1
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Lockyer SJ, Asthana D, Whitehead GFS, Vitorica‐Yrezabal IJ, Timco GA, McInnes EJL, Winpenny REP. Control and Transferability of Magnetic Interactions in Supramolecular Structures: Trimers of {Cr 7 Ni} Antiferromagnetic Rings. Chemistry 2023; 29:e202302360. [PMID: 37737455 PMCID: PMC10947047 DOI: 10.1002/chem.202302360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 09/13/2023] [Accepted: 09/22/2023] [Indexed: 09/23/2023]
Abstract
A synthetic strategy is demonstrated to prepare two distinct trimers of antiferromagnetically coupled {Cr7 Ni} rings, substantially varying the magnetic interactions between the spin centres. The interactions were studied using multi-frequency cw EPR: in a trimer linked via non-covalent H-bonding interactions no measurable interaction between rings was seen, while in a trimer linked via iso-nicotinate groups isotropic and anisotropic exchange interactions of +0.42 and -0.8 GHz, respectively, were observed. The latter are the same as those for a simpler hetero-dimer system, showing how the spin-spin interactions can be built in a predictable and modular manner in these systems.
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Affiliation(s)
- Selena J. Lockyer
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - Deepak Asthana
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - George F. S. Whitehead
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | | | - Grigore. A. Timco
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - Eric J. L. McInnes
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
| | - Richard E. P. Winpenny
- Department of ChemistryThe University of ManchesterOxford RoadManchesterM13 9PLUnited Kingdom
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2
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Alotaibi R, Booth A, Little E, Brookfield A, Achari A, Lockyer SJ, Timco GA, Whitehead GFS, Vitórica-Yrezábal IJ, Chilton NF, Nair RR, Collison D, Winpenny REP. Synthesis and characterization of heterometallic rings templated through alkylammonium or imidazolium cations. Dalton Trans 2023; 52:7473-7481. [PMID: 37194350 PMCID: PMC10242454 DOI: 10.1039/d3dt00982c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023]
Abstract
We report the synthesis and structural characterization of a series of heterometallic rings templated via alkylammonium or imidazolium cations. The template and preference of each metal's coordination geometry can control the structure of heterometallic compounds, leading to octa-, nona-, deca-, dodeca-, and tetradeca-metallic rings. The compounds were characterized by single-crystal X-ray diffraction, elemental analysis, magnetometry, and EPR measurements. Magnetic measurements show that the exchange coupling between metal centres is antiferromagnetic. EPR spectroscopy shows that the spectra of {Cr7Zn} and {Cr9Zn} have S = 3/2 ground states, while the spectra of {Cr12Zn2} and {Cr8Zn} are consistent with S = 1 and 2 excited states. The EPR spectra of {(ImidH)-Cr6Zn2}, {(1-MeImH)-Cr8Zn2}, and {(1,2-diMeImH)-Cr8Zn2} include a combination of linkage isomers. The results on these related compounds allow us to examine the transferability of magnetic parameters between compounds.
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Affiliation(s)
- Rajeh Alotaibi
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Amy Booth
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Edmund Little
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Amritroop Achari
- Department of Chemical Engineering and Analytical Science and National Graphene Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Selena J Lockyer
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Grigore A Timco
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - George F S Whitehead
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Iñigo J Vitórica-Yrezábal
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Nicholas F Chilton
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Rahul R Nair
- Department of Chemical Engineering and Analytical Science and National Graphene Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - David Collison
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
| | - Richard E P Winpenny
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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3
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Rogers CJ, Asthana D, Brookfield A, Chiesa A, Timco GA, Collison D, Natrajan LS, Carretta S, Winpenny REP, Bowen AM. Modelling Conformational Flexibility in a Spectrally Addressable Molecular Multi‐Qubit Model System. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202207947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ciarán J. Rogers
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Deepak Asthana
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
- Department of Chemistry Ashoka University Sonipat Haryana India
| | - Adam Brookfield
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Alessandro Chiesa
- Dipartimento di Scienze Matematiche Fisiche e Informatiche Università di Parma 43124 Parma Italy
- INFN–Sezione di Milano-Bicocca Gruppo Collegato di Parma I-43124 Parma Italy
- UdR Parma INSTM I-43124 Parma Italy
| | - Grigore A. Timco
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - David Collison
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Louise S. Natrajan
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Stefano Carretta
- Dipartimento di Scienze Matematiche Fisiche e Informatiche Università di Parma 43124 Parma Italy
- INFN–Sezione di Milano-Bicocca Gruppo Collegato di Parma I-43124 Parma Italy
- UdR Parma INSTM I-43124 Parma Italy
| | - Richard E. P. Winpenny
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Alice M. Bowen
- National Research Facility for Electron Paramagnetic Resonance Spectroscopy Department of Chemistry and Photon Science Institute The University of Manchester Oxford Road Manchester M13 9PL UK
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4
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Rogers CJ, Asthana D, Brookfield A, Chiesa A, Timco GA, Collison D, Natrajan LS, Carretta S, Winpenny REP, Bowen AM. Modelling Conformational Flexibility in a Spectrally Addressable Molecular Multi-Qubit Model System. Angew Chem Int Ed Engl 2022; 61:e202207947. [PMID: 36222278 PMCID: PMC9828767 DOI: 10.1002/anie.202207947] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Indexed: 11/11/2022]
Abstract
Dipolar coupled multi-spin systems have the potential to be used as molecular qubits. Herein we report the synthesis of a molecular multi-qubit model system with three individually addressable, weakly interacting, spin 1 / 2 ${{ 1/2 }}$ centres of differing g-values. We use pulsed Electron Paramagnetic Resonance (EPR) techniques to characterise and separately address the individual electron spin qubits; CuII , Cr7 Ni ring and a nitroxide, to determine the strength of the inter-qubit dipolar interaction. Orientation selective Relaxation-Induced Dipolar Modulation Enhancement (os-RIDME) detecting across the CuII spectrum revealed a strongly correlated CuII -Cr7 Ni ring relationship; detecting on the nitroxide resonance measured both the nitroxide and CuII or nitroxide and Cr7 Ni ring correlations, with switchability of the interaction based on differing relaxation dynamics, indicating a handle for implementing EPR-based quantum information processing (QIP) algorithms.
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Affiliation(s)
- Ciarán J. Rogers
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Deepak Asthana
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK,Department of ChemistryAshoka UniversitySonipatHaryanaIndia
| | - Adam Brookfield
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Alessandro Chiesa
- Dipartimento di Scienze Matematiche Fisiche e InformaticheUniversità di Parma43124ParmaItaly,INFN–Sezione di Milano-BicoccaGruppo Collegato di ParmaI-43124ParmaItaly,UdR ParmaINSTMI-43124ParmaItaly
| | - Grigore A. Timco
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - David Collison
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Louise S. Natrajan
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Stefano Carretta
- Dipartimento di Scienze Matematiche Fisiche e InformaticheUniversità di Parma43124ParmaItaly,INFN–Sezione di Milano-BicoccaGruppo Collegato di ParmaI-43124ParmaItaly,UdR ParmaINSTMI-43124ParmaItaly
| | - Richard E. P. Winpenny
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Alice M. Bowen
- National Research Facility for Electron Paramagnetic Resonance SpectroscopyDepartment of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
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5
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Lockyer SJ, Chiesa A, Brookfield A, Timco GA, Whitehead GFS, McInnes EJL, Carretta S, Winpenny REP. Five-Spin Supramolecule for Simulating Quantum Decoherence of Bell States. J Am Chem Soc 2022; 144:16086-16092. [PMID: 36007954 PMCID: PMC9460766 DOI: 10.1021/jacs.2c06384] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
We report a supramolecule that contains five spins of
two different
types and with, crucially, two different and predictable interaction
energies between the spins. The supramolecule is characterized, and
the interaction energies are demonstrated by electron paramagnetic
resonance (EPR) spectroscopy. Based on the measured parameters, we
propose experiments that would allow this designed supramolecule to
be used to simulate quantum decoherence in maximally entangled Bell
states that could be used in quantum teleportation.
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Affiliation(s)
- Selena J Lockyer
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Alessandro Chiesa
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy.,INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, I-43124 Parma, Italy.,UdR Parma, INSTM, I-43124 Parma, Italy
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Grigore A Timco
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - George F S Whitehead
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Eric J L McInnes
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Stefano Carretta
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy.,INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, I-43124 Parma, Italy.,UdR Parma, INSTM, I-43124 Parma, Italy
| | - Richard E P Winpenny
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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6
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Asthana D, Thomas D, Lockyer SJ, Brookfield A, Timco GA, Vitorica-Yrezabal IJ, Whitehead GFS, McInnes EJL, Collison D, Leigh DA, Winpenny REP. Decorating polymer beads with 10 14 inorganic-organic [2]rotaxanes as shown by spin counting. Commun Chem 2022; 5:73. [PMID: 36697699 PMCID: PMC9814693 DOI: 10.1038/s42004-022-00689-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 05/27/2022] [Indexed: 01/28/2023] Open
Abstract
Polymer beads have been used as the core of magnetic particles for around twenty years. Here we report studies to attach polymetallic complexes to polymer beads for the first time, producing beads of around 115 microns diameter that are attached to 1014 hybrid inorganic-organic [2]rotaxanes. The bead is then formally a [1014] rotaxane. The number of complexes attached is counted by EPR spectroscopy after including TEMPO radicals within the thread of the hybrid [2]rotaxanes.
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Affiliation(s)
- Deepak Asthana
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK ,grid.449178.70000 0004 5894 7096Department of Chemistry, Ashoka University, Sonipat, Haryana India
| | - Dean Thomas
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Selena J. Lockyer
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Adam Brookfield
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Grigore A. Timco
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Iñigo J. Vitorica-Yrezabal
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - George F. S. Whitehead
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Eric J. L. McInnes
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - David Collison
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - David A. Leigh
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
| | - Richard E. P. Winpenny
- grid.5379.80000000121662407Department of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9Pl UK
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7
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Alotaibi R, Little E, Fowler JM, Brookfield A, Adams RW, Achari A, Timco GA, Whitehead GFS, Chilton NF, Nair RR, Collison D, Winpenny REP. Single Isomer Heterometallic {Cr III6M II2} Rings Templated by Tetramethylammonium. Inorg Chem 2021; 60:15675-15685. [PMID: 34613713 DOI: 10.1021/acs.inorgchem.1c02342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A family of heterometallic rings [Me4N]2[CrIII6MII2F8(O2CtBu)16] is reported using tetramethylammonium hydroxide pentahydrate as the source of a template, where M = Zn, Mn, Ni, and Co. The metal cores are octagons with metal-metal edges bridged by one fluoride and two carboxylate ligands. The divalent metal ions are found ordered at positions 1 and 5 in the octagon. The tetramethylammonium cations are above and below the metal plane of the ring in the crystal structure. Magnetic studies show antiferromagnetic coupling between the paramagnetic metal ions present, leading to paramagnetic ground states in each case. 1H NMR spectroscopy confirms that the structure of the {CrIII6CoII2} ring exists in solution, and electron paramagnetic resonance spectroscopy confirms the magnetic structure of the other three rings.
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Affiliation(s)
- Rajeh Alotaibi
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Edmund Little
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Jonathan M Fowler
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Adam Brookfield
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Ralph W Adams
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Amritroop Achari
- Department of Physics and Astronomy and National Graphene Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Grigore A Timco
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - George F S Whitehead
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Nicholas F Chilton
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Rahul R Nair
- Department of Physics and Astronomy and National Graphene Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - David Collison
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Richard E P Winpenny
- Department of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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8
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Lockyer S, Fielding AJ, Whitehead GFS, Timco GA, Winpenny REP, McInnes EJL. Close Encounters of the Weak Kind: Investigations of Electron-Electron Interactions between Dissimilar Spins in Hybrid Rotaxanes. J Am Chem Soc 2019; 141:14633-14642. [PMID: 31411874 PMCID: PMC6814243 DOI: 10.1021/jacs.9b05590] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Indexed: 01/14/2023]
Abstract
We report a family of hybrid [2]rotaxanes based on inorganic [Cr7NiF8(O2CtBu)16]- ("{Cr7Ni}") rings templated about organic threads that are terminated at one end with pyridyl groups. These rotaxanes can be coordinated to [Cu(hfac)2] (where Hhfac = 1,1,1,5,5,5-hexafluoroacetylacetone), to give 1:1 or 1:2 Cu:{Cr7Ni} adducts: {[Cu(hfac)2](py-CH2NH2CH2CH2Ph)[Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2][py-CH2NH2CH2CH3][Cr7NiF8(O2CtBu)16]}, {[Cu(hfac)2]([py-CH2CH2NH2CH2C6H4SCH3][Cr7NiF8(O2CtBu)16])2}, {[Cu(hfac)2]([py-C6H4-CH2NH2(CH2)4Ph][Cr7NiF8(O2CtBu)16])2}, and {[Cu(hfac)2]([3-py-CH2CH2NH2(CH2)3SCH3][Cr7NiF8(O2CtBu)16])2}, the structures of which have been determined by X-ray diffraction. The {Cr7Ni} rings and CuII ions both have electronic spin S = 1/2, but with very different g-values. Continuous-wave EPR spectroscopy reveals the exchange interactions between these dissimilar spins, and hence the communication between the different molecular components that comprise these supramolecular systems. The interactions are weak such that we observe AX or AX2 type spectra. The connectivity between the {Cr7Ni} ring and thread terminus is varied such that the magnitude of the exchange interaction J can be tuned. The coupling is shown to be dominated by through-bond rather than through-space mechanisms.
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Affiliation(s)
- Selena
J. Lockyer
- School
of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Alistair J. Fielding
- School
of Pharmacy and Biomolecular Sciences, Liverpool
John Moores University, Liverpool L3 5UX, U.K.
| | - George F. S. Whitehead
- School
of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Grigore A. Timco
- School
of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Richard E. P. Winpenny
- School
of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
| | - Eric J. L. McInnes
- School
of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K.
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9
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Weissman S, Antkowiak M, Brzostowski B, Kamieniarz G, Kronik L. Accurate Magnetic Couplings in Chromium-Based Molecular Rings from Broken-Symmetry Calculations within Density Functional Theory. J Chem Theory Comput 2019; 15:4885-4895. [PMID: 31393723 DOI: 10.1021/acs.jctc.9b00459] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a comprehensive analysis of magnetic coupling in a group of three popular chromium-based molecular rings, the homometallic Cr8 ring and the heterometallic Cr7Ni and Cr7Zn molecules. We show conclusively that the broken symmetry approach within density functional theory (DFT), based on suitable conventional or range-separated hybrid functionals, provides a quantitatively reliable tool to extract magnetic exchange coupling parameters in all rings considered, which opens a window for additional applications in molecular magnetism. We further show that a nonempirical model spin Hamiltonian, based on the parameters extracted from DFT, leads to excellent agreement with experimental susceptibility data and energy spectra. Moreover, based on an optimally tuned range-separated hybrid functional approach, we find that gas-phase gaps of the studied molecular rings are much larger than previously calculated and discuss the implications of the revised electronic structure to potential applications in molecular spintronics.
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Affiliation(s)
- Shira Weissman
- Department of Materials and Interfaces , Weizmann Institute of Science , Rehovoth 76100 , Israel
| | - Michał Antkowiak
- Faculty of Physics , A. Mickiewicz University , 61-614 Poznań , Poland
| | - Bartosz Brzostowski
- Institute of Physics , University of Zielona Góra , 65-516 Zielona Góra , Poland
| | | | - Leeor Kronik
- Department of Materials and Interfaces , Weizmann Institute of Science , Rehovoth 76100 , Israel
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10
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Mitcov D, Pedersen AH, Ceccato M, Gelardi RM, Hassenkam T, Konstantatos A, Reinholdt A, Sørensen MA, Thulstrup PW, Vinum MG, Wilhelm F, Rogalev A, Wernsdorfer W, Brechin EK, Piligkos S. Molecular multifunctionality preservation upon surface deposition for a chiral single-molecule magnet. Chem Sci 2019; 10:3065-3073. [PMID: 30996888 PMCID: PMC6428142 DOI: 10.1039/c8sc04917c] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/23/2019] [Indexed: 01/06/2023] Open
Abstract
Simultaneous retention of SMM behaviour and of optical activity is demonstrated upon surface deposition for a chiral SMM.
The synthesis and characterization of a chiral, enneanuclear Mn(iii)-based, Single-Molecule Magnet, [Mn9O4(Me-sao)6(L)3(MeO)3(MeOH)3]Cl (1; Me-saoH2 = methylsalicylaldoxime, HL = lipoic acid) is reported. Compound 1 crystallizes in the orthorhombic P212121 space group and consists of a metallic skeleton describing a defect super-tetrahedron missing one vertex. The chirality of the [MnIII9] core originates from the directional bridging of the Me-sao2– ligands via the –N–O– oximate moieties, which define a clockwise (1ΔΔ) or counter-clockwise (1ΛΛ) rotation in both the upper [MnIII3] and lower [MnIII6] subunits. Structural integrity and retention of chirality upon dissolution and upon deposition on (a) gold nanoparticles, 1@AuNPs, (b) transparent Au(111) surfaces, 1ΛΛ@t-Au(111); 1ΔΔ@t-Au(111), and (c) epitaxial Au(111) on mica surfaces, 1@e-Au(111), was confirmed by CD and IR spectroscopies, mass spectrometry, TEM, XPS, XAS, and AFM. Magnetic susceptibility and magnetization measurements demonstrate the simultaneous retention of SMM behaviour and optical activity, from the solid state, via dissolution, to the surface deposited species.
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Affiliation(s)
- Dmitri Mitcov
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Anders H Pedersen
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Marcel Ceccato
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Rikke M Gelardi
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Tue Hassenkam
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Andreas Konstantatos
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Anders Reinholdt
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Mikkel A Sørensen
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Peter W Thulstrup
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Morten G Vinum
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
| | - Fabrice Wilhelm
- ESRF-The European Synchrotron , CS 40220 , 38043 Grenoble Cedex 9 , France
| | - Andrei Rogalev
- ESRF-The European Synchrotron , CS 40220 , 38043 Grenoble Cedex 9 , France
| | - Wolfgang Wernsdorfer
- Institute Néel , CNRS , BP 166 , 25 Avenue de Martyrs , Grenoble , 38042 Cedex 9 , France
| | - Euan K Brechin
- EaStCHEM School of Chemistry , The University of Edinburgh , David Brewster Road , Edinburgh , EH9 3FJ , UK
| | - Stergios Piligkos
- Department of Chemistry , University of Copenhagen , Universitetsparken 5 , DK-2100 , Copenhagen , Denmark .
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11
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Abstract
A viable qubit must have a long coherence time T 2 . In molecular nanomagnets, T 2 is often limited at low temperatures by the presence of dipole and hyperfine interactions, which are often mitigated through sample dilution, chemical engineering and isotope substitution in synthesis. Atomic-clock transitions offer another route to reducing decoherence from environmental fields by reducing the effective susceptibility of the working transition to field fluctuations. The Cr7Mn molecular nanomagnet, a heterometallic ring, features a clock transition at zero field. Both continuous-wave and spin-echo electron-spin resonance experiments on Cr7Mn samples, diluted via co-crystallization, show evidence of the effects of the clock transition with a maximum T 2 ∼ 390 ns at 1.8 K. We discuss improvements to the experiment that may increase T 2 further.
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12
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Timco GA, Fernandez A, Kostopoulos AK, Charlton JF, Lockyer SJ, Hailes TR, Adams RW, McInnes EJL, Tuna F, Vitorica-Yrezabal IJ, Whitehead GFS, Winpenny REP. Hybrid Organic-Inorganic Rotaxanes, Including a Hetero-Hybrid [3]Rotaxane Featuring Two Distinct Heterometallic Rings and a Molecular Shuttle. Angew Chem Int Ed Engl 2018; 57:10919-10922. [PMID: 29932482 DOI: 10.1002/anie.201805439] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 06/08/2018] [Indexed: 01/03/2023]
Abstract
[2] and [3] hybrid rotaxanes are reported based on {Ti7 M} rings (M is a trivalent metal such as FeIII or GaIII ). NMR studies show that [2]rotaxanes can act as molecular shuttles, while EPR studies of [3]rotaxanes show weak interactions between the paramagnetic components of the supramolecular assemblies.
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Affiliation(s)
- Grigore A Timco
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Antonio Fernandez
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Andreas K Kostopoulos
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Jodie F Charlton
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Selena J Lockyer
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Thomas R Hailes
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Ralph W Adams
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Eric J L McInnes
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Floriana Tuna
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | | | - George F S Whitehead
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Richard E P Winpenny
- The School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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13
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Timco GA, Fernandez A, Kostopoulos AK, Charlton JF, Lockyer SJ, Hailes TR, Adams RW, McInnes EJL, Tuna F, Vitorica-Yrezabal IJ, Whitehead GFS, Winpenny REP. Hybrid Organic-Inorganic Rotaxanes, Including a Hetero-Hybrid [3]Rotaxane Featuring Two Distinct Heterometallic Rings and a Molecular Shuttle. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805439] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Grigore A. Timco
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Antonio Fernandez
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Andreas K. Kostopoulos
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Jodie F. Charlton
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Selena J. Lockyer
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Thomas R. Hailes
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Ralph W. Adams
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Eric J. L. McInnes
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Floriana Tuna
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | | | - George F. S. Whitehead
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Richard E. P. Winpenny
- The School of Chemistry; The University of Manchester; Oxford Road Manchester M13 9PL UK
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14
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Fraser HWL, Smythe L, Dey S, Nichol GS, Piligkos S, Rajaraman G, Brechin EK. A simple methodology for constructing ferromagnetically coupled Cr(iii) compounds. Dalton Trans 2018; 47:8100-8109. [PMID: 29877529 DOI: 10.1039/c8dt01963k] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A large family of chromium(iii) dimers has been synthesised and magneto-structurally characterised using a combination of carboxylate and diethanolamine type ligands. The compounds have the general formula [Cr2(R1-deaH)2(O2CR2)Cl2]Cl where R1 = Me and R2 = H (1), Me (2), CMe3 (3), Ph (4), 3,5-(Cl)2Ph (5), (Me)5Ph (6), R1 = Et and R2 = H (7), Ph (8). The compound [Cr2(Me-deaH)2Cl4] (9) was synthesised in order to study the effect of removing/adding the carboxylate bridge on the observed magnetic behaviour. Direct current (DC) magnetic susceptibility measurements showed ferromagnetic (FM) exchange interactions between the Cr(iii) centres in the carboxylate bridged family with coupling constants in the range +0.37 < J < +8.02 cm-1. Removal of the carboxylate to produce the dialkoxide-bridged compound 9 resulted in antiferromagnetic (AFM) exchange between the Cr(iii) ions. DFT calculations reveal the ferromagnetic exchange is the result of an orbital counter-complementarity effect occuring upon introduction of the bridging carboxylate.
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Affiliation(s)
- Hector W L Fraser
- EaStCHEM School of Chemistry, The University of Edinburgh, David Brewster Road, Edinburgh, EH9 3FJ Scotland, UK.
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15
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16
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17
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Leng JD, Kostopoulos AK, Isherwood LH, Ariciu AM, Tuna F, Vitórica-Yrezábal IJ, Pritchard RG, Whitehead GFS, Timco GA, Mills DP, Winpenny REP. Chromium chains as polydentate fluoride ligands for actinides and group IV metals. Dalton Trans 2018; 47:6361-6369. [DOI: 10.1039/c8dt00803e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
New heterometallic rings containing Cr(iii) and tetravalent metals are reported, including a {Cr6Th2} cage.
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Affiliation(s)
- Ji-Dong Leng
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology
- School of Chemistry and Chemical Engineering
- Guangzhou University
- 230 Wai Huan Xi Road
- Guangzhou Higher Education Mega Center
| | | | - Liam H. Isherwood
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
| | - Ana-Maria Ariciu
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
| | - Floriana Tuna
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
| | | | - Robin G. Pritchard
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
| | | | - Grigore A. Timco
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
| | - David P. Mills
- School of Chemistry and Photon Science Institute
- University of Manchester
- Manchester
- UK
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18
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Liu JJ, Liu T, Xia SB, Cheng FX, Huang CC. Synthesis, crystal structures and photochromic properties of two coordination polymers based on a rigid tetracarboxylic acid ligand. TRANSIT METAL CHEM 2017. [DOI: 10.1007/s11243-017-0157-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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19
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Boulon M, Fernandez A, Moreno Pineda E, Chilton NF, Timco G, Fielding AJ, Winpenny REP. Measuring Spin⋅⋅⋅Spin Interactions between Heterospins in a Hybrid [2]Rotaxane. Angew Chem Int Ed Engl 2017; 56:3876-3879. [PMID: 28276620 PMCID: PMC5434811 DOI: 10.1002/anie.201612249] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Indexed: 12/29/2022]
Abstract
Use of molecular electron spins as qubits for quantum computing will depend on the ability to produce molecules with weak but measurable interactions between the qubits. Here we demonstrate use of pulsed EPR spectroscopy to measure the interaction between two inequivalent spins in a hybrid rotaxane molecule.
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Affiliation(s)
- Marie‐Emmanuelle Boulon
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Antonio Fernandez
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Eufemio Moreno Pineda
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Nicholas F. Chilton
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Grigore Timco
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Alistair J. Fielding
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
| | - Richard E. P. Winpenny
- The School of Chemistry and Photon Science InstituteThe University of ManchesterOxford RoadManchesterM13 9PLUK
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20
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Boulon ME, Fernandez A, Moreno Pineda E, Chilton NF, Timco G, Fielding AJ, Winpenny REP. Measuring Spin⋅⋅⋅Spin Interactions between Heterospins in a Hybrid [2]Rotaxane. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201612249] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Marie-Emmanuelle Boulon
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Antonio Fernandez
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Eufemio Moreno Pineda
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Nicholas F. Chilton
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Grigore Timco
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Alistair J. Fielding
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
| | - Richard E. P. Winpenny
- The School of Chemistry and Photon Science Institute; The University of Manchester; Oxford Road Manchester M13 9PL UK
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21
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Ferrando-Soria J, Magee S, Chiesa A, Carretta S, Santini P, Vitorica-Yrezabal I, Tuna F, Whitehead G, Sproules S, Lancaster K, Barra AL, Timco G, McInnes E, Winpenny R. Switchable Interaction in Molecular Double Qubits. Chem 2016. [DOI: 10.1016/j.chempr.2016.10.001] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Timco G, Marocchi S, Garlatti E, Barker C, Albring M, Bellini V, Manghi F, McInnes EJL, Pritchard RG, Tuna F, Wernsdorfer W, Lorusso G, Amoretti G, Carretta S, Affronte M, Winpenny REP. Heterodimers of heterometallic rings. Dalton Trans 2016; 45:16610-16615. [PMID: 27477766 DOI: 10.1039/c6dt01941b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Nine new complexes are reported involving linked heterometallic rings; one ring is designed as a ligand for the second, and the compounds produced can be regarded as molecular prototypes for implementing quantum gates featuring two subtly different qubits.
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Affiliation(s)
- Grigore Timco
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | - Simone Marocchi
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, via Campi 213/a, 41125 Modena, Italy and CNR-NANO-S3 via Campi 213/a, 41100 Modena, Italy
| | - Elena Garlatti
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
| | - Claire Barker
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | - Morten Albring
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | | | - Franca Manghi
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, via Campi 213/a, 41125 Modena, Italy and CNR-NANO-S3 via Campi 213/a, 41100 Modena, Italy
| | - Eric J L McInnes
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | - Robin G Pritchard
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | - Floriana Tuna
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
| | - Wolfgang Wernsdorfer
- Laboratoire Louis Néel - CNRS, BP 166, 25 Avenue des Martyrs, 38042 GRENOBLE Cedex 9, France
| | - Giulia Lorusso
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, via Campi 213/a, 41125 Modena, Italy and CNR-NANO-S3 via Campi 213/a, 41100 Modena, Italy
| | - Giuseppe Amoretti
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
| | - Stefano Carretta
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
| | - Marco Affronte
- Dipartimento di Scienze Fisiche, Informatiche e Matematiche, Università di Modena e Reggio Emilia, via Campi 213/a, 41125 Modena, Italy and CNR-NANO-S3 via Campi 213/a, 41100 Modena, Italy
| | - Richard E P Winpenny
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road. M13 9PL, Manchester, UK.
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23
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Morsing TJ, Weihe H, Bendix J. Probing Effective Hamiltonian Operators by Single-Crystal EPR: A Case Study Using Dinuclear Cr(III) Complexes. Inorg Chem 2016; 55:1453-60. [DOI: 10.1021/acs.inorgchem.5b02164] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thorbjørn J. Morsing
- Department of Chemistry, University of Copenhagen, Universitetsparken
5, DK-2100 København, Denmark
| | - Høgni Weihe
- Department of Chemistry, University of Copenhagen, Universitetsparken
5, DK-2100 København, Denmark
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Universitetsparken
5, DK-2100 København, Denmark
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24
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Walsh JPS, Meadows SB, Ghirri A, Moro F, Jennings M, Smith WF, Graham DM, Kihara T, Nojiri H, Vitorica-Yrezabal IJ, Timco GA, Collison D, McInnes EJL, Winpenny REP. Electronic Structure of a Mixed-Metal Fluoride-Centered Triangle Complex: A Potential Qubit Component. Inorg Chem 2015; 54:12019-26. [PMID: 26636473 DOI: 10.1021/acs.inorgchem.5b01898] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel fluoride-centered triangular-bridged carboxylate complex, [Ni2Cr(μ3-F)(O2C(t)Bu)6(HO2C(t)Bu)3] (1), is reported. Simple postsynthetic substitution of the terminal pivalic acids in 1 with pyridine and 4-methylpyridine led to the isolation of [Ni2Cr(μ3-F)(O2C(t)Bu)6(C5H5N)3] (2) and [Ni2Cr(μ3-F)(O2C(t)Bu)6((4-CH3)C5H4N)3] (3). Structural and magnetic characterizations carried out on the series reveal a dominating antiferromagnetic interaction between the nickel and chromium centers leading to an S = (1)/2 ground state with a very unusual value of geff = 2.48.
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Affiliation(s)
- James P S Walsh
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Sarah B Meadows
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Alberto Ghirri
- S3 Centre, Institute Nanoscience (CNR) , via G. Campi 213/A, 41125 Modena, Italy
| | - Fabrizio Moro
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Martin Jennings
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - William F Smith
- School of Physics and Astronomy and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Darren M Graham
- School of Physics and Astronomy and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Takumi Kihara
- Institute for Materials Research, Tohoku University , Katahira, Sendai 980-8577, Japan
| | - Hiroyuki Nojiri
- Institute for Materials Research, Tohoku University , Katahira, Sendai 980-8577, Japan
| | - Iñigo J Vitorica-Yrezabal
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Grigore A Timco
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - David Collison
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Eric J L McInnes
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
| | - Richard E P Winpenny
- School of Chemistry and Photon Science Institute, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom
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25
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McInnes EJL, Timco GA, Whitehead GFS, Winpenny REP. Heterometallic Rings: Their Physics and use as Supramolecular Building Blocks. Angew Chem Int Ed Engl 2015; 54:14244-69. [PMID: 26459810 DOI: 10.1002/anie.201502730] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Indexed: 11/10/2022]
Abstract
An enormous family of heterometallic rings has been made. The first were Cr7 M rings where M = Ni(II), Zn(II), Mn(II), and rings have been made with as many as fourteen metal centers in the cyclic structure. They are bridged externally by carboxylates, and internally by fluorides or a penta-deprotonated polyol. The size of the rings is controlled through templates which have included a range of ammonium or imidazolium ions, alkali metals and coordination compounds. The rings can be functionalized to act as ligands, and incorporated into hybrid organic-inorganic rotaxanes and into molecules containing up to 200 metal centers. Physical studies reported include: magnetic measurements, inelastic neutron scattering (including single crystal measurements), electron paramagnetic resonance spectroscopy (including measurements of phase memory times), NMR spectroscopy (both solution and solid state), and polarized neutron diffraction. The rings are hence ideal for understanding magnetism in elegant exchange-coupled systems.
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Affiliation(s)
- Eric J L McInnes
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Grigore A Timco
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - George F S Whitehead
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Richard E P Winpenny
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL (UK).
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26
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McInnes EJL, Timco GA, Whitehead GFS, Winpenny REP. Heterometallische Ringe: physikalische Eigenschaften und Verwendung als supramolekulare Bausteine. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201502730] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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27
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Abstract
This chapter summarizes the core concepts underlying the simulation of EPR spectra from biological samples in the solid state, from a user perspective. The key choices and decisions that have to be made by a user when simulating an experimental EPR spectrum are outlined. These include: the choice of the simulation model (the network of spins and the associated spin Hamiltonian), the dynamic regime (solid, liquid, slow motion), the level of theory used in the simulation (matrix diagonalization, perturbation theory, etc.), the treatment of orientational order and disorder (powder, crystal, partial ordering), the inclusion of the effects of structural disorder (strains), the effects of other line broadening mechanisms (unresolved hyperfine couplings, relaxation), and the inclusion of experimental distortions (field modulation, power saturation, filtering). Additionally, the salient aspects of utilizing least-squares fitting algorithms to aid the analysis of experimental spectra with the help of simulations are outlined. Although drawing from the experience gained from implementing EasySpin and from interacting with EasySpin's user base, this chapter applies to any EPR simulation software.
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Affiliation(s)
- Stefan Stoll
- Department of Chemistry, University of Washington, Seattle, Washington, USA.
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28
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Fernandez A, Moreno Pineda E, Muryn CA, Sproules S, Moro F, Timco GA, McInnes EJL, Winpenny REP. g-Engineering in Hybrid Rotaxanes To Create AB and AB2 Electron Spin Systems: EPR Spectroscopic Studies of Weak Interactions between Dissimilar Electron Spin Qubits. Angew Chem Int Ed Engl 2015. [PMID: 26224489 DOI: 10.1002/anie.201504487] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Hybrid [2]rotaxanes and pseudorotaxanes are reported where the magnetic interaction between dissimilar spins is controlled to create AB and AB2 electron spin systems, allowing independent control of weakly interacting S=${{ 1/2 }}$ centers.
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Affiliation(s)
- Antonio Fernandez
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Eufemio Moreno Pineda
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK).,Current address: Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen (Germany)
| | - Christopher A Muryn
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Stephen Sproules
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK).,Current address: WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ (UK)
| | - Fabrizio Moro
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK).,Current address: School of Physics and Astronomy, The University of Nottingham, University Park, NG7 2RD, Nottingham (UK)
| | - Grigore A Timco
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Eric J L McInnes
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Richard E P Winpenny
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL (UK).
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29
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Fernandez A, Moreno Pineda E, Muryn CA, Sproules S, Moro F, Timco GA, McInnes EJL, Winpenny REP. g-Engineering in Hybrid Rotaxanes To Create AB and AB2Electron Spin Systems: EPR Spectroscopic Studies of Weak Interactions between Dissimilar Electron Spin Qubits. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201504487] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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30
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Caballero-Jiménez J, Habib F, Ramírez-Rosales D, Grande-Aztatzi R, Merino G, Korobkov I, Singh MK, Rajaraman G, Reyes-Ortega Y, Murugesu M. Inducing magnetic communication in caged dinuclear Co(ii) systems. Dalton Trans 2015; 44:8649-59. [DOI: 10.1039/c5dt00497g] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Magnetic interactions were probed for a series of mono and tri atomic bridged dinuclear Co(ii) azacryptand complexes. Magneto-structural correlations were established usingab initiocalculations.
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Affiliation(s)
| | - Fatemah Habib
- Department of Chemistry
- University of Ottawa
- Ottawa
- Canada K1N6N5
| | - Daniel Ramírez-Rosales
- Departamento de Física
- Escuela Superior de Física y Matemáticas
- I.P.N
- Av. Instituto Politécnico Nacional s/n San Pedro Zacatenco
- México 07738
| | - Rafael Grande-Aztatzi
- Departamento de Física Aplicada
- Centro de Investigación de Estudios Avanzados Unidad Mérida. km 6 Antigua carretera a Progreso
- Mérida
- México
| | - Gabriel Merino
- Departamento de Física Aplicada
- Centro de Investigación de Estudios Avanzados Unidad Mérida. km 6 Antigua carretera a Progreso
- Mérida
- México
| | - Ilia Korobkov
- Department of Chemistry
- University of Ottawa
- Ottawa
- Canada K1N6N5
| | | | - Gopalan Rajaraman
- Department of Chemistry
- Indian Institute of Technology Bombay
- Mumbai
- India
| | - Yasmi Reyes-Ortega
- Centro de Química
- Instituto de Ciencias
- Universidad Autónoma de Puebla
- 72000 Puebla
- México
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31
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Fernandez A, Moreno Pineda E, Ferrando-Soria J, McInnes EJL, Timco GA, Winpenny REP. A hybrid organic–inorganic molecular daisy chain. Chem Commun (Camb) 2015; 51:11126-9. [DOI: 10.1039/c5cc02216a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A hybrid daisy-chain has been made, involving an organic thread for an inorganic ring, where the organic thread for the ring also acts as a ligand for a second ring. The ring contains six chromium(iii) and two zinc(ii) ions, and two isomers of the rings are found in the daisy-chain.
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Affiliation(s)
- Antonio Fernandez
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
| | - Eufemio Moreno Pineda
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
| | - Jesùs Ferrando-Soria
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
| | - Grigore A. Timco
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
| | - Richard E. P. Winpenny
- School of Chemistry and Photon Science Institute
- The University of Manchester
- Manchester M13 9PL
- UK
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32
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Walsh JPS, Sproules S, Chilton NF, Barra AL, Timco GA, Collison D, McInnes EJL, Winpenny REP. On the Possibility of Magneto-Structural Correlations: Detailed Studies of Dinickel Carboxylate Complexes. Inorg Chem 2014; 53:8464-72. [DOI: 10.1021/ic501036h] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- James P. S. Walsh
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Stephen Sproules
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
- WestCHEM, School of Chemistry, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Nicholas F. Chilton
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Anne-Laure Barra
- Laboratoire National des Champs Magnétiques Intenses, 25, rue des
Martyrs, B.P. 166, 38042 Grenoble Cedex, France
| | - Grigore A. Timco
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - David Collison
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
| | - Richard E. P. Winpenny
- School of Chemistry and Photon Science
Institute, The University of Manchester, Manchester M13 9PL, United Kingdom
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33
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Singh SK, Gupta T, Badkur P, Rajaraman G. Magnetic anisotropy of mononuclear Ni(II) complexes: on the importance of structural diversity and the structural distortions. Chemistry 2014; 20:10305-13. [PMID: 25042299 DOI: 10.1002/chem.201402694] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Indexed: 11/06/2022]
Abstract
Mononuclear Ni(II) complexes are particularly attractive in the area of single-molecule magnets as the axial zero-field splitting (D) for the Ni(II) complexes is in the range of -200 to +200 cm(-1) . Despite this advantage, very little is known on the origin of anisotropy across various coordination ligands, coordination numbers, and particularly what factors influence the D parameter in these complexes. To answer some of these questions, herein we have undertaken a detailed study of a series of mononuclear Ni(II) complexes with ab initio calculations. Our results demonstrate that three prominent spin-conserved low-lying d-d transitions contribute significantly to the D value. Variation in the sign and the magnitude of D values are found to correlate to the specific structural distortions. Apart from the metal-ligand bond lengths, two different parameters, namely, Δα and Δβ, which are correlated to the cis angles present in the coordination environment, are found to significantly influence the axial D values. Developed magneto-structural D correlations suggest that the D values can be enhanced significantly by fine tuning the structural distortion in the coordination environment. Calculations performed on a series of Ni(II) models with coordination numbers two to six unfold an interesting observation-the D parameter increases significantly upon a reduction in coordination number compared with a reference octahedral coordination. Besides, if high symmetry is maintained, even larger coordination numbers yield large D values.
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Affiliation(s)
- Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai,Mumbai,Maharashtra,India-400 076, Fax: (+91) 22-2576-7152
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34
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Antkowiak M, Kucharski Ł, Kamieniarz G. Non-uniform coupling model of the frustrated chromium-based ring Cr8Ni. EPJ WEB OF CONFERENCES 2014. [DOI: 10.1051/epjconf/20147505007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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35
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Garlatti E, Albring MA, Baker ML, Docherty RJ, Mutka H, Guidi T, Garcia Sakai V, Whitehead GFS, Pritchard RG, Timco GA, Tuna F, Amoretti G, Carretta S, Santini P, Lorusso G, Affronte M, McInnes EJL, Collison D, Winpenny REP. A Detailed Study of the Magnetism of Chiral {Cr7M} Rings: An Investigation into Parametrization and Transferability of Parameters. J Am Chem Soc 2014; 136:9763-72. [DOI: 10.1021/ja5047445] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Elena Garlatti
- Dipartimento
di Fisica e Scienze della Terra, Università di Parma, via G.P. Usberti
7/a, 43123 Parma, Italy
| | - Morten A. Albring
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Michael L. Baker
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
- Institut Laue-Langevin, BP 156, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Rebecca J. Docherty
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Hannu Mutka
- Institut Laue-Langevin, BP 156, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France
| | - Tatiana Guidi
- ISIS
Facility, Rutherford Appleton Laboratory, Didcot OX11 0QX, United Kingdom
| | | | - George F. S. Whitehead
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Robin G. Pritchard
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Grigore A. Timco
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Floriana Tuna
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Giuseppe Amoretti
- Dipartimento
di Fisica e Scienze della Terra, Università di Parma, via G.P. Usberti
7/a, 43123 Parma, Italy
| | - Stefano Carretta
- Dipartimento
di Fisica e Scienze della Terra, Università di Parma, via G.P. Usberti
7/a, 43123 Parma, Italy
| | - Paolo Santini
- Dipartimento
di Fisica e Scienze della Terra, Università di Parma, via G.P. Usberti
7/a, 43123 Parma, Italy
| | - Giulia Lorusso
- Dipartimento
di Fisica, Università di Modena e Reggio Emilia, via Campi
213/a, 41100 Modena, Italy
| | - Marco Affronte
- Dipartimento
di Fisica, Università di Modena e Reggio Emilia, via Campi
213/a, 41100 Modena, Italy
| | - Eric J. L. McInnes
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - David Collison
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Richard E. P. Winpenny
- School
of Chemistry and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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36
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Magee SA, Sproules S, Barra AL, Timco GA, Chilton NF, Collison D, Winpenny REP, McInnes EJL. Large zero-field splittings of the ground spin state arising from antisymmetric exchange effects in heterometallic triangles. Angew Chem Int Ed Engl 2014; 53:5310-3. [PMID: 24737709 DOI: 10.1002/anie.201400655] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Indexed: 11/08/2022]
Abstract
[Ru2Mn(O)(O2CtBu)6(py)3] has an S=5/2 ground state with a very large zero-field splitting (ZFS) of D=2.9 cm(-1), as characterized by EPR spectroscopy at 4-330 GHz. This is far too large to be due to the Mn(II) ion (D <0.2 cm(-1)), as shown from the {Fe2Mn} analogue, but can be modeled by antisymmetric exchange effects.
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Affiliation(s)
- Samantha A Magee
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL (UK)
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37
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Magee SA, Sproules S, Barra AL, Timco GA, Chilton NF, Collison D, Winpenny REP, McInnes EJL. Large Zero-Field Splittings of the Ground Spin State Arising from Antisymmetric Exchange Effects in Heterometallic Triangles. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201400655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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38
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Singh SK, Rajaraman G. Probing the Origin of Magnetic Anisotropy in a Dinuclear {MnIIICuII} Single-Molecule Magnet: The Role of Exchange Anisotropy. Chemistry 2014; 20:5214-8. [DOI: 10.1002/chem.201304357] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/27/2014] [Indexed: 11/07/2022]
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39
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Moro F, Kaminski D, Tuna F, Whitehead GFS, Timco GA, Collison D, Winpenny REP, Ardavan A, McInnes EJL. Coherent electron spin manipulation in a dilute oriented ensemble of molecular nanomagnets: pulsed EPR on doped single crystals. Chem Commun (Camb) 2014; 50:91-3. [DOI: 10.1039/c3cc46326e] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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40
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Pascu G, Deville C, Clifford SE, Guenée L, Besnard C, Krämer KW, Liu SX, Decurtins S, Tuna F, McInnes EJL, Winpenny REP, Williams AF. The coordination chemistry of tartronic acid with copper: magnetic studies of a quasi-equilateral tricopper triangle. Dalton Trans 2014; 43:656-62. [DOI: 10.1039/c3dt51838h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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41
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Retegan M, Collomb MN, Neese F, Duboc C. A combined high-field EPR and quantum chemical study on a weakly ferromagnetically coupled dinuclear Mn(iii) complex. A complete analysis of the EPR spectrum beyond the strong coupling limit. Phys Chem Chem Phys 2013; 15:223-34. [DOI: 10.1039/c2cp42955a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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A classification of spin frustration in molecular magnets from a physical study of large odd-numbered-metal, odd electron rings. Proc Natl Acad Sci U S A 2012; 109:19113-8. [PMID: 23132941 DOI: 10.1073/pnas.1213127109] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The term "frustration" in the context of magnetism was originally used by P. W. Anderson and quickly adopted for application to the description of spin glasses and later to very special lattice types, such as the kagomé. The original use of the term was to describe systems with competing antiferromagnetic interactions and is important in current condensed matter physics in areas such as the description of emergent magnetic monopoles in spin ice. Within molecular magnetism, at least two very different definitions of frustration are used. Here we report the synthesis and characterization of unusual nine-metal rings, using magnetic measurements and inelastic neutron scattering, supported by density functional theory calculations. These compounds show different electronic/magnetic structures caused by frustration, and the findings lead us to propose a classification for frustration within molecular magnets that encompasses and clarifies all previous definitions.
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43
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Timco GA, McInnes EJL, Winpenny REP. Physical studies of heterometallic rings: an ideal system for studying magnetically-coupled systems. Chem Soc Rev 2012; 42:1796-806. [PMID: 22990593 DOI: 10.1039/c2cs35232j] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterometallic rings of general formula [Cat][M(7)M'F(8)(O(2)C(t)Bu)(8)] (M = a trivalent metal, M' = a divalent metal, cat = a secondary ammonium cation, caesium or rubidium) contain an octagon of metal centres with each metal-metal edge bridged by a fluoride and two carboxylates. The rings when M = Cr(III) give remarkably beautiful EPR and INS spectra, and allow us to examine new techniques. Use of these techniques allows us to study the models used to describe magnetic behaviour in exchange coupled systems. In this tutorial review we discuss the two main approaches to modelling magnetic data - the strong exchange limit and the microscopic Hamiltonian approaches, aiming to explain the major differences between the two approaches. We also describe some more esoteric measurements and theories.
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Affiliation(s)
- Grigore A Timco
- The School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
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44
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Wedge CJ, Timco GA, Spielberg ET, George RE, Tuna F, Rigby S, McInnes EJL, Winpenny REP, Blundell SJ, Ardavan A. Chemical engineering of molecular qubits. PHYSICAL REVIEW LETTERS 2012; 108:107204. [PMID: 22463450 DOI: 10.1103/physrevlett.108.107204] [Citation(s) in RCA: 156] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Indexed: 05/05/2023]
Abstract
We show that the electron spin phase memory time, the most important property of a molecular nanomagnet from the perspective of quantum information processing, can be improved dramatically by chemically engineering the molecular structure to optimize the environment of the spin. We vary systematically each structural component of the class of antiferromagnetic Cr(7)Ni rings to identify the sources of decoherence. The optimal structure exhibits a phase memory time exceeding 15 μs.
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Affiliation(s)
- C J Wedge
- Centre for Advanced Electron Spin Resonance, Clarendon Laboratory, Department of Physics, University of Oxford, OX1 3PU, United Kingdom
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45
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Faust TB, Bellini V, Candini A, Carretta S, Lorusso G, Allan DR, Carthy L, Collison D, Docherty RJ, Kenyon J, Machin J, McInnes EJL, Muryn CA, Nowell H, Pritchard RG, Teat SJ, Timco GA, Tuna F, Whitehead GFS, Wernsdorfer W, Affronte M, Winpenny REP. Chemical Control of Spin Propagation between Heterometallic Rings. Chemistry 2011; 17:14020-30. [DOI: 10.1002/chem.201101785] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Indexed: 11/09/2022]
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46
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Aravena D, Ruiz E. The Dilemma of CrIIINiII Exchange Interactions: Ferromagnetism versus Antiferromagnetism. Chemistry 2011; 17:8841-9. [DOI: 10.1002/chem.201100163] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2011] [Revised: 05/06/2011] [Indexed: 11/08/2022]
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47
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Timco GA, Faust TB, Tuna F, Winpenny REP. Linking heterometallic rings for quantum information processing and amusement. Chem Soc Rev 2011; 40:3067-75. [PMID: 21243130 DOI: 10.1039/c0cs00151a] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Linking polymetallic cages can be a method for creating new structures and new properties. In this tutorial review we use heterometallic anti-ferromagnetically coupled rings (AF-rings) as exemplars for three approaches that can be used to link cage compounds. The first of three routes involves an ion-pair interaction supported by hydrogen-bonding interactions, which allows the synthesis of hybrid rotaxanes among other materials. The second route involves functionalising the exterior of the AF-ring so that it will act as a Lewis base; complexes involving coordination of pyridine to bridging monometallic and dimetallic fragments are discussed. The third route involves creating a vacancy on one site of the AF-ring, and then using the ring as a Lewis acid. Di-imine ligands can then be used to link the AF-rings into dimers. A brief discussion of the physical properties of these systems is also included.
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Affiliation(s)
- Grigore A Timco
- The Lewis Magnetism Laboratory, School of Chemistry, The University of Manchester, Manchester, UK.
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48
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Baker ML, Piligkos S, Bianchi A, Carretta S, Collison D, McDouall JJW, McInnes EJL, Mutka H, Timco GA, Tuna F, Vadivelu P, Weihe H, Güdel HU, Winpenny REP. Modification of the magnetic properties of a heterometallic wheel by inclusion of a Jahn–Teller distorted Cu(ii) ion. Dalton Trans 2011; 40:8533-9. [DOI: 10.1039/c1dt10547g] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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49
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Boron TT, Kampf JW, Pecoraro VL. A Mixed 3d−4f 14-Metallacrown-5 Complex That Displays Slow Magnetic Relaxation through Geometric Control of Magnetoanisotropy. Inorg Chem 2010; 49:9104-6. [DOI: 10.1021/ic101121d] [Citation(s) in RCA: 98] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thaddeus T. Boron
- Willard H. Dow Chemical Laboratories, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Jeff W. Kampf
- Willard H. Dow Chemical Laboratories, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
| | - Vincent L. Pecoraro
- Willard H. Dow Chemical Laboratories, Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-1055
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50
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Dreiser J, Waldmann O, Carver G, Dobe C, Güdel HU, Weihe H, Barra AL. High-Frequency Electron-Spin-Resonance Study of the Octanuclear Ferric Wheel CsFe8. Inorg Chem 2010; 49:8729-35. [DOI: 10.1021/ic100664g] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jan Dreiser
- Physikalisches Institut, Universität Freiburg, D-79104 Freiburg, Germany
| | - Oliver Waldmann
- Physikalisches Institut, Universität Freiburg, D-79104 Freiburg, Germany
| | - Graham Carver
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Christopher Dobe
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Hans-Ulrich Güdel
- Department of Chemistry and Biochemistry, University of Bern, 3012 Bern, Switzerland
| | - Høgni Weihe
- Department of Chemistry, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Anne-Laure Barra
- Grenoble High Magnetic Field Laboratory, CNRS, BP 166, 38042 Grenoble Cedex 9, France
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