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Hu Z, Yang S. Endohedral metallofullerene molecular nanomagnets. Chem Soc Rev 2024; 53:2863-2897. [PMID: 38324027 DOI: 10.1039/d3cs00991b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
Magnetic lanthanide (Ln) metal complexes exhibiting magnetic bistability can behave as molecular nanomagnets, also known as single-molecule magnets (SMMs), suitable for storing magnetic information at the molecular level, thus attracting extensive interest in the quest for high-density information storage and quantum information technologies. Upon encapsulating Ln ion(s) into fullerene cages, endohedral metallofullerenes (EMFs) have been proven as a promising and versatile platform to realize chemically robust SMMs, in which the magnetic properties are able to be readily tailored by altering the configurations of the encapsulated species and the host cages. In this review, we present critical discussions on the molecular structures and magnetic characterizations of EMF-SMMs, with the focus on their peculiar molecular and electronic structures and on the intriguing molecular magnetism arising from such structural uniqueness. In this context, different families of magnetic EMFs are summarized, including mononuclear EMF-SMMs wherein single-ion anisotropy is decisive, dinuclear clusterfullerenes whose magnetism is governed by intramolecular magnetic interaction, and radical-bridged dimetallic EMFs with high-spin ground states that arise from the strong ferromagnetic coupling. We then discuss how molecular assemblies of SMMs can be constructed, in a way that the original SMM behavior is either retained or altered in a controlled manner, thanks to the chemical robustness of EMFs. Finally, on the basis of understanding the structure-magnetic property correlation, we propose design strategies for high-performance EMF-SMMs by engineering ligand fields, electronic structures, magnetic interactions, and molecular vibrations that can couple to the spin states.
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Affiliation(s)
- Ziqi Hu
- Key Laboratory of Precision and Intelligent Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Materials Science and Engineering, Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China.
| | - Shangfeng Yang
- Key Laboratory of Precision and Intelligent Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Materials Science and Engineering, Anhui Laboratory of Advanced Photon Science and Technology, University of Science and Technology of China, Hefei 230026, China.
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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: 19] [Impact Index Per Article: 4.8] [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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Schlesier C, Liu F, Dubrovin V, Spree L, Büchner B, Avdoshenko SM, Popov AA. Mixed dysprosium-lanthanide nitride clusterfullerenes DyM 2N@C 80-I h and Dy 2MN@C 80-I h (M = Gd, Er, Tm, and Lu): synthesis, molecular structure, and quantum motion of the endohedral nitrogen atom. NANOSCALE 2019; 11:13139-13153. [PMID: 31268459 DOI: 10.1039/c9nr03593a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Systematic exploration of the synthesis of mixed-metal Dy-M nitride clusterfullerenes (NCFs, M = Gd, Er, Tm, Lu) is performed, and the impact of the second metal on the relative yield is evaluated. We demonstrate that the ionic radius of the metal appears to be the main factor allowing explanation of the relative yields in Dy-M mixed-metal systems with M = Sc, Lu, Er, and Gd. At the same time, Dy-Tm NCFs show anomalously low yields, which is not consistent with the relatively small ionic radius of Tm3+ but can be explained by the high third ionization potential of Tm. Complete separation of Dy-Gd and Dy-Er, as well as partial separation of Dy-Lu M3N@C80 nitride clusterfullerenes, is accomplished by recycling HPLC. The molecular structures of DyGd2N@C80 and DyEr2N@C80 are analyzed by means of single-crystal X-ray diffraction. A remarkable ordering of mixed-metal nitride clusters is found despite similar size and electronic properties of the metals. Possible pyramidalization of the nitride clusters in these and other nitride clusterfullerenes is critically analyzed with the help of DFT calculations and reconstruction of the nitrogen inversion barrier in M3N@C80 molecules is performed. Although a double-well potential with a pyramidal cluster structure is found to be common for most of them, the small size of the inversion barrier often leads to an apparent planar structure of the cluster. This situation is found for those M3N@C80 molecules in which the energy of the lowest vibrational level exceeds that of the inversion barrier, including Dy3N@C80 and DyEr2N@C80. The genuine pyramidal structure can be observed by X-ray diffraction only when the lowest vibrational level is below the inversion barrier, such as those found in Gd3N@C80 and DyGd2N@C80. The quantum nature of molecular vibrations becomes especially apparent when the size of the inversion barrier is comparable to the energy of the lowest vibrational levels.
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Affiliation(s)
- C Schlesier
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - F Liu
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - V Dubrovin
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - L Spree
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - B Büchner
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - S M Avdoshenko
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
| | - A A Popov
- Leibniz Institute for Solid State and Materials Research (IFW Dresden), Helmholtzstrasse 20, 01069 Dresden, Germany.
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Brandenburg A, Krylov DS, Beger A, Wolter AUB, Büchner B, Popov AA. Carbide clusterfullerene DyYTiC@C 80 featuring three different metals in the endohedral cluster and its single-ion magnetism. Chem Commun (Camb) 2018; 54:10683-10686. [PMID: 30087957 PMCID: PMC6839965 DOI: 10.1039/c8cc04736g] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Carbide clusterfullerene DyYTiC@C80-Ih with three different metal atoms in the endohedral cluster is obtained by arc-discharge synthesis with methane as reactive gas and is successfully isolated by HPLC. The compound shows single-molecule magnetism (SMM) with magnetic hysteresis below 8 K. The SMM properties of DyYTiC@C80 are compared to those of DySc2N@C80 and the influence of the central atom in the endohedral cluster is analyzed.
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Affiliation(s)
- Ariane Brandenburg
- Leibniz Institute for Solid State and Materials Research (IFW), D-01069 Dresden, Germany.
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Krylov DS, Liu F, Brandenburg A, Spree L, Bon V, Kaskel S, Wolter AUB, Büchner B, Avdoshenko SM, Popov AA. Magnetization relaxation in the single-ion magnet DySc 2N@C 80: quantum tunneling, magnetic dilution, and unconventional temperature dependence. Phys Chem Chem Phys 2018; 20:11656-11672. [PMID: 29671443 PMCID: PMC5933001 DOI: 10.1039/c8cp01608a] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Quantum tunneling and relaxation of magnetization in single molecule magnet DySc2N@C80 is thoroughly studied as a function of magnetic dilution, temperature, and magnetic field.
Relaxation of magnetization in endohedral metallofullerenes DySc2N@C80 is studied at different temperatures, in different magnetic fields, and in different molecular arrangements. Magnetization behavior and relaxation are analyzed for powder sample, and for DySc2N@C80 diluted in non-magnetic fullerene Lu3N@C80, adsorbed in voids of a metal–organic framework, and dispersed in a polymer. The magnetic field dependence and zero-field relaxation are also studied for single-crystals of DySc2N@C80 co-crystallized with Ni(ii) octaethylporphyrin, as well as for the single crystal diluted with Lu3N@C80. Landau–Zener theory is applied to analyze quantum tunneling of magnetization in the crystals. The field dependence of relaxation rates revealed a dramatic dependence of the zero-field tunneling resonance width on the dilution and is explained with the help of an analysis of dipolar field distributions. AC magnetometry is used then to get access to the relaxation of magnetization in a broader temperature range, from 2 to 87 K. Finally, a theoretical framework describing the spin dynamics with dissipation is proposed to study magnetization relaxation phenomena in single molecule magnets.
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Affiliation(s)
- D S Krylov
- Leibniz Institute for Solid State and Materials Research, 01069 Dresden, Germany.
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6
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Chen CH, Krylov DS, Avdoshenko S, Liu F, Spree L, Yadav R, Alvertis A, Hozoi L, Nenkov K, Kostanyan A, Greber T, Wolter AUB, Popov AA. Selective arc-discharge synthesis of Dy 2S-clusterfullerenes and their isomer-dependent single molecule magnetism. Chem Sci 2017; 8:6451-6465. [PMID: 29263779 PMCID: PMC5734629 DOI: 10.1039/c7sc02395b] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 06/29/2017] [Indexed: 01/04/2023] Open
Abstract
A method for the selective synthesis of sulfide clusterfullerenes Dy2S@C2n is developed. Addition of methane to the reactive atmosphere reduces the formation of empty fullerenes in the arc-discharge synthesis, whereas the use of Dy2S3 as a source of metal and sulfur affords sulfide clusterfullerenes as the main fullerene products along with smaller amounts of carbide clusterfullerenes. Two isomers of Dy2S@C82 with Cs(6) and C3v(8) cage symmetry, Dy2S@C72-Cs(10528), and a carbide clusterfullerene Dy2C2@C82-Cs(6) were isolated. The molecular structure of both Dy2S@C82 isomers was elucidated by single-crystal X-ray diffraction. SQUID magnetometry demonstrates that all of these clusterfullerenes exhibit hysteresis of magnetization, with Dy2S@C82-C3v(8) being the strongest single molecule magnet in the series. DC- and AC-susceptibility measurements were used to determine magnetization relaxation times in the temperature range from 1.6 K to 70 K. Unprecedented magnetization relaxation dynamics with three consequent Orbach processes and energy barriers of 10.5, 48, and 1232 K are determined for Dy2S@C82-C3v(8). Dy2S@C82-Cs(6) exhibits faster relaxation of magnetization with two barriers of 15.2 and 523 K. Ab initio calculations were used to interpret experimental data and compare the Dy-sulfide clusterfullerenes to other Dy-clusterfullerenes. The smallest and largest barriers are ascribed to the exchange/dipolar barrier and relaxation via crystal-field states, respectively, whereas an intermediate energy barrier of 48 K in Dy2S@C82-C3v(8) is assigned to the local phonon mode, corresponding to the librational motion of the Dy2S cluster inside the carbon cage.
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Affiliation(s)
- Chia-Hsiang Chen
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Denis S. Krylov
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Stanislav M. Avdoshenko
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Fupin Liu
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Lukas Spree
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Ravi Yadav
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Antonis Alvertis
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Liviu Hozoi
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Konstantin Nenkov
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Aram Kostanyan
- Physik-Institut , Universität Zürich , Zürich , Switzerland
| | - Thomas Greber
- Physik-Institut , Universität Zürich , Zürich , Switzerland
| | - Anja U. B. Wolter
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
| | - Alexey A. Popov
- Leibniz Institute for Solid State and Materials Research Dresden , 01069 Dresden , Germany .
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7
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The key energy scales of Gd-based metallofullerene determined by resonant inelastic x-ray scattering spectroscopy. Sci Rep 2017; 7:8125. [PMID: 28811581 PMCID: PMC5557834 DOI: 10.1038/s41598-017-08685-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 07/12/2017] [Indexed: 11/12/2022] Open
Abstract
Endohedral metallofullerenes, formed by encaging Gd inside fullerenes like C80, can exhibit enhanced proton relaxitivities compared with other Gd-chelates, making them the promising contrast agents for magnetic resonance imaging (MRI). However, the underlying key energy scales of GdxSc3−xN@C80 (x = 1–3) remain unclear. Here, we carry out resonant inelastic x-ray scattering (RIXS) experiments on GdxSc3−xN@C80 at Gd N4,5-edges to directly study the electronic structure and spin flip excitations of Gd 4f electrons. Compared with reference Gd2O3 and contrast agent Gadodiamide, the features in the RIXS spectra of all metallofullerenes exhibit broader spectral lineshape and noticeable energy shift. Using atomic multiplet calculations, we have estimated the key energy scales such as the inter-site spin exchange field, intra-atomic 4f–4f Coulomb interactions, and spin-orbit coupling. The implications of these parameters to the 4f states of encapsulated Gd atoms are discussed.
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8
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Enhancing T 1 magnetic resonance imaging contrast with internalized gadolinium(III) in a multilayer nanoparticle. Proc Natl Acad Sci U S A 2017. [PMID: 28630340 DOI: 10.1073/pnas.1701944114] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Multifunctional nanoparticles for biomedical applications have shown extraordinary potential as contrast agents in various bioimaging modalities, near-IR photothermal therapy, and for light-triggered therapeutic release processes. Over the past several years, numerous studies have been performed to synthesize and enhance MRI contrast with nanoparticles. However, understanding the MRI enhancement mechanism in a multishell nanoparticle geometry, and controlling its properties, remains a challenge. To systematically examine MRI enhancement in a nanoparticle geometry, we have synthesized MRI-active Au nanomatryoshkas. These are Au core-silica layer-Au shell nanoparticles, where Gd(III) ions are encapsulated within the silica layer between the inner core and outer Au layer of the nanoparticle (Gd-NM). This multifunctional nanoparticle retains its strong near-IR Fano-resonant optical absorption properties essential for photothermal or other near-IR light-triggered therapy, while simultaneously providing increased T1 contrast in MR imaging by concentrating Gd(III) within the nanoparticle. Measurements of Gd-NM revealed a strongly enhanced T1 relaxivity (r1 ∼ 24 mM-1⋅s-1) even at 4.7 T, substantially surpassing conventional Gd(III) chelating agents (r1 ∼ 3 mM-1⋅s-1 at 4.7 T) currently in clinical use. By varying the thickness of the outer gold layer of the nanoparticle, we show that the observed relaxivities are consistent with Solomon-Bloembergen-Morgan (SBM) theory, which takes into account the longer-range interactions between the encapsulated Gd(III) and the protons of the H2O molecules outside the nanoparticle. This nanoparticle complex and its MRI T1-enhancing properties open the door for future studies on quantitative tracking of therapeutic nanoparticles in vivo, an essential step for optimizing light-induced, nanoparticle-based therapies.
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9
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Electronic Structures, and Optical and Magnetic Properties of Quadruple-Decker Phthalocyanines. MAGNETOCHEMISTRY 2017. [DOI: 10.3390/magnetochemistry3020021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
For applications of magnetic devices with operating nuclear-spin-based quantum bits in quantum computing, electronic structures, and magnetic and optical properties of quadruple-decker phthalocyanines with 3d transition metals, such as scandium, yttrium, and lanthanum atoms (M3Pc4: M = Sc, Y, and La), were studied by quantum calculation using density function theory. Electron density distributions at the highest occupied molecular orbital and lowest unoccupied molecular orbital were considerably delocalized on the phthalocyanine ring with considerable bias of the electrostatic potential. The wide energy gaps and the ultraviolet-visible-near infrared spectra of the systems were based on the phthalocyanine ring-ring interactions with overlapping π-orbitals on the phthalocyanine rings. The chemical shift behavior of 13C and 14N-NMR of Sc3(Pc)4, Y3(Pc)4, and La3(Pc)4 depended on the deformation of their structures owing to Jahn-Teller splitting of the d-orbital in the metal ligand field, the considerable perturbation of the metal ligand crystal field on the phthalocyanine ring, the electronic structure based on the electron density distribution, and the magnetic interaction of the nuclear quadrupole interaction. The magnetic parameters of the principle g-tensor, the V-tensor of the electronic field gradient, and the asymmetric parameters were influenced by the deformed structures of the complex with the considerable deviation of the charge density distribution. The quadruple-decker metal phthalocyanines using 3d transition metals have an advantage in controlling the electronic structure and magnetic parameters based on the nuclear spin interaction in spin lattice relaxation with respect to applications of single-molecular magnets.
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Stevenson S, Thompson HR, Arvola KD, Ghiassi KB, Olmstead MM, Balch AL. Isolation of CeLu2N@Ih-C80through a Non-Chromatographic, Two-Step Chemical Process and Crystallographic Characterization of the Pyramidalized CeLu2N within the Icosahedral Cage. Chemistry 2015; 21:10362-8. [DOI: 10.1002/chem.201500915] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Indexed: 11/07/2022]
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11
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Zhao J, Huang X, Jin P, Chen Z. Magnetic properties of atomic clusters and endohedral metallofullerenes. Coord Chem Rev 2015. [DOI: 10.1016/j.ccr.2014.12.013] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Zhang Y, Krylov D, Rosenkranz M, Schiemenz S, Popov AA. Magnetic anisotropy of endohedral lanthanide ions: paramagnetic NMR study of MSc 2N@C 80- Ih with M running through the whole 4f row. Chem Sci 2015; 6:2328-2341. [PMID: 29308147 PMCID: PMC5645780 DOI: 10.1039/c5sc00154d] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 01/28/2015] [Indexed: 12/27/2022] Open
Abstract
Paramagnetic and variable temperature 13C and 45Sc nuclear magnetic resonance studies are performed for nitride clusterfullerenes MSc2N@C80 with icosahedral Ih(7) carbon cage, where M runs through all lanthanides forming nitride clusters. The influence of the endohedral lanthanide ions on the NMR spectral pattern is carefully followed, and dramatic differences are found in peak positions and line widths. Thus, 13C lines broaden from 0.01-0.02 ppm in diamagnetic MSc2N@C80 molecules (M = La, Y, Lu) to several ppm in TbSc2N@C80 and DySc2N@C80. Direction of the paramagnetic shift depends on the shape of the 4f electron density in corresponding lanthanide ions. In TmSc2N@C80 and ErSc2N@C80 with prolate 4f-density of lanthanide ions, 13C signals are shifted down-field, whereas 45Sc peaks are shifted up-field versus diamagnetic values. In all other MSc2N@C80 molecules lanthanide ions have oblate-shaped 4f electron density, and the lanthanide-induced shift is negative for 13C and positive for 45Sc peaks. Analysis of the pseudocontact and contact contributions to chemical shifts revealed that the pseudocontact term dominates both in 13C and 45Sc NMR spectra, although contact shifts for 13C signals are also considerable. Point charge computations of the ligand field splitting are performed to explain experimental results, and showed reasonable agreement with experimental pseudocontact shifts. Nitrogen atom bearing large negative charge and located close to the lanthanide ion results in large magnetic anisotropy of lanthanide ions in nitride clusterfullerenes with quasi-uniaxial ligand field.
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Affiliation(s)
- Y Zhang
- Leibniz Institute for Solid State and Materials Research , 01069 Dresden , Germany .
| | - D Krylov
- Leibniz Institute for Solid State and Materials Research , 01069 Dresden , Germany .
| | - M Rosenkranz
- Leibniz Institute for Solid State and Materials Research , 01069 Dresden , Germany .
| | - S Schiemenz
- Leibniz Institute for Solid State and Materials Research , 01069 Dresden , Germany .
| | - A A Popov
- Leibniz Institute for Solid State and Materials Research , 01069 Dresden , Germany .
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Feng Y, Li J, Zhang Z, Wu B, Li Y, Jiang L, Wang C, Wang T. A highly soluble gadofullerene salt and its magnetic properties. Dalton Trans 2015; 44:7781-4. [DOI: 10.1039/c5dt00432b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
A stable complex of highly soluble Gd@C82/TBPA with improved paramagnetic properties and extensive applications was investigated.
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Affiliation(s)
- Yongqiang Feng
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Jie Li
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Zhuxia Zhang
- Key Laboratory of Interface Science and Engineering in Advanced Materials
- Taiyuan University of Technology
- Ministry of Education
- Research Center of Advanced Materials Science and Technology
- Taiyuan University of Technology
| | - Bo Wu
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Yongjian Li
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Li Jiang
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Chunru Wang
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
| | - Taishan Wang
- Beijing National Laboratory for Molecular Sciences
- Laboratory of Molecular Nanostructure and Nanotechnology
- Institute of Chemistry
- Chinese Academy of Sciences
- Beijing 100190
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14
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Zhang Y, Krylov D, Schiemenz S, Rosenkranz M, Westerström R, Dreiser J, Greber T, Büchner B, Popov AA. Cluster-size dependent internal dynamics and magnetic anisotropy of Ho ions in HoM2N@C80 and Ho2MN@C80 families (M = Sc, Lu, Y). NANOSCALE 2014; 6:11431-11438. [PMID: 25149908 DOI: 10.1039/c4nr02864c] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The paramagnetic NMR study of HoM2N@C80-Ih and Ho2MN@C80-Ih nitride cluster fullerenes (M = Sc, Lu, Y) reveals strong dependence of Ho-induced paramagnetic shifts (δ(para)) in (13)C NMR spectra on the size of the diamagnetic metal in the cluster. In particular, the δ(para) value in HoY2N@C80 is almost doubled in comparison to that in HoSc2N@C80. X-ray magnetic circular dichroism studies show that all Ho-nitride cluster fullerenes have the same magnetic ground state of Ho(3+). Point-charge ligand-field splitting calculations show that the increase of the M(3+) radius in going from Sc to Y results in a considerable increase of the energy splitting between different Jz states. This leads to a 19% higher magnetic anisotropy of Ho(3+) in HoY2N@C80 than in HoSc2N@C80 at 300 K. Variations of the molecular geometry and cluster dynamics with the size of the cluster are found to have even greater influence on δ(para) values. This work shows that the magnetic properties of the species confined inside the fullerene cages can be tuned using the geometrical factors such as the cluster and the cage size.
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Affiliation(s)
- Y Zhang
- Leibniz-Institute for Solid State and Materials Research (IFW Dresden), D-01171 Dresden, Germany.
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