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Yang W, Rosenkranz M, Velkos G, Ziegs F, Dubrovin V, Schiemenz S, Spree L, de Souza Barbosa MF, Guillemard C, Valvidares M, Büchner B, Liu F, Avdoshenko SM, Popov AA. Covalency versus magnetic axiality in Nd molecular magnets: Nd-photoluminescence, strong ligand-field, and unprecedented nephelauxetic effect in fullerenes NdM 2N@C 80 (M = Sc, Lu, Y). Chem Sci 2024; 15:2141-2157. [PMID: 38332818 PMCID: PMC10848757 DOI: 10.1039/d3sc05146c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 12/20/2023] [Indexed: 02/10/2024] Open
Abstract
Nd-based nitride clusterfullerenes NdM2N@C80 with rare-earth metals of different sizes (M = Sc, Y, Lu) were synthesized to elucidate the influence of the cluster composition, shape and internal strain on the structural and magnetic properties. Single crystal X-ray diffraction revealed a very short Nd-N bond length in NdSc2N@C80. For Lu and Y analogs, the further shortening of the Nd-N bond and pyramidalization of the NdM2N cluster are predicted by DFT calculations as a result of the increased cluster size and a strain caused by the limited size of the fullerene cage. The short distance between Nd and nitride ions leads to a very large ligand-field splitting of Nd3+ of 1100-1200 cm-1, while the variation of the NdM2N cluster composition and concomitant internal strain results in the noticeable modulation of the splitting, which could be directly assessed from the well-resolved fine structure in the Nd-based photoluminescence spectra of NdM2N@C80 clusterfullerenes. Photoluminescence measurements also revealed an unprecedentedly strong nephelauxetic effect, pointing to a high degree of covalency. The latter appears detrimental to the magnetic axiality despite the strong ligand field. As a result, the ground magnetic state has considerable transversal components of the pseudospin g-tensor, and the slow magnetic relaxation of NdSc2N@C80 could be observed by AC magnetometry only in the presence of a magnetic field. A combination of the well-resolved magneto-optical states and slow relaxation of magnetization suggests that Nd clusterfullerenes can be useful building blocks for magneto-photonic quantum technologies.
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Affiliation(s)
- Wei Yang
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Marco Rosenkranz
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Georgios Velkos
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Frank Ziegs
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Vasilii Dubrovin
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Sandra Schiemenz
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Lukas Spree
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
- Center for Quantum Nanoscience, Institute for Basic Science (IBS) Seoul Republic of Korea
| | | | | | | | - Bernd Büchner
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Fupin Liu
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Stanislav M Avdoshenko
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
| | - Alexey A Popov
- Leibniz Institute for Solid State and Materials Research (IFW Dresden) 01069 Dresden Germany
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Windorff CJ, Dumas MT, Ziller JW, Gaunt AJ, Kozimor SA, Evans WJ. Small-Scale Metal-Based Syntheses of Lanthanide Iodide, Amide, and Cyclopentadienyl Complexes as Analogues for Transuranic Reactions. Inorg Chem 2017; 56:11981-11989. [PMID: 28915015 DOI: 10.1021/acs.inorgchem.7b01968] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Small-scale reactions of the Pu analogues La, Ce, and Nd have been explored in order to optimize reaction conditions for milligram scale reactions of radioactive plutonium starting from the metal. Oxidation of these lanthanide metals with iodine in ether and pyridine has been studied, and LnI3(Et2O)x (1-Ln; x = 0.75-1.9) and LnI3(py)4 (2-Ln; py = pyridine, NC5H5) have been synthesized on scales ranging from 15 mg to 2 g. The THF adducts LnI3(THF)4 (3-Ln) were synthesized by dissolving 1-Ln in THF. The viability of these small-scale samples as starting materials for amide and cyclopentadienyl f-element complexes was tested by reacting KN(SiMe3)2, KCp' (Cp' = C5H4SiMe3), KCp'' (Cp'' = C5H3(SiMe3)2-1,3), and KC5Me4H with 1-Ln generated in situ. These reactions produced Ln[N(SiMe3)2]3 (4-Ln), Cp'3Ln (5-Ln), Cp″3Ln (6-Ln), and (C5Me4H)3Ln (7-Ln), respectively. Small-scale samples of Cp'3Ce (5-Ce) and Cp'3Nd (5-Nd) were reduced with potassium graphite (KC8) in the presence of 2.2.2-cryptand to check the viability of generating the crystallographically characterizable Ln2+ complexes [K(2.2.2-cryptand)][Cp'3Ln] (8-Ln; Ln = Ce, Nd).
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Affiliation(s)
- Cory J Windorff
- Department of Chemistry, University of California , Irvine, California 92697, United States.,Los Alamos National Laboratory , Los Alamos, New Mexico 87544, United States
| | - Megan T Dumas
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California , Irvine, California 92697, United States
| | - Andrew J Gaunt
- Los Alamos National Laboratory , Los Alamos, New Mexico 87544, United States
| | - Stosh A Kozimor
- Los Alamos National Laboratory , Los Alamos, New Mexico 87544, United States
| | - William J Evans
- Department of Chemistry, University of California , Irvine, California 92697, United States
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Lukens WW, Speldrich M, Yang P, Duignan TJ, Autschbach J, Kögerler P. The roles of 4f- and 5f-orbitals in bonding: a magnetochemical, crystal field, density functional theory, and multi-reference wavefunction study. Dalton Trans 2016; 45:11508-21. [PMID: 27349178 DOI: 10.1039/c6dt00634e] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structures of 4f(3)/5f(3) Cp''3M and Cp''3M·alkylisocyanide complexes, where Cp'' is 1,3-bis-(trimethylsilyl)cyclopentadienyl, are explored with a focus on the splitting of the f-orbitals, which provides information about the strengths of the metal-ligand interactions. While the f-orbital splitting in many lanthanide complexes has been reported in detail, experimental determination of the f-orbital splitting in actinide complexes remains rare in systems other than halide and oxide compounds, since the experimental approach, crystal field analysis, is generally significantly more difficult for actinide complexes than for lanthanide complexes. In this study, a set of analogous neodymium(iii) and uranium(iii) tris-cyclopentadienyl complexes and their isocyanide adducts was characterized by electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility. The crystal field model was parameterized by combined fitting of EPR and susceptibility data, yielding an accurate description of f-orbital splitting. The isocyanide derivatives were also studied using density functional theory, resulting in f-orbital splitting that is consistent with crystal field fitting, and by multi-reference wavefunction calculations that support the electronic structure analysis derived from the crystal-field calculations. The results highlight that the 5f-orbitals, but not the 4f-orbitals, are significantly involved in bonding to the isocyanide ligands. The main interaction between isocyanide ligand and the metal center is a σ-bond, with additional 5f to π* donation for the uranium complexes. While interaction with the isocyanide π*-orbitals lowers the energies of the 5fxz(2) and 5fyz(2)-orbitals, spin-orbit coupling greatly reduces the population of 5fxz(2) and 5fyz(2) in the ground state.
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Affiliation(s)
- W W Lukens
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Amberger HD, Reddmann H, Mueller TJ, Evans WJ. Electronic structures of organometallic complexes of f elements LXXXIII: First comparison of experimental and calculated (on the basis of density functional theory) polarized Raman spectra of an oriented organometallic single crystal: Tris(pentamethylcyclopentadienyl)lanthanum. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 131:577-586. [PMID: 24845734 DOI: 10.1016/j.saa.2014.04.068] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 04/01/2014] [Accepted: 04/13/2014] [Indexed: 06/03/2023]
Abstract
The polarized Raman spectra of an oriented La(η(5)-C5Me5)3 (1) single crystal (where the principal axes of the two molecules per unit cell are uniformly oriented) as well as the mid (ca. 90K) and far infrared spectra of pellets have been recorded. Applying the selection rules of C3h symmetry to the spectra obtained, the irreducible representations (irreps) of numerous lines/bands of intra-ligand character were derived. In the range <400cm(-1), where 28 Raman-allowed lines and 20 FIR-allowed bands of both skeletal and intra-ligand character are expected, only few assignments based on symmetry considerations were possible. In order to increase the number of identifications, model calculations on the basis of density functional theory (DFT) were performed. In the intra-ligand range >400cm(-1), the obtained results agree well with the experimental findings. Because of the strong mixing at lower wavenumbers, even the separation of calculated skeletal and intra-ligand modes and the identification of the former was only successful by comparing the calculated FIR and averaged Raman spectra of compound 1 with those of La(η(5)-C5Me4H)3 (2). Making use of both the calculated frequencies of normal modes and their polarizability tensors, the polarized Raman spectra of an oriented single crystal of 1 in the range <400cm(-1) were calculated and compared to the experimental ones. Because of an overestimation of the mixing of normal vibrations of A' symmetry, the experimental intensities of the lines of the symmetric stretch ν1(A') were not reproduced by the calculation for compound 1 but by that for Sm(η(5)-C5Me5)3 (3). Skeletal and intra-ligand modes were separated and designated. Neglecting νC-H modes, the DFT calculation for 1 achieved an r.m.s. deviation of 17.9cm(-1) for 72 assignments.
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Affiliation(s)
- Hanns-Dieter Amberger
- Institut für Anorganische und Angewandte Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany.
| | - Hauke Reddmann
- Institut für Anorganische und Angewandte Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
| | - Thomas J Mueller
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - William J Evans
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
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Amberger HD, Reddmann H. Electronic structures of organometallic complexes of f elements LXXXII: comparison of assigned experimental and calculated (on the basis of density functional theory) frequencies of normal vibrations of the first homoleptic organometallic complex of the lanthanides: tris(η(5)-tetramethylcyclopentadienyl)lanthanum. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2014; 124:519-527. [PMID: 24508890 DOI: 10.1016/j.saa.2014.01.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 12/19/2013] [Accepted: 01/05/2014] [Indexed: 06/03/2023]
Abstract
The far and mid infrared spectra of powdered La(η(5)-C5Me4H)3 as well as polarized Raman spectra of an oriented single crystal (where the principal axes of the two molecules per unit cell are uniformly oriented) have been recorded. Applying the selection rules of C3h symmetry to the experimental data, numerous signals were assigned which agree well with the predictions of a calculation based on density functional theory. Neglecting νC-H and γCp-H (out of plane) modes, an r.m.s. deviation of 21.9 cm(-1) for 71 assignments was achieved. Skeletal and intra-ligand vibrations were separated and an inspection of the vibronic sidebands of the purely electronic hypersensitive absorption transitions (4)I9/2→(4)G5/2 of Nd(η(5)-C5Me4H)3 showed that mainly the latter are coupled.
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Affiliation(s)
- Hanns-Dieter Amberger
- Institut für Anorganische und Angewandte Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany.
| | - Hauke Reddmann
- Institut für Anorganische und Angewandte Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany
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Coreno M, de Simone M, Green JC, Kaltsoyannis N, Coates R, Hunston C, Narband N, Sella A. Variable photon energy photoelectron spectroscopy of tris-cyclopentadienyl lanthanides. Dalton Trans 2014; 43:5134-41. [DOI: 10.1039/c3dt53512f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Gas-phase photoelectron spectra are presented for LnCp3 (Cp = η-C5H5; Ln = Pr, Nd, Sm) in which f ionization gives rise to bands associated with 4fn configurations in addition to the expected 4fn−1 bands.
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Affiliation(s)
| | | | | | | | - Rosemary Coates
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
| | - Charlene Hunston
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
| | - Naima Narband
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
| | - Andrea Sella
- Department of Chemistry
- University College London
- London WC1H 0AJ, UK
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Lanthanides and actinides: Annual survey of their organometallic chemistry covering the year 2011. Coord Chem Rev 2013. [DOI: 10.1016/j.ccr.2012.12.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Amberger HD, Reddmann H. Zur Elektronenstruktur metallorganischer Komplexe der f-Elemente. 80[1] Gelingt die Identifizierung der Streck- und Kippschwingungen des pseudo-trigonal-planaren La(η5-C5H5)3-Fragments in den Schwingungsspektren von [La(η5-C5H5)3(NCCH3)2] ohne die Hilfe. Z Anorg Allg Chem 2012. [DOI: 10.1002/zaac.201200451] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Amberger HD, Reddmann H, Liu G. Electronic structures of organometallic complexes of f elements LXXIX: Truncated crystal field splitting patterns of monomeric pseudo trigonal planar Yb(η5-C5H4R)3 (R = Me, Et, tBu, SiMe3) complexes and polymeric [(η5-C5H5)2Yb(μ-η5:η1-C5H5)] as well as selected mono adducts. J Organomet Chem 2012. [DOI: 10.1016/j.jorganchem.2012.06.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Jank S, Reddmann H, Zhang L, Amberger HD. Zur Elektronenstruktur hochsymmetrischer Verbindungen der f-Elemente. 45[1]Ungewöhnliche spektrochemische Eigenschaften des Triphenylphosphanoxido-Liganden im Falle von Mono- und Bisaddukten homoleptischer Samarium(III)silylamide. Z Anorg Allg Chem 2012. [DOI: 10.1002/zaac.201200177] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Reddmann H, Prosenc MH, Amberger HD. Zur Elektronenstruktur metallorganischer Komplexe der f-Elemente. 78[1]Ergänzende Informationen von “polarisierten” Raman-Spektren orientierter Einkristalle und Modellrechnungen auf der Grundlage der Dichtefunktionaltheorie bei der Zuordnung der Schwingun. Z Anorg Allg Chem 2012. [DOI: 10.1002/zaac.201100548] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Prosenc MH, Reddmann H, Amberger HD. Electronic structures of organometallic complexes of f elements LXXVI: Correlation of experimental and calculated (on the basis of density functional theory) vibrational spectra of bis(η5-cyclopentadienyl)ruthenium and bis(η5-pentamethylcyclopentadienyl)ruthenium. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2012; 87:126-134. [PMID: 22169027 DOI: 10.1016/j.saa.2011.11.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 10/28/2011] [Accepted: 11/10/2011] [Indexed: 05/31/2023]
Abstract
Previous empirical assignments of the normal modes of Ru(η(5)-C(5)H(5))(2) were checked against the results of a calculation applying density functional theory (DFT). After some reassignments, following those recently suggested for Fe(η(5)-C(5)H(5))(2) (after theoretical model calculations), a satisfactory agreement was observed. Recently communicated polarized Raman spectra of an oriented Ru(η(5)-C(5)Me(5))(2) single crystal were used here for the identification of the irreducible representations of a number of Raman active normal modes (assuming molecular D(5h) symmetry) which agree well with the results of the DFT calculation. The energies of IR active fundamental vibrations, extracted from recently communicated FIR/MIR spectra (pellets), were correlated with comparable energies of IR allowed irreducible representations of the DFT calculation and assigned. Both the skeletal and the intra-ligand normal modes could be correlated with the idealized standard motions (ν(i)s) of the model sandwich complex Ru(C(5)C(5))(2), and previous assignments had to be revised. Neglecting the νCH vibrations (which are off by ca. 50cm(-1)) an r.m.s. deviation of 9.8cm(-1) (for 47 assignments) of the remaining normal modes could be achieved.
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Affiliation(s)
- Marc Heinrich Prosenc
- Institut für Anorganische und Angewandte Chemie der Universität Hamburg, Martin-Luther-King-Platz 6, D-20146 Hamburg, Germany.
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