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Rubín J, Arauzo A, Bartolomé E, Sedona F, Rancan M, Armelao L, Luzón J, Guidi T, Garlatti E, Wilhelm F, Rogalev A, Amann A, Spagna S, Bartolomé J, Bartolomé F. Origin of the Unusual Ground-State Spin S = 9 in a Cr 10 Single-Molecule Magnet. J Am Chem Soc 2022; 144:12520-12535. [PMID: 35759747 PMCID: PMC9979690 DOI: 10.1021/jacs.2c05453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular wheel [Cr10(OMe)20(O2CCMe3)10], abbreviated {Cr10}, with an unusual intermediate total spin S = 9 and non-negligible cluster anisotropy, D/kB = -0.045(2) K, is a rare case among wheels based on an even number of 3d-metals, which usually present an antiferromagnetic (AF) ground state (S = 0). Herein, we unveil the origin of such a behavior. Angular magnetometry measurements performed on a single crystal confirmed the axial anisotropic behavior of {Cr10}. For powder samples, the temperature dependence of the susceptibility plotted as χT(T) showed an overall ferromagnetic (FM) behavior down to 1.8 K, whereas the magnetization curve M(H) did not saturate at the expected 30 μB/fu for 10 FM coupled 3/2 spin Cr3+ ions, but to a much lower value, corresponding to S = 9. In addition, the X-ray magnetic circular dichroism (XMCD) measured at high magnetic field (170 kOe) and 7.5 K showed the polarization of the cluster moment up to 23 μB/fu. The magnetic results can be rationalized within a model, including the cluster anisotropy, in which the {Cr10} wheel is formed by two semiwheels, each with four Cr3+ spins FM coupled (JFM/kB = 2.0 K), separated by two Cr3+ ions AF coupled asymmetrically (J23/kB = J78/kB = -2.0 K; J34/kB = J89/kB = -0.25 K). Inelastic neutron scattering and heat capacity allowed us to confirm this model leading to the S = 9 ground state and first excited S = 8. Single-molecule magnet behavior with an activation energy of U/kB = 4.0(5) K in the absence of applied field was observed through ac susceptibility measurements down to 0.1 K. The intriguing magnetic behavior of {Cr10} arises from the detailed asymmetry in the molecule interactions produced by small-angle distortions in the angles of the Cr-O-Cr alkoxy bridges coupling the Cr3+ ions, as demonstrated by ab initio and density functional theory calculations, while the cluster anisotropy can be correlated to the single-ion anisotropies calculated for each Cr3+ ion in the wheel.
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Affiliation(s)
- Javier Rubín
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Ciencia y Tecnología de Materiales y Fluidos, Universidad de Zaragoza, 50018 Zaragoza, Spain,
| | - Ana Arauzo
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Servicio
de Medidas Físicas, Universidad de
Zaragoza, Pedro Cerbuna
12, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Elena Bartolomé
- Escola
Universitària Salesiana de Sarrià (EUSS), Passeig Sant Joan Bosco 74, 08017 Barcelona, Spain,
| | - Francesco Sedona
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Marzio Rancan
- Institute
of Condensed Matter Chemistry and Technologies for Energy (ICMATE),
National Research Council (CNR), c/o Department of Chemistry, University of Padova, via F. Marzolo 1, 35131 Padova, Italy
| | - Lidia Armelao
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy,Department
of Chemical Sciences and Materials Technologies (DSCTM), National Research Council (CNR), Piazzale A. Moro 7, 00185 Roma, Italy
| | - Javier Luzón
- Academia
General Militar, Centro Universitario de
la Defensa, 50090 Zaragoza, Spain
| | - Tatiana Guidi
- Physics
Division, School of Science and Technology, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, MC, Italy,ISIS
Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, Oxfordshire, U.K.
| | - Elena Garlatti
- Dipartimento
di Science Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
| | - Fabrice Wilhelm
- ESRF − The European Synchrotron Radiation Facility, 71 Avenue des Martyrs CS40220, F-38043 Grenoble Cedex 09, France
| | - Andrei Rogalev
- ESRF − The European Synchrotron Radiation Facility, 71 Avenue des Martyrs CS40220, F-38043 Grenoble Cedex 09, France
| | - Andreas Amann
- Quantum Design Inc., San Diego, California 92121, United States
| | - Stefano Spagna
- Quantum Design Inc., San Diego, California 92121, United States
| | - Juan Bartolomé
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Fernando Bartolomé
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain,
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Adelnia F, Chiesa A, Bordignon S, Carretta S, Ghirri A, Candini A, Cervetti C, Evangelisti M, Affronte M, Sheikin I, Winpenny R, Timco G, Borsa F, Lascialfari A. Low temperature magnetic properties and spin dynamics in single crystals of Cr8Zn antiferromagnetic molecular rings. J Chem Phys 2015; 143:244321. [DOI: 10.1063/1.4938086] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Fatemeh Adelnia
- Dipartimento di Fisica, Università degli Studi di Milano and INSTM, I-20133 Milano, Italy
- Dipartimento di Fisica, Università degli Studi di Pavia and INSTM, I-27100 Pavia, Italy
| | - Alessandro Chiesa
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, I-43124 Parma, Italy
| | - Sara Bordignon
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, I-43124 Parma, Italy
| | - Stefano Carretta
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, I-43124 Parma, Italy
| | | | | | - Christian Cervetti
- Dipartimento di Scienze Fisiche, Informatiche, Matematiche, Università di Modena e Reggio Emilia, I-41125 Modena, Italy
| | - Marco Evangelisti
- CNR Institute Nanosciences S3, I- 41125 Modena, Italy
- Dipartimento di Scienze Fisiche, Informatiche, Matematiche, Università di Modena e Reggio Emilia, I-41125 Modena, Italy
- Instituto de Ciencia de Materiales de Aragón and Departamento de Física de la Materia Condensada, CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Marco Affronte
- CNR Institute Nanosciences S3, I- 41125 Modena, Italy
- Dipartimento di Scienze Fisiche, Informatiche, Matematiche, Università di Modena e Reggio Emilia, I-41125 Modena, Italy
| | - Ilya Sheikin
- Grenoble High Magnetic Field Laboratory, CNRS-LNCMI, 25, B.P. 166, 38042 Grenoble Cedex 9, France
| | - Richard Winpenny
- The Lewis Magnetism Laboratory, The University of Manchester, M13 9PL Manchester, United Kingdom
| | - Grigore Timco
- The Lewis Magnetism Laboratory, The University of Manchester, M13 9PL Manchester, United Kingdom
| | - Ferdinando Borsa
- Dipartimento di Fisica, Università degli Studi di Pavia and INSTM, I-27100 Pavia, Italy
| | - Alessandro Lascialfari
- Dipartimento di Fisica, Università degli Studi di Milano and INSTM, I-20133 Milano, Italy
- Dipartimento di Fisica, Università degli Studi di Pavia and INSTM, I-27100 Pavia, Italy
- Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Parma, I-43124 Parma, Italy
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