51
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Gu L, Wu R. Origins of Slow Magnetic Relaxation in Single-Molecule Magnets. PHYSICAL REVIEW LETTERS 2020; 125:117203. [PMID: 32975970 DOI: 10.1103/physrevlett.125.117203] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 07/17/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Exponential and power law temperature dependences are widely used to fit experimental data of magnetic relaxation time in single molecular magnets. We derived a theory to show how these rules arise from the underling relaxation mechanisms and to clarify the conditions for their occurrence. The theory solves the puzzle of lower-than-expected Orbach barriers found in recent experiments, and elucidates it as a result of the Raman process in disguise. Our results highlight the importance of reducing the rate of direct tunneling between the ground state doublet so as to achieve longtime coherence in magnetic molecules. To this end, large spin and small transverse magnetic anisotropy can reduce magnitude of the transition operator, and rigid ligands may weaken the spin-phonon coupling in that they raise the energy of vibrational modes and better screen the acoustic phonons.
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Affiliation(s)
- Lei Gu
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
| | - Ruqian Wu
- Department of Physics and Astronomy, University of California, Irvine, California 92697, USA
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52
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Abstract
The development of spin qubits for quantum technologies requires their protection from the main source of finite-temperature decoherence: atomic vibrations. Here we eliminate one of the main barriers to the progress in this field by providing a complete first-principles picture of spin relaxation that includes up to two-phonon processes. Our method is based on machine learning and electronic structure theory and makes the prediction of spin lifetime in realistic systems feasible. We study a prototypical vanadium-based molecular qubit and reveal that the spin lifetime at high temperature is limited by Raman processes due to a small number of THz intramolecular vibrations. These findings effectively change the conventional understanding of spin relaxation in this class of materials and open new avenues for the rational design of long-living spin systems.
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Affiliation(s)
- Alessandro Lunghi
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
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53
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Aravena D, Ruiz E. Spin dynamics in single-molecule magnets and molecular qubits. Dalton Trans 2020; 49:9916-9928. [PMID: 32589181 DOI: 10.1039/d0dt01414a] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Over recent decades, much effort has been made to lengthen spin relaxation/decoherence times of single-molecule magnets and molecular qubits by following different chemical design rules such as maximizing the total spin value, controlling symmetry, enhancing the ligand field or inhibiting key vibrational modes. Simultaneously, electronic structure calculations have been employed to provide an understanding of the processes involved in the spin dynamics of molecular systems and served to refine or introduce new design rules. This review focuses on contemporary theoretical approaches focused on the calculation of spin relaxation/decoherence times, highlighting their main features and scope. Fundamental aspects of experimental techniques for the determination of key Single Molecule Magnet/Spin Qubit properties are also reviewed.
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Affiliation(s)
- Daniel Aravena
- Departamento de Química de los Materiales, Universidad de Santiago de Chile, Santiago 9170022, Chile
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54
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Scherthan L, Pfleger RF, Auerbach H, Hochdörffer T, Wolny JA, Bi W, Zhao J, Hu MY, Alp EE, Anson CE, Diller R, Powell AK, Schünemann V. Exploring the Vibrational Side of Spin-Phonon Coupling in Single-Molecule Magnets via 161 Dy Nuclear Resonance Vibrational Spectroscopy. Angew Chem Int Ed Engl 2020; 59:8818-8822. [PMID: 32181552 PMCID: PMC7317570 DOI: 10.1002/anie.201914728] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/14/2020] [Indexed: 11/06/2022]
Abstract
Synchrotron-based nuclear resonance vibrational spectroscopy (NRVS) using the Mössbauer isotope 161 Dy has been employed for the first time to study the vibrational properties of a single-molecule magnet (SMM) incorporating DyIII , namely [Dy(Cy3 PO)2 (H2 O)5 ]Br3 ⋅2 (Cy3 PO)⋅2 H2 O ⋅2 EtOH. The experimental partial phonon density of states (pDOS), which includes all vibrational modes involving a displacement of the DyIII ion, was reproduced by means of simulations using density functional theory (DFT), enabling the assignment of all intramolecular vibrational modes. This study proves that 161 Dy NRVS is a powerful experimental tool with significant potential to help to clarify the role of phonons in SMMs.
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Affiliation(s)
- Lena Scherthan
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
| | - Rouven F. Pfleger
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstr. 1576131KarlsruheGermany
| | - Hendrik Auerbach
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
| | - Tim Hochdörffer
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
| | - Juliusz A. Wolny
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
| | - Wenli Bi
- Advanced Photon SourceArgonne National Laboratory9700 South Cass AvenueArgonneIL60439USA
- Department of PhysicsUniversity of Alabama at BirminghamBirminghamAL35294USA
| | - Jiyong Zhao
- Advanced Photon SourceArgonne National Laboratory9700 South Cass AvenueArgonneIL60439USA
| | - Michael Y. Hu
- Advanced Photon SourceArgonne National Laboratory9700 South Cass AvenueArgonneIL60439USA
| | - E. Ercan Alp
- Advanced Photon SourceArgonne National Laboratory9700 South Cass AvenueArgonneIL60439USA
| | - Christopher E. Anson
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstr. 1576131KarlsruheGermany
| | - Rolf Diller
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
| | - Annie K. Powell
- Institute of Inorganic ChemistryKarlsruhe Institute of TechnologyEngesserstr. 1576131KarlsruheGermany
- Institute of NanotechnologyKarlsruhe Institute of Technology76021KarlsruheGermany
| | - Volker Schünemann
- Department of PhysicsTechnische Universität KaiserslauternErwin-Schrödinger-Str. 4667663KaiserslauternGermany
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55
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Higdon NJ, Barth AT, Kozlowski PT, Hadt RG. Spin-phonon coupling and dynamic zero-field splitting contributions to spin conversion processes in iron(II) complexes. J Chem Phys 2020; 152:204306. [PMID: 32486684 DOI: 10.1063/5.0006361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Magnetization dynamics of transition metal complexes manifest in properties and phenomena of fundamental and applied interest [e.g., slow magnetic relaxation in single molecule magnets, quantum coherence in quantum bits (qubits), and intersystem crossing (ISC) rates in photophysics]. While spin-phonon coupling is recognized as an important determinant of these dynamics, additional fundamental studies are required to unravel the nature of the coupling and, thus, leverage it in molecular engineering approaches. To this end, we describe here a combined ligand field theory and multireference ab initio model to define spin-phonon coupling terms in S = 2 transition metal complexes and demonstrate how couplings originate from both the static and dynamic properties of ground and excited states. By extending concepts to spin conversion processes, ligand field dynamics manifest in the evolution of the excited state origins of zero-field splitting (ZFS) along specific normal mode potential energy surfaces. Dynamic ZFSs provide a powerful means to independently evaluate contributions from spin-allowed and/or spin-forbidden excited states to spin-phonon coupling terms. Furthermore, ratios between various intramolecular coupling terms for a given mode drive spin conversion processes in transition metal complexes and can be used to analyze the mechanisms of ISC. Variations in geometric structure strongly influence the relative intramolecular linear spin-phonon coupling terms and will define the overall spin state dynamics. While the findings of this study are of general importance for understanding magnetization dynamics, they also link the phenomenon of spin-phonon coupling across fields of single molecule magnetism, quantum materials/qubits, and transition metal photophysics.
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Affiliation(s)
- Nicholas J Higdon
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Alexandra T Barth
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Patryk T Kozlowski
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Ryan G Hadt
- Division of Chemistry and Chemical Engineering, Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena, California 91125, USA
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56
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Scherthan L, Pfleger RF, Auerbach H, Hochdörffer T, Wolny JA, Bi W, Zhao J, Hu MY, Alp EE, Anson CE, Diller R, Powell AK, Schünemann V. Untersuchung von Schwingungen in Bezug auf Spin‐Phonon‐Kopplung in Einzelmolekülmagneten mittels nuklearer inelastischer Streuung am
161
Dy‐Kern. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201914728] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lena Scherthan
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
| | - Rouven F. Pfleger
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology Engesserstr. 15 76131 Karlsruhe Deutschland
| | - Hendrik Auerbach
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
| | - Tim Hochdörffer
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
| | - Juliusz A. Wolny
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
| | - Wenli Bi
- Advanced Photon Source Argonne National Laboratory 9700 S. Cass Avenue Argonne IL 60439 USA
- Department of Physics University of Alabama at Birmingham Birmingham AL 35294 USA
| | - Jiyong Zhao
- Advanced Photon Source Argonne National Laboratory 9700 S. Cass Avenue Argonne IL 60439 USA
| | - Michael Y. Hu
- Advanced Photon Source Argonne National Laboratory 9700 S. Cass Avenue Argonne IL 60439 USA
| | - E. Ercan Alp
- Advanced Photon Source Argonne National Laboratory 9700 S. Cass Avenue Argonne IL 60439 USA
| | - Christopher E. Anson
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology Engesserstr. 15 76131 Karlsruhe Deutschland
| | - Rolf Diller
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
| | - Annie K. Powell
- Institute of Inorganic Chemistry Karlsruhe Institute of Technology Engesserstr. 15 76131 Karlsruhe Deutschland
- Institute of Nanotechnology Karlsruhe Institute of Technology 76021 Karlsruhe Deutschland
| | - Volker Schünemann
- Department of Physics Technische Universität Kaiserslautern Erwin-Schrödinger-Str. 46 67663 Kaiserslautern Deutschland
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57
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Moseley DH, Stavretis SE, Zhu Z, Guo M, Brown CM, Ozerov M, Cheng Y, Daemen LL, Richardson R, Knight G, Thirunavukkuarasu K, Ramirez-Cuesta AJ, Tang J, Xue ZL. Inter-Kramers Transitions and Spin-Phonon Couplings in a Lanthanide-Based Single-Molecule Magnet. Inorg Chem 2020; 59:5218-5230. [PMID: 32196322 DOI: 10.1021/acs.inorgchem.0c00523] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Spin-phonon coupling plays a critical role in magnetic relaxation in single-molecule magnets (SMMs) and molecular qubits. Yet, few studies of its nature have been conducted. Phonons here refer to both intermolecular and intramolecular vibrations. In the current work, we show spin-phonon couplings between IR-active phonons in a lanthanide molecular complex and Kramers doublets (from the crystal field). For the SMM Er[N(SiMe3)2]3 (1, Me = methyl), the couplings are observed in the far-IR magnetospectroscopy (FIRMS) of crystals with coupling constants ≈ 2-3 cm-1. In particular, one of the magnetic excitations couples to at least two phonon excitations. The FIRMS reveals at least three magnetic excitations (within the 4I15/2 ground state/manifold; hereafter, manifold) at 0 T at 104, ∼180, and 245 cm-1, corresponding to transitions from the ground state, MJ = ±15/2, to the first three excited states, MJ = ±13/2, ±11/2, and ±9/2, respectively. The transition between the ground and first excited Kramers doublet in 1 is also observed in inelastic neutron scattering (INS) spectroscopy, moving to a higher energy with an increasing magnetic field. INS also gives complete phonon spectra of 1. Periodic DFT computations provide the energies of all phonon excitations, which compare well with the spectra from INS, supporting the assignment of the inter-Kramers doublet (magnetic) transitions in the spectra. The current studies unveil and measure the spin-phonon couplings in a typical lanthanide complex and throw light on the origin of the spin-phonon entanglement.
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Affiliation(s)
- Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Zhenhua Zhu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Mei Guo
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Craig M Brown
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Tallahassee, Florida 32310, United States
| | - Yongqiang Cheng
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Luke L Daemen
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Rachael Richardson
- Department of Physics, Florida A&M University, Tallahassee, Florida 32307, United States
| | - Gary Knight
- Department of Physics, Florida A&M University, Tallahassee, Florida 32307, United States
| | | | - Anibal J Ramirez-Cuesta
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Jinkui Tang
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, United States
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58
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Spree L, Schlesier C, Kostanyan A, Westerström R, Greber T, Büchner B, Avdoshenko SM, Popov AA. Single-Molecule Magnets DyM 2 N@C 80 and Dy 2 MN@C 80 (M=Sc, Lu): The Impact of Diamagnetic Metals on Dy 3+ Magnetic Anisotropy, Dy⋅⋅⋅Dy Coupling, and Mixing of Molecular and Lattice Vibrations. Chemistry 2020; 26:2436-2449. [PMID: 31774196 PMCID: PMC7065109 DOI: 10.1002/chem.201904879] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Indexed: 01/11/2023]
Abstract
The substitution of scandium in fullerene single-molecule magnets (SMMs) DySc2 N@C80 and Dy2 ScN@C80 by lutetium has been studied to explore the influence of the diamagnetic metal on the SMM performance of dysprosium nitride clusterfullerenes. The use of lutetium led to an improved SMM performance of DyLu2 N@C80 , which shows a higher blocking temperature of magnetization (TB =9.5 K), longer relaxation times, and broader hysteresis than DySc2 N@C80 (TB =6.9 K). At the same time, Dy2 LuN@C80 was found to have a similar blocking temperature of magnetization to Dy2 ScN@C80 (TB =8 K), but substantially different interactions between the magnetic moments of the dysprosium ions in the Dy2 MN clusters. Surprisingly, although the intramolecular dipolar interactions in Dy2 LuN@C80 and Dy2 ScN@C80 are of similar strength, the exchange interactions in Dy2 LuN@C80 are close to zero. Analysis of the low-frequency molecular and lattice vibrations showed strong mixing of the lattice modes and endohedral cluster librations in k-space. This mixing simplifies the spin-lattice relaxation by conserving the momentum during the spin flip and helping to distribute the moment and energy further into the lattice.
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Affiliation(s)
- Lukas Spree
- Leibniz Institute for Solid State and Materials Research (IFW Dresden)01069DresdenGermany
| | - Christin Schlesier
- Leibniz Institute for Solid State and Materials Research (IFW Dresden)01069DresdenGermany
| | - Aram Kostanyan
- Physik-Institut der Universität ZürichWinterthurerstr. 1908057ZürichSwitzerland
| | - Rasmus Westerström
- Physik-Institut der Universität ZürichWinterthurerstr. 1908057ZürichSwitzerland
- The Division of Synchrotron Radiation ResearchLund University22100LundSweden
| | - Thomas Greber
- Physik-Institut der Universität ZürichWinterthurerstr. 1908057ZürichSwitzerland
| | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research (IFW Dresden)01069DresdenGermany
| | | | - Alexey A. Popov
- Leibniz Institute for Solid State and Materials Research (IFW Dresden)01069DresdenGermany
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59
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Escalera-Moreno L, Baldoví JJ, Gaita-Ariño A, Coronado E. Design of high-temperature f-block molecular nanomagnets through the control of vibration-induced spin relaxation. Chem Sci 2020; 11:1593-1598. [PMID: 32153756 PMCID: PMC7025469 DOI: 10.1039/c9sc03133b] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 12/01/2019] [Indexed: 12/20/2022] Open
Abstract
One of the main roadblocks that still hamper the practical use of molecular nanomagnets is their cryogenic working temperature. In the pursuit of rational strategies to design new molecular nanomagnets with increasing blocking temperature, ab initio methodologies play an important role by guiding synthetic efforts at the lab stage. Nevertheless, when evaluating vibration-induced spin relaxation, these methodologies are still far from being computationally fast enough to provide a useful predictive framework. Herein, we present an inexpensive first-principles method devoted to evaluating vibration-induced spin relaxation in molecular f-block single-ion magnets, with the important advantage of requiring only one CASSCF calculation. The method is illustrated using two case studies based on uranium as the magnetic centre. Finally, we propose chemical modifications in the ligand environment with the aim of suppressing spin relaxation.
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Affiliation(s)
- Luis Escalera-Moreno
- Instituto de Ciencia Molecular (ICMol) , Universitat de València , c/ Catedrático José Beltrán 2 , Paterna , 46980 , Spain .
| | - José J Baldoví
- Instituto de Ciencia Molecular (ICMol) , Universitat de València , c/ Catedrático José Beltrán 2 , Paterna , 46980 , Spain .
| | - Alejandro Gaita-Ariño
- Instituto de Ciencia Molecular (ICMol) , Universitat de València , c/ Catedrático José Beltrán 2 , Paterna , 46980 , Spain .
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol) , Universitat de València , c/ Catedrático José Beltrán 2 , Paterna , 46980 , Spain .
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60
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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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61
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Ma F, Sun R, Sun AH, Xiong J, Sun HL, Gao S. Regulating the structural dimensionality and dynamic properties of a porous dysprosium coordination polymer through solvent molecules. Inorg Chem Front 2020. [DOI: 10.1039/c9qi01440c] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The solvent molecules can regulate the structural dimensionality of a porous dysprosium coordination polymer from three to two and its dynamic behavior, as evidenced by the increase of the effective energy barriers and slowdown of quantum tunneling.
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Affiliation(s)
- Fang Ma
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Rong Sun
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Ai-Huan Sun
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Jin Xiong
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
| | - Hao-Ling Sun
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Song Gao
- Beijing National Laboratory for Molecular Sciences
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- College of Chemistry and Molecular Engineering
- Peking University
- Beijing 100871
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62
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Yin B, Li CC. A method to predict both the relaxation time of quantum tunneling of magnetization and the effective barrier of magnetic reversal for a Kramers single-ion magnet. Phys Chem Chem Phys 2020; 22:9923-9933. [DOI: 10.1039/d0cp00933d] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A method to predict the relaxation time of quantum tunneling of magnetization and the magnetic reversal barrier with efficiency and reliability.
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Affiliation(s)
- Bing Yin
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education
- College of Chemistry and Materials Science
- Northwest University
- Xi'an
- P. R. China
| | - Chao-Chao Li
- Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education
- College of Chemistry and Materials Science
- Northwest University
- Xi'an
- P. R. China
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63
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Mirzoyan R, Hadt RG. The dynamic ligand field of a molecular qubit: decoherence through spin–phonon coupling. Phys Chem Chem Phys 2020; 22:11249-11265. [DOI: 10.1039/d0cp00852d] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A ligand field model highlights chemical design principles for the development of room temperature coherent materials for quantum information processing.
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Affiliation(s)
- Ruben Mirzoyan
- Division of Chemistry and Chemical Engineering
- Arthur Amos Noyes Laboratory of Chemical Physics
- California Institute of Technology
- Pasadena
- USA
| | - Ryan G. Hadt
- Division of Chemistry and Chemical Engineering
- Arthur Amos Noyes Laboratory of Chemical Physics
- California Institute of Technology
- Pasadena
- USA
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64
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Harriman KLM, Murillo J, Suturina EA, Fortier S, Murugesu M. Relaxation dynamics in see-saw shaped Dy(iii) single-molecule magnets. Inorg Chem Front 2020. [DOI: 10.1039/d0qi01007c] [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
Unusual see-saw shaped Dy(iii) single-molecule magnets, [K(DME)n][LArDy(X)2] (LAr = {C6H4[(2,6-iPrC6H3)NC6H4]2}2−), X = Cl (1) and X = I (2) were synthesized and display high effective energy barriers (Ueff = 1278–1334 K) in zero field.
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Affiliation(s)
- Katie L. M. Harriman
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada
| | - Jesse Murillo
- Department of Chemistry and Biochemistry
- University of Texas at El Paso
- El Paso
- USA
| | | | - Skye Fortier
- Department of Chemistry and Biochemistry
- University of Texas at El Paso
- El Paso
- USA
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences
- University of Ottawa
- Ottawa
- Canada
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65
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Ullah A, Cerdá J, Baldoví JJ, Varganov SA, Aragó J, Gaita-Ariño A. In Silico Molecular Engineering of Dysprosocenium-Based Complexes to Decouple Spin Energy Levels from Molecular Vibrations. J Phys Chem Lett 2019; 10:7678-7683. [PMID: 31755716 DOI: 10.1021/acs.jpclett.9b02982] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Molecular nanomagnets hold great promise for spintronics and quantum technologies, provided that their spin memory can be preserved above liquid-nitrogen temperatures. In the past few years, the magnetic hysteresis records observed for two related dysprosocenium-type complexes have highlighted the potential of molecular engineering to decouple vibrational excitations from spin states and thereby enhance magnetic memory. Herein, we study the spin-vibrational coupling in [(CpiPr5)Dy(Cp*)]+ (CpiPr5 = pentaisopropylcyclopentadienyl, Cp* = pentamethylcyclopentadienyl), which currently holds the hysteresis record (80 K), by means of a computationally affordable methodology that combines first-principles electronic structure calculations with a phenomenological ligand field model. Our analysis is in good agreement with the previously reported state-of-the-art ab initio calculations, with the advantage of drastically reducing the computation time. We then apply the proposed methodology to three alternative dysprosocenium-type complexes, extracting physical insights that demonstrate the usefulness of this strategy to efficiently engineer and screen magnetic molecules with the potential of retaining spin information at higher temperatures.
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Affiliation(s)
- Aman Ullah
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , c/Catedrático José Beltrán, 2 , 46980 Paterna , Spain
| | - Jesús Cerdá
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , c/Catedrático José Beltrán, 2 , 46980 Paterna , Spain
| | - José J Baldoví
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , c/Catedrático José Beltrán, 2 , 46980 Paterna , Spain
| | - Sergey A Varganov
- Department of Chemistry , University of Nevada, Reno , 1664 North Virginia Street , Reno , Nevada 89557-0216 , United States
| | - Juan Aragó
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , c/Catedrático José Beltrán, 2 , 46980 Paterna , Spain
| | - Alejandro Gaita-Ariño
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , c/Catedrático José Beltrán, 2 , 46980 Paterna , Spain
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66
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Vallejo J, Viciano-Chumillas M, Lloret F, Julve M, Castro I, Krzystek J, Ozerov M, Armentano D, De Munno G, Cano J. Coligand Effects on the Field-Induced Double Slow Magnetic Relaxation in Six-Coordinate Cobalt(II) Single-Ion Magnets (SIMs) with Positive Magnetic Anisotropy. Inorg Chem 2019; 58:15726-15740. [PMID: 31738531 DOI: 10.1021/acs.inorgchem.9b01719] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two mononuclear cobalt(II) compounds of formula [Co(dmphen)2(OOCPh)]ClO4·1/2H2O·1/2CH3OH (1) and [Co(dmbipy)2(OOCPh)]ClO4 (2) (dmphen = 2,9-dimethyl-1,10-phenanthroline, dmbipy = 6,6'-dimethyl-2,2'-bipyridine and HOOCPh = benzoic acid) are prepared and magnetostructurally investigated. Each cobalt(II) ion is six-coordinate with a distorted octahedral CoN4O2 environment. The complex cations are interlinked leading to supramolecular chains (1) and pairs (2) that grow along the crystallographic c-axis with racemic mixtures of (Δ,Λ)-Co units. FIRMS allowed us to directly measure the zero-field splitting between the two lowest Kramers doublets, which led to axial anisotropy values of 58.3 cm-1 ≤ D < 60.7 cm-1 (1) and 63.8 cm-1 ≤ D < 64.1 cm-1 (2). HFEPR spectra of polycrystalline samples of 1 and 2 at low temperatures confirm the positive sign of D and provide an estimate of the E/D quotient [0.147/0.187 (1) and 0.052 (2)]. Detailed ac and dc magnetic studies reveal that 1 and 2 are new examples of field-induced single-ion magnets (SIMs) with small transversal anisotropy. CASSCF/NEVPT2 calculations support these results. Two Orbach processes or one Orbach plus a direct relaxation mechanism provide similar agreements with the nonlinear experimental Arrhenius plots at Hdc = 500 and 2500 G for 1. Two independent relaxation processes occur in 2, but in contrast to 1, an observed linear dependence of ln(τ) vs 1/T substantiates Orbach processes against the most widely proposed Raman and direct mechanisms. The analysis of each relaxation process in 2 provided values for Ea and τ0 that are very close to those found for 1, validating the predominant role of the Orbach relaxations in both compounds and, probably, also in other cobalt(II) SIMs. A mechanism based on a spin-phonon coupling is proposed to account for the SIM behavior in 1 and 2 with any Raman or direct processes being discarded.
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Affiliation(s)
- Julia Vallejo
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
| | - Marta Viciano-Chumillas
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
| | - Francisco Lloret
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
| | - Miguel Julve
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
| | - Isabel Castro
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
| | - J Krzystek
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory , Florida State University , Tallahassee , Florida 32310 , United States
| | - Donatella Armentano
- Dipartamento di Chimica e Tecnologie Chimiche , Università della Calabria , 87036 Rende , Cosenza Italy
| | - Giovanni De Munno
- Dipartamento di Chimica e Tecnologie Chimiche , Università della Calabria , 87036 Rende , Cosenza Italy
| | - Joan Cano
- Institut de Ciència Molecular (ICMol) and Departament de Química Inorgànica , Universitat de València , 46980 Paterna , València
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67
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Spectroscopic Studies of the Magnetic Excitation and Spin‐Phonon Couplings in a Single‐Molecule Magnet. Chemistry 2019; 25:15846-15857. [DOI: 10.1002/chem.201903635] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Indexed: 12/11/2022]
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68
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Escalera-Moreno L, Baldoví JJ. Unveiling the Effect of Magnetic Noise in the Coherence of Single-Molecule Quantum Processors. Front Chem 2019; 7:662. [PMID: 31632953 PMCID: PMC6779859 DOI: 10.3389/fchem.2019.00662] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 09/17/2019] [Indexed: 11/13/2022] Open
Abstract
Quantum bits (qubits) constitute the most elementary building-blocks of any quantum technology, where information is stored and processed in the form of quantum superpositions between discrete energy levels. In particular, the fabrication of quantum processors is a key long-term goal that will allow us conducting specific tasks much more efficiently than the most powerful classical computers can do. Motivated by recent experiments in which three addressable spin qubits are defined on a potential single-molecule quantum processor, namely the [Gd(H2O)P5W30O110]12- polyoxometalate, we investigate the decohering effect of magnetic noise on the encoded quantum information. Our state-of-the-art model, which provides more accurate results than previous estimates, show a noticeable contribution of magnetic noise in limiting the survival timescale of the qubits. Yet, our results suggest that it might not be the only dephasing mechanism at play but other mechanisms, such as lattice vibrations and physical movement of magnetic nuclei, must be considered to understand the whole decoherence process.
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Affiliation(s)
| | - José J Baldoví
- Max Planck Institute for the Structure and Dynamics of Matter, Hamburg, Germany
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69
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Kotrle K, Herchel R. Are Inorganic Single-Molecule Magnets a Possibility? A Theoretical Insight into Dysprosium Double-Deckers with Inorganic Ring Systems. Inorg Chem 2019; 58:14046-14057. [DOI: 10.1021/acs.inorgchem.9b02039] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
Affiliation(s)
- Kamil Kotrle
- Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
| | - Radovan Herchel
- Department of Inorganic Chemistry, Faculty of Science, Palacký University Olomouc, 17. listopadu 12, 771 46 Olomouc, Czech Republic
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70
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Escalera-Moreno L, Baldoví JJ, Gaita-Ariño A, Coronado E. Exploring the High-Temperature Frontier in Molecular Nanomagnets: From Lanthanides to Actinides. Inorg Chem 2019; 58:11883-11892. [PMID: 31490061 DOI: 10.1021/acs.inorgchem.9b01610] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Molecular nanomagnets based on mononuclear metal complexes, also known as single-ion magnets (SIMs), are crossing challenging boundaries in molecular magnetism. From an experimental point of view, this class of magnetic molecules has expanded from lanthanoid complexes to both d-transition metal and actinoid complexes. From a theoretical point of view, more and more improved models have been developed, and we are now able not only to calculate the electronic structure of these systems on the basis of their molecular structures but also to unveil the role of vibrations in the magnetic relaxation processes, at least for lanthanoid and d-transition metal SIMs. This knowledge has allowed us to optimize the behavior of dysprosocenium-based SIMs until reaching magnetic hysteresis above liquid-nitrogen temperature. In this contribution, we offer a brief perspective of the progress of theoretical modeling in this field. We start by reviewing the developed methodologies to investigate the electronic structures of these systems and then move on focus to the open problem of understanding and optimizing the vibrationally induced spin relaxation, especially in uranium-based molecular nanomagnets. Finally, we discuss the differences in the design strategies for 4f and 5f SIMs, including an analysis of the metallocenium family.
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Affiliation(s)
- Luis Escalera-Moreno
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , C/Catedrático José Beltrán 2 , E-46980 Paterna , Spain
| | - José J Baldoví
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , D-22761 Hamburg , Germany
| | - Alejandro Gaita-Ariño
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , C/Catedrático José Beltrán 2 , E-46980 Paterna , Spain
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol) , Universidad de Valencia , C/Catedrático José Beltrán 2 , E-46980 Paterna , Spain
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71
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Czap G, Wagner PJ, Li J, Xue F, Yao J, Wu R, Ho W. Detection of Spin-Vibration States in Single Magnetic Molecules. PHYSICAL REVIEW LETTERS 2019; 123:106803. [PMID: 31573305 DOI: 10.1103/physrevlett.123.106803] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Indexed: 06/10/2023]
Abstract
The spin states of magnetic molecules have advantageous attributes as carriers of quantum information. However, spin-vibration coupling in molecules causes a decay of excited spin states and a loss of spin coherence. Here, we detect excitations of spin-vibration states in single nickelocene molecules on Ag(110) with a scanning tunneling microscope. By transferring a nickelocene to the tip, the joint spin-vibration states with an adsorbed nickelocene were measured. Chemical variations in magnetic molecules offer the opportunity to tune spin-vibration coupling for controlling the spin coherence.
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Affiliation(s)
- Gregory Czap
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Peter J Wagner
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Jie Li
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - Feng Xue
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences, Fudan University, Shanghai, China 200433
| | - Jiang Yao
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
| | - R Wu
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
- State Key Laboratory of Surface Physics and Key Laboratory of Computational Physical Sciences, Fudan University, Shanghai, China 200433
| | - W Ho
- Department of Physics and Astronomy, University of California, Irvine, California 92697-4575, USA
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
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72
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The Role of Vibrational Anharmonicity in the Computational Study of Thermal Spin Crossover. MAGNETOCHEMISTRY 2019. [DOI: 10.3390/magnetochemistry5030049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Spin crossover in transition metal complexes can be studied in great detail with computational chemistry. Over the years, the understanding has grown that the relative stability of high-spin (HS) versus low-spin (LS) states is a subtle balance of many factors that all need to be taken into account for a reliable description. Among the different contributions, the zero-point energy (ZPE) and the entropy play key roles. These quantities are usually calculated assuming a harmonic oscillator model for the molecular vibrations. We investigated the impact of including anharmonic corrections on the ZPE and the entropy and indirectly on the critical temperature of spin crossover. As test systems, we used a set of ten Fe(II) complexes and one Fe(III) complex, covering different coordination modes (mono-, bi-, and tri-dentate ligands), decreasing coordination number upon spin crossover, coordination by second- and third-row atoms, and changes in the oxidation state. The results show that the anharmonicity has a measurable effect, but it is in general rather small, and tendencies are not easily recognized. As a conclusion, we put forward that for high precision results, one should be aware of the anharmonic effects, but as long as computational chemistry is still struggling with other larger factors like the influence of the environment and the accurate determination of the electronic energy difference between HS and LS, the anharmonicity of the vibrational modes is a minor concern.
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73
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Lunghi A, Sanvito S. How do phonons relax molecular spins? SCIENCE ADVANCES 2019; 5:eaax7163. [PMID: 31598553 PMCID: PMC6764833 DOI: 10.1126/sciadv.aax7163] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 08/29/2019] [Indexed: 05/31/2023]
Abstract
The coupling between electronic spins and lattice vibrations is fundamental for driving relaxation in magnetic materials. The debate over the nature of spin-phonon coupling dates back to the 1940s, but the role of spin-spin, spin-orbit, and hyperfine interactions has never been fully established. Here, we present a comprehensive study of the spin dynamics of a crystal of Vanadyl-based molecular qubits by means of first-order perturbation theory and first-principles calculations. We quantitatively determine the role of the Zeeman, hyperfine, and electronic spin dipolar interactions in the direct mechanism of spin relaxation. We show that, in a high magnetic field regime, the modulation of the Zeeman Hamiltonian by the intramolecular components of the acoustic phonons dominates the relaxation mechanism. In low fields, hyperfine coupling takes over, with the role of spin-spin dipolar interaction remaining the less important for the spin relaxation.
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74
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Albino A, Benci S, Tesi L, Atzori M, Torre R, Sanvito S, Sessoli R, Lunghi A. First-Principles Investigation of Spin–Phonon Coupling in Vanadium-Based Molecular Spin Quantum Bits. Inorg Chem 2019; 58:10260-10268. [DOI: 10.1021/acs.inorgchem.9b01407] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | | | | | - Stefano Sanvito
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | | | - Alessandro Lunghi
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
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75
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Hay MA, McMonagle CJ, Wilson C, Probert MR, Murrie M. Trigonal to Pentagonal Bipyramidal Coordination Switching in a Co(II) Single-Ion Magnet. Inorg Chem 2019; 58:9691-9697. [DOI: 10.1021/acs.inorgchem.9b00515] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Moya A. Hay
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - Charles J. McMonagle
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Claire Wilson
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
| | - Michael R. Probert
- Chemistry, School of Natural and Environmental Sciences, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom
| | - Mark Murrie
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow, G12 8QQ, United Kingdom
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76
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Liu BC, Ge N, Zhai YQ, Zhang T, Ding YS, Zheng YZ. An imido ligand significantly enhances the effective energy barrier of dysprosium(iii) single-molecule magnets. Chem Commun (Camb) 2019; 55:9355-9358. [PMID: 31314022 DOI: 10.1039/c9cc04687a] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report herein an imido ligand 1,3-bis(2,6-diisopropylphenyl) imidazolin-2-imine (ImDippNH) that can form a very short Dy-N bond (2.12 Å) with the dysprosium(iii) ion, which leads to a much larger effective energy barrier for magnetisation reversal (803 K) compared to the analogous alkoxide ligand (53 K). Moreover, we predict that a linear two-coordinate [Dy(ImDippN)2]+ complex may have an effective energy barrier larger than 4000 K.
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Affiliation(s)
- Bing-Cheng Liu
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China.
| | - Ning Ge
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China.
| | - Yuan-Qi Zhai
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China.
| | - Tao Zhang
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China.
| | - You-Song Ding
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China.
| | - Yan-Zhen Zheng
- Frontier Institute of Science and Technology (FIST), State Key Laboratory of Mechanical Behaviour for Materials, MOE Key Laboratory for Nonequilibrium Synthesis of Condensed Matter, Xi'an Key Laboratory of Sustainable Energy and Materials Chemistry and School of Science, Xi'an Jiaotong University, 99 Yanxiang Road, Xi'an, Shaanxi 710054, P. R. China. and Shenzhen Research School, Xian Jiaotong University, China
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77
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Hay MA, Sarkar A, Craig GA, Bhaskaran L, Nehrkorn J, Ozerov M, Marriott KER, Wilson C, Rajaraman G, Hill S, Murrie M. In-depth investigation of large axial magnetic anisotropy in monometallic 3d complexes using frequency domain magnetic resonance and ab initio methods: a study of trigonal bipyramidal Co(ii). Chem Sci 2019; 10:6354-6361. [PMID: 31341591 PMCID: PMC6601423 DOI: 10.1039/c9sc00987f] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Accepted: 05/19/2019] [Indexed: 11/21/2022] Open
Abstract
The magnetic properties of 3d monometallic complexes can be tuned through geometric control, owing to their synthetic accessibility and relative structural simplicity. Monodentate ligands offer great potential for fine-tuning the coordination environment to engineer both the axial and rhombic zero-field splitting (ZFS) parameters. In [CoCl3(DABCO)(HDABCO)] (1), the trigonal bipyramidal Co(ii) centre has two bulky axial ligands and three equatorial chloride ligands. An in-depth experimental and theoretical study of 1 reveals a large easy-plane magnetic anisotropy (+ve D) with a negligible rhombic zero-field splitting (E) due to the strict axial symmetry imposed by the C 3 symmetric ligand and trigonal space group. The large easy-plane magnetic anisotropy (D = +44.5 cm-1) is directly deduced using high-field EPR and frequency-domain magnetic resonance (FDMR) studies. Ab initio calculations reveal a large positive contribution to the D term arising from ground state/excited state mixing of the 4E'' states at ∼4085 cm-1 and a minor contribution from the spin-flip transition as well. The nature of the slow relaxation in 1 is elucidated through analysis of the rates of relaxation of magnetisation, taking into account Raman and direct spin-lattice relaxation processes and Quantum Tunnelling of the Magnetisation (QTM). The terms relating to the direct process and QTM were found based on the fit of the field-dependence of τ at 2 K. Subsequently, these were used as fixed parameters in the fit of the temperature-dependence of τ to obtain the Raman terms. This experimental-theoretical investigation provides further insight into the power of FDMR and ab initio methods for the thorough investigation of magnetic anisotropy. Thus, these results contribute to design criteria for high magnetic anisotropy systems.
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Affiliation(s)
- Moya A Hay
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Arup Sarkar
- Department of Chemistry , Institute of Technology Bombay , Powai , Mumbai , Maharashtra 400 076 , India .
| | - Gavin A Craig
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Lakshmi Bhaskaran
- Department of Physics , Florida State University , Tallahassee , FL 32306 , USA .
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Joscha Nehrkorn
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
- Max Planck Institute for Chemical Energy Conversion , Stiftstr. 34-36 , 45470 Mülheim an der Ruhr , Germany
| | - Mykhailo Ozerov
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Katie E R Marriott
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Claire Wilson
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
| | - Gopalan Rajaraman
- Department of Chemistry , Institute of Technology Bombay , Powai , Mumbai , Maharashtra 400 076 , India .
| | - Stephen Hill
- Department of Physics , Florida State University , Tallahassee , FL 32306 , USA .
- National High Magnetic Field Laboratory , 1800 E. Paul Dirac Drive Tallahassee , FL 32310 , USA
| | - Mark Murrie
- WestCHEM , School of Chemistry , University of Glasgow , University Avenue , Glasgow , G12 8QQ , UK .
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78
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Fataftah MS, Krzyaniak MD, Vlaisavljevich B, Wasielewski MR, Zadrozny JM, Freedman DE. Metal-ligand covalency enables room temperature molecular qubit candidates. Chem Sci 2019; 10:6707-6714. [PMID: 31367325 PMCID: PMC6625489 DOI: 10.1039/c9sc00074g] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 05/27/2019] [Indexed: 12/29/2022] Open
Abstract
Metal–ligand covalency enables observation of coherent spin dynamics to room temperature in a series of vanadium(iv) and copper(ii) catechol complexes.
Harnessing synthetic chemistry to design electronic spin-based qubits, the smallest unit of a quantum information system, enables us to probe fundamental questions regarding spin relaxation dynamics. We sought to probe the influence of metal–ligand covalency on spin–lattice relaxation, which comprises the upper limit of coherence time. Specifically, we studied the impact of the first coordination sphere on spin–lattice relaxation through a series of four molecules featuring V–S, V–Se, Cu–S, and Cu–Se bonds, the Ph4P+ salts of the complexes [V(C6H4S2)3]2– (1), [Cu(C6H4S2)2]2– (2), [V(C6H4Se2)3]2– (3), and [Cu(C6H4Se2)2]2– (4). The combined results of pulse electron paramagnetic resonance spectroscopy and ac magnetic susceptibility studies demonstrate the influence of greater M–L covalency, and consequently spin-delocalization onto the ligand, on elongating spin–lattice relaxation times. Notably, we observe the longest spin–lattice relaxation times in 2, and spin echos that survive until room temperature in both copper complexes (2 and 4).
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Affiliation(s)
- Majed S Fataftah
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA . ;
| | - Matthew D Krzyaniak
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA . ; .,The Institute for Sustainability and Energy at Northwestern , Northwestern University , Evanston , IL 60208 , USA
| | - Bess Vlaisavljevich
- Department of Chemistry , University of South Dakota , Vermillion , South Dakota 57069 , USA
| | - Michael R Wasielewski
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA . ; .,The Institute for Sustainability and Energy at Northwestern , Northwestern University , Evanston , IL 60208 , USA
| | - Joseph M Zadrozny
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , USA .
| | - Danna E Freedman
- Department of Chemistry , Northwestern University , Evanston , IL 60208 , USA . ;
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79
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Rosaleny LE, Zinovjev K, Tuñón I, Gaita-Ariño A. A first peek into sub-picosecond dynamics of spin energy levels in magnetic biomolecules. Phys Chem Chem Phys 2019; 21:10908-10913. [PMID: 31080970 DOI: 10.1039/c9cp01909j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We estimate the time- and temperature-evolution of spin energy levels in a metallopeptide by combining molecular dynamics with crystal field analysis. Fluctuations of tens of cm-1 for spin energy levels at fs times gradually average out at longer times. We confirm that local vibrations are key in spin dynamics.
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Affiliation(s)
- Lorena E Rosaleny
- Departament de Química Física, Universitat de València, 46100 Burjassot, Spain. and Instituto de Ciencia Molecular, Universitat de València, 46980 Paterna, Spain
| | - Kirill Zinovjev
- Departament de Química Física, Universitat de València, 46100 Burjassot, Spain.
| | - Iñaki Tuñón
- Departament de Química Física, Universitat de València, 46100 Burjassot, Spain.
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80
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Abstract
Spins in solids or in molecules possess discrete energy levels, and the associated quantum states can be tuned and coherently manipulated by means of external electromagnetic fields. Spins therefore provide one of the simplest platforms to encode a quantum bit (qubit), the elementary unit of future quantum computers. Performing any useful computation demands much more than realizing a robust qubit-one also needs a large number of qubits and a reliable manner with which to integrate them into a complex circuitry that can store and process information and implement quantum algorithms. This 'scalability' is arguably one of the challenges for which a chemistry-based bottom-up approach is best-suited. Molecules, being much more versatile than atoms, and yet microscopic, are the quantum objects with the highest capacity to form non-trivial ordered states at the nanoscale and to be replicated in large numbers using chemical tools.
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81
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Lin CY, Ngendahimana T, Eaton GR, Eaton SS, Zadrozny JM. Counterion influence on dynamic spin properties in a V(iv) complex. Chem Sci 2019; 10:548-555. [PMID: 30746097 PMCID: PMC6335635 DOI: 10.1039/c8sc04122a] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 10/17/2018] [Indexed: 12/18/2022] Open
Abstract
Using transition metal ions for spin-based applications, such as electron paramagnetic resonance imaging (EPRI) or quantum computation, requires a clear understanding of how local chemistry influences spin properties. Herein we report a series of four ionic complexes to provide the first systematic study of one aspect of local chemistry on the V(iv) spin - the counterion. To do so, the four complexes (Et3NH)2[V(C6H4O2)3] (1), (n-Bu3NH)2[V(C6H4O2)3] (2), (n-Hex3NH)2[V(C6H4O2)3] (3), and (n-Oct3NH)2[V(C6H4O2)3] (4) were probed by EPR spectroscopy in solid state and solution. Room temperature, solution X-band (ca. 9.8 GHz) continuous-wave electron paramagnetic resonance (CW-EPR) spectroscopy revealed an increasing linewidth with larger cations, likely a counterion-controlled tumbling in solution via ion pairing. In the solid state, variable-temperature (5-180 K) X-band (ca. 9.4 GHz) pulsed EPR studies of 1-4 in o-terphenyl glass demonstrated no effect on spin-lattice relaxation times (T 1), indicating little role for the counterion on this parameter. However, the phase memory time (T m) of 1 below 100 K is markedly smaller than those of 2-4. This result is counterintuitive, as 2-4 are relatively richer in 1H nuclear spin, hence, expected to have shorter T m. Thus, these data suggest an important role for counterion methyl groups on T m, and moreover provide the first instance of a lengthening T m with increasing nuclear spin quantity on a molecule.
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Affiliation(s)
- Chun-Yi Lin
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , USA .
| | - Thacien Ngendahimana
- Department of Chemistry and Biochemistry , University of Denver , Denver , Colorado 80208 , USA . ;
| | - Gareth R Eaton
- Department of Chemistry and Biochemistry , University of Denver , Denver , Colorado 80208 , USA . ;
| | - Sandra S Eaton
- Department of Chemistry and Biochemistry , University of Denver , Denver , Colorado 80208 , USA . ;
| | - Joseph M Zadrozny
- Department of Chemistry , Colorado State University , Fort Collins , Colorado 80523 , USA .
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82
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Ortu F, Reta D, Ding YS, Goodwin CAP, Gregson MP, McInnes EJL, Winpenny REP, Zheng YZ, Liddle ST, Mills DP, Chilton NF. Studies of hysteresis and quantum tunnelling of the magnetisation in dysprosium(iii) single molecule magnets. Dalton Trans 2019; 48:8541-8545. [DOI: 10.1039/c9dt01655d] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report a study of quantum tunneling of the magnetisation in three Dy(iii) single-molecule magnets.
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Affiliation(s)
- Fabrizio Ortu
- School of Chemistry
- The University of Manchester
- Manchester
- UK
| | - Daniel Reta
- School of Chemistry
- The University of Manchester
- Manchester
- UK
| | - You-Song Ding
- Frontier Institute of Science and Technology
- Xi'an Jiaotong University
- Xi'an
- China
| | | | | | | | | | - Yan-Zhen Zheng
- Frontier Institute of Science and Technology
- Xi'an Jiaotong University
- Xi'an
- China
| | | | - David P. Mills
- School of Chemistry
- The University of Manchester
- Manchester
- UK
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83
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Chen XR, Hu WY, Xu XY, Ren FF. Crystal structure and magnetic properties of two salts of nickel-bis-1,2-dithiolene with ammonium organic cation. Polyhedron 2019. [DOI: 10.1016/j.poly.2018.10.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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84
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Li M, Wu H, Xia Z, Montigaud V, Cador O, Le Guennic B, Ke H, Wang W, Xie G, Chen S. Bromine-bridged Dy2 single-molecule magnet: magnetic anisotropy driven by cis/trans stereoisomers. Chem Commun (Camb) 2019; 55:14661-14664. [DOI: 10.1039/c9cc07552f] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The peculiar cis/trans stereoisomers in a bromine-bridged Dy2 single-molecule magnet drive the orthogonal magnetic moments and tune the magnetic interactions, leading to a large energy barrier of 684 K.
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85
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Świtlicka A, Palion-Gazda J, Machura B, Cano J, Lloret F, Julve M. Field-induced slow magnetic relaxation in pseudooctahedral cobalt(ii) complexes with positive axial and large rhombic anisotropy. Dalton Trans 2019; 48:1404-1417. [DOI: 10.1039/c8dt03965h] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The preparation, X-ray crystal structure, spectroscopic and variable-temperature dc and ac magnetic properties of two six-coordinate cobalt(ii) complexes of formula [Co(bim)4(tcm)2] (1) and [Co(bmim)4(tcm)2] (2) are reported.
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Affiliation(s)
- Anna Świtlicka
- Department of Crystallography
- Institute of Chemistry
- University of Silesia
- 40-006 Katowice
- Poland
| | - Joanna Palion-Gazda
- Department of Crystallography
- Institute of Chemistry
- University of Silesia
- 40-006 Katowice
- Poland
| | - Barbara Machura
- Department of Crystallography
- Institute of Chemistry
- University of Silesia
- 40-006 Katowice
- Poland
| | - Joan Cano
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Facultat de Quimica de la Universitat de València
- 46980 Paterna
- Spain
- Fundació General de la Universitat de València (FGUV)
| | - Francesc Lloret
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Facultat de Quimica de la Universitat de València
- 46980 Paterna
- Spain
| | - Miguel Julve
- Department of Química Inorgànica/Instituto de Ciencia Molecular (ICMol)
- Facultat de Quimica de la Universitat de València
- 46980 Paterna
- Spain
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86
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Pointillart F, Ou-Yang JK, Fernandez Garcia G, Montigaud V, Flores Gonzalez J, Marchal R, Favereau L, Totti F, Crassous J, Cador O, Ouahab L, Le Guennic B. Tetrathiafulvalene-Based Helicene Ligand in the Design of a Dysprosium Field-Induced Single-Molecule Magnet. Inorg Chem 2018; 58:52-56. [PMID: 30550268 PMCID: PMC6400426 DOI: 10.1021/acs.inorgchem.8b02830] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The design of a coordination
complex that involves a ligand combining both a tetrathiafulvalene
core and a helicene fragment was achieved thanks to the reaction between
the new 2-{1-[2-methyl[6]helicene]-4,5-[4,5-bis(propylthio)tetrathiafulvalenyl]-1H-benzimidazol-2-yl}pyridine ligand (L) and
the Dy(hfac)3·2H2O metalloprecursor. Magnetic
investigations showed field-induced single-molecule-magnet (SMM) behavior
under an applied magnetic field of 1000 Oe for [Dy(hfac)3(L)]·0.5CH2Cl2, while experimentally
oriented single-crystal magnetic measurements allowed for determination
of the magnetic anisotropy orientation. The magnetic behavior was
rationalized through ab initio
CASSCF/SI-SO calculations. This redox-active chiral-field-induced
SMM paves the way for the design of switchable-multiproperty SMMs. A redox-active chiral-field-induced single-molecule
magnet was achieved through a coordination reaction of the [Dy(hfac)3] precursor to a ligand that combines a redox-active tetrathiafulvalene
core and a chiral carbo[6]helicene fragment. This multiproperty system
was characterized using X-ray crystallography, magnetism, and ab initio
calculations.
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Affiliation(s)
- Fabrice Pointillart
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Jiang-Kun Ou-Yang
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Guglielmo Fernandez Garcia
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France.,Department of Chemistry "Ugo Schiff" and INSTM RU , University of Florence , 50019 Sesto Fiorentino , Italy
| | - Vincent Montigaud
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Jessica Flores Gonzalez
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Rémi Marchal
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Ludovic Favereau
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226 , 35000 Rennes , France
| | - Federico Totti
- Department of Chemistry "Ugo Schiff" and INSTM RU , University of Florence , 50019 Sesto Fiorentino , Italy
| | - Jeanne Crassous
- 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
| | - Lahcène Ouahab
- 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
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87
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He JY, Chen XR, Qian Y, Liu JL, Ren XM. Crystal structures and dielectric properties of two salts of nickel-bis-1,2-dithiolene with noncentrosymmetric organic cations. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.08.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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88
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Yamabayashi T, Atzori M, Tesi L, Cosquer G, Santanni F, Boulon ME, Morra E, Benci S, Torre R, Chiesa M, Sorace L, Sessoli R, Yamashita M. Scaling Up Electronic Spin Qubits into a Three-Dimensional Metal-Organic Framework. J Am Chem Soc 2018; 140:12090-12101. [PMID: 30145887 DOI: 10.1021/jacs.8b06733] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Practical implementation of highly coherent molecular spin qubits for challenging technological applications, such as quantum information processing or quantum sensing, requires precise organization of electronic qubit molecular components into extended frameworks. Realization of spatial control over qubit-qubit distances can be achieved by coordination chemistry approaches through an appropriate choice of the molecular building blocks. However, translating single qubit molecular building units into extended arrays does not guarantee a priori retention of long quantum coherence and spin-lattice relaxation times due to the introduced modifications over qubit-qubit reciprocal distances and molecular crystal lattice phonon structure. In this work, we report the preparation of a three-dimensional (3D) metal-organic framework (MOF) based on vanadyl qubits, [VO(TCPP-Zn2-bpy)] (TCPP = tetracarboxylphenylporphyrinate; bpy = 4,4'-bipyridyl) (1), and the investigation of how such structural modifications influence qubits' performances. This has been done through a multitechnique approach where the structure and properties of a representative molecular building block of formula [VO(TPP)] (TPP = tetraphenylporphyrinate) (2) have been compared with those of the 3D MOF 1. Pulsed electron paramagnetic resonance measurements on magnetically diluted samples in titanyl isostructural analogues revealed that coherence times are retained almost unchanged for 1 with respect to 2 up to room temperature, while the temperature dependence of the spin-lattice relaxation time revealed insights into the role of low-energy vibrations, detected through terahertz spectroscopy, on the spin dynamics.
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Affiliation(s)
- Tsutomu Yamabayashi
- Department of Chemistry, Graduate School of Science , Tohoku University , 6-3 Aramaki Aza-Aoba , Aoba-ku, Sendai 980-8578 , Japan
| | - Matteo Atzori
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Lorenzo Tesi
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Goulven Cosquer
- Department of Chemistry, Graduate School of Science , Tohoku University , 6-3 Aramaki Aza-Aoba , Aoba-ku, Sendai 980-8578 , Japan
| | - Fabio Santanni
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Marie-Emmanuelle Boulon
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Elena Morra
- Dipartimento di Chimica e NIS Centre , Università di Torino , Via P. Giuria 7 , I10125 Torino , Italy
| | - Stefano Benci
- European Laboratory for Non-Linear Spectroscopy , Università degli Studi di Firenze , Via Nello Carrara 1 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Renato Torre
- European Laboratory for Non-Linear Spectroscopy , Università degli Studi di Firenze , Via Nello Carrara 1 , I50019 Sesto Fiorentino, Firenze , Italy.,Dipartimento di Fisica ed Astronomia , Università degli Studi di Firenze , Via G. Sansone 1 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Mario Chiesa
- Dipartimento di Chimica e NIS Centre , Università di Torino , Via P. Giuria 7 , I10125 Torino , Italy
| | - Lorenzo Sorace
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Roberta Sessoli
- Dipartimento di Chimica "Ugo Schiff" and INSTM RU , Università degli Studi di Firenze , Via della Lastruccia 3 , I50019 Sesto Fiorentino, Firenze , Italy.,Istituto di Chimica dei Composti Organometallici - ICCOM-CNR , Research Area Firenze , Via Madonna del Piano 10 , I50019 Sesto Fiorentino, Firenze , Italy
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science , Tohoku University , 6-3 Aramaki Aza-Aoba , Aoba-ku, Sendai 980-8578 , Japan.,WPI, Advanced Institute for Materials Research , Tohoku University , 2-1-1 Katahira , Aoba-Ku, Sendai 980-8577 , Japan.,School of Materials Science and Engineering , Nankai University , Tianjin 300350 , China
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89
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Pearson TJ, Laorenza DW, Krzyaniak MD, Wasielewski MR, Freedman DE. Octacyanometallate qubit candidates. Dalton Trans 2018; 47:11744-11748. [PMID: 29993061 DOI: 10.1039/c8dt02312c] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We report the temperature dependence of the spin dynamics of the octacyanometallates [Mo(CN)8]3- and [W(CN)8]3-. At 5 K, these complexes display remarkably long spin-lattice relaxation times of 1.05 s, and 0.63 s, respectively. We probe the contributing factors to the spin relaxation and demonstrate the impact of spin-orbit coupling as a handle to tune vibrationally mediated spin-lattice relaxation.
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Affiliation(s)
- Tyler J Pearson
- Department of Chemistry, Northwestern University, Technological Institute, 2145 N. Sheridan Rd., Evanston, Illinois 60208-3113, USA.
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90
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Bhowmick I, Roehl AJ, Neilson JR, Rappé AK, Shores MP. Slow magnetic relaxation in octahedral low-spin Ni(iii) complexes. Chem Sci 2018; 9:6564-6571. [PMID: 30310588 PMCID: PMC6115677 DOI: 10.1039/c7sc04482h] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 06/28/2018] [Indexed: 11/28/2022] Open
Abstract
Herein we report the first examples of single-molecule magnet (SMM) behaviour in S = 1/2 Ni(iii) complexes. We find that low-spin 3d7 trans-[NiIII(cyclam)(X)2]Y complexes (cyclam = 1,4,8,11-tetraazacyclotetradecane; X and Y are singly charged anions) exhibit field-induced slow relaxation of magnetization for O-donor axial ligands (nitrate) but not for N-donor variants (isothiocyanate). Experimental and electronic structure computational investigations indicate that intrinsic spin polarisation of low-spin Ni(iii) is modulated significantly by local coordination geometry and supramolecular interactions. Solid state dilution of Ni(iii) with diamagnetic Co(iii) ions forms a related complex salt, [Ni x Co1-x (cyclam)(NO3)2](NO3)·2HNO3 (0.1 < x < 1), which preserves slow magnetic dynamics, thus supporting a molecular component to slow relaxation. An initial analysis of magnetic relaxation lifetime fits best to a combination of Raman and direct relaxation processes.
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Affiliation(s)
- Indrani Bhowmick
- Department of Chemistry , Colorado State University , Fort Collins , CO 80523-1872 , USA . ;
| | - Andrew J Roehl
- Department of Chemistry , Colorado State University , Fort Collins , CO 80523-1872 , USA . ;
| | - James R Neilson
- Department of Chemistry , Colorado State University , Fort Collins , CO 80523-1872 , USA . ;
| | - Anthony K Rappé
- Department of Chemistry , Colorado State University , Fort Collins , CO 80523-1872 , USA . ;
| | - Matthew P Shores
- Department of Chemistry , Colorado State University , Fort Collins , CO 80523-1872 , USA . ;
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91
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Stavretis SE, Mamontov E, Moseley DH, Cheng Y, Daemen LL, Ramirez-Cuesta AJ, Xue ZL. Effect of magnetic fields on the methyl rotation in a paramagnetic cobalt(ii) complex. Quasielastic neutron scattering studies. Phys Chem Chem Phys 2018; 20:21119-21126. [PMID: 30079409 DOI: 10.1039/c8cp01660g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Molecular dynamics is a fundamental property of metal complexes. These dynamic processes, especially for paramagnetic complexes under external magnetic fields, are in general not well understood. Quasielastic neutron scattering (QENS) in 0-4 T magnetic fields has been used to study the dynamics of Co(acac)2(D2O)2 (1-d4, acac = acetylacetonate). At 80-100 K, rotation of the methyl groups on the acac ligands is the dominant dynamical process. This rotation is slowed down by the magnetic field increase. Rotation times at 80 K are 5.6(3) × 10-10 s at 0 T and 2.04(10) × 10-9 s at 4 T. The QENS studies suggest that methyl groups in these paramagnetic Co(ii) molecules do not behave as isolated units, which is consistent with results from earlier magnetic susceptibility studies indicating the presence of intermolecular interactions. DFT calculations show that unpaired electron spin density in 1 is dispersed to the atoms of both acac and H2O ligands. Methyl torsions in 1-d4 have also been observed at 5-100 K in inelastic neutron spectroscopy (INS). The QENS and INS results here help understand the dynamics of the compound in the solid state.
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Affiliation(s)
- Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee 37996, USA.
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92
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Rosaleny LE, Cardona-Serra S, Escalera-Moreno L, Baldoví JJ, Gołȩbiewska V, Wlazło K, Casino P, Prima-García H, Gaita-Ariño A, Coronado E. Peptides as Versatile Platforms for Quantum Computing. J Phys Chem Lett 2018; 9:4522-4526. [PMID: 30044106 DOI: 10.1021/acs.jpclett.8b01813] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The pursuit of novel functional building blocks for the emerging field of quantum computing is one of the most appealing topics in the context of quantum technologies. Herein we showcase the urgency of introducing peptides as versatile platforms for quantum computing. In particular, we focus on lanthanide-binding tags, originally developed for the study of protein structure. We use pulsed electronic paramagnetic resonance to demonstrate quantum coherent oscillations in both neodymium and gadolinium peptidic qubits. Calculations based on density functional theory followed by a ligand field analysis indicate the possibility of influencing the nature of the spin qubit states by means of controlled changes in the peptidic sequence. We conclude with an overview of the challenges and opportunities opened by this interdisciplinary field.
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Affiliation(s)
- Lorena E Rosaleny
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Salvador Cardona-Serra
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Luis Escalera-Moreno
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - José J Baldoví
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , D-22761 Hamburg , Germany
| | - Violetta Gołȩbiewska
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Karolina Wlazło
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Patricia Casino
- Departamento de Bioquı́mica y Biologı́a Molecular , ERI BioTecMed, Universitat de València , Dr. Moliner 50 , 46100 Burjassot , Spain
| | - Helena Prima-García
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Alejandro Gaita-Ariño
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
| | - Eugenio Coronado
- Institut de Ciència Molecular , Universitat de València , Cat. José Beltrán 2 , 46980 Paterna , Spain
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93
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Field- and temperature-dependent quantum tunnelling of the magnetisation in a large barrier single-molecule magnet. Nat Commun 2018; 9:3134. [PMID: 30087339 PMCID: PMC6081483 DOI: 10.1038/s41467-018-05587-6] [Citation(s) in RCA: 138] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 07/05/2018] [Indexed: 01/09/2023] Open
Abstract
Understanding quantum tunnelling of the magnetisation (QTM) in single-molecule magnets (SMMs) is crucial for improving performance and achieving molecule-based information storage above liquid nitrogen temperatures. Here, through a field- and temperature-dependent study of the magnetisation dynamics of [Dy(tBuO)Cl(THF)5][BPh4]·2THF, we elucidate the different relaxation processes: field-independent Orbach and Raman mechanisms dominate at high temperatures, a single-phonon direct process dominates at low temperatures and fields >1 kOe, and a field- and temperature-dependent QTM process operates near zero field. Accounting for the exponential temperature dependence of the phonon collision rate in the QTM process, we model the magnetisation dynamics over 11 orders of magnitude and find a QTM tunnelling gap on the order of 10−4 to 10−5 cm−1. We show that removal of Dy nuclear spins does not suppress QTM, and argue that while internal dipolar fields and hyperfine coupling support QTM, it is the dynamic crystal field that drives efficient QTM. Understanding quantum tunnelling of the magnetisation in single-molecule magnets is crucial for their potential application in information storage. Here the authors conduct a field- and temperature-dependent study of the magnetisation dynamics of a dysprosium-based SMM, finding four distinct relaxation processes that dominate in different regimes.
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94
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Moseley DH, Stavretis SE, Thirunavukkuarasu K, Ozerov M, Cheng Y, Daemen LL, Ludwig J, Lu Z, Smirnov D, Brown CM, Pandey A, Ramirez-Cuesta AJ, Lamb AC, Atanasov M, Bill E, Neese F, Xue ZL. Spin-phonon couplings in transition metal complexes with slow magnetic relaxation. Nat Commun 2018; 9:2572. [PMID: 29968702 PMCID: PMC6030095 DOI: 10.1038/s41467-018-04896-0] [Citation(s) in RCA: 66] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 05/18/2018] [Indexed: 11/28/2022] Open
Abstract
Spin–phonon coupling plays an important role in single-molecule magnets and molecular qubits. However, there have been few detailed studies of its nature. Here, we show for the first time distinct couplings of g phonons of CoII(acac)2(H2O)2 (acac = acetylacetonate) and its deuterated analogs with zero-field-split, excited magnetic/spin levels (Kramers doublet (KD)) of the S = 3/2 electronic ground state. The couplings are observed as avoided crossings in magnetic-field-dependent Raman spectra with coupling constants of 1–2 cm−1. Far-IR spectra reveal the magnetic-dipole-allowed, inter-KD transition, shifting to higher energy with increasing field. Density functional theory calculations are used to rationalize energies and symmetries of the phonons. A vibronic coupling model, supported by electronic structure calculations, is proposed to rationalize the behavior of the coupled Raman peaks. This work spectroscopically reveals and quantitates the spin–phonon couplings in typical transition metal complexes and sheds light on the origin of the spin–phonon entanglement. Transition metal complexes that display slow magnetic relaxation show promise for information storage, but our mechanistic understanding of the magnetic relaxation of such compounds remains limited. Here, the authors spectroscopically and computationally characterize the strength of spin–phonon couplings, which play an important role in the relaxation process.
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Affiliation(s)
- Duncan H Moseley
- Department of Chemistry, University of Tennessee, Knoxville, TN, 37996, USA
| | - Shelby E Stavretis
- Department of Chemistry, University of Tennessee, Knoxville, TN, 37996, USA
| | | | - Mykhaylo Ozerov
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Yongqiang Cheng
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Luke L Daemen
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Jonathan Ludwig
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Zhengguang Lu
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Dmitry Smirnov
- National High Magnetic Field Laboratory, Tallahassee, FL, 32310, USA
| | - Craig M Brown
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Anup Pandey
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - A J Ramirez-Cuesta
- Chemical and Engineering Materials Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN, 37830, USA
| | - Adam C Lamb
- Department of Chemistry, University of Tennessee, Knoxville, TN, 37996, USA
| | - Mihail Atanasov
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470, Mülheim an der Ruhr, Germany. .,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113, Sofia, Bulgaria.
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, D-45470, Mülheim an der Ruhr, Germany.
| | - Frank Neese
- Max Planck Institute for Coal Research, Kaiser-Wilhelm-Platz 1, D-45470, Mülheim an der Ruhr, Germany
| | - Zi-Ling Xue
- Department of Chemistry, University of Tennessee, Knoxville, TN, 37996, USA.
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95
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Izuogu DC, Yoshida T, Zhang H, Cosquer G, Katoh K, Ogata S, Hasegawa M, Nojiri H, Damjanović M, Wernsdorfer W, Uruga T, Ina T, Breedlove BK, Yamashita M. Slow Magnetic Relaxation in a Palladium-Gadolinium Complex Induced by Electron Density Donation from the Palladium Ion. Chemistry 2018; 24:9285-9294. [PMID: 29663534 DOI: 10.1002/chem.201800699] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 04/12/2018] [Indexed: 11/06/2022]
Abstract
Incorporating palladium in the first coordination sphere of acetato-bridged lanthanoid complexes, [Pd2 Ln2 (H2 O)2 (AcO)10 ]⋅2 AcOH (Ln=Gd (1), Y (2), Gd0.4 Y1.6 (3), Eu (4)), led to significant bonding interactions between the palladium and the lanthanoid ions, which were demonstrated by experimental and theoretical methods. We found that electron density was donated from the d8 Pd2+ ion to Gd3+ ion in 1 and 3, leading to the observed slow magnetic relaxation by using local orbital locator (LOL) and X-ray absorption near-edge structure (XANES) analysis. Field-induced dual slow magnetic relaxation was observed for 1 up to 20 K. Complex 3 and frozen aqueous and acetonitrile solutions of 1 showed only one relaxation peak, which confirms the role of intermolecular dipolar interactions in slowing the magnetic relaxation of 1. The slow magnetic relaxation occurred through a combination of Orbach and Direct processes with the highest pre-exponential factor (τo =0.06 s) reported so far for a gadolinium complex exhibiting slow magnetic relaxation. The results revealed that transition metal-lanthanoid (TM-Ln) axial interactions indeed could lead to new physical properties by affecting both the electronic and magnetic states of the compounds.
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Affiliation(s)
- David C Izuogu
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan.,Department of Pure & Industrial Chemistry, University of Nigeria, Nsukka, 410001, Nigeria.,Department of Chemistry, University of Cambridge, Lensfield Rd., Cambridge, CB2 1EW, UK
| | - Takefumi Yoshida
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan.,Electronic Functional Macromolecules Group, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Japan
| | - Haitao Zhang
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan
| | - Goulven Cosquer
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan
| | - Keiichi Katoh
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan
| | - Shuhei Ogata
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama-Gakuin University, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5258, Japan
| | - Miki Hasegawa
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama-Gakuin University, Fuchinobe, Chuo-ku, Sagamihara, Kanagawa, 252-5258, Japan
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University, Sendai, Miyagi, 980-8577, Japan
| | - Marko Damjanović
- Physikalisches Institut and Institute of Nanotechnology, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany
| | - Wolfgang Wernsdorfer
- Physikalisches Institut and Institute of Nanotechnology, Karlsruhe Institute of Technology, Wolfgang-Gaede-Strasse 1, 76131, Karlsruhe, Germany.,CNRS and Université Grenoble Alpes, Institut Néel, 38042, Grenoble, France
| | - Tomoya Uruga
- Research & Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), 1-1-1 Kouto, Sayo, Hyogo, 679-5198, Japan
| | - Toshiaki Ina
- Research & Utilization Division, Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), 1-1-1 Kouto, Sayo, Hyogo, 679-5198, Japan
| | - Brian K Breedlove
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan
| | - Masahiro Yamashita
- Department of Chemistry, Graduate School of Science, Tohoku University, 6-3 Aramaki-Aza-Aoba, Sendai, 980-8578, Japan.,WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Sendai, 980-8577, Japan.,School of Materials Science and Engineering, Nankai University, Tianjin, 300350, China
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96
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Crystal structures, electronic spectra and magnetic properties of homoleptic and heteroleptic metal-dithiolate molecular solids. Polyhedron 2018. [DOI: 10.1016/j.poly.2018.03.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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97
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Cardona-Serra S, Gaita-Ariño A. Vanadyl dithiolate single molecule transistors: the next spintronic frontier? Dalton Trans 2018; 47:5533-5537. [PMID: 29589024 DOI: 10.1039/c8dt00139a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
On the road towards quantum devices, chemistry can offer elementary pieces with a built-in function, like [TbPc2]- which functions as a molecular transistor for nuclear spin detection. We argue that a large class of molecules have similar potential. In particular, we review the recent progress regarding highly coherent spin qubits based on vanadium dithiolate complexes. We propose their use as single molecule transistors to read and control a triple nuclear spin qubit, which could enable a low-current nuclear spin detection scheme by means of a spin valve effect.
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Affiliation(s)
- S Cardona-Serra
- Instituto de Ciencia Molecular, Universitat de València, Spain.
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98
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Escalera-Moreno L, Baldoví JJ, Gaita-Ariño A, Coronado E. Spin states, vibrations and spin relaxation in molecular nanomagnets and spin qubits: a critical perspective. Chem Sci 2018; 9:3265-3275. [PMID: 29780458 PMCID: PMC5935026 DOI: 10.1039/c7sc05464e] [Citation(s) in RCA: 148] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Accepted: 03/07/2018] [Indexed: 12/23/2022] Open
Abstract
Very recently the closely related fields of molecular spin qubits, single ion magnets and single atom magnets have been shaken by unexpected results. We have witnessed a jump in the phase memory times of spin qubits from a few microseconds to almost a millisecond in a vanadium complex, magnetic hysteresis up to 60 K in a dysprosium-based magnetic molecule and magnetic memory up to 30 K in a holmium atom deposited on a surface. With single-molecule magnets being more than two decades old, this rapid improvement in the physical properties is surprising and its explanation deserves urgent attention. The general assumption of focusing uniquely on the energy barrier is clearly insufficient to model magnetic relaxation. Other factors, such as vibrations that couple to spin states, need to be taken into account. In fact, this coupling is currently recognised to be the key factor that accounts for the slow relaxation of magnetisation at higher temperatures. Herein we will present a critical perspective of the recent advances in molecular nanomagnetism towards the goal of integrating spin-phonon interactions into the current computational methodologies of spin relaxation. This presentation will be placed in the context of the well-known models developed in solid state physics, which, as we will explain, are severely limited for molecular systems.
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Affiliation(s)
- Luis Escalera-Moreno
- Instituto de Ciencia Molecular (ICMol) , Univ. de Valencia , C/Catedrático Beltrán 2 , E-46980 Paterna , Spain . ;
| | - José J Baldoví
- Max Planck Institute for the Structure and Dynamics of Matter , Luruper Chaussee 149 , D-22761 Hamburg , Germany
| | - Alejandro Gaita-Ariño
- Instituto de Ciencia Molecular (ICMol) , Univ. de Valencia , C/Catedrático Beltrán 2 , E-46980 Paterna , Spain . ;
| | - Eugenio Coronado
- Instituto de Ciencia Molecular (ICMol) , Univ. de Valencia , C/Catedrático Beltrán 2 , E-46980 Paterna , Spain . ;
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99
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Chen XX, Ma F, Xu MX, Bi JC, Sun HL, Wang BW, Gao S. A neutral auxiliary ligand enhanced dysprosium(iii) single molecule magnet. Dalton Trans 2018; 47:7395-7398. [DOI: 10.1039/c8dt01102h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
An approximately equatorial three-coordinated dysprosium(iii) complex DyL2[N(SiMe3)2] (L = bis(2-(2,5-dimethyl-1H-pyrrol-1-yl)ethyl)amine) with an additional neutral auxiliary pyrrole ligand was synthesised and structurally characterized.
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Affiliation(s)
- Xiao-Xiang Chen
- Beijing National Laboratory of Molecular Science
- College of Chemistry and Molecular Engineering
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- Peking University
- Beijing
| | - Fang Ma
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Mei-Xing Xu
- Beijing National Laboratory of Molecular Science
- College of Chemistry and Molecular Engineering
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- Peking University
- Beijing
| | - Jin-Cheng Bi
- Beijing National Laboratory of Molecular Science
- College of Chemistry and Molecular Engineering
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- Peking University
- Beijing
| | - Hao-Ling Sun
- Department of Chemistry and Beijing Key Laboratory of Energy Conversion and Storage Materials
- Beijing Normal University
- Beijing 100875
- P. R. China
| | - Bing-Wu Wang
- Beijing National Laboratory of Molecular Science
- College of Chemistry and Molecular Engineering
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- Peking University
- Beijing
| | - Song Gao
- Beijing National Laboratory of Molecular Science
- College of Chemistry and Molecular Engineering
- State Key Laboratory of Rare Earth Materials Chemistry and Applications
- Peking University
- Beijing
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100
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Chen Z, Lan Y, Su C, Zhang YQ, Wernsdorfer W. A belt-like one-dimensional Dy chain exhibiting slow magnetic relaxation behavior. Dalton Trans 2018; 47:15298-15302. [DOI: 10.1039/c8dt03751e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A belt-like Dy chain compound was synthesized, which exhibited slow magnetic relaxation behavior and clear hysteresis loops below 0.6 K.
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Affiliation(s)
- Zhi Chen
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education
- College of Optoelectronic Engineering
- Shenzhen University
- Shenzhen 518060
- China
| | - Yanhua Lan
- Laboratoire Louis Néel–CNRS
- 38042 Grenoble Cedex 9
- France
| | - Chenliang Su
- International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of Education
- College of Optoelectronic Engineering
- Shenzhen University
- Shenzhen 518060
- China
| | - Yi-Quan Zhang
- Jiangsu Key Laboratory for NSLSCS
- School of Physical Science and Technology
- Nanjing Normal University
- Nanjing 210023
- China
| | - Wolfgang Wernsdorfer
- Institute of Nanotechnology
- Karlsruhe Institute of Technology (KIT)
- Eggenstein-Leopoldshafen
- Germany
- Laboratoire Louis Néel–CNRS
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