and anion-π interactions. This is verified by structures, detailed theoretical analyses concerning frontier molecular orbital energy differences and Mulliken charge variations of the N atoms within the Co(II)N(6) sphere, and magnetism. Meanwhile, these kinds of supramolecular interactions are not found in complex 2, so it shows the ordinary magnetic behavior of the high-spin Co(II) ion. Our investigations highlight that for quantitative comprehension of spin-state energetic ordering in transition metal complexes, the supramolecular interactions must be taken into account in addition to classical ligand field theory. Moreover, we find that the [Co(II)(phen)(3)](2+) dication is sensitive to its surroundings in the solid state, which is beneficial for magnetic adjustment for the further synthesis of tunable molecular magnets and spin crossover systems.
Collapse
Affiliation(s)
- Bo Li
- Faculty of Chemistry, Northeast Normal University, Changchun, 130024, China
| | | | | | | | | |
Collapse
|
41
|
Halcrow MA. Structure:function relationships in molecular spin-crossover complexes. Chem Soc Rev 2011; 40:4119-42. [PMID: 21483934 DOI: 10.1039/c1cs15046d] [Citation(s) in RCA: 668] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin-crossover compounds are becoming increasingly popular for device and sensor applications, and in soft materials, that make use of their switchable colour, paramagnetism and conductivity. The de novo design of new solid spin-crossover compounds with pre-defined switching properties is desirable for application purposes. This challenging problem of crystal engineering requires an understanding of how the temperature and cooperativity of a spin-transition are influenced by the structure of the bulk material. Towards that end, this critical review presents a survey of molecular spin-crossover compounds with good availability of crystallographic data. A picture is emerging that changes in molecular shape between the high- and low-spin states, and the ability of a lattice to accommodate such changes, can play an important role in determining the existence and the cooperativity of a thermal spin-transition in the solid state (198 references).
Collapse
Affiliation(s)
- Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT. m.a.halcrow@ leeds.ac.uk
| |
Collapse
|
42
|
Ni Z, Fiedler SR, Shores MP. Investigation of anion-dependence in the spin-state switching properties of [(H2bip)2Fe(6-Mebpy)]X2. Dalton Trans 2011; 40:944-50. [DOI: 10.1039/c0dt01079k] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|