1
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Borah A, Dey S, Siddiqui K, Gupta SK, Rajaraman G, Murugavel R. Magnetic anisotropy in octahedral Dy(III) and Yb(III) complexes. Dalton Trans 2024; 53:7263-7267. [PMID: 38618749 DOI: 10.1039/d3dt04352e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2024]
Abstract
New organophosphate complexes [Ln(dippH)3(dippH2)3]·(H2O)6, (Ln = Dy, Yb and Y; dippH2 = 2,6-diisopropylphenyl phosphate), displaying octahedral coordination geometry around the metal ion, exhibit unusual slow relaxation of magnetisation, which is investigated through experimental studies and ab initio CASSCF calculations.
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Affiliation(s)
- Aditya Borah
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
- Department of Chemistry, Jengraimukh College, Majuli, Assam, 785105, India
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
| | - Kehkasha Siddiqui
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
| | - Sandeep K Gupta
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, Delhi, 110016, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, Maharashtra, 400076, India.
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2
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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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3
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Pramanik K, Jagličić Z, Herchel R, Brandão P, Jana NC, Panja A. Combined experimental and theoretical studies on a series of mononuclear Ln III single-molecule magnets: dramatic influence of remote substitution on the magnetic dynamics in Dy analogues. Dalton Trans 2023; 52:1241-1256. [PMID: 36606746 DOI: 10.1039/d2dt03354b] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A series of LnIII complexes of general formula [Ln(H2L1)2(NO3)2(H2O)](NO3) (1-5) [Ln = Dy (1), Tb (2) Ho (3), Er (4), and Yb (5)] and an analogous DyIII complex with ligand H2L2, [Dy(H2L2)2(NO3)3(H2O)](NO3) (6), where H2L1 and H2L2 stand for (E)-2-[(2-hydroxyphenyl)iminomethyl]-6-methoxy-4-methylphenol and (E)-2-[(2-hydroxy-5-methylphenyl)iminomethyl]-6-methoxy-4-methylphenol, respectively, have been synthesized and magneto-structurally characterized. All these complexes are isostructural and isomorphous, in which the zwitterionic form of the ligands predominantly coordinate the metal centers. The magnetic study revealed that complex 3 displays negligible SMM behaviour, while 1 and 6 are zero field SMMs, the performance of which can largely be improved in the presence of an applied dc field by lowering under barrier relaxation processes, and finally 2, 4, and 5 are field-induced SMMs. The most remarkable observation in the present study is the dramatically-enhanced SMM performance in 6 compared to 1, achieved by only a remote methyl substitution at the ligand framework to increase the intermolecular separation. Although SINGLE_ANISO ab initio calculations for 1 and 6 are very similar, the POLY_ANISO module revealed weak dipolar interactions in both the compounds but significant antiferromagnetic interaction in 1, thereby justifying the experimental fact. The present work discloses that even a small substitution such as a methyl group can adequately increase the intermolecular separation, leading to several-fold enhanced effective energy barrier.
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Affiliation(s)
- Kuheli Pramanik
- 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
| | - Zvonko Jagličić
- Institute of Mathematics, Physics and Mechanics & Faculty of Civil and Geodetic Engineering, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - Paula Brandão
- Department of Chemistry, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Narayan Ch Jana
- Department of Chemistry, Panskura Banamali College, Panskura RS, WB 721152, India
| | - 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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4
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Zhao C, Zhu Z, Wu J, Yang Q, Gebretsadik Ashebr T, Li XL, Tang J. Chiral All-Nitrogen-Coordinated Dysprosium Single-Molecule Magnets. Chemistry 2023; 29:e202202896. [PMID: 36326186 DOI: 10.1002/chem.202202896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 11/01/2022] [Accepted: 11/03/2022] [Indexed: 11/06/2022]
Abstract
Two pairs of chiral end-on azido-bridged dinuclear hexaazamacrocycles, [Dy2 (LN6 R/S )2 (N3 )2 Cl2 ](BPh4 )2 (1R/1S) and [Dy2 (LN6 R/S )2 (N3 )4 ]Cl2 (2R/2S) (LN6 R/S is hexaazamacrocyclic neutral Schiff base ligand derived from 2,6-diformylpyridine and (1R, 2R)/(1S, 2S)-diaminocyclohexane), were constructed by adjusting the molar ratio of sodium azide to Dy(III) macrocycle precursor. Structural analyses reveal that all Dy(III) centers in complexes 1R/1S and 2R/2S are nine-coordinate with hula-loop coordination geometry, and the differences between 1R/1S and 2R/2S are the terminal coordination anion and counter anion. Magnetic studies indicate that complex 2S displays typical SMM behaviors under a zero dc field, whereas 1S just shows slow relaxation of magnetization resulting from a relatively weak axial crystal field. Significantly, complex 2R/2S represents the first homochiral all-nitrogen-coordinated lanthanide single-molecule magnet.
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Affiliation(s)
- 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
| | - 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
| | - 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
| | - Qianqian Yang
- 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
| | - Tesfay Gebretsadik Ashebr
- 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.,Department of Industrial Chemistry College of Applied Sciences, Addis Ababa Science and Technology University, Addis Ababa, 16417, Ethiopia
| | - 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
| | - 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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5
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Long J, Selikhov AN, Cherkasov AV, Nelyubina YV, Salles F, Guari Y, Larionova J, Trifonov AA. Base‐Free Alkoxide Dysprosium(III) Complexes with an Unusual Tetraphenylborate Coordination: Study of the Slow Relaxation of the Magnetization. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jérôme Long
- ICGM Univ. Montpellier CNRS ENSCM Montpellier France
- Institut Universitaire de France (IUF) 1 rue Descartes 75231 Paris Cedex 05 France
| | - Alexander N. Selikhov
- Institute of Organometallic Chemistry of Russian Academy of Sciences 49 Tropinina str., GSP-445 630950 Nizhny Novgorod Russia
- Institute of Organoelement Compounds of Russian Academy of Sciences 28 Vavilova str. 119334 Moscow Russia
| | - Anton V. Cherkasov
- Institute of Organometallic Chemistry of Russian Academy of Sciences 49 Tropinina str., GSP-445 630950 Nizhny Novgorod Russia
| | - Yulia V. Nelyubina
- Institute of Organoelement Compounds of Russian Academy of Sciences 28 Vavilova str. 119334 Moscow Russia
| | | | - Yannick Guari
- ICGM Univ. Montpellier CNRS ENSCM Montpellier France
| | | | - Alexander A. Trifonov
- Institute of Organometallic Chemistry of Russian Academy of Sciences 49 Tropinina str., GSP-445 630950 Nizhny Novgorod Russia
- Institute of Organoelement Compounds of Russian Academy of Sciences 28 Vavilova str. 119334 Moscow Russia
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6
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Gil Y, Castro-Alvarez A, Fuentealba P, Spodine E, Aravena D. Lanthanide SMMs Based on Belt Macrocycles: Recent Advances and General Trends. Chemistry 2022; 28:e202200336. [PMID: 35648577 DOI: 10.1002/chem.202200336] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Indexed: 11/06/2022]
Abstract
Enhancement of axial magnetic anisotropy is the central objective to push forward the performance of Single-Molecule Magnet (SMM) complexes. In the case of mononuclear lanthanide complexes, the chemical environment around the paramagnetic ion must be tuned to place strongly interacting ligands along either the axial positions or the equatorial plane, depending on the oblate or prolate preference of the selected lanthanide. One classical strategy to achieve a precise chemical environment for a metal centre is using highly structured, chelating ligands. A natural approach for axial-equatorial control is the employment of macrocycles acting in a belt conformation, providing the equatorial coordination environment, and leaving room for axial ligands. In this review, we present a survey of SMMs based on the macrocycle belt motif. Literature systems are divided in three families (crown ether, Schiff-base and metallacrown) and their general properties in terms of structural stability and SMM performance are briefly discussed.
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Affiliation(s)
- Yolimar Gil
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile.,Centro para la Nanociencia y Nanotecnología (CEDENNA), Santiago, Estación Central, Región Metropolitana, Chile
| | - Alejandro Castro-Alvarez
- Departamento de Química de los Materiales, Facultad de Química y Biología, Universidad de Santiago de Chile, Casilla 40, Correo 33, Santiago, Chile
| | - Pablo Fuentealba
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile
| | - Evgenia Spodine
- Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Casilla 233, Santiago, Chile.,Centro para la Nanociencia y Nanotecnología (CEDENNA), Santiago, Estación Central, Región Metropolitana, 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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7
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Dey S, Rajaraman G. Deciphering the Role of Symmetry and Ligand Field in Designing Three-Coordinate Uranium and Plutonium Single-Molecule Magnets. Inorg Chem 2022; 61:1831-1842. [PMID: 35025497 DOI: 10.1021/acs.inorgchem.1c02646] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Actinide single-molecule magnets (SMMs) have gained paramount interest in molecular magnetism as they offer a larger barrier height of magnetization (Ueff) reversal compared to the lanthanide analogue, thanks to their greater metal-ligand covalency. However, the reported actinide SMMs to date yield a relatively smaller Ueff as there is no established design principle to enhance Ueff values. To address this issue, we have employed ab initio CASSCF/CASPT2/NEVPT2 calculations to study a series of three-coordinate U3+ and Pu3+ SMMs. To begin with, we have studied two experimentally characterized U3+ ion-field-induced SMMs, namely, planar [U{N(SiMe2tBu)2}3] (1) and pyramidal [U{N(SiMe3)2}3] (2) complexes reported earlier. Both the complexes were found to stabilize mJ = |±1/2⟩ as the ground state with a very strong quantum tunneling of magnetization (QTM), rendering them unsuitable for SMMs. Our calculations reveal that in the pyramidal geometry (such as in 2), the energy of the 5f26d1 state is lowered compared to the planar geometry (as in 1), resulting in a slightly better SMM characteristic in the former. To unravel the effect of symmetry in magnetic properties, ab initio calculations were performed on two reported T-shaped complexes [U(NSiiPr2)2(I)] (3) and [U(NHAriPr6)2I] (4, AriPr6 = 2,6-(2,4,6-iPr3C6H2)2C6H3). Quite interestingly, mJ = |±9/2⟩ is found to be the ground state for both the complexes with a blocking barrier exceeding 900 cm-1. Furthermore, to decipher the effect of the transuranic element in magnetic anisotropy, ab initio calculations were extended to the Pu analogue of 2, [Pu{N(SiMe3)2}3] (5), which yields a record-breaking blocking barrier of ∼1933 cm-1. Among the three-coordinate geometries studied, the pyramidal geometry was found to offer substantial magnetic anisotropy for Pu3+ ions, while a T-shaped geometry is best suited for U3+ ions. While the chosen theoretical protocols' overestimation of barrier height cannot be avoided, these values are still several orders of magnitude larger than the Ueff values reported for any actinide SMMs and unveil a design principle for superior three-coordinate actinide-based SMMs.
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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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8
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Roy S, Shukla P, Prakash Sahu P, Sun Y, Ahmed N, Chandra Sahoo S, Wang X, Kumar Singh S, Das S. Zero‐field Slow Magnetic Relaxation Behavior of Dy
2
in a Series of Dinuclear {Ln
2
} (Ln=Dy, Tb, Gd and Er) Complexes: A Combined Experimental and Theoretical Study. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202100983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Soumalya Roy
- Department of Basic Sciences, Chemistry Discipline Institute of Infrastructure Technology Research And Management Near Khokhra Circle, Maninagar East Ahmedabad 380026, Gujarat India
| | - Pooja Shukla
- Department of Basic Sciences, Chemistry Discipline Institute of Infrastructure Technology Research And Management Near Khokhra Circle, Maninagar East Ahmedabad 380026, Gujarat India
| | - Prem Prakash Sahu
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi- 502285, Sangareddy Telangana India
| | - Yu‐Chen Sun
- State Key Laboratory of Coordination Chemistry Collaborative Innovation Center of Advanced Microstructures School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Naushad Ahmed
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi- 502285, Sangareddy Telangana India
| | | | - Xin‐Yi Wang
- State Key Laboratory of Coordination Chemistry Collaborative Innovation Center of Advanced Microstructures School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Saurabh Kumar Singh
- Department of Chemistry Indian Institute of Technology Hyderabad Kandi- 502285, Sangareddy Telangana India
| | - Sourav Das
- Department of Basic Sciences, Chemistry Discipline Institute of Infrastructure Technology Research And Management Near Khokhra Circle, Maninagar East Ahmedabad 380026, Gujarat India
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9
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Yang H, Liu SS, Meng YS, Zhang YQ, Pu L, Wang X, Lin S. Four mononuclear dysprosium complexes with neutral Schiff-base ligands: syntheses, crystal structures and slow magnetic relaxation behavior. Dalton Trans 2021; 51:1415-1422. [PMID: 34951422 DOI: 10.1039/d1dt03701c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Four mononuclear 9-coordinate Dy-based complexes, [Dy(HL1)2(NO3)3(CH3OH)] (1Dy), [Dy(HL2)2(NO3)3(H2O)] (2Dy), [Dy(HL3)3(NO3)3]·CH3CN (3Dy), and [Dy(HL4)3(NO3)3] (4Dy), have been constructed by neutral Schiff-base ligands (1-[N-(4-R)aminomethylidene-2(1H)-naphthalenone, R = -Cl (HL1), -NO2 (HL2), -OCH3 (HL3), -I (HL4)). By tuning the terminal substituent group of HL ligands, the number of HL ligands coordinated to the central Dy3+ ion unexpectedly varies from 2 to 3, and the local symmetry around the Dy3+ ion reduces from D3h to Cs. Magnetic measurements reveal that 2Dy can display single-ion magnet (SIM) behavior in zero dc field, while 1Dy, 3Dy and 4Dy show field-induced slow magnetic relaxation. Ab initio calculations were employed to elucidate magnetic anisotropy in the complexes, including g-tensors, averaged transition magnetic moments and magnetic easy axes. The difference in magnetic behaviors of the four complexes can be ascribed to the terminal substituent effect of neutral Schiff-base ligands.
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Affiliation(s)
- Hui Yang
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
| | - Shan-Shan Liu
- Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction Technology, College of New Materials and Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, P. R. China.
| | - Yin-Shan Meng
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian, 2 Linggong Rd., Dalian 116024, 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
| | - Lin Pu
- Key Laboratory of Green Chemistry and Technology, Ministry of Education, College of Chemistry, Sichuan University, Chengdu 610064, P. R. China
| | - Xincheng Wang
- Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction Technology, College of New Materials and Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, P. R. China.
| | - Shijing Lin
- Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction Technology, College of New Materials and Chemical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617, P. R. China.
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10
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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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11
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Gupta SK, Dey S, Rajeshkumar T, Rajaraman G, Murugavel R. Deciphering the Role of Anions and Secondary Coordination Sphere in Tuning Anisotropy in Dy(III) Air-Stable D 5h SIMs*. Chemistry 2021; 28:e202103585. [PMID: 34788493 DOI: 10.1002/chem.202103585] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Indexed: 01/05/2023]
Abstract
Precise control of the crystal field and symmetry around the paramagnetic spin centre has recently facilitated the engineering of high-temperature single-ion magnets (SIMs), the smallest possible units for future spin-based devices. In the present work, we report a series of air-stable seven coordinate Dy(III) SIMs {[L2 Dy(H2 O)5 ][X]3 ⋅L2 ⋅n(H2 O), n = 0, X = Cl (1), n=1, X = Br (2), I (3)} possessing pseudo-D5h symmetry or pentagonal bipyramidal coordination geometry with high anisotropy energy barrier (Ueff ) and blocking temperature (TB ). While the strong axial coordination from the sterically encumbered phosphonamide, t BuPO(NHi Pr)2 (L), increases the overall anisotropy of the system, the presence of high symmetry significantly quenches quantum tunnelling of magnetization, which is the prominent deactivating factor encountered in SIMs. The energy barrier (Ueff ) and the blocking temperature (TB ) decrease in the order 3>2>1 with the change of anions from larger iodide to smaller strongly hydrogen-bonded chloride in the secondary coordination sphere, albeit the local coordination geometry and the symmetry around the Dy(III) display only slight deviations. Ab initio CASSCF/RASSI-SO/SINGLE_ANISO calculations provide deeper insights into the dynamics of magnetic relaxation in addition to the role of the secondary coordination sphere in modulating the anisotropy of the D5h systems, using diverse models. Thus, in addition to the importance of the crystal field and the symmetry to obtain high-temperature SIMs, this study also probes the significance of the secondary coordination sphere that can be tailored to accomplish novel SIMs.
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Affiliation(s)
- Sandeep K Gupta
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Thayalan Rajeshkumar
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay Powai, Mumbai, 400 076, India
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12
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Dey S, Rajaraman G. Attaining record-high magnetic exchange, magnetic anisotropy and blocking barriers in dilanthanofullerenes. Chem Sci 2021; 12:14207-14216. [PMID: 34760206 PMCID: PMC8565386 DOI: 10.1039/d1sc03925c] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 10/06/2021] [Indexed: 11/29/2022] Open
Abstract
While the blocking barrier (U eff) and blocking temperature (T B) for "Dysprocenium" SIMs have been increased beyond liquid N2 temperature, device fabrication of these molecules remains a challenge as low-coordinate Ln3+ complexes are very unstable. Encapsulating the lanthanide ion inside a cage such as a fullerene (called endohedral metallofullerene or EMF) opens up a new avenue leading to several Ln@EMF SMMs. The ab initio CASSCF calculations play a pivotal role in identifying target metal ions and suitable cages in this area. Encouraged by our earlier prediction on Ln2@C79N, which was verified by experiments, here we have undertaken a search to enhance the exchange coupling in this class of molecules beyond the highest reported value. Using DFT and ab initio calculations, we have studied a series of Gd2@C2n (30 ≤ 2n ≤ 80), where an antiferromagnetic J Gd⋯Gd of -43 cm-1 was found for a stable Gd2@C38-D 3h cage. This extremely large and exceptionally rare 4f⋯4f interaction results from a direct overlap of 4f orbitals due to the confinement effect. In larger cages such as Gd2@C60 and Gd2@C80, the formation of two centre-one-electron (2c-1e-) Gd-Gd bonds is perceived. This results in a radical formation in the fullerene cage leading to its instability. To avoid this, we have studied heterofullerenes where one of the carbon atoms is replaced by a nitrogen atom. Specifically, we have studied Ln2@C59N and Ln2@C79N, where strong delocalisation of the electron yields a mixed valence-like behaviour. This suggests a double-exchange (B) is operational, and CASSCF calculations yield a B value of 434.8 cm-1 and resultant J Gd-rad of 869.5 cm-1 for the Gd2@C59N complex. These parameters are found to be two times larger than the world-record J reported for Gd2@C79N. Further ab initio calculations reveal an unprecedented U cal of 1183 and 1501 cm-1 for Dy2@C59N and Tb2@C59N, respectively. Thus, this study offers strong exchange coupling as criteria for new generation SMMs as the existing idea of enhancing the blocking barrier via crystal field modulation has reached its saturation point.
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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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13
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Pfleger RF, Schlittenhardt S, Merkel MP, Ruben M, Fink K, Anson CE, Bendix J, Powell AK. Terminal Ligand and Packing Effects on Slow Relaxation in an Isostructural Set of [Dy(H 2 dapp)X 2 ] + Single Molecule Magnets*. Chemistry 2021; 27:15085-15094. [PMID: 34597423 PMCID: PMC8596592 DOI: 10.1002/chem.202102918] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Indexed: 11/11/2022]
Abstract
We report three structurally related single ion Dy compounds using the pentadentate ligand 2,6-bis((E)-1-(2-(pyridin-2-yl)-hydrazineylidene)ethyl)pyridine (H2 dapp) [Dy(H2 dapp)(NO3 )2 ]NO3 (1), [Dy(H2 dapp)(OAc)2 ]Cl (2) and [Dy(H2 dapp)(NO3 )2 ]Cl0.92 (NO3 )0.08 (3). The (H2 dapp) occupies a helical twisted pentagonal equatorial arrangement with two anionic ligands in the axial positions. Further influence on the electronic and magnetic structure is provided by a closely associated counterion interacting with the central N-H group of the (H2 dapp). The slow relaxation of the magnetisation shows that the anionic acetates give the greatest slowing down of the magnetisation reversal. Further influence on the relaxation properties of compounds1 and 2 is the presence of short nitrate-nitrate intermolecular ligand contact opening further lattice relaxation pathways.
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Affiliation(s)
- Rouven F. Pfleger
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstraße 1576131KarlsruheGermany
| | - Sören Schlittenhardt
- Institute of Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Marcel P. Merkel
- Institute of Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Mario Ruben
- Institute of Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS, UMR 7006)CNRS-Université de Strasbourg8 allée Gaspard Monge, BP 7002867083Strasbourg CedexFrance
| | - Karin Fink
- Institute of Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
| | - Christopher E. Anson
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstraße 1576131KarlsruheGermany
| | - Jesper Bendix
- Department of ChemistryUniversity of CopenhagenUniversitetparken 52100CopenhagenDenmark
| | - Annie K. Powell
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstraße 1576131KarlsruheGermany
- Institute of Nanotechnology (INT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
- Institute for Quantum Materials and Technologies (IQMT)Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz 176344Eggenstein-LeopoldshafenGermany
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14
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Chen H, Voigt L, Kubus M, Mihrin D, Mossin S, Larsen RW, Kegnæs S, Piligkos S, Pedersen KS. Magnetic Archimedean Tessellations in Metal-Organic Frameworks. J Am Chem Soc 2021; 143:14041-14045. [PMID: 34374526 DOI: 10.1021/jacs.1c05057] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The self-assembly of lanthanide ions with ditopic organic spacers results in the formation of complex tiling patterns that mimic the structural motifs of quasi-periodic 2D materials. The linking of trans-{LnI2}+ nodes (Ln = Gd, Dy) by both closed-shell and anion radicals of 4,4'-bipyridine affords rare examples of Archimedean tessellations in a metal-organic framework. We furthermore demonstrate the occurrence of sizable magnetic exchange interactions and slow relaxation of magnetization behavior in a complex tessellation pattern. The implementation of Archimedean tessellations in lanthanide(III) coordination solids couriers a strategy to design elusive quasi-periodic metal-organic frameworks with inimitable magnetic properties.
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Affiliation(s)
- Hua Chen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Laura Voigt
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Mariusz Kubus
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Dmytro Mihrin
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Susanne Mossin
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - René W Larsen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Søren Kegnæs
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
| | - Stergios Piligkos
- Department of Chemistry, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Kasper S Pedersen
- Department of Chemistry, Technical University of Denmark, Kemitorvet, Building 207, DK-2800 Kgs. Lyngby, Denmark
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15
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Jung J, Benner F, Herbst‐Irmer R, Demir S, Stalke D. Slow Magnetic Relaxation in Mono- and Bimetallic Lanthanide Tetraimido-Sulfate S(NtBu) 4 2- Complexes. Chemistry 2021; 27:12310-12319. [PMID: 33978251 PMCID: PMC8453918 DOI: 10.1002/chem.202101076] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Indexed: 12/16/2022]
Abstract
Lanthanide ions are particularly well-suited for the design of single-molecule magnets owing to their large unquenched orbital angular momentum and strong spin-orbit coupling that gives rise to high magnetic anisotropy. Such nanoscopic bar magnets can potentially revolutionize high-density information storage and processing technologies, if blocking temperatures can be increased substantially. Exploring non-classical ligand scaffolds with the aim to boost the barriers to spin-relaxation are prerequisite. Here, the synthesis, crystallographic and magnetic characterization of a series of each isomorphous mono- and dinuclear lanthanide (Ln=Gd, Tb, Dy, Ho, Er) complexes comprising tetraimido sulfate ligands are presented. The dinuclear Dy complex [{(thf)2 Li(NtBu)2 S(tBuN)2 DyCl2 }2 ⋅ ClLi(thf)2 ] (1c) shows true signatures of single-molecule magnet behavior in the absence of a dc field. In addition, the mononuclear Dy and Tb complexes [{(thf)2 Li(NtBu)2 S(tBuN)2 LnCl2 (thf)2 ] (2b,c) show slow magnetic relaxation under applied dc fields.
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Affiliation(s)
- Jochen Jung
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
| | - Florian Benner
- Department of ChemistryMichigan State University578 S Shaw LaneEast LansingMI 48824USA
| | - Regine Herbst‐Irmer
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
| | - Selvan Demir
- Department of ChemistryMichigan State University578 S Shaw LaneEast LansingMI 48824USA
| | - Dietmar Stalke
- Institut für Anorganische ChemieGeorg-August Universität GöttingenTammannstraße 437077GöttingenGermany
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16
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Li H, Jing P, Lu J, Xie J, Zhai L, Xi L. Dipyridyl-Decorated Nitronyl Nitroxide-Dy III Single-Molecule Magnet with a Record Energy Barrier of 146 K. Inorg Chem 2021; 60:7622-7626. [PMID: 34010554 DOI: 10.1021/acs.inorgchem.1c00809] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A nitronyl nitroxide biradical with a capping N-donor group was discovered to improve single-molecule-magnet behavior of the Dy-biradical cluster, generating a magnetic reversal barrier of 146 K. As far as we know, the effective energy barrier of the Dy compound is largest in the nitronyl nitroxide 4f system by far.
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Affiliation(s)
- Hongdao Li
- Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China.,Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Pei Jing
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Jiao Lu
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Jing Xie
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
| | - Lijun Zhai
- Department of Chemistry and Chemical Engineering, Taiyuan Institute of Technology, Taiyuan 030008, China
| | - Lu Xi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry and Tianjin Key Laboratory of Metal and Molecule-based Material Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China
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17
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Jing P, Xi L, Lu J, Han J, Huang X, Jin C, Xie J, Li L. Regulating Spin Dynamics of Nitronyl Nitroxide Biradical Lanthanide Complexes through Introducing Different Transition Metals. Chem Asian J 2021; 16:793-800. [PMID: 33590716 DOI: 10.1002/asia.202100062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/14/2021] [Indexed: 11/05/2022]
Abstract
Four biradical-Ln complexes with different transition metal ions, namely [LnM(hfac)5 (NITPh-PyPzbis)] (MII =MnII and LnIII =Gd 1, Dy 2; MII =NiII and LnIII =Tb 3, Dy 4), were prepared by the reaction of Ln(hfac)3 ⋅ 2H2 O, Mn(hfac)2 ⋅ 2H2 O or Ni(hfac)2 ⋅ 2H2 O with NITPh-PyPzbis biradical (hfac=hexafluoroacetylacetonate, NITPh-PyPzbis=5-(3-(2-pyridinyl)-1H-pyrazol-1-yl)-1,3-bis(1'-oxyl-3'-oxido- 4',4',5',5'-tetramethyl-4,5-hydro-1H-imidazol-2-yl)benzene). In complexes 1-4, the NITPh-PyPzbis biradical chelates one LnIII ion by means of its aminoxyl moieties and the transition metal ion is introduced through the two N donors from the pyridyl pyrazolyl moiety. Magnetic investigations indicate that complex 4 displays visible maxima in frequency/temperature-dependent χ'' signals with two-step relaxation processes, but complex 2 exhibits no slow magnetization relaxation. The comparison of structure parameters of both Dy complexes indicates that the symmetries of coordination spheres of two Dy ions are D2d for 2 and C2v for 4, which thus probably results in different magnetic relaxation behaviors. This work provides new insight for improving properties of Ln-biradical based SMMs.
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Affiliation(s)
- Pei Jing
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Lu Xi
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Jiao Lu
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Jing Han
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Xiaohui Huang
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Chaoyi Jin
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Junfang Xie
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
| | - Licun Li
- Department of Chemistry, Key Laboratory of Advanced Energy Materials Chemistry, College of Chemistry, Nankai University, Tianjin, 300071, P. R China
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18
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Parmar VS, Mills DP, Winpenny REP. Mononuclear Dysprosium Alkoxide and Aryloxide Single-Molecule Magnets. Chemistry 2021; 27:7625-7645. [PMID: 33555090 PMCID: PMC8252031 DOI: 10.1002/chem.202100085] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Indexed: 12/17/2022]
Abstract
Recent studies have shown that mononuclear lanthanide (Ln) complexes can be high‐performing single‐molecule magnets (SMMs). Recently, there has been an influx of mononuclear Ln alkoxide and aryloxide SMMs, which have provided the necessary geometrical control to improve SMM properties and to allow the intricate relaxation dynamics of Ln SMMs to be studied in detail. Here non‐aqueous Ln alkoxide and aryloxide chemistry applied to the synthesis of low‐coordinate mononuclear Ln SMMs are reviewed. The focus is on mononuclear DyIII alkoxide and aryloxide SMMs with coordination numbers up to eight, covering synthesis, solid‐state structures and magnetic attributes. Brief overviews are also provided of mononuclear TbIII, HoIII, ErIII and YbIII alkoxide and aryloxide SMMs.
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Affiliation(s)
- Vijay S Parmar
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - David P Mills
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Richard E P Winpenny
- Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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19
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A Local
D
4h
Symmetric Dysprosium(III) Single‐Molecule Magnet with an Energy Barrier Exceeding 2000 K**. Chemistry 2021; 27:2623-2627. [DOI: 10.1002/chem.202003931] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/23/2020] [Indexed: 11/07/2022]
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20
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Xi J, Ma X, Cen P, Wu Y, Zhang YQ, Guo Y, Yang J, Chen L, Liu X. Regulating the magnetic dynamics of mononuclear β-diketone Dy(iii) single-molecule magnets through the substitution effect on capping N-donor coligands. Dalton Trans 2021; 50:2102-2111. [DOI: 10.1039/d0dt03780j] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Substituent change modulates the coordination symmetries and magnetic dynamics of five mononuclear β-diketonate-Dy(iii) complexes with capping N-donor coligands, which is studied by the combination of magnetic investigation and ab initio calculation.
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Affiliation(s)
- 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
| | - Xiufang Ma
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
- China
| | - Peipei Cen
- College of Public Health and Management
- Ningxia Medical University
- Yinchuan 750021
- China
| | - 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
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS
- School of Physical Science and Technology
- Nanjing Normal University
- Nanjing 210023
- 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
| | - Jinhui Yang
- State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering
- College of Chemistry and Chemical Engineering
- Ningxia University
- Yinchuan 750021
- China
| | - Lei Chen
- School of Environmental and Chemical Engineering
- Jiangsu University of Science and Technology
- Zhenjiang 212003
- P. R. 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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21
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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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22
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Borah A, Dey S, Gupta SK, Walawalkar MG, Rajaraman G, Murugavel R. Enhancing the barrier height for Yb(III) single-ion magnets by modulating axial ligand fields. Chem Commun (Camb) 2020; 56:11879-11882. [PMID: 33021294 DOI: 10.1039/d0cc01370f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The effect of systematic modification of the axial ligand field X on Ueff values in Yb(iii)-based SIMs, [Yb(Ph3PO)4X2]X' (X, X' = NO3 (1), OTf (2) and X = I/Br/Cl; X' = I3 (3)), whose equatorial Ph3PO ligation remains unchanged, has been investigated. Combined magnetic studies coupled with ab initio calculations reveal weakening of the axial ligand fields leading to the increase in the energy barrier, apart from suggesting the operation of different relaxation pathways.
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Affiliation(s)
- Aditya Borah
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | - Sandeep K Gupta
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | | | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
| | - Ramaswamy Murugavel
- Department of Chemistry, Indian Institute of Technology Bombay, Mumbai-400076, India.
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23
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Sarkar A, Rajaraman G. Modulating magnetic anisotropy in Ln(iii) single-ion magnets using an external electric field. Chem Sci 2020; 11:10324-10330. [PMID: 34123178 PMCID: PMC8162309 DOI: 10.1039/d0sc03982a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 08/20/2020] [Indexed: 11/25/2022] Open
Abstract
Single-molecule magnets have potential uses in several nanotechnology applications, including high-density information storage devices, the realisation of which lies in enhancing the barrier height for magnetisation reversal (U eff). However, Ln(iii) single-ion magnets (SIMs) that have been reported recently reveal that the maximum value of U eff values that can be obtained by modulating the ligand fields has already been achieved. Here, we have explored, using a combination of DFT and ab initio CASSCF calculations, a unique way to enhance the magnetisation reversal barrier using an oriented external electric field in three well-known Ln(iii) single-ion magnets: [Dy(Py)5(O t Bu)2]+ (1), [Er{N(SiMe3)2}3Cl]- (2) and [Dy(CpMe3)Cl] (3). Our study reveals that, for apt molecules, if the appropriate direction and values of the electric fields are chosen, the barrier height can be enhanced by twice that of the limit set by the ligand field. The application of an electric field along the equatorial direction was found to be suitable for oblate shaped Dy(iii) complexes and an electric field along the axial direction was found to enhance the barrier height for a prolate Er(iii) complex. For complexes 2 and 3, the external electric field was able to magnify the barrier height to 2-3 times that of the original complexes. However, a moderate enhancement was noticed after application of the external electric field in the case of complex 1. This novel non-chemical fine-tuning approach to modulate magnetic anisotropy is expected to yield a new generation of SIMs.
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Affiliation(s)
- Arup Sarkar
- 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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24
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Arumugam S, Kumar Kushvaha S, Shankar B, Gorantla SMNVT, Roy S, Sana B, Khuntia P, Chandra Mondal K. Tuning Nuclearity of Dysprosium (III) Complexes by Controlling Substitution on Ligand Molecule. ChemistrySelect 2020. [DOI: 10.1002/slct.202001766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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25
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Jin C, Li XL, Liu Z, Mansikkamäki A, Tang J. An investigation into the magnetic interactions in a series of Dy 2 single-molecule magnets. Dalton Trans 2020; 49:10477-10485. [PMID: 32685954 DOI: 10.1039/d0dt01926g] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Three di-nuclear DyIII complexes [Dy2(H2L)2(tfa)]·Cl·3DMF (1), [Dy2(H2L)2(MeO)(SCN)]·MeOH (2) and [Dy2(H2L)2(MeOH)Cl]·Cl·2MeOH (3) were synthesized and structurally and magnetically characterized. The Dy1/Dy2 centers in these complexes are all nine-coordinate with spherical capped square antiprism (local C4v symmetry) environments. All complexes display single-molecule magnet (SMM) behavior under zero applied dc field with their properties dependent on the nature of the magnetic interactions between the DyIII ions. Ab initio calculations substantiate that all DyIII ions show a weakly axial crystal-field environment with the exception of one of the DyIII ions in complex 2. The ground Kramers doublets show modest amounts of quantum tunneling of magnetization that gets blocked by the interaction between the DyIII ions, leading to a thermally activated slow relaxation of magnetization. The interaction between the ions is ferromagnetic and mostly originates from the dipolar interaction. However, anti-ferromagnetic intermolecular interaction plays an important role and in the case of complex 2 it is sufficiently strong to mask the ferromagnetic intramolecular interaction.
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Affiliation(s)
- Chaoyi Jin
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China. and College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, 010021, 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.
| | - Zhiliang Liu
- College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot, 010021, 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. and School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, P. R. China
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26
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Fondo M, Corredoira-Vázquez J, García-Deibe AM, Gómez-Coca S, Ruiz E, Sanmartín-Matalobos J. Dysprosium-based complexes with a flat pentadentate donor: a magnetic and ab initio study. Dalton Trans 2020; 49:8389-8401. [PMID: 32520050 DOI: 10.1039/d0dt01293a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactivity of the well-known pentadentate N3O2 Schiff base H2L (2,6-bis(2-hydroxyphenyliminomethyl)pyridine) towards a lanthanoid metal, in this case DyIII, has been investigated for the first time. This reactivity markedly depends on the pH of the medium and, accordingly, two different complexes, [Dy(HL)(NO3)2]·H2O (1·H2O) and [Dy(L)(NO3)(EtOH)(H2O)]·2H2O (2·2H2O), could be isolated from dysprosium(iii) nitrate and H2L. In addition, reaction of H2L with dysprosium(iii) chloride in methanol yields [Dy(HL')2][Dy(L)(Cl2)] (3), where H2L' ((6-(2-hydroxyphenyliminomethyl)-2-methoxyhydroxymethyl)pyridine) is an N2O2 hemiacetal donor derived from the partial hydrolysis of the H2L ligand, and subsequent addition of the methanol solvent to the carbonyl group. This latter reaction has been firstly observed for a lanthanoid metal. Single crystal X-ray diffraction studies of 1·1.15Py·0.3CH3C6H5, 2·2H2O and 3 show that the Schiff base is acting as a nearly flat pentadentate donor in all the cases, this behaviour being independent of the deprotonation degree of the phenolic oxygen atoms, both mono- or bisdeprotonated. Complexes 1·1.15Py·0.3CH3C6H5 and 2·2H2O show DyN3O6 cores, with distorted geometries closer to spherical tricapped trigonal prism or spherical capped square antiprism for 1·1.15Py·0.3CH3C6H5 and 2·2H2O, respectively. In the case of 3, the [Dy(HL')2]+ cation shows a dysprosium ion in an N4O4 triangular dodecahedron environment, while the [Dy(L)(Cl2)]- anion displays a DyN3O2Cl2 core with distorted pentagonal bipyramidal geometry. Moreover, attempts to dilute 1·H2O with yttrium yielded single crystals of (Et3NH)[Dy0.09Y0.91(L)(NO3)2] (4), where the Schiff base shows a similar pentadentate coordination mode. Dynamic magnetic studies of 1·H2O, 2·2H2O and 3 show that 2·2H2O and 3 present field-induced slow relaxation of the magnetisation, with Ueff barriers of 46.1(9) and 31.0(7) K for 2·2H2O and 3, respectively, while 1·H2O does not exhibit frequency-dependent peaks of the out of phase susceptibility, even in the presence of an external dc magnetic field. By contrast, the dilute sample 4 behaves as a SIM at zero dc field, with an energy barrier of ca. 49 K. Ab initio calculations using CASSCF methods including spin-orbit effects qualitatively support the obtained magnetic results, indicating that axiality is not the only factor that should be taken into account in order to increase effective energy barriers.
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Affiliation(s)
- Matilde Fondo
- Departamento de Química Inorgánica, Facultade de Química, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
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27
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Canaj AB, Dey S, Wilson C, Céspedes O, Rajaraman G, Murrie M. Engineering macrocyclic high performance pentagonal bipyramidal Dy(iii) single-ion magnets. Chem Commun (Camb) 2020; 56:12037-12040. [DOI: 10.1039/d0cc04559d] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We highlight the vast synthetic scope for macrocyclic engineering of magnetic anisotropy, generating a high performance pentagonal bipyramidal Dy(iii) single-ion magnet where the weak equatorial ligand field is created entirely by using a macrocycle.
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Affiliation(s)
- Angelos B. Canaj
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
| | - Sourav Dey
- Department of Chemistry
- Indian Institute of Technology Bombay
- Powai
- Mumbai
- India
| | - Claire Wilson
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
| | - Oscar Céspedes
- School of Physics and Astronomy
- University of Leeds
- Leeds LS2 9JT
- UK
| | - Gopalan Rajaraman
- Department of Chemistry
- Indian Institute of Technology Bombay
- Powai
- Mumbai
- India
| | - Mark Murrie
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
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28
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Canaj AB, Dey S, Céspedes O, Wilson C, Rajaraman G, Murrie M. There is nothing wrong with being soft: using sulfur ligands to increase axiality in a Dy(iii) single-ion magnet. Chem Commun (Camb) 2020; 56:1533-1536. [DOI: 10.1039/c9cc07292f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Sulfur co-ligands boost axiality in Dy(iii); computational studies show higher energy barriers when compared to oxygen co-ligands and suggest further improvements by moving to selenium or tellurium co-ligands.
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Affiliation(s)
- Angelos B. Canaj
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
| | - Sourav Dey
- Department of Chemistry, Indian Institute of Technology Bombay
- Mumbai
- India
| | - Oscar Céspedes
- School of Physics and Astronomy
- University of Leeds
- Leeds LS2 9JT
- UK
| | - Claire Wilson
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
| | - Gopalan Rajaraman
- Department of Chemistry, Indian Institute of Technology Bombay
- Mumbai
- India
| | - Mark Murrie
- School of Chemistry
- University of Glasgow
- University Avenue
- Glasgow
- UK
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29
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Castro-Alvarez A, Gil Y, Llanos L, Aravena D. High performance single-molecule magnets, Orbach or Raman relaxation suppression? Inorg Chem Front 2020. [DOI: 10.1039/d0qi00487a] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Relaxation mechanisms limiting the blocking temperature for high-performance single molecule magnets (SMMs) are investigated. Best SMMs are limited by the exponential regime. Current ab initio methods can yield accurate estimations for this limit.
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Affiliation(s)
- Alejandro Castro-Alvarez
- Departamento de Química de los Materiales
- Facultad de Química y Biología
- Universidad de Santiago de Chile
- Santiago
- Chile
| | - Yolimar Gil
- Departamento de Química Inorgánica y Analítica
- Facultad de Ciencias Químicas y Farmacéuticas
- Universidad de Chile
- Santiago
- Chile
| | - Leonel Llanos
- Departamento de Química de los Materiales
- Facultad de Química y Biología
- Universidad de Santiago de Chile
- Santiago
- Chile
| | - Daniel Aravena
- Departamento de Química de los Materiales
- Facultad de Química y Biología
- Universidad de Santiago de Chile
- Santiago
- Chile
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30
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Li Z, Zhai Y, Chen W, Ding Y, Zheng Y. Air‐Stable Hexagonal Bipyramidal Dysprosium(III) Single‐Ion Magnets with Nearly Perfect
D
6
h
Local Symmetry. Chemistry 2019; 25:16219-16224. [DOI: 10.1002/chem.201904325] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 10/17/2019] [Indexed: 11/10/2022]
Affiliation(s)
- Zi‐Han Li
- Frontier Institute of Science and Technology (FIST)Shenzhen Research SchoolState Key Laboratory for, Mechanical Behaviour of MaterialsMOE Key Laboratory for, Nonequilibrium Synthesis of Condensed MatterXi'an Key Laboratory of, Sustainable Energy and Materials Chemistry and School of ScienceXi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
| | - Yuan‐Qi Zhai
- Frontier Institute of Science and Technology (FIST)Shenzhen Research SchoolState Key Laboratory for, Mechanical Behaviour of MaterialsMOE Key Laboratory for, Nonequilibrium Synthesis of Condensed MatterXi'an Key Laboratory of, Sustainable Energy and Materials Chemistry and School of ScienceXi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
| | - Wei‐Peng Chen
- Frontier Institute of Science and Technology (FIST)Shenzhen Research SchoolState Key Laboratory for, Mechanical Behaviour of MaterialsMOE Key Laboratory for, Nonequilibrium Synthesis of Condensed MatterXi'an Key Laboratory of, Sustainable Energy and Materials Chemistry and School of ScienceXi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
| | - You‐Song Ding
- Frontier Institute of Science and Technology (FIST)Shenzhen Research SchoolState Key Laboratory for, Mechanical Behaviour of MaterialsMOE Key Laboratory for, Nonequilibrium Synthesis of Condensed MatterXi'an Key Laboratory of, Sustainable Energy and Materials Chemistry and School of ScienceXi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
| | - Yan‐Zhen Zheng
- Frontier Institute of Science and Technology (FIST)Shenzhen Research SchoolState Key Laboratory for, Mechanical Behaviour of MaterialsMOE Key Laboratory for, Nonequilibrium Synthesis of Condensed MatterXi'an Key Laboratory of, Sustainable Energy and Materials Chemistry and School of ScienceXi'an Jiaotong University 99 Yanxiang Road Xi'an Shaanxi 710054 P. R. China
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