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Zhou X, Qin H, Zeng Z, Luo S, Yang T, Cen P, Liu X. Modulation of the magnetic properties of mononuclear Dy(III) complexes by tuning the coordination geometry and local symmetry. Dalton Trans 2024; 53:16219-16228. [PMID: 39298127 DOI: 10.1039/d4dt02135e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/09/2024]
Abstract
Precise control of the crystal field and local symmetry around the paramagnetic spin center is crucial for the design and synthesis of single-molecule magnets (SMMs). Herein, three mononuclear Dy(III)-based complexes, [Dy(LN6)(CH3COO)2](BPh4)(CH2Cl2) (1), [Dy(LN6)(2,6-Cl-4-NO2-PhO)(H2O)2]2(PF6)2(H2O)(2,6-Cl-4-NO2-PhO)2 (2) and [Dy(LN6)(2,6-Cl-4-NO2-PhO)2](BPh4)(CH2Cl2)2 (3) (LN6 = N6-hexagonal plane accomplished by a neutral Schiff base ligand formed from 2,6-diacetylpyridine and ethylenediamine), are successfully isolated. In these complexes, the Dy(III) centers are coordinated with six neutral N atoms from a nonrigid equatorial ligand, while different oxygen-bearing ligands are arranged at the axial positions of the central ions by gradual regularization of the axial ligands. As a result, Dy(III) ions in the three complexes exhibit various coordination geometries, forming a ten-coordinate tetradecahedron for 1, a nine-coordinate muffin configuration for 2 and a distorted eight-coordinate hexagonal bipyramid for 3. Magnetic studies reveal that all complexes exhibit no SIM behaviour under zero dc field, due to the predominant quantum tunneling of magnetization (QTM), which can be effectively suppressed by additional dc fields. Experiments, coupled with theoretical calculations, demonstrate that varying local symmetries and coordination geometries are synergistically responsible for the disparities of QTM and uniaxial anisotropy, resulting in notably different magnetic properties.
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Affiliation(s)
- Xuejuan Zhou
- College of Public Health, Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, Yinchuan 750004, China.
| | - Huiliang Qin
- College of Public Health, Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, Yinchuan 750004, China.
| | - Zhaopeng Zeng
- State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China.
| | - Shuchang Luo
- College of Chemical Engineering, Guizhou University of Engineering Science, Bijie 551700, China.
| | - Tao Yang
- Ningxia People's Hospital, Yinchuan 753009, China
| | - Peipei Cen
- College of Public Health, Key Laboratory of Environmental Factors and Chronic Disease Control, Ningxia Medical University, Yinchuan 750004, China.
| | - Xiangyu Liu
- State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, School of Civil and Hydraulic Engineering, Ningxia University, Yinchuan 750021, China.
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2
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Wang Y, Zeng Z, Luo S, Guo Y, Liu X. Enhancing the single-molecule magnetic performance of β-diketonate Dy(III) complexes by modulating the coordination microenvironment and magnetic interaction: from a mononuclear to a dinuclear structure. Dalton Trans 2024. [PMID: 39370881 DOI: 10.1039/d4dt02179g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/08/2024]
Abstract
Based on a β-diketonate ligand, a mononuclear Dy(III) complex, [Dy(dmpd)3(bpy)] (1) (dmpd = 4,4-dimethyl-1-phenylpentane-1,3-dione, bpy = 2,2'-dipyridyl), of [DyN2O6] type has been synthesized with a capping nitrogen-containing coligand. Then, a dual capping coligand 2,2'-bipyrimidine (bmp) is introduced to be a bridge to link two β-diketonate-Dy(III) motifs, leading to a new dinuclear Dy(III) complex, [Dy2(dmpd)6(bmp)] (2). Dy(III) centers in both complexes feature an N2O6 octacoordinated environment with an approximate square-antiprism geometry (D4d). Without a dc field, the SMM behaviour is absent in complex 1, but can be clearly observed in dinuclear 2 with a Ueff of 87.29 K. The significantly improved magnetism arising in 2 is mainly due to the modulation of the coordination environment around the Dy(III) ions and the superexchange magnetic interactions inside the dinuclear units, thus allowing for the effective inhibition of the quantum tunneling of magnetization at low temperatures and promotion of the uniaxial magnetic anisotropy. For 1, a diamagnetic Y(III) analogue [Y(dmpd)3(bpy)] (3) and diluted sample 1@Y were constructed to further perform the dilution experiment, coupled with theoretical calculations further supporting that the synergetic contributions of intermolecular dipole-dipole interactions, intramolecular coupling and uniaxial magnetic anisotropy cause the enhancement of dynamic magnetic relaxation.
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Affiliation(s)
- Yafu Wang
- State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
| | - Zhaopeng Zeng
- State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China.
- Xinhua College of Ningxia University, Yinchuan 750021, China
| | - Shuchang Luo
- College of Chemical Engineering, Guizhou University of Engineering Science, Bijie 551700, China.
| | - Yan Guo
- State Key Laboratory of High-Efficiency Utilization of Coal and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, 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.
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3
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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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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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Chen QW, Ding YS, Zhu XF, Wang BW, Zheng Z. Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands. Inorg Chem 2024; 63:9511-9519. [PMID: 38135507 DOI: 10.1021/acs.inorgchem.3c03369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)2]n (Er1) and [Na(DME)3][Er(COT1,3-TMS2)2] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)3][Er(COT1,4-TMS2)2] (A) and [K(DME)2][Er(COT1,4-TMS2)2] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.
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Affiliation(s)
- Qi-Wei Chen
- School of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, China
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - You-Song Ding
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Key University Laboratory of Rare Earth Chemistry of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Xiao-Fei Zhu
- School of Chemistry and Life Science, Changchun University of Technology, Changchun 130012, China
| | - Bing-Wu Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Zhiping Zheng
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
- Key University Laboratory of Rare Earth Chemistry of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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6
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Yang QQ, Wang YF, Wang YX, Tang MJ, Yin B. Ab initio prediction of key parameters and magneto-structural correlation of tetracoordinated lanthanide single-ion magnets. Phys Chem Chem Phys 2023. [PMID: 37401358 DOI: 10.1039/d3cp01766d] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Single-molecule magnets (SMMs) have great potential in becoming revolutionary materials for micro-electronic devices. As one type of SMM and holding the performance record, lanthanide single-ion magnets (Ln-SIMs) stand at the forefront of the family. Lowering the coordination number (CN) is an important strategy to improve the performance of Ln-SIMs. Here, we report a theoretical study on a typical group of low-CN Ln-SIMs, i.e., tetracoordinated structures. Our results are consistent with those of experiments and they identify the same three best Ln-SIMs via a concise criterion, i.e., the co-existence of long τQTM and high Ueff. Compared to the record-holding dysprosocenium systems, the best SIMs here possess τQTM values that are shorter by several orders of magnitude and Ueff values that are lower by ∼1000 Kelvin (K). These are important reasons for the fact that the tetracoordinated Ln-SIMs are clearly inferior to dysprosocenium. A simple but intuitive crystal-field analysis leads to several routes to improve the performance of a given Ln-SIM, including compression of the axial bond length, widening the axial bond angle, elongation of the equatorial bond length and usage of weaker equatorial donor ligands. Although these routes are not brand-new, the most efficient option and the degree of improvement resulting from it are not known in advance. Consequently, a theoretical magneto-structural study, covering various routes, is carried out for the best Ln-SIM here and the most efficient route is shown to be widening the axial ∠O-Dy-O angle. The most optimistic case, having a ∠O-Dy-O of 180°, could have a τQTM (up to 103 s) and Ueff (∼2400 K) close to those of the record-holders. Subsequently, a blocking temperature (TB) of 64 K is predicted to be possible for it. A more practical case, with ∠O-Dy-O being 160°, could have a τQTM of up to 400 s, Ueff of around 2200 K and the possibility of a TB of 57 K. Although having an inherent precision limit, these predictions provide a guide to performance improvement, starting from an existing system.
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Affiliation(s)
- Qi-Qi Yang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism (LTMM), College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
| | - Yu-Fei Wang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism (LTMM), 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 (LTMM), College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
| | - Ming-Jing Tang
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, Lab of Theoretical Molecular Magnetism (LTMM), 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 (LTMM), College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
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Tang J, Zhang S, Li L, Yao L, Zhang R, Yin B, Zhang J. Influence of ligand substitution and the solvent effect on the structures and magnetic properties of dinuclear Dy 2 supramolecular architectures constructed with the bis-β-diketonate-Dy 2 building block as a metalloligand. Dalton Trans 2023; 52:1366-1377. [PMID: 36633156 DOI: 10.1039/d2dt03468a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Based on the bis-β-diketonate-Dy2 metalloligand [Dy2(pbth)4]·2Et3N (1, pbth = (3z,3'z)-4,4'-(1,3-phenylene)bis(1,1,1-trifluoro-4-hydroxybut-3-en-2-one)), six dinuclear complexes with eight-coordinated geometries were synthesized solvothermally through different capping N-donor coligands or solvent systems. These complexes are namely [Dy2(pbth)3(Phen)2]·2C2H5OH (2), [Dy2(pbth)3(BPhen)2]·2C2H5OH (3), [Dy2(pbth)3(Dppz)2]·2C2H5OH (4), [Dy2(pbth)3(Dppz)2]·2CH3OH (4a), [Dy2(pbth)3(4-Dmbp)2]·CH3OH·C2H5OH (5) and [Dy2(pbth)3(5-Dmbp)2]·CH3OH (6) (Phen = 1,10-phenanthroline, BPhen = 4,7-diphenyl-1,10-phenanthroline, dppz = dipyrido [3,2-a:2',3'-c] phenazine, 4-Dmbp = 4,4'-dimethyl-2,2'-bipyridyl, 5-Dmbp = 5,5'-dimethyl-2,2'-bipyridyl), respectively. In the synthetic processes of 2-6, one of four bis-β-diketonate ligands in the metalloligand is replaced by two capping N-donor coligands. The coordination geometries, metal distances and M-L-M torsion angles of the synthesized complexes are perceptibly fine-tuned by the modification of the capping N-donor coligands or the latticed solvent molecules. Systematic magnetic investigations indicate the different magnetic relaxation dynamics of 1-6. Complex 1 displays no characteristics of single-molecule magnets (SMMs), while complexes 2-6 exhibit SMM behaviours in the absence of a static magnetic field. Complexes 2 and 3 possess effective energy barriers (Ueff) of 110.18 (2) K and 133.21 (4) K, respectively. Theoretical analysis based on ab initio calculation provides some interpretations of experimental observation.
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Affiliation(s)
- Jiamin Tang
- School of Science, Hainan University, Haikou 570228, China.
| | - Sheng Zhang
- School of Science, Hainan University, Haikou 570228, China.
| | - Linzhou Li
- School of Science, Hainan University, Haikou 570228, China.
| | - Linbin Yao
- School of Science, Hainan University, Haikou 570228, China.
| | - Ronghu Zhang
- Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University, Haikou 570228, China. .,Institute of Processing&Design of Agroproducts, Hainan Academy of Agricultural Science, Haikou 571100, China
| | - Bing Yin
- Lab of Theoretical Molecular Magnetism (LTMM), College of Chemistry and Materials Science, Northwest University, Xi'an, 710127, P. R. China.
| | - Jiangwei Zhang
- Science Center of Energy Material and Chemistry, College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021, P. R. China.
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Dergachev VD, Nakritskaia DD, Varganov SA. Strong Relativistic Effects in Lanthanide-Based Single-Molecule Magnets. J Phys Chem Lett 2022; 13:6749-6754. [PMID: 35852301 DOI: 10.1021/acs.jpclett.2c01627] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Lanthanide-based single-molecule magnets (SMMs) are promising building blocks for quantum memory and spintronic devices. Designing lanthanide-based SMMs with long spin relaxation time requires a detailed understanding of their electronic structure, including the crucial role of the spin-orbit coupling (SOC). While traditional calculations of SOC using the perturbation theory applied to a solution of the nonrelativistic Schrödinger equation are valid for light atoms, this approach is questionable for systems containing heavy elements such as lanthanides. We investigate the accuracy of the perturbation estimates of SOC by variationally solving the Dirac equation for the [DyO]+ molecule, a prototype of a lanthanide-based SMM. We show that the energy splittings between the M J states involved in spin relaxation depend on the interplay between strong SOC and dynamic electron correlation. We demonstrate that this interplay affects the resonances between the spin and vibrational transitions and, therefore, the spin relaxation time.
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Affiliation(s)
- Vsevolod D Dergachev
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0216, United States
| | - Daria D Nakritskaia
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0216, United States
| | - Sergey A Varganov
- Department of Chemistry, University of Nevada, Reno, 1664 N. Virginia Street, Reno, Nevada 89557-0216, United States
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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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10
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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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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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12
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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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13
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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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14
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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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15
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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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16
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Qu YX, Ruan ZY, Huang GZ, Chen YC, Liu Y, Jia JH, Liu JL, Tong ML. Sensitive magnetic-field-response magnetization dynamics in a one-dimensional dysprosium coordination polymer. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00873k] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A Dy(iii) coordination polymer shows significant single-molecule magnet behavior with a sensitive low-field response.
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Affiliation(s)
- Yun-Xia Qu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Ze-Yu Ruan
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Guo-Zhang Huang
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Yan-Cong Chen
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Yang Liu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Jian-Hua Jia
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Jun-Liang Liu
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
| | - Ming-Liang Tong
- Key Laboratory of Bioinorganic and Synthetic Chemistry of Ministry of Education, School of Chemistry, Sun Yat-Sen University, 510006 Guangzhou, Guangdong, P. R. China
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17
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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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18
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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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