1
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Peng XH, Shang T, Zheng J, Liu M, Zheng Q, Guo FS. Enhancing the magnetic properties of Dy(III) single-molecule magnets in octahedral coordination symmetry by tuning the equatorial ligands. Dalton Trans 2024. [PMID: 39344482 DOI: 10.1039/d4dt02482f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Conventionally, octahedral (Oh) coordination symmetry of lanthanide centers is not ideal for constructing high-performance single-molecule magnets (SMMs). However, introducing a strong ligand field in the axial direction to increase crystal field splitting can potentially overcome this limitation. Herein, we successfully obtained two dysprosium(III) single-molecule magnets, [Dy(OCtBu3)X2(py)3] (X = Cl (1), I (2), py = pyridine), in Oh coordination symmetry. The two complexes differ only in the coordinating anions on the equatorial plane, yet their magnetic performances are distinctly different. When chloride is replaced by a weaker donor iodide, the energy barrier is dramatically improved from 29 cm-1 (1) to 860 cm-1 (2), highlighting the importance of weakening the transverse ligand field and maximizing the axial ligand field for high-performance SMMs.
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Affiliation(s)
- Xiao-Han Peng
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
| | - Tao Shang
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
| | - Jieyu Zheng
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK
| | - Ming Liu
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
| | - Qi Zheng
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
| | - Fu-Sheng Guo
- Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Xiyuan Avenue 2006, Chengdu 611731, China.
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2
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Kumari K, Singh SK. Substituted fullerenes as a promising capping ligand towards stabilization of exohedral Dy(III) based single-ion magnets: a theoretical study. Dalton Trans 2024. [PMID: 39228355 DOI: 10.1039/d4dt02090a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Organometallic dysprosocenium-based molecular magnets are the forefront runners in offering giant magnetic anisotropy and blocking temperatures close to the boiling point of liquid nitrogen. Attaining linearity in the organometallic dysprosocenium complexes is the key to generating giant magnetic anisotropy and blocking barriers. In the present study, we have unravelled the coordination ability of the substituted fullerene (C55X5)- (where X = CCH3, B, and N) generated by fencing around the five-membered ring of fullerene towards stabilizing a new family of exohedral dysprosium organometallic complexes showcasing giant magnetic anisotropy and blockade barriers. Eight exohedral mononuclear dysprosium organometallic complexes, namely [Dy(η5-C55X5)(η4-C4H4)] (1), [Dy(η5-C55X5)(η5-Cp)]+ (2), [Dy(η5-C55X5)(η5-Cp*)]+ (3), [Dy(η5-C55X5)(η6-C6H6)]2+ (4), [Dy(η5-C55X5)(η8-C8H8)] (5), [Dy(η5-C55X5)2]+ (6) (where X = CCH3), [Dy(η5-C55B5)2]+ (7) and [Dy(η5-C55N5)2]+ (8), were studied using scalar relativistic density functional theory (SR-DFT) and the complete active space self-consistent field (CASSCF) methodology to shed light on the structure, stability, bonding and single-ion magnetic properties. SR-DFT calculations predict complexes 1-8 to be highly stable, with a strictly linear geometry around the Dy(III) ion in complexes 6-8. Energy Decomposition Analysis (EDA) predicts the following order for interaction energy (ΔEint value): 5 > 1 > 2 ≈ 3 > 6 > 7 > 8 > 4, with sizable 4f-ligand covalency in all the complexes. CASSCF calculations on complexes 1-8 predict stabilization of mJ |±15/2〉 as the ground state for all the complexes except for 5, with the following trend in the Ucal values: 6 (1573 cm-1) ≈ 3 (1569 cm-1) > 1 (1538 cm-1) > 8 (1347 cm-1) > 2 (1305 cm-1) > 7 (1284 cm-1) > 4 (1125 cm-1) > 5 (108 cm-1). Ab initio ligand field theory (AILFT) analysis provides a rationale for Ucal ordering, where π-type 4f-ligand interactions in complexes 1-4 and 6-8 offer giant barrier height while the large (C8H8)2- rings generate δ-type interaction in 5, which diminishes the axiality in the ligand field. Our detailed finding suggests that the exohedral organometallic dysprosocenium complexes are more linear compared to bent [DyCp*2]+ cations and display a giant barrier height exceeding 1500 cm-1 with negligible quantum tunnelling of magnetization (QTM) - a new approach to design highly anisotropic dysprosium organometallic complexes.
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Affiliation(s)
- Kusum Kumari
- Computational Inorganic Chemistry Group, Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana-502284, India.
| | - Saurabh Kumar Singh
- Computational Inorganic Chemistry Group, Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana-502284, India.
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3
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Nandy R, Jagličić Z, Jana NC, Brandão P, Bustamante F, Aravena D, Panja A. The effect of co-ligands on the performance of single-molecule magnet behaviours in a family of linear trinuclear Zn-Dy-Zn complexes with a compartmental Schiff base. Dalton Trans 2024; 53:13968-13981. [PMID: 39101745 DOI: 10.1039/d4dt01582g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
We present herein magneto-structural studies of three heterometallic Zn2Dy complexes: [Zn2Dy(L)2Cl2(H2O)](ClO4)·4H2O (1), [Zn2Dy(L)2Br2(H2O)](ClO4)·4H2O (2) and [Zn2Dy(L)2(OAc)I(H2O)]I3·4H2O (3), utilizing a new Schiff base ligand, N,N'-bis(3-methoxy-5-methylsalicylidene)-1,2-diaminocyclohexane (H2L). Complexes 1 and 2 exhibit remarkable magnetic relaxation behaviour with relatively high energy barriers in zero field (Ueff: 244 K for 1 and 211 K for 2) and notable hysteresis temperatures, despite the low local geometric symmetry around the central DyIII ions. The SMM performance of these complexes is further enhanced under an applied magnetic field, with Ueff increasing to 309 K for 1 and 269 K for 2, positioning them as elite members within the Zn-Dy SMM family. These findings emphasize the substantial influence of remote modulation on ZnII beyond the first coordination sphere of DyIII ions on their dynamic magnetic relaxation properties. Ab initio studies demonstrate that the relative orientation of the phenoxo-oxygen donor atoms around the DyIII ion is critical for determining the magnetic anisotropy and relaxation dynamics in these systems. Additionally, experimental and theoretical investigations reveal that the coordination of the bridging acetate towards the hard plane, combined with significant distortion from the ideal ZnO2Dy diamond core arrangement caused by the acetate ion, results in low magnetic anisotropy in complex 3, thereby leading to field-induced SMM behaviour. Overall, this study unveils the effects of co-ligands on the SMM performance in a series of linear trinuclear Zn-Dy-Zn complexes, which exhibit low local geometric symmetry around the DyIII centres.
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Affiliation(s)
- Rakhi Nandy
- Department of Chemistry, Gokhale Memorial Girls' College, 1/1 Harish Mukherjee Road, Kolkata-700020, India.
| | - Zvonko Jagličić
- Institute of Mathematics, Physics and Mechanics & Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
| | - Narayan Ch Jana
- Department of Chemistry, Panskura Banamali College, Panskura RS, WB 721152, India
| | - Paula Brandão
- Department of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Fabián Bustamante
- Department of Materials Chemistry, Faculty of Chemistry and Biology, University of Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile
| | - Daniel Aravena
- Department of Materials Chemistry, Faculty of Chemistry and Biology, University of Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile
| | - Anangamohan Panja
- Department of Chemistry, Gokhale Memorial Girls' College, 1/1 Harish Mukherjee Road, Kolkata-700020, India.
- Department of Chemistry, Panskura Banamali College, Panskura RS, WB 721152, India
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Deng W, Wu SG, Ruan ZY, Gong YP, Du SN, Wang HL, Chen YC, Zhang WX, Liu JL, Tong ML. Spin-State Control in Dysprosium(III) Metallacrown Magnets via Thioacetal Modification. Angew Chem Int Ed Engl 2024; 63:e202404271. [PMID: 38700507 DOI: 10.1002/anie.202404271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Indexed: 06/19/2024]
Abstract
Integrating controllable spin states into single-molecule magnets (SMMs) enables precise manipulation of magnetic interactions at a molecular level, but remains a synthetic challenge. Herein, we developed a 3d-4f metallacrown (MC) magnet [DyNi5(quinha)5(Clsal)2(py)8](ClO4) ⋅ 4H2O (H2quinha=quinaldichydroxamic acid, HClsal=5-chlorosalicylaldehyde) wherein a square planar NiII is stabilized by chemical stacking. Thioacetal modification was employed via post-synthetic ligand substitutions and yielded [DyNi5(quinha)5(Clsaldt)2(py)8](ClO4) ⋅ 3H2O (HClsaldt=4-chloro-2-(1,3-dithiolan-2-yl)phenol). Thanks to the additional ligations of thioacetal onto the NiII site, coordination-induced spin state switching (CISSS) took place with spin state altering from low-spin S=0 to high-spin S=1. The synergy of CISSS effect and magnetic interactions results in distinct energy splitting and magnetic dynamics. Magnetic studies indicate prominent enhancement of reversal barrier from 57 cm-1 to 423 cm-1, along with hysteresis opening and an over 200-fold increment in coercive field at 2 K. Ab initio calculations provide deeper insights into the exchange models and rationalize the relaxation/tunnelling pathways. These results demonstrate here provide a fire-new perspective in modulating the magnetization relaxation via the incorporation of controllable spin states and magnetic interactions facilitated by the CISSS approach.
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Affiliation(s)
- Wei Deng
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Si-Guo Wu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Ze-Yu Ruan
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Ya-Ping Gong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Shan-Nan Du
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Hai-Ling Wang
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Yan-Cong Chen
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Wei-Xiong Zhang
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Jun-Liang Liu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, IGCME, GBRCE for Functional Molecular Engineering, Sun Yat-Sen University, Guangzhou, 510006, P. R. China
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5
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Moorthy S, Tarannum I, Kumari K, Singh SK. A highly anisotropic family of hexagonal bipyramidal Dy(III) unsaturated 18-crown-6 complexes exceeding the blockade barrier over 2700 K: a computational exploration. Dalton Trans 2024; 53:12073-12079. [PMID: 38787652 DOI: 10.1039/d4dt00632a] [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
In the present work, we have explored a series of unsaturated hexa-18-crown-6 (U18C6) ligands towards designing highly anisotropic Dy(III) based single-ion magnets (SIMs) with the general formula [Dy(U18C6)X2]+ (where U18C6 = [C12H12O6] (1), [C12H12S6] (2), [C12H12Se6] (3), [C12H12O4S2] (4), [C12H12O4Se2] (5) and X = F, Cl, Br, I, OtBu and OSiPh3). By analysing the electronic structure, bonding and magnetic properties, we find that the U18C6 ligands prefer stabilising the highly symmetric eight-coordinated hexagonal bipyramidal geometry (HBPY-8), which is the source of the near-Ising type anisotropy in all the [Dy(U18C6)X2]+ complexes. Moreover, the ability of sulfur/selenium substituted U18C6 ligands to stabilize the highly anisotropic HBPY-8 geometry makes them more promising towards engineering the equatorial ligand field compared to substituted saturated 18C6 ligands where the exodentate arrangement of the S lone pairs results in low symmetry. Magnetic relaxation analysis predicts a record barrier height over 2700 K for [Dy(C12H12O6)F2]+ and [Dy(C12H12S6)X2]+ (where X = F, OtBu and OSiPh3) complexes, nearly 23% higher than those of the top performing Dy(III) based SIMs in the literature.
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Affiliation(s)
- Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy, Telangana, 502284, India.
| | - Ibtesham Tarannum
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy, Telangana, 502284, India.
| | - Kusum Kumari
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy, Telangana, 502284, India.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology, Hyderabad, Kandi, Sangareddy, Telangana, 502284, India.
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6
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Wang YF, Wang YX, Yang QQ, Yin B. Auxiliary Rather Than Dominant. The Role of Direct Dy-S Coordination in Single-Molecule Magnet Unveiled via ab initio Study. J Phys Chem A 2024; 128:5285-5297. [PMID: 38950340 DOI: 10.1021/acs.jpca.4c02003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/03/2024]
Abstract
The role of Dy-S coordination in a single-molecule magnet (SMM) is investigated via an ab initio study in a group of mononuclear structures. The SMM performance of this group is well interpreted via a concise criterion consisting of long quantum tunneling of magnetization (QTM) time τQTM and high effective barrier for magnetic reversal Ueff. The best SMMs in the selected group, i.e., 1Dy (CCDC refcode: PUKFAF) and 2Dy (CCDC refcode: NIKSEJ), are just those holding the longest τQTM and the highest Ueff simultaneously. Further analysis based on the crystal field model and ab initio magneto-structural exploration indicates that the influence of Dy-S coordination on the SMM performance of 1Dy is weaker than that of axial Dy-O coordination. Thus, Dy-S coordination is more likely to play an auxiliary role rather than a dominant one. However, if placed at the suitable equatorial position, Dy-S coordination could provide important support for good SMM performance. Consequently, starting from 1Dy, we built two new structures where Dy-S coordination only exists at the equatorial position and two axial positions are occupied by strong Dy-O/Dy-F coordination. Compared to 1Dy and 2Dy, these new ones are predicted to have significantly longer τQTM and higher Ueff, as well as a nearly doubled blocking temperature TB. Thus, they are probable candidates of SMM having clearly improved performance.
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Affiliation(s)
- Yu-Fei Wang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an 710127 P. R. China
| | - Yu-Xi Wang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an 710127 P. R. China
| | - Qi-Qi Yang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an 710127 P. R. China
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an 710127 P. R. China
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7
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Wang JL, Chen JT, Yan H, Wang TT, Zhang YQ, Sun WB. Constructing high axiality mononuclear dysprosium molecular magnets via a regulation-of-co-ligands strategy. Dalton Trans 2024; 53:10982-10990. [PMID: 38874222 DOI: 10.1039/d4dt00040d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Two lanthanide complexes with formulae [DyIII(LN5)(pentafluoro-PhO)3] (1) and [DyIII(LN5)(2,6-difluoro-PhO)2](BPh4) (2) (LN5 = 2,14-dimethyl-3,6,10,13,19-pentaazabicyclo[13.3.1]nonadecal (19),2,13,15,17-pentaene) were structurally and magnetically characterized. DyIII ions lie in the cavity of a five coordinate nitrogen macrocycle, and in combination with the introduction of multi-fluorinated monodentate phenoxyl coligands a high axiality coordination symmetry is built. Using the pentafluorophenol co-ligand, complex 1 with a D2d coordination environment, is obtained and displays moderate single-molecule magnets (SMMs) behavior. When difluorophenol co-ligands were used, a higher local axisymmetric pentagonal bipyramidal coordination geometry was observed in complex 2, which displays apparent slow magnetic relaxation behavior with a hysteresis temperature of up to 5 K. Further magnetic studies of diluted samples combined with ab initio calculations indicate that the high axiality plays a crucial role in suppressing quantum tunneling of magnetization (QTM) and consequently results in good slow magnetic relaxation behavior. Different fluoro-substituted phenoxyl co-ligands have phenoloxy oxygen atoms with different electrostatic potentials as well as a different number of phenoloxy coligands along the magnetic axis, resulting in different ligand field strengths and coordination symmetries.
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Affiliation(s)
- Jia-Ling Wang
- Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
| | - Ji-Tun Chen
- Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
| | - Han Yan
- Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
| | - Tian-Tian Wang
- Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China.
| | - Wen-Bin Sun
- Key Laboratory of Functional Inorganic Material Chemistry Ministry of Education, School of Chemistry and Material Science Heilongjiang University, 74 Xuefu Road, Harbin 150080, P. R. China.
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Pointillart F, Le Guennic B, Cador O. Pressure-Induced Structural, Optical and Magnetic Modifications in Lanthanide Single-Molecule Magnets. Chemistry 2024; 30:e202400610. [PMID: 38511968 DOI: 10.1002/chem.202400610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/20/2024] [Accepted: 03/21/2024] [Indexed: 03/22/2024]
Abstract
Lanthanide Single-Molecule Magnets are fascinating objects that break magnetic performance records with observable magnetic bistability at the boiling temperature of liquid nitrogen, paving the way for potential applications in high-density data storage. The switching of lanthanide SMM has been successfully achieved using several external stimuli such as redox reaction, pH titration, light irradiation or solvation/desolvation thanks to the high sensitivity of the magnetic anisotropy to any structural change in the lanthanide surrounding. Nevertheless, the use of applied high pressure as an external stimulus is largely underused, especially considering that it can be combined with high pressure X-ray diffraction to establish a complementary structure-property relationship. This Concept article summarizes the few relevant examples of investigations of lanthanide SMMs under applied high pressure, provides conclusions on the effect of such stimulus on molecular structures and magnetic anisotropy, and finally draws perspective on the future development of magnetic measurements under applied pressure.
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Affiliation(s)
- Fabrice Pointillart
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000, Rennes, France
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000, Rennes, France
| | - Olivier Cador
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, 35000, Rennes, France
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Liu CM, Hao X, Zhu DM, Zhang YQ. Effect of coordinated anions on ferromagnetically coupled Dy 2 zero-field single-molecule magnets. Dalton Trans 2024; 53:6120-6127. [PMID: 38482711 DOI: 10.1039/d4dt00293h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
A new hydrazone Schiff base ligand was condensed from 2-hydroxy-3-methoxybenzaldehyde and pyrimidine-4-carbohydrazide {H2L = (E)-N'-(2-hydroxy-3-methoxybenzylidene)pyrimidine-4-carbohydrazide}, which was used to assemble two new Dy2 complexes Dy2L2(DMF)2(NO3)2 (1) and Dy2L2(DMF)2(AcO)2 (2). Notably, the coordinated anions have a subtle effect on the coordination configurations of the Dy3+ ions and the magnetic properties of the two Dy2 complexes. The Dy3+ ions in 1 and 2 have the same N2O5 coordination environment but show the triangular dodecahedron and the biaugmented trigonal prism coordination configurations, respectively. Magnetic measurements revealed that both 1 and 2 have intramolecular ferromagnetic interactions between the Dy3+ ions and show single-molecule magnet behaviors at 0 Oe, with Ueff/k values of 58.2 K for 1 and 59.9 K for 2. These magnetic properties may be explained by theoretical calculations.
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Affiliation(s)
- Cai-Ming Liu
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Xiang Hao
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory for Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
| | - Dong-Mei Zhu
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China.
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, China.
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Takiguchi Y, Nakane D, Akitsu T. The prediction of single-molecule magnet properties via deep learning. IUCRJ 2024; 11:182-189. [PMID: 38299376 PMCID: PMC10916298 DOI: 10.1107/s2052252524000770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 01/22/2024] [Indexed: 02/02/2024]
Abstract
This paper uses deep learning to present a proof-of-concept for data-driven chemistry in single-molecule magnets (SMMs). Previous discussions within SMM research have proposed links between molecular structures (crystal structures) and single-molecule magnetic properties; however, these have only interpreted the results. Therefore, this study introduces a data-driven approach to predict the properties of SMM structures using deep learning. The deep-learning model learns the structural features of the SMM molecules by extracting the single-molecule magnetic properties from the 3D coordinates presented in this paper. The model accurately determined whether a molecule was a single-molecule magnet, with an accuracy rate of approximately 70% in predicting the SMM properties. The deep-learning model found SMMs from 20 000 metal complexes extracted from the Cambridge Structural Database. Using deep-learning models for predicting SMM properties and guiding the design of novel molecules is promising.
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Affiliation(s)
- Yuji Takiguchi
- Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 1628601, Japan
| | - Daisuke Nakane
- Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 1628601, Japan
| | - Takashiro Akitsu
- Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 1628601, Japan
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11
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Gil Y, Aravena D. Understanding Single-Molecule Magnet properties of lanthanide complexes from 4f orbital splitting. Dalton Trans 2024; 53:2207-2217. [PMID: 38193335 DOI: 10.1039/d3dt04179d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
We present an approach for connecting the magnetic anisotropy of lanthanide mononuclear complexes with their f-orbital splitting for both idealized and real coordination environments. Our proposal is straightforward to apply and provides sensible estimations of the energy spacing of the ground multiplet for axial magnetic systems. This energy splitting controls Single-Molecule Magnet properties of lanthanide complexes, determining key parameters such as the demagnetization energy barrier (Ueff). Importantly, this approach is consistent with the current paradigm of oblate and prolate preferences for the distribution of the f-electron density, but delivers a finer description for ions belonging to the same group (e.g. the oblates TbIII and DyIII). The model provides simple explanations for some general trends observed experimentally (e.g. the low barriers for ErIII complexes in comparison to DyIII or the large barriers observed for cyclopentadienyl DyIII complexes in comparison with other ligands based on organometallic rings), contributing as a valuable tool to expand our description of ligand field effects in lanthanide-based SMMs.
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Affiliation(s)
- Yolimar Gil
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile
| | - Daniel Aravena
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile.
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12
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Gil Y, de Santana RC, Vega A, Aravena D, Spodine E. Influence of symmetry on the magneto-optical properties of a bifunctional macrocyclic Dy III complex. Dalton Trans 2023. [PMID: 38014706 DOI: 10.1039/d3dt03042c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
In this work, a novel complex, [Dy(LPr)(NO3)2]·(H2O)·(NO3) (1), containing a highly distorted macrocyclic ligand (LPr) and weak axial anions (NO3-), was synthesized and characterized. Even though this coordination environment is not ideal for maximizing the magnetic anisotropy of a DyIII ion, a magneto-structural analysis reveals that the high distortion of the macrocycle promotes a disposition of the hard plane and easy axis opposite to the expected one. This results in a quite symmetrical environment which allows obtaining a field induced SMM behaviour. The magnetic relaxation properties of this complex were rationalized with the aid of ab initio multireference calculations. Moreover, 1 showed the characteristic emission bands of DyIII ion, indicating that the macrocyclic ligand acts as an efficient sensitizer in the energy transfer process to the emissive state of the DyIII ion. Due to the symmetric environment of 1, the Y/B intensity ratio (0.61) results in CIE coordinates (0.278; 0.314), close to those of the white light region. To gain further insight into the mechanism leading to the luminescence properties, ab initio calculations were performed to elucidate the key factors controlling the Y/B intensity ratio in this bifunctional complex.
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Affiliation(s)
- Yolimar Gil
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Olivos 1007, 8380544, Santiago, Chile.
| | - Ricardo Costa de Santana
- Instituto de Física, Universidade Federal de Goiás, Campus Samambaia, 74690-900, Goiânia (GO), Brazil
| | - Andrés Vega
- Departamento de Ciencias Químicas, Universidad Andrés Bello, Santiago, Chile
| | - Daniel Aravena
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile.
| | - Evgenia Spodine
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Olivos 1007, 8380544, Santiago, Chile.
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13
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Tarannum I, Moorthy S, Singh SK. Understanding electrostatics and covalency effects in highly anisotropic organometallic sandwich dysprosium complexes [Dy(C mR m) 2] (where R = H, SiH 3, CH 3 and m = 4 to 9): a computational perspective. Dalton Trans 2023; 52:15576-15589. [PMID: 37786345 DOI: 10.1039/d3dt01646c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
In this article, we have thoroughly studied the electronic structure and 4f-ligand covalency of six mononuclear dysprosium organometallic sandwich complexes [Dy(CmRm)2]n+/- (where R = H, SiH3, CH3; m = 4 to 9; n = 1, 3) using both the scalar relativistic density functional and complete active space self-consistent field (CASSCF) and N-electron valence perturbation theory (NEVPT2) method to shed light on the ligand field effects in fine-tuning the magnetic anisotropy of these complexes. Energy decomposition analysis (EDA) and ab initio-based ligand field theory AILFT calculations predict the sizable 4f-ligand covalency in all these complexes. The analysis of CASSCF/NEVPT2 computed spin-Hamiltonian (SH) parameters indicates the stabilization of mJ |±15/2〉 for [Dy(C4(SiH3)4)2]- (1), [Dy(C5(CH3)5)2]+ (2) and [Dy(C6H6)2]3+ (3) complexes with the Ucal value of 1867.5, 1621.5 and 1070.8 cm-1, respectively. On the other hand, we observed mJ |±9/2〉 as the ground state for [Dy(C7H7)2]3- (4) and [Dy(C8H8)2]- (5) complexes with significantly smaller Ucal values of 237.1 and 38.6 cm-1 respectively. For the nine-membered ring [Dy(C9H9)2]+ (6) complex, we observed the stabilization of the mJ |±1/2〉 ground state, with the first excited state being located ∼29 cm-1 higher in energy. AILFT-NEVPT2 ligand field splitting analysis indicates that the presence of π-type 4f-ligand interactions in complexes 1-3 help generate the axial-ligand field, while the δ-type interactions in complexes 4-5 generate the equatorial ligand field despite the ligands approaching from the axial direction. As the ring size increases, φ-type interactions dominate, generating a pure equatorial ligand field stabilising mJ |±1/2〉 as the ground state for 6. Calculations suggest that the nature of the ligand field mainly governs the Ucal values in the following order: 4f-Lσ > 4f-Lπ > 4f-Lδ > 4f-Lφ. Calculations were performed by replacing ligands with CHELPG charges to access the crystal field (CF) effects which suggests the stabilization of pure mJ |±15/2〉 in all the charge-embedded models (1Q-6Q). Our findings point out that the crystal field and ligand field effects complement each other and generate a giant barrier for magnetic relaxation in the small ring complexes 1-3, while a relatively weak crystal field and adverse 4f-Lδ/4f-Lφ interactions diminish the SMM behaviour in the large ring complexes 4-6.
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Affiliation(s)
- Ibtesham Tarannum
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
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14
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Kotrle K, Atanasov M, Neese F, Herchel R. Theoretical Magnetic Relaxation and Spin-Phonon Coupling Study in a Series of Molecular Engineering Designed Bridged Dysprosocenium Analogues. Inorg Chem 2023; 62:17499-17509. [PMID: 37812145 PMCID: PMC10598879 DOI: 10.1021/acs.inorgchem.3c02916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Indexed: 10/10/2023]
Abstract
A detailed computational study of hypothetical sandwich dysprosium double-decker complexes, bridged by various numbers of aliphatic linkers, was performed to evaluate the effect of the structural modifications on their ground-state magnetic sublevels and assess their potential as candidates for single-molecule magnets (SMMs). The molecular structures of seven complexes were optimized using the TPSSh functional, and the electronic structure and magnetic properties were investigated using the complete active space self-consistent field method (CASSCF). Estimates of the magnetic moment blocking barrier (Ueff) and blocking temperatures (TB) are reported. In addition, a new method based on computed derivatives of effective demagnetization barriers Ueff with respect to vibrational normal modes was introduced and applied to evaluate the impact of spin-phonon coupling on the SMM properties. On the basis of the computed parameters, we have identified promising candidates with properties superior to those of the existing single-molecule magnets.
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Affiliation(s)
- Kamil Kotrle
- Department
of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc CZ-77146, Czech Republic
| | - Mihail Atanasov
- Max-Planck-Institut
für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany
- Institute
of General and Inorganic Chemistry, Bulgarian
Academy of Sciences, Sofia 1113, Bulgaria
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Mülheim an der Ruhr D-45470, Germany
| | - Radovan Herchel
- Department
of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, Olomouc CZ-77146, Czech Republic
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15
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Joshi S, Roy Chowdhury S, Mishra S. Spin-state energetics and magnetic anisotropy in penta-coordinated Fe(III) complexes with different axial and equatorial ligand environments. Phys Chem Chem Phys 2023. [PMID: 37367302 DOI: 10.1039/d3cp02182c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
The penta-coordinated trigonal-bi-pyramidal (TBP) Fe(III) complex (PMe2Ph)2FeCl3 shows a reduced magnetic anisotropy in its intermediate-spin (IS) state as compared to its methyl-analog (PMe3)2Fe(III)Cl3. In this work, the ligand environment in (PMe2Ph)2FeCl3 is systematically altered by replacing the axial -P with -N and -As, the equatorial -Cl with other halides, and the axial methyl group with an acetyl group. This has resulted in a series of Fe(III) TBP complexes modelled in their IS and high-spin (HS) states. Lighter ligands -N and -F stabilize the complex in the HS state, while the magnetically anisotropic IS state is stabilized by -P and -As at the axial site, and -Cl, -Br, and -I at the equatorial site. Larger magnetic anisotropies appear for complexes with nearly degenerate ground electronic states that are well separated from the higher excited states. This requirement, largely controlled by the d-orbital splitting pattern due to the changing ligand field, is achieved with a certain combination of axial and equatorial ligands, such as -P and -Br, -As and -Br, and -As and -I. In most cases, the acetyl group at the axial site enhances the magnetic anisotropy compared to its methyl counterpart. In contrast, the presence of -I at the equatorial site compromises the uniaxial type of anisotropy of the Fe(III) complex leading to an enhanced rate of quantum tunneling of magnetization.
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Affiliation(s)
- Shalini Joshi
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India.
| | | | - Sabyashachi Mishra
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India.
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16
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Werner I, Griebel J, Masip-Sánchez A, López X, Załęski K, Kozłowski P, Kahnt A, Boerner M, Warneke Z, Warneke J, Monakhov KY. Hybrid Molecular Magnets with Lanthanide- and Countercation-Mediated Interfacial Electron Transfer between Phthalocyanine and Polyoxovanadate. Inorg Chem 2023; 62:3761-3775. [PMID: 36534941 DOI: 10.1021/acs.inorgchem.2c03599] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A series of {V12}-nuclearity polyoxovanadate cages covalently functionalized with one or sandwiched by two phthalocyaninato (Pc) lanthanide (Ln) moieties via V-O-Ln bonds were prepared and fully characterized for paramagnetic Ln = SmIII-ErIII and diamagnetic Ln = LuIII, including YIII. The LnPc-functionalized {V12O32} cages with fully oxidized vanadium centers in the ground state were isolated as (nBu4N)3[HV12O32Cl(LnPc)] and (nBu4N)2[HV12O32Cl(LnPc)2] compounds. As corroborated by a combined experimental (EPR, DC and AC SQUID, laser photolysis transient absorption spectroscopy, and electrochemistry) and computational (DFT, MD, and model Hamiltonian approach) methods, the compounds feature intra- and intermolecular electron transfer that is responsible for a partial reduction at V(3d) centers from VV to VIV in the solid state and at high sample concentrations. The effects are generally Ln dependent and are clearly demonstrated for the (nBu4N)3[HV12O32Cl(LnPc)] representative with Ln = LuIII or DyIII. Intramolecular charge transfer takes place for Ln = LuIII and occurs from a Pc ligand via the Ln center to the {V12O32} core of the same molecule, whereas for Ln = DyIII, only intermolecular charge transfer is allowed, which is realized from Pc in one molecule to the {V12O32} core of another molecule usually via the nBu4N+ countercation. For all Ln but DyIII, two of these phenomena may be present in different proportions. Besides, it is demonstrated that (nBu4N)3[HV12O32Cl(DyPc)] is a field-induced single molecule magnet with a maximal relaxation time of the order 10-3 s. The obtained results open up the way to further exploration and fine-tuning of these three modular molecular nanocomposites regarding tailoring and control of their Ln-dependent charge-separated states (induced by intramolecular transfer) and relaxation dynamics as well as of electron hopping between molecules. This should enable us to realize ultra-sensitive polyoxometalate powered quasi-superconductors, sensors, and data storage/processing materials for quantum technologies and neuromorphic computing.
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Affiliation(s)
- Irina Werner
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany
| | - Jan Griebel
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany
| | - Albert Masip-Sánchez
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo 1, Tarragona43007, Spain
| | - Xavier López
- Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, Marcel·lí Domingo 1, Tarragona43007, Spain
| | - Karol Załęski
- NanoBioMedical Centre, Adam Mickiewicz University in Poznań, Poznań61-614, Poland
| | - Piotr Kozłowski
- Institute of Spintronics and Quantum Information, Faculty of Physics, Adam Mickiewicz University in Poznań, ul. Uniwersytetu Poznańskiego 2, Poznań61-614, Poland
| | - Axel Kahnt
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany
| | - Martin Boerner
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany.,Institute of Inorganic Chemistry, Leipzig University, Johannisallee 29, Leipzig04103, Germany
| | - Ziyan Warneke
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany.,Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Linnéstr. 2, Leipzig04103, Germany
| | - Jonas Warneke
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany.,Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry, Leipzig University, Linnéstr. 2, Leipzig04103, Germany
| | - Kirill Yu Monakhov
- Leibniz Institute of Surface Engineering (IOM), Permoserstr. 15, Leipzig04318, Germany
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17
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Mondal S, Lunghi A. Unraveling the Contributions to Spin-Lattice Relaxation in Kramers Single-Molecule Magnets. J Am Chem Soc 2022; 144:22965-22975. [PMID: 36490388 PMCID: PMC9782788 DOI: 10.1021/jacs.2c08876] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Indexed: 12/14/2022]
Abstract
The study of how spin interacts with lattice vibrations and relaxes to equilibrium provides unique insights into its chemical environment and the relation between electronic structure and molecular composition. Despite its importance for several disciplines, ranging from magnetic resonance to quantum technologies, a convincing interpretation of spin dynamics in crystals of magnetic molecules is still lacking due to the challenging experimental determination of the correct spin relaxation mechanism. We apply ab initio spin dynamics to a series of 12 coordination complexes of Co2+ and Dy3+ ions selected among ∼240 compounds that largely cover the literature on single-molecule magnets and well represent different regimes of spin relaxation. Simulations reveal that the Orbach spin relaxation rate of known compounds mostly depends on the ions' zero-field splitting and little on the details of molecular vibrations. Raman relaxation is instead found to be also significantly affected by the features of low-energy phonons. These results provide a complete understanding of the factors limiting spin lifetime in single-molecule magnets and revisit years of experimental investigations by making it possible to transparently distinguish Orbach and Raman relaxation mechanisms.
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Affiliation(s)
- Sourav Mondal
- School of Physics, AMBER
and CRANN Institute, Trinity College, Dublin2, Ireland
| | - Alessandro Lunghi
- School of Physics, AMBER
and CRANN Institute, Trinity College, Dublin2, Ireland
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18
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Wang M, Meng X, Liu N, Zhang YQ, Xu N, Shi W, Cheng P. Two monofluoride-bridged DyIII dimers with different magnetization dynamics. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.107995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Khurana R, Ali ME. Single-Molecule Magnetism in Linear Fe(I) Complexes with Aufbau and Non-Aufbau Ground States. Inorg Chem 2022; 61:15335-15345. [PMID: 36129329 DOI: 10.1021/acs.inorgchem.2c00981] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
With the ongoing efforts on synthesizing mononuclear single-ion magnets (SIMs) with promising applications in high-density data storage and spintronics devices, the linear or quasi-linear Fe(I) complexes emerge as the enticing candidates possessing large unquenched angular momentum. Herein, we have studied five experimentally synthesized linear Fe(I) complexes to uncover the origin of single-molecule magnetic behavior of these complexes. To begin with, we benchmarked the methodology on the experimentally and theoretically well-studied complex [Fe(C(SiMe3)3)2]-1 (1) (SiMe3 = trimethylsilyl), which is characterized with a large spin-reversal barrier of 226 cm-1. Subsequently, the spin-phonon coupling coefficients are calculated for the low-frequency vibrational modes to understand the relaxation mechanism of the complex. Furthermore, the two Fe(I) complexes, that is, [Fe(cyIDep)2]+1 (2) (cyIDep = 1,3-bis(2',6'-diethylphenyl)-4,5-(CH2)4-imidazole-2-ylidene) and [Fe(sIDep)2]+1 (3) (sIDep = 1,3-bis(2',6'-diethylphenyl)-imidazolin-2-ylidene), are studied that are experimentally reported with no SIM behavior under ac or dc magnetic fields; however, they exhibit large opposite axial zero field splitting (-62.4 and +34.0 cm-1, respectively) from ab initio calculations. We have unwrapped the origin of this contrasting observation between experiment and theory by probing their magnetic relaxation pathways and the pattern of d orbital splitting. Additionally, the two experimentally synthesized Fe(I) complexes, that is, [(η6-C6H6)FeAr*-3,5-Pr2i] (4) (Ar*-3,5-Pr2i = C6H-2,6-(C6H2-2,4,6-Pr3i)2-3,5-Pr2i) and [(CAAC)2Fe]+1 (5) (CAAC = cyclic (alkyl) (amino)carbene), are investigated for SIM behavior, since there is no report on their magnetic anisotropy. To this end, complex 4 presents itself as the possible candidate for SIM.
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Affiliation(s)
- Rishu Khurana
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
| | - Md Ehesan Ali
- Institute of Nano Science and Technology, Sector-81, Mohali, Punjab 140306, India
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20
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Wang M, Guo Y, Han Z, Cheng X, Zhang YQ, Shi W, Cheng P. Impact of Ligand Substituents on the Magnetization Dynamics of Mononuclear Dy III Single-Molecule Magnets. Inorg Chem 2022; 61:9785-9791. [PMID: 35700445 DOI: 10.1021/acs.inorgchem.2c01299] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two mononuclear DyIII single-molecule magnets with different ligand substituents located far from the coordinating atoms, [Dy(L-NO2)(NO3)] (1) and [Dy(L-Me)(NO3)] (2), and their diamagnetic-ion diluted analogues, 1' and 2', were structurally and magnetically characterized. 1 and 2 have nearly identical coordination environments of DyIII ions with D2d symmetry but different magnetization dynamics. No Orbach process was observed for 1 and 1' in the testing temperature and frequency range, but effective energy barriers of 575 and 829 K for 2 and 2' were obtained, respectively. The opened hysteresis loops were observed until 6 K for 1 and 10 K for 2. Ab initio calculations reveal that the energy gaps between ground and low-lying excited states of 2 are higher than those of 1 and the relaxation rate through quantum tunneling of magnetization of 2 is lower than that of 1 due to the electronic effect of the axial coordinating oxygen atoms influenced by ligand substitutions.
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Affiliation(s)
- Mengmeng Wang
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Ying Guo
- School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Zongsu Han
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Xi Cheng
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Yi-Quan Zhang
- School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Wei Shi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
| | - Peng Cheng
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry (MOE), Renewable Energy Conversion and Storage Center (RECAST), College of Chemistry, Nankai University, Tianjin 300071, China
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21
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Li XL, Wang A, Cui M, Gao C, Yu X, Su B, Zhou L, Liu CM, Xiao HP, Zhang YQ. Modulating Two Pairs of Chiral Dy III Enantiomers by Distinct β-Diketone Ligands to Show Giant Differences in Single-Ion Magnet Performance and Nonlinear Optical Response. Inorg Chem 2022; 61:9283-9294. [PMID: 35658475 DOI: 10.1021/acs.inorgchem.2c01031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Using Dy(dbm)3(H2O) and Dy(btfa)3(H2O)2 to react with enantiopure N-donors, (-)/(+)-4,5-pinenepyridyl-2-pyrazine (LR/LS), respectively, two pairs of chiral DyIII enantiomers, Dy(dbm)3LR/Dy(dbm)3LS (R-1-Dy/S-1-Dy) and Dy(btfa)3LR/Dy(btfa)3LS (R-2-Dy/S-2-Dy) were obtained, wherein one of the benzene rings of dbm- (dibenzoylmethanate) in R-1-Dy/S-1-Dy is displaced by the -CF3 group of btfa- (4,4,4-trifluoro-1-phenyl-1,3-butanedionate) in R-2-Dy/S-2-Dy. Interestingly, this substitution results not only in giant differences in their single-ion magnetic (SIM) performances but also in their completely different nonlinear optical (NLO) responses. R-1-Dy presents a large effective energy barrier (Ueff = 265.47 K) under zero applied field, being more than 4 × R-2-Dy (61.40 K). The discrepancy on their magnetic performances has been further elucidated by ab initio calculations. Meanwhile, R-1-Dy/S-1-Dy display the strongest third-harmonic generation responses (35/33 × α-SiO2) among the known lanthanide NLO-active coordination compounds (CCs). On the contrary, R-2-Dy/S-2-Dy exhibit moderate second-harmonic generation responses (0.65/0.70 × KDP). These results not only give the first example of the CCs with both SMM/SIM behavior and a THG response but also provide an efficient strategy for achieving the function regulation and switch in multifunctional CCs.
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Affiliation(s)
- Xi-Li Li
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Ailing Wang
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Minghui Cui
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Congli Gao
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Xiaojing Yu
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Bing Su
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Liming Zhou
- Henan Provincial Key Laboratory of Surface and Interface Science, Zhengzhou University of Light Industry, Zhengzhou 450002, P.R. China
| | - Cai-Ming Liu
- Beijing National Laboratory for Molecular Sciences, Institution of Chemistry, Chinese Academy of Sciences, Beijing 100190, P.R. China
| | - Hong-Ping Xiao
- School of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325027, P.R. China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P.R. China
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22
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Dey S, Rajaraman G. In silico design criteria for high blocking barrier uranium (III) SIMs. Chem Commun (Camb) 2022; 58:6817-6820. [PMID: 35615940 DOI: 10.1039/d2cc01356h] [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 combination of DFT and ab initio CASSCF/PT2 calculations on U(III) fictitious models and numerous reported X-ray structures unveils several geometries from coordination number 1 to 12 that can be targeted to design potential U(III) SIMs with attractive barrier heights. Among the geometries studied, the T-shaped and capped pentagonal antiprism geometries yield values exceeding 1500 cm-1 - a value that is elusive for any uranium SIMs.
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Affiliation(s)
- Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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23
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Liu H, Li JF, Yin B. The coexistence of long τQTM and high Ueff as a concise criterion for a good single-molecule magnet: a theoretical case study of square antiprism dysprosium single-ion magnets. Phys Chem Chem Phys 2022; 24:11729-11742. [PMID: 35506508 DOI: 10.1039/d2cp00776b] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A systematic theoretical study is performed on a group of 16 square antiprism dysprosium single-ion magnets. Based on ab initio calculations, the quantum tunneling of magnetization (QTM) time, i.e., τQTM, and effective barrier of magnetic reversal, Ueff, are theoretically predicted. The theoretical τQTM is able to identify the ones with the longest QTM time with small numerical deviations. Similar results occur with respect to Ueff too. The systems possessing the best single-molecule magnet (SMM) properties here are just the ones having both the longest τQTM and the highest Ueff, from either experiment or theory. Thus, our results suggest the coexistence of long τQTM and high Ueff to be a criterion for high-performance SMMs. Although having its own limits, this criterion is easy to be applied in a large number of systems since both τQTM and Ueff could be predicted by theory with satisfactory efficiency and reliability. Therefore, this concise criterion could provide screened candidates for high-performance SMMs quickly and, hence, ease the burden of further exploration aiming for a higher degree of precision. This screening is important since the further exploration could easily demand tens or even hundreds of ab initio calculations for a single SMM. A semi-quantitative crystal field (CF) analysis is performed and shown here to be capable of indicating the general trends in a more chemically intuitive way. This analysis could help to identify the most important coordinating atoms for both diagonal and non-diagonal CF components. Thus, it could give some direct clues for improving the SMM properties: reducing the distance of the axial atom to the central ion, rotating the axial atom closer to the easy axis or increasing the amount of its negative charge. Correspondingly, opposite operations on the equatorial atom could give the same result.
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Affiliation(s)
- Hong Liu
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
| | - Jin-Feng Li
- College of Chemistry and Chemical Engineering, Yan'an University, Yan'an, 716000, P. R. China
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
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Luo QC, Ge N, Zhai YQ, Wang T, Sun L, Sun Q, Li F, Fu Z, Zheng YZ. Switching the coordination geometry to enhance erbium(III) single-molecule magnets. CHINESE CHEM LETT 2022. [DOI: 10.1016/j.cclet.2022.05.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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25
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Mondal A, Konar S. Effect of an axial coordination environment on quantum tunnelling of magnetization for dysprosium single-ion magnets with theoretical insight. Dalton Trans 2022; 51:1464-1473. [PMID: 34988577 DOI: 10.1039/d1dt03678e] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Herein, we report two mononuclear dysprosium complexes [Dy(H4L){B(OMe)2(Ph)2}2](Cl)·MeOH (1) and [Dy(H4L){MeOH)2(NCS)2}](Cl) (2) [where H4L = 2,2'-(pyridine-2,6-diylbis(ethan-1-yl-1-ylidene))bis(N-phenylhydrazinecarboxamide)] with different axial coordination environments. The structural analysis revealed that the pentadentate H4L ligand binds through the equatorial position in both complexes. In complex 1, the axial positions are occupied by bidentate dimethoxydiphenyleborate [B(OMe)2(Ph)2]-. On the other hand, in complex 2, one axial position is occupied by two NCS- and one MeOH molecule while another MeOH molecule is coordinated to the other axial position. Magnetic measurements disclose the presence of field-induced slow relaxation of magnetization with an energy barrier of Ueff = 30 K for 1 whereas no such effective barrier was observed in complex 2. Detailed analysis of field and temperature dependence of the relaxation time confirms the major role of Raman, QTM, and direct processes rather than the Orbach process in complex 1. It was observed that [B(OMe)2(Ph)2]- provides higher axial anisotropy which slows down the QTM process (relaxation time for the QTM process is 2.70 × 10-5 s) in 1 as compared to NCS anions and MeOH molecules in 2 (1.03 × 10-8 s), and is responsible for the absence of an effective energy barrier in the latter complex as confirmed by ab initio calculations. The calculations also show that the presence of a large bidentate dimethoxydiphenyleborate ligand in axial positions may result in high-performance Dy-based single-ion magnets.
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Affiliation(s)
- Arpan Mondal
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass road, Bhauri, Bhopal-462066, MP, India.
| | - Sanjit Konar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass road, Bhauri, Bhopal-462066, MP, India.
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26
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Zhang B, Cheng Z, Wu Y, Chen L, Jing R, Cai X, Jiang C, Zhang YQ, Yuan A, Cui HH, Li ZY. Pseudo-mono-axial ligand fields that support high energy barriers in triangular dodecahedral Dy( iii) single-ion magnets. Chem Sci 2022; 13:13231-13240. [DOI: 10.1039/d2sc03182e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 10/30/2022] [Indexed: 11/05/2022] Open
Abstract
Air-stable triangular dodecahedral Dy(iii) single-ion magnets with pseudo-mono-axial linear ligand fields exhibit high energy barrier exceeding 600 K, which represent the highest energy barrier for mononuclear SMMs with triangular dodecahedron.
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Affiliation(s)
- Ben Zhang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Zhijie Cheng
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Yingying Wu
- School of Materials Science and Engineering, Nankai University, 38 Tongyan Road, Haihe Educational Park, Tianjin 300350, PR China
| | - Lei Chen
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Rong Jing
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Xingwei Cai
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Chunhui Jiang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, PR China
| | - Aihua Yuan
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, PR China
| | - Hui-Hui Cui
- School of Chemistry and Chemical Engineering, Nantong University, Jiangsu 226019, PR China
| | - Zhao-Yang Li
- School of Materials Science and Engineering, Nankai University, 38 Tongyan Road, Haihe Educational Park, Tianjin 300350, PR China
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27
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Wu X, Li J, Yin B. The interpretation and prediction of lanthanide single-ion magnet from ab initio electronic structure calculation: The capability and limit. Dalton Trans 2022; 51:14793-14816. [DOI: 10.1039/d2dt01507b] [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
Single-molecule magnet (SMM) is a fascinating system holding the potential of being revolutionary micro-electronic device in information technology. However current SMMs are still far away from real-life application due to...
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28
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Zhu Z, Tang J. Metal–metal bond in lanthanide single-molecule magnets. Chem Soc Rev 2022; 51:9469-9481. [DOI: 10.1039/d2cs00516f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review surveys recent critical advances in lanthanide SMMs, highlighting the influences of metal–metal bonds on the magnetization dynamics.
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Affiliation(s)
- Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
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29
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Xu F, Zhang J, Gu H, Ma R, Zhang S, Feng J, Yin B. Influence of synthesis conditions on the preparation of mononuclear Dy(III) compounds based on β-diketone ligands: Synthesis, structure, magnetic behavior and theoretical analysis. J SOLID STATE CHEM 2022. [DOI: 10.1016/j.jssc.2021.122686] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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30
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Ding MM, Shang T, Hu R, Zhang YQ. Understanding the Magnetic Anisotropy for Linear Sandwich [Er(COT)]+-based Compounds: A Theoretical Investigation. Dalton Trans 2022; 51:3295-3303. [DOI: 10.1039/d1dt04157f] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of linear sandwich single-ion magnets containing [Er(COT)]+ fragment were selected to probe the magneto-structural correlations using ab initio methods. For prolate shaped ErIII ion, an equatorially coordinating geometry...
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31
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Liu S, Gil Y, Zhao C, Wu J, Zhu Z, Li XL, Aravena D, Tang J. A conjugated Schiff-base macrocycle weakens the transverse crystal field of air-stable dysprosium single-molecule magnets. Inorg Chem Front 2022. [DOI: 10.1039/d2qi01565j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The dominance of a self-condensed conjugated macrocycle over a [2 + 2] conventional macrocycle in weakening the transverse crystal field and boosting axiality provides a new route to construct high-performance air-stable lanthanide SMMs.
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Affiliation(s)
- Shuting Liu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Yolimar Gil
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile
| | - Chen Zhao
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Jinjiang Wu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Xiao-Lei Li
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Daniel Aravena
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
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32
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Lu F, Guo WX, Zhang YQ. Largely Enhancing the Blocking Energy Barrier and Temperature of a Linear Cobalt(II) Complex through the Structural Distortion: A Theoretical Exploration. Inorg Chem 2021; 61:295-301. [PMID: 34923824 DOI: 10.1021/acs.inorgchem.1c02858] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Complete-active-space self-consistent field and N-electron valence second-order perturbation theory have both been employed to investigate the magnetic anisotropy of one two-coordinate cobalt(II) compound via altering the Co-C bond lengths and twist angle φ. The calculated energy barrier Ueff decreases with the decrease in the Co-C bond lengths due to the gradually increasing interaction between the 3d orbitals of CoII and the coordination ligand field and then to the decrease in the ground orbital angular moment L of CoII. Thus, we cannot improve Ueff simply by shortening the Co-C bond lengths. However, by rotating the twist angle φ from 60 to 0°, it is surprising to find that the energy barrier and blocking temperature can be enhanced up to 1559.1 cm-1 and 90 K, respectively, with φ = 0°, which are prominent even among lanthanide-based single-molecule magnets.
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Affiliation(s)
- Fang Lu
- Jiangsu Key Lab for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Wen-Xiao Guo
- Jiangsu Key Lab for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China
| | - Yi-Quan Zhang
- Jiangsu Key Lab for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing 210023, P. R. China
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33
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Spillecke L, Koo C, Maximova O, Mironov VS, Kopotkov VA, Korchagin DV, Vasiliev AN, Yagubskii EB, Klingeler R. Magnetic behavior of the novel pentagonal-bipyramidal erbium(III) complex (Et 3NH)[Er(H 2DAPS)Cl 2]: high-frequency EPR study and crystal-field analysis. Dalton Trans 2021; 50:18143-18154. [PMID: 34854436 DOI: 10.1039/d1dt03228c] [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
We report the synthesis, crystal structure and magnetic properties of the new heptacoordinated mononuclear erbium(III) complex (Et3NH)[Er(H2DAPS)Cl2] (H4DAPS = 2,6-diacetylpyridine bis-(salicylhydrazone)) (1). The coordination polyhedron around the Er(III) ion features a slightly distorted pentagonal bipyramid formed by the pentagonal N3O2 chelate ring of the H2DAPS ligand in the equatorial plane and two apical chloride ligands. Detailed high-frequency/high-field electron paramagnetic resonance (HF-EPR) studies of 1 result in the precise determination of the crystal field (CF) splitting energies (0, 290 and 460 GHz) and effective g-values of the three lowest Kramers doublets (KDs) of the Er(III) ion. The obtained HF-EPR data are in good agreement with the results from CF analysis for the Er(III) ion based on the simulation of the dc magnetic data of 1. The results from dynamic susceptibility measurements indicate that there is no slow relaxation of magnetisation behaviour. This observation is discussed in terms of the electronic structure of 1 obtained from experimental and theoretical results.
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Affiliation(s)
- Lena Spillecke
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany.
| | - Changhyun Koo
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany.
| | - Olga Maximova
- Lomonosov Moscow State University, Moscow 119991, Russia
| | - Vladimir S Mironov
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia. .,Shubnikov Institute of Crystallography of Federal Scientific Research Centre 'Crystallography and Photonics', RAS, Moscow 119333, Russia.
| | | | - Denis V Korchagin
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia.
| | - Alexander N Vasiliev
- Lomonosov Moscow State University, Moscow 119991, Russia.,National University of Science and Technology "MISiS", Moscow 119049, Russia
| | - Eduard B Yagubskii
- Institute of Problems of Chemical Physics, RAS, Chernogolovka 142432, Russia.
| | - Rüdiger Klingeler
- Kirchhoff Institute for Physics, Heidelberg University, INF 227, D-69120, Heidelberg, Germany. .,Centre for Advanced Materials (CAM), Heidelberg University, Germany
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34
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Dong Y, Zhu L, Yin B, Zhu X, Li D. Regulating the magnetic properties of seven-coordinated Dy(III) single-ion magnets through the effect of positional isomers on axial crystal-field. Dalton Trans 2021; 50:17328-17337. [PMID: 34787614 DOI: 10.1039/d1dt02925h] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Six Dy(III) single-ion magnets (SIMs) [Dy(n-OMe-bbpen)X] were synthesized by a solvothermal reaction with three positional isomers (ortho, meta, and para) of ligands n-OMe-H2bbpen and dysprosium halides DyX3, (n-OMe-H2bbpen = N,N'-bis(2-hydroxy-n-methoxybenzyl)-N,N'-bis(2-methylpyridyl)ethylenediamine; n = 3, X = Cl, 1; n = 3, X = Br, 2; n = 4, X = Cl, 3; n = 4, X = Br, 4; n = 5, X = Cl, 5; n = 5, X = Br, 6). Dynamic magnetic measurements revealed that the six complexes possess notably different effective barriers of magnetic reversal: 872.0 K (1), 1210.1 K (2), 137.9 K (3), 602.6 K (4), 907.0 K (5) and 1216.7 K (6). 6 showed the best performance as SIMs among the six Dy(III) complexes. Moreover, the magnetic hysteresis loops of 6 remained open at 21 K. The crystal structures indicate the switching of local symmetry around Dy(III) ion, aroused by the variation in intermolecular interactions and steric effects. This switch is primarily correlated with the distinction of magnetic properties. In addition, ab initio calculations confirmed that the different electrostatic potential around Dy(III) ion stemming from the electronic effect of the OMe-substituted group is another factor leading to the distinction in magnetic properties. This work warns us that when designing ligands for Dy-SIMs, the effect of positional isomerism on magnetic performance must be considered, which is one of the factors that can easily be overlooked.
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Affiliation(s)
- Yubao Dong
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
| | - Li Zhu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, Lab of Theoretical Molecular Magnetism, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China.
| | - Xinrui Zhu
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
| | - Dongfeng Li
- Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
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35
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Amoza M, Maxwell L, Aliaga‐Alcalde N, Gómez‐Coca S, Ruiz E. Spin-Phonon Coupling and Slow-Magnetic Relaxation in Pristine Ferrocenium. Chemistry 2021; 27:16440-16447. [PMID: 34582589 PMCID: PMC9298439 DOI: 10.1002/chem.202102603] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Indexed: 01/23/2023]
Abstract
We report the spin dynamic properties of non-substituted ferrocenium complexes. Ferrocenium shows a field-induced single-molecule magnet behaviour in DMF solution while cobaltocene lacks slow spin relaxation neither in powder nor in solution. Multireference quantum mechanical calculations give a non-Aufbau orbital occupation for ferrocenium with small first excitation energy that agrees with the relatively large measured magnetic anisotropy for a transition metal S=1/2 system. The analysis of the spin relaxation shows an important participation of quantum tunnelling, Raman, direct and local-mode mechanisms which depend on temperature and the external field conditions. The calculation of spin-phonon coupling constants for the vibrational modes shows that the first vibrational mode, despite having a low spin-phonon constant, is the most efficient process for the spin relaxation at low temperatures. In such conditions, vibrational modes with higher spin-phonon coupling constants are not populated. Additionally, the vibrational energy of this first mode is in excellent agreement with the experimental fitted value obtained from the local-mode mechanism.
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Affiliation(s)
- Martín Amoza
- Departament de Química Inorgànica i Orgànica andInstitut de Recerca de Química Teòrica i ComputacionalUniversitat de BarcelonaDiagonal 64508028BarcelonaSpain
| | - Lindley Maxwell
- Departament de Química Inorgànica i Orgànica andInstitut de Recerca de Química Teòrica i ComputacionalUniversitat de BarcelonaDiagonal 64508028BarcelonaSpain
- Advanced Lithium and Industrial Minerals Research CenterUniversidad de AntofagastaAv. Universidad de Antofagasta02800AntofagastaChile
| | - Núria Aliaga‐Alcalde
- ICREA, Institució Catalana de Recerca i Estudis AvançatsPasseig, Passeig Lluis Companys 2308010BarcelonaSpain
- Institut de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB08193BellaterraCataloniaSpain
| | - Silvia Gómez‐Coca
- Departament de Química Inorgànica i Orgànica andInstitut de Recerca de Química Teòrica i ComputacionalUniversitat de BarcelonaDiagonal 64508028BarcelonaSpain
| | - Eliseo Ruiz
- Departament de Química Inorgànica i Orgànica andInstitut de Recerca de Química Teòrica i ComputacionalUniversitat de BarcelonaDiagonal 64508028BarcelonaSpain
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36
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Zakrzewski J, Kumar K, Zychowicz M, Jankowski R, Wyczesany M, Sieklucka B, Ohkoshi SI, Chorazy S. Combined Experimental and Ab Initio Methods for Rationalization of Magneto-Luminescent Properties of Yb III Nanomagnets Embedded in Cyanido/Thiocyanidometallate-Based Crystals. J Phys Chem Lett 2021; 12:10558-10566. [PMID: 34694818 PMCID: PMC8573772 DOI: 10.1021/acs.jpclett.1c02942] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/19/2021] [Indexed: 06/13/2023]
Abstract
The ab initio calculations were correlated with magnetic and emission characteristics to understand the modulation of properties of NIR-emissive [YbIII(2,2'-bipyridine-1,1'-dioxide)4]3+ single-molecule magnets by cyanido/thiocyanidometallate counterions, [AgI(CN)2]- (1), [AuI(SCN)2]- (2), [CdII(CN)4]2-/[CdII2(CN)7]3- (3), and [MIII(CN)6]3- [MIII = Co (4), Ir (5), Fe (6), Cr (7)]. Theoretical studies indicate easy-axis-type ground doublets for all YbIII centers. They differ in the magnetic axiality; however, transversal g-tensor components are always large enough to explain the lack of zero-dc-field relaxation. The excited doublets lie more than 120 cm-1 above the ground one for all YbIII centers. It was confirmed by high-resolution emission spectra reproduced from the ab initio calculations that give reliable insight into energies and oscillator strengths of optical transitions. These findings indicate the dominance of Raman relaxation with the power n varying from 2.93(4) to 6.9(2) in the 4-3-5-1-2 series. This trend partially follows the magnetic axiality, being deeper correlated with the phonon modes schemes of (thio)cyanido matrices.
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Affiliation(s)
- Jakub
J. Zakrzewski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Kunal Kumar
- Department
of Chemistry, School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mikolaj Zychowicz
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Robert Jankowski
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Maciej Wyczesany
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Barbara Sieklucka
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
| | - Shin-ichi Ohkoshi
- Department
of Chemistry, School of Science, The University
of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Szymon Chorazy
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Krakow, Poland
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37
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Zhu L, Dong Y, Yin B, Ma P, Li D. Improving the single-molecule magnet properties of two pentagonal bipyramidal Dy 3+ compounds by the introduction of both electron-withdrawing and -donating groups. Dalton Trans 2021; 50:12607-12618. [PMID: 34545871 DOI: 10.1039/d1dt00964h] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Two mononuclear Dy3+ compounds [Dy(bmbpen-F)X] (X = Cl, 1; Br, 2) with a pentagonal bipyramidal (PBP) geometry were obtained from N,N'-bis-(5-methyl-2-hydroxybenzyl)-N,N'-bis(5-fluoro-2-methylpyridyl)ethylenediamine (H2bmbpen-F) and dysprosium halides. The magnetic anisotropy and single-molecule magnet (SMM) behavior of these PBP compounds were regulated by introducing both electron-withdrawing F atoms into the equatorial pyridine rings and electron-donating -CH3 groups into the axial phenolic hydroxyl rings. The results of magnetic characterization show that 1 and 2 exhibit single molecule magnet behavior with magnetization reversal barriers of 990(13) and 1189(16) K under a zero dc external field and magnetic hysteresis loops up to 26 K and 36 K, respectively. The results of ab initio calculations are consistent with the experimental observations, confirming that the simultaneous introduction of electron-withdrawing groups into the equatorial positions and electron-donating groups into the axial positions can lead to PBP Dy-SMMs with improved properties.
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Affiliation(s)
- Li Zhu
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
| | - Yubao Dong
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an 710127, P. R. China.
| | - Pengtao Ma
- Henan Key Laboratory of Polyoxometalate Chemistry, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China
| | - Dongfeng Li
- Key Laboratory of Pesticide & Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, P. R. China.
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38
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Briganti M, Totti F. Magnetic anisotropy on demand exploiting high-pressure as remote control: an ab initio proof of concept. Dalton Trans 2021; 50:10621-10628. [PMID: 34286784 DOI: 10.1039/d1dt01719e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Lanthanide based single molecule magnets have recently become very promising systems for creating single molecule devices working at high temperatures (nitrogen boiling temperature). However, the variation of the direction of the anisotropy tensor as a function of the applied pressure still represents a quite unexplored field. Application of external pressure can be a promising method toward neat control of magnetic anisotropy and relaxation processes in the bulk phase. Required criteria for being eligible for such systems are as follows: the presence of first excited energy levels with significantly different orientations of its anisotropy tensor; sufficiently low energies of such levels so that they can mix with the ground state; and the possibility of tuning their energies by small geometrical perturbations. The archetype compound {Na[DyDOTA(H2O)]·4H2O} (1) (H4DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-N,N',N'',N'''-tetraacetic acid) fulfils all such criteria. A state-of-the-art in silico proof of concept study on the possibility of controlling the orientation of the anisotropy tensor as a function of pressure in [DyDOTA(H2O)]- by inducing different apical water molecule (AWM) orientations and/or DOTA-induced crystal field is presented.
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Affiliation(s)
- Matteo Briganti
- Department of Chemistry "U. Schiff" and INSTM UdR Firenze, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
| | - Federico Totti
- Department of Chemistry "U. Schiff" and INSTM UdR Firenze, University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
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Horii Y, Damjanović M, Katoh K, Yamashita M. Structural, magnetic and theoretical analyses of anionic and cationic phthalocyaninato-terbium(III) double-decker complexes: magnetic relaxation via higher ligand-field sublevels enhanced by oxidation. Dalton Trans 2021; 50:9719-9724. [PMID: 34227629 DOI: 10.1039/d1dt00775k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Crystal structural and magnetic analyses were performed for the anionic (1-) and cationic (1+) forms of phthalocyaninato-Tb3+ double-decker single-molecule magnets (SMMs). Both charged species showed slow magnetic relaxations and magnetic hysteresis characteristics for SMMs. 1+ showed longer magnetic relaxation times (τ) and higher activation energy for spin reversal (ΔE) than 1- did. Ligand field (LF) splitting calculated using ab initio methods revealed that the experimental ΔE values in 1- and 1+ were considerably larger than the first excited LF levels but rather close to the higher excited ones, indicating the magnetic relaxation via higher excited states.
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Affiliation(s)
- Yoji Horii
- Department of Chemistry, Faculty of Science, Nara Women's University, Nara 630-8506, Japan
| | - Marko Damjanović
- Institute of Inorganic Chemistry, Heidelberg University Im Neuenheimer Feld 270, 69120 Heidelberg, Germany
| | - Keiichi Katoh
- Department of Chemistry, Graduate School of Science, Josai University, 1-1 Keyakidai, Sakado, Saitama 350-0295, Japan
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aza-Aoba Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan and School of Materials Science and Technology, Nankai University, Tianjin 300350, China
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Weng GG, Huang XD, Hu R, Bao SS, Zou Q, Wen GH, Zhang YQ, Zheng LM. Homochiral Dysprosium Phosphonate Nanowires: Morphology Control and Magnetic Dynamics. Chem Asian J 2021; 16:2648-2658. [PMID: 34288530 DOI: 10.1002/asia.202100670] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/19/2021] [Indexed: 02/03/2023]
Abstract
Controllable synthesis of uniformly distributed nanowires of coordination polymers with inherent physical functions is highly desirable but challenging. In particular, the combination of chirality and magnetism into nanowires has potential applications in multifunctional materials and spintronic devices. Herein, we report four pairs of enantiopure coordination polymers with formulae S-, R-Dy(cyampH)3 ⋅ CH3 COOH ⋅ 2H2 O (S-1, R-1), S-, R-Dy(cyampH)3 ⋅ 3H2 O (S-2, R-2), S-, R-Dy(cyampH)2 (C2 H5 COO) ⋅ 3H2 O (S-3, R-3) and S-, R-Dy(cyampH)3 ⋅ 0.5C2 H5 COOH ⋅ 2H2 O (S-4, R-4) [cyampH2 =S-, R-(1-cyclohexylethyl)aminomethylphosphonic acids], which were obtained depending on the pH of the reaction mixtures and the specific carboxylic acid used as pH regulator. Interestingly, compounds 3 were obtained as superlong nanowires, showing 1D neutral chain structure which contains both phosphonate and propionate anion ligands. While compounds 1, 2 and 4 appeared as block-like crystals, superhelices and nanorods, respectively, and exhibited similar neutral chain structures containing only phosphonate ligand. Slow magnetization relaxation characteristic of single-molecule magnet (SMM) behavior was observed for compounds S-1 and S-3. Theoretical calculations were performed to rationalize the magneto-structural relationships.
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Affiliation(s)
- Guo-Guo Weng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
| | - Xin-Da Huang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
| | - Rui Hu
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing, 210023, P. R. China
| | - Song-Song Bao
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
| | - Qian Zou
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
| | - Ge-Hua Wen
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS, School of Physical Science and Technology, Nanjing Normal University, Nanjing, 210023, P. R. China
| | - Li-Min Zheng
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, P. R. China
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Pilichos E, Font-Bardia M, Escuer A, Mayans J. Structural and magnetic studies of mononuclear lanthanide complexes derived from N-rich chiral Schiff bases. Dalton Trans 2021; 50:1746-1753. [PMID: 33459319 DOI: 10.1039/d0dt04224b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A new family of mononuclear lanthanide complexes with the formula [CeIII(L)(NO3)3(MeOH)] (1) and [LnIII(L)(NO3)3]·MeOH where Ln = Gd (2) or Dy (3) and L = N,N'-bis(pyridin-2-ylmethylene)cyclohexane-1,2-diamine has been obtained with the use of enantiomerically pure Schiff bases. Dynamic magnetic studies indicate that 1-3 present field-induced slow relaxation of the magnetization and their response has been compared with the magnetically diluted complexes 2d and 3d. Structural studies have been carried out by single crystal X-ray and powder diffraction.
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Affiliation(s)
- E Pilichos
- Departament de Química Inorgànica i Orgànica, Secció Inorgànica and Institute of Nanoscience (IN2UB) and Nanotecnology, Universitat de Barcelona, Marti i Franques 1-11, Barcelona-08028, Spain.
| | - M Font-Bardia
- Departament de Mineralogia, Cristal·lografia i Dipòsits Minerals and Unitat de Difracció de R-X, Centre Científic i Tecnològic de la Universitat de Barcelona (CCiTUB), Universitat de Barcelona, Solé i Sabarís 1-3, 08028 Barcelona, Spain
| | - A Escuer
- Departament de Química Inorgànica i Orgànica, Secció Inorgànica and Institute of Nanoscience (IN2UB) and Nanotecnology, Universitat de Barcelona, Marti i Franques 1-11, Barcelona-08028, Spain.
| | - J Mayans
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltran 2, 46980 Paterna, Valencia, Spain.
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Yin B, Luo L. The anisotropy of the internal magnetic field on the central ion is capable of imposing great impact on the quantum tunneling of magnetization of Kramers single-ion magnets. Phys Chem Chem Phys 2021; 23:3093-3105. [PMID: 33491709 DOI: 10.1039/d0cp05470d] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
In this work, a theoretical method, taking into account the anisotropy of the internal magnetic field (B[combining right harpoon above]int), is proposed to predict the rate of quantum tunneling of magnetization (QTM), i.e., τQTM-1, for Kramers single-ion magnets (SIMs). Direct comparison to both experimental and previous theoretical results of three typical Kramers SIMs indicates the necessity of the inclusion of the anisotropy of B[combining right harpoon above]int for accurate description of QTM. The predictions of the method here are consistent with the theory proposed by Prokof'ev and Stamp (PS). For Kramers SIMs of high magnetic axiality, the QTM rates, predicted by the method here, are almost linearly proportional to the results by the PS method. The dependence of τQTM-1 on various parameters is analyzed for model systems. The averaged magnitude of B[combining right harpoon above]int (Bave) and principal g value of the axial direction (gZ) are the parameters on which τQTM-1 is linearly dependent. The ones on which τQTM-1 is quadratically dependent are gXY, i.e., the principal g value of the transversal direction, and xaniso characterizing the anisotropy of B[combining right harpoon above]int. Compared to Bave and gZ, gXY and xaniso provide a higher order of dependence for QTM. Therefore regulation of the SMM property via introduction of desired values of gXY and xaniso ought to be a strategy more efficient than the one via Bave and gZ. Being different from the one via gXY, the strategy via xaniso to regulate the QTM has been rarely touched upon according to our best knowledge. However, this strategy could also lead to significant improvement since it is the same as gXY in the aspect of the dependence of τQTM-1.
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Affiliation(s)
- Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
| | - Lan Luo
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
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Zhang S, Shen N, Zhang J, Xu F, Zhang J, Tang J, Hu D, Yin B, Chen S. Solvent responses and substituent effects upon magnetic properties of mononuclear Dy III compounds. Dalton Trans 2021; 50:624-637. [PMID: 33320134 DOI: 10.1039/d0dt03477k] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Solvent responsive magnets comprise a class of molecule-based materials where lattice solvent driven structural transformation leads to the switching of magnetic properties. Herein, we present a special type of magnet where single-crystal to single-crystal (SCSC) transformations within mononuclear DyIII compounds result in the switching of DyIII single-molecule magnets (SMMs). This structural transformation involves lattice solvents which leads to significant changes in the color and magnetic properties. Additionally, the relaxation dynamics of mononuclear DyIII compounds are perceptibly fine-tuned by the modification of β-diketonate ligands. The uniaxial magnetic anisotropies, magneto-structural correlations and the relaxation mechanism were investigated by magnetic studies and ab initio calculations. These experimental and theoretical studies indicate that compound 2 exhibits the best magnetic properties in compounds 1-4. The experimental observation is supported by the theoretical prediction of QTM time (τZeeQTM) as theτZeeQTM of 2 is remarkably longer than those of the other three compounds by an order of magnitude. This means that, compared with 1, 3, and 4, the magnetic relaxation of 2 is significantly slower. Meanwhile, 2 has the largest value of axial ESP (the axial electrostatic potential), which supports the smallest gXY value in these compounds, resulting in better SMM properties. The present results offer a systematic synthesis regulation to change the magnetization dynamics and further understand magneto-structural correlations for DyIII SMMs.
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Affiliation(s)
- Sheng Zhang
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China.
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Zhang S, Tang J, Zhang J, Xu F, Chen S, Hu D, Yin B, Zhang J. In Situ Ligand Formation in the Synthetic Processes from Mononuclear Dy(III) Compounds to Binuclear Dy(III) Compounds: Synthesis, Structure, Magnetic Behavior, and Theoretical Analysis. Inorg Chem 2021; 60:816-830. [PMID: 33390004 DOI: 10.1021/acs.inorgchem.0c02863] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Guided by the self-assembled process and mechanism, the strategy of in situ Schiff base reaction would be capable of bringing a feasible method to construct and synthesize lanthanide compounds with distinct structures and magnetic properties. A mononuclear Dy(III) compound was synthesized through a multidentate Schiff base ligand and a chelating β-diketonate ligand, which was named as [Dy(L)(bppd)]·CH3OH [1; H2L = N,N'-bis(2-hydroxy-5-methyl-3-formylbenzyl)-N,N'-bis(pyridin-2-ylmethyl)ethylenediamine and bppd = 3-bis(pyridin-2-yl)propane-1,3-dione]. Furthermore, a new binuclear Dy(III) compound, [Dy2(H2Lox)(bppd)3]·8CH3OH [2; H4Lox = N,N'-bis[2-hydroxy-5-methyl-3-(hydroxyiminomethyl)benzyl]-N,N'-bis(pyridin-2-ylmethyl)ethylenediamine], was obtained via an in situ synthetic process. Under similar synthetic conditions, [Dy(L)(ctbd)] [3; ctbd = 1-(4-chlorophenyl)-4,4,4-trifluoro-1,3-butanedione] and [Dy2(H2Lox)(ctbd)3]·CH3OH·C4H10O (4) were synthesized by modifying the β-diketonate ligand and in situ Schiff base reaction. Compound 3 is a mononuclear configuration, while compound 4 exhibits a binuclear Dy(III) unit. Therein, formylbenzyl groups of H2L in 1 and 3 were changed to (hydroxyiminomethyl)benzyl groups in 2 and 4, respectively. In isomorphous 2 and 4, two Dy(III) centers are connected through two phenol O- atoms of the H2Lox2- ligand to form a binuclear structure. Eight-coordinated Dy(III) ions with different distortions can be observed in 1-4. The crystals of 1 and 3 suffered dissolution/precipitation to obtain 2 and 4, respectively. The relationship between the structure and magnetism in compounds 1-4 was discussed through the combination of structural, experimental, and theoretical investigations. Especially, the rates of quantum tunneling of magnetization of 1-4 were theoretically predicted and are consistent with the experimental results. For 2 and 4, the theoretically calculated dipolar parameters Jdip are consistent with the experimental observation of weak ferromagnetic coupling.
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Affiliation(s)
- Sheng Zhang
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China
| | - Jiamin Tang
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China
| | - Jin Zhang
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China
| | - Fang Xu
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China
| | - Sanping Chen
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, China
| | - Dengwei Hu
- Faculty of Chemistry and Chemical Engineering, Engineering Research Center of Advanced Ferroelectric Functional Materials, Key Laboratory of Phytochemistry of Shaanxi Province, Baoji University of Arts and Sciences, 1 Hi-Tech Avenue, Baoji, Shaanxi 721013, China
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry and Materials Science, Northwest University, Xi'an, Shaanxi 710127, China
| | - Jiangwei Zhang
- Dalian National Laboratory for Clean Energy and State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
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Shen N, Liang J, Qu X, Liu S, Zhu L, Zhang S, Chen L, Zhang J, Hu D, Yin B. The influence of organic bases and substituted groups on coordination structures affording two mononuclear Dy( iii) single-molecule magnets (SMMs) and a novel Dy( iii)–K( i) compound with unusually coordinated fluorine atoms. CrystEngComm 2021. [DOI: 10.1039/d1ce00431j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The different organic bases and substituted groups of auxiliary ligands play an important role in synthetic processes, finally affording distinct structures and magnetic properties.
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Affiliation(s)
- Nan Shen
- Faculty of Chemistry and Chemical Engineering
- Engineering Research Center of Advanced Ferroelectric Functional Materials
- Key Laboratory of Phytochemistry of Shaanxi Province
- Baoji University of Arts and Sciences
- Baoji
| | - Jing Liang
- Shaanxi Provincial Cancer Hospital
- Xi' an 710069
- China
| | - Xiaoni Qu
- College of Environment and Chemistry Engineering
- Xi'an Polytechnic University
- Xi'an 710048
- P. R. China
| | - Sha Liu
- Faculty of Chemistry and Chemical Engineering
- Engineering Research Center of Advanced Ferroelectric Functional Materials
- Key Laboratory of Phytochemistry of Shaanxi Province
- Baoji University of Arts and Sciences
- Baoji
| | - Lin Zhu
- Faculty of Chemistry and Chemical Engineering
- Engineering Research Center of Advanced Ferroelectric Functional Materials
- Key Laboratory of Phytochemistry of Shaanxi Province
- Baoji University of Arts and Sciences
- Baoji
| | - Sheng Zhang
- Faculty of Chemistry and Chemical Engineering
- Engineering Research Center of Advanced Ferroelectric Functional Materials
- Key Laboratory of Phytochemistry of Shaanxi Province
- Baoji University of Arts and Sciences
- Baoji
| | - Ling Chen
- Shaanxi Provincial Cancer Hospital
- Xi' an 710069
- China
| | - Jiangwei Zhang
- State Key Laboratory of Catalysis
- Dalian Institute of Chemical Physics, Chinese Academy of Sciences (CAS)
- Dalian 116023
- P. R. China
| | - Dengwei Hu
- Faculty of Chemistry and Chemical Engineering
- Engineering Research Center of Advanced Ferroelectric Functional Materials
- Key Laboratory of Phytochemistry of Shaanxi Province
- Baoji University of Arts and Sciences
- Baoji
| | - Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education
- College of Chemistry and Materials Science
- Northwest University
- Xi'an
- China
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Meng X, Wang M, Gou X, Lan W, Jia K, Wang YX, Zhang YQ, Shi W, Cheng P. Two C2v symmetry dysprosium(iii) single-molecule magnets with effective energy barriers over 600 K. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00145k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Two high-performance C2v symmetry dysprosium(iii) single-molecule magnets were synthesized. The mechanism of magnetization dynamics was studied in detail.
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Affiliation(s)
- Xixi Meng
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Mengmeng Wang
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Xiaoshuang Gou
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Wenlong Lan
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Kexin Jia
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Yu-Xia Wang
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Yi-Quan Zhang
- Jiangsu Key Lab for NSLSCS
- School of Physical Science and Technology
- Nanjing Normal University
- Nanjing 210023
- P. R. China
| | - Wei Shi
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
| | - Peng Cheng
- Department of Chemistry and Key Laboratory of Advanced Energy Materials Chemistry (MOE)
- College of Chemistry
- Nankai University
- Tianjin 300071
- China
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Wu Y, Xi J, Xiao T, Ferrando-Soria J, Ouyang Z, Wang Z, Luo S, Liu X, Pardo E. Switching of easy-axis to easy-plane anisotropy in cobalt( ii) complexes. Inorg Chem Front 2021. [DOI: 10.1039/d1qi01208h] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In situ microcalorimetry monitored assembly and coligand induced switching of the magnetic anisotropy sign have been observed in a β-diketonate-Co(ii) system.
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Affiliation(s)
- Yuewei Wu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Jing Xi
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
| | - Tongtong Xiao
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Jesús Ferrando-Soria
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMOL), Universidad de Valencia, Paterna 46980, Valencia, Spain
| | - Zhongwen Ouyang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Zhenxing Wang
- Wuhan National High Magnetic Field Center & School of Physics, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Shuchang Luo
- College of Chemical Engineering, Guizhou University of Engineering Science, Bijie 551700, China
| | - Xiangyu Liu
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China
- China State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing, 210023, China
| | - Emilio Pardo
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMOL), Universidad de Valencia, Paterna 46980, Valencia, Spain
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49
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Gil Y, Fuentealba P, Vega A, Spodine E, Aravena D. Control of magnetic anisotropy by macrocyclic ligand distortion in a family of Dy III and Er III single molecule magnets. Dalton Trans 2020; 49:17709-17718. [PMID: 33237049 DOI: 10.1039/d0dt03370g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A family of hexaazamacrocyclic lanthanide complexes, [Ln(Ln)(NCS)3] (LnIII = Dy, Er; n = 1-3) has been synthesized and characterized by single-crystal X-ray diffraction, magnetic measurements and ab initio calculations. Macrocyclic ligands (Ln) differ in the lateral spacers, which are aliphatic chains with two and three carbons (for Ln, n = 1 and 2, respectively), and an aromatic ring for Ln = 3. Modification of the macrocycle spacer tunes planarity and rigidity of the equatorial coordination for both oblate (Dy) and prolate (Er) lanthanide ions. Ac-susceptibility studies showed that four of the six complexes are field induced single molecule magnets (SMMs). Trends in magnetic relaxation properties are rationalized with the aid of ab initio multireference calculations, highlighting the combined influence of macrocycle planarity, lanthanide electronic density distribution and intermolecular interactions for the achievement of slow demagnetization.
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Affiliation(s)
- Yolimar Gil
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile.
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50
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Dey S, Rajaraman G. An approach to estimate the barrier height for magnetisation reversal in {Dy 2} SMMs using ab initio calculations. Dalton Trans 2020; 49:14781-14785. [PMID: 33079112 DOI: 10.1039/d0dt03129a] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although ab initio CASSCF calculations yield a good numerical estimate of barrier height for magnetisation reversal for mononuclear Dy(iii) SIMs, obtaining a reliable value for higher nuclearity clusters such as {Dy2} are challenging. By analysing ab initio computed data of thirty-one different {Dy2} SMMs, we propose a model equation that relates the calculated barrier heights to the experimental values and offers a viable way to predict the barrier heights in {Dy2} SMMs.
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Affiliation(s)
- Sourav Dey
- Department of Chemistry. Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
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