1
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Gunther SO, Qiao Y, Smith PW, Ciccone SR, Ditter AS, Huh DN, Moreau LM, Shuh DK, Sun T, Arnold PL, Booth CH, de Jong WA, Evans WJ, Lukens WW, Minasian SG. 4f-Orbital mixing increases the magnetic susceptibility of Cp' 3Eu. Chem Sci 2024; 15:12667-12675. [PMID: 39148767 PMCID: PMC11322928 DOI: 10.1039/d4sc01300j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Accepted: 06/05/2024] [Indexed: 08/17/2024] Open
Abstract
Traditional models of lanthanide electronic structure suggest that bonding is predominantly ionic, and that covalent orbital mixing is not an important factor in determining magnetic properties. Here, 4f orbital mixing and its impact on the magnetic susceptibility of Cp'3Eu (Cp' = C5H4SiMe3) was analyzed experimentally using magnetometry and X-ray absorption spectroscopy (XAS) methods at the C K-, Eu M5,4-, and L3-edges. Pre-edge features in the experimental and TDDFT-calculated C K-edge XAS spectra provided unequivocal evidence of C 2p and Eu 4f orbital mixing in the π-antibonding orbital of a' symmetry. The charge-transfer configurations resulting from 4f orbital mixing were identified spectroscopically by using Eu M5,4-edge and L3-edge XAS. Modeling of variable-temperature magnetic susceptibility data showed excellent agreement with the XAS results and indicated that increased magnetic susceptibility of Cp'3Eu is due to removal of the degeneracy of the 7F1 excited state due to mixing between the ligand and Eu 4f orbitals.
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Affiliation(s)
- S Olivia Gunther
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Yusen Qiao
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Patrick W Smith
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Sierra R Ciccone
- Department of Chemistry, University of California Irvine CA 92697 USA
| | - Alexander S Ditter
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Daniel N Huh
- Department of Chemistry, University of California Irvine CA 92697 USA
| | - Liane M Moreau
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry, Washington State University Pullman WA 99164 USA
| | - David K Shuh
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Taoxiang Sun
- Institute of Nuclear and New Energy Technology, Tsinghua University Beijing 100084 P. R. China
| | - Polly L Arnold
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
- Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Corwin H Booth
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Wibe A de Jong
- Computational Research Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA
| | - William J Evans
- Department of Chemistry, University of California Irvine CA 92697 USA
| | - Wayne W Lukens
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
| | - Stefan G Minasian
- Chemical Sciences Division, Lawrence, Berkeley National Laboratory Berkeley CA 94720 USA
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2
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Li BY, Dickerson CE, Shin AJ, Zhao C, Shen Y, He Y, Diaconescu PL, Alexandrova AN, Caram JR. Elucidating ultranarrow 2F 7/2 to 2F 5/2 absorption in ytterbium(iii) complexes. Chem Sci 2024; 15:12451-12458. [PMID: 39118624 PMCID: PMC11304733 DOI: 10.1039/d4sc02944e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Accepted: 06/30/2024] [Indexed: 08/10/2024] Open
Abstract
Achieving ultranarrow absorption linewidths in the condensed phase enables optical state preparation of specific non-thermal states, a prerequisite for quantum-enabled technologies. The 4f orbitals of lanthanide(iii) complexes are often referred to as "atom-like," reflecting their isolated nature, and are promising substrates for the optical preparation of specific quantum states. To better understand the photophysical properties of 4f states and assess their potential for quantum applications, theoretical building blocks are required for rapid screening. In this study, an atomic-level perturbative calculation (i.e., spin-orbit crystal field, SOCF) is applied to various Yb(iii) complexes to investigate their linear absorption and emission through a fitting mechanism of their experimentally determined transition energies and oscillator strengths. In particular, the optical properties of (thiolfan)YbCl(THF) (thiolfan = 1,1'-bis(2,4-di-tert-butyl-6-thiomethylenephenoxy)ferrocene), a recently reported complex with an ultranarrow optical linewidth, are computed and compared to those of other Yb(iii) compounds. Through a transition energy sampling study, major contributors to the optical linewidth are identified. We observe particularly isolated f-f transitions and narrow linewidths, which we attribute to two distinct factors. Firstly, the ultra-high atomic similarity of the orbitals involved in the optical transition, along with the presence of an anisotropic crystal field, collectively contribute to the observed narrow transitions. Secondly, we note highly correlated excited-ground energy fluctuations that serve to greatly suppress inhomogeneous line-broadening. This article illustrates how SOCF can be used as a low-cost method to probe the influence of crystal field environment on the optical properties of Yb(iii) complexes to assist the development of novel lanthanide series quantum materials.
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Affiliation(s)
- Barry Y Li
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Claire E Dickerson
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Ashley J Shin
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Changling Zhao
- Department of Physics and Astronomy, University of California Los Angeles California 90095 USA
| | - Yi Shen
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Yongjia He
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Paula L Diaconescu
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
| | - Anastassia N Alexandrova
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
- Department of Materials Science and Engineering, University of California Los Angeles California 90095 USA
| | - Justin R Caram
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
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3
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Ashuiev A, Allouche F, Islam MA, Carvalho JP, Sanders KJ, Conley MP, Klose D, Lapadula G, Wörle M, Baabe D, Walter MD, Pell AJ, Copéret C, Jeschke G, Pintacuda G, Andersen RA. Geometry and electronic structure of Yb(III)[CH(SiMe 3) 2] 3 from EPR and solid-state NMR augmented by computations. Phys Chem Chem Phys 2024; 26:8734-8747. [PMID: 38416412 PMCID: PMC10936694 DOI: 10.1039/d4cp00281d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 02/12/2024] [Indexed: 02/29/2024]
Abstract
Characterization of paramagnetic compounds, in particular regarding the detailed conformation and electronic structure, remains a challenge, and - still today it often relies solely on the use of X-ray crystallography, thus limiting the access to electronic structure information. This is particularly true for lanthanide elements that are often associated with peculiar structural and electronic features in relation to their partially filled f-shell. Here, we develop a methodology based on the combined use of state-of-the-art magnetic resonance spectroscopies (EPR and solid-state NMR) and computational approaches as well as magnetic susceptibility measurements to determine the electronic structure and geometry of a paramagnetic Yb(III) alkyl complex, Yb(III)[CH(SiMe3)2]3, a prototypical example, which contains notable structural features according to X-ray crystallography. Each of these techniques revealed specific information about the geometry and electronic structure of the complex. Taken together, both EPR and NMR, augmented by quantum chemical calculations, provide a detailed and complementary understanding of such paramagnetic compounds. In particular, the EPR and NMR signatures point to the presence of three-centre-two-electron Yb-γ-Me-β-Si secondary metal-ligand interactions in this otherwise tri-coordinate metal complex, similarly to its diamagnetic Lu analogues. The electronic structure of Yb(III) can be described as a single 4f13 configuration, while an unusually large crystal-field splitting results in a thermally isolated ground Kramers doublet. Furthermore, the computational data indicate that the Yb-carbon bond contains some π-character, reminiscent of the so-called α-H agostic interaction.
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Affiliation(s)
- Anton Ashuiev
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Florian Allouche
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Md Ashraful Islam
- Université de Lyon, Centre de RMN à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, Université Claude Bernard Lyon 1), F-69100 Villeurbanne, France.
| | - José P Carvalho
- Department of Materials and Environmental Chemistry, Stockholm University, Svänte Arrhenius väg 16 C, 106 91 Stockholm, Sweden
| | - Kevin J Sanders
- Université de Lyon, Centre de RMN à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, Université Claude Bernard Lyon 1), F-69100 Villeurbanne, France.
| | - Matthew P Conley
- Department of Chemistry and Chemical Sciences, University of California Riverside, 501 Big Springs Road, Riverside, CA 92521, USA
| | - Daniel Klose
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Giuseppe Lapadula
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Michael Wörle
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Dirk Baabe
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Marc D Walter
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Andrew J Pell
- Université de Lyon, Centre de RMN à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, Université Claude Bernard Lyon 1), F-69100 Villeurbanne, France.
| | - Christophe Copéret
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5, 8093 Zurich, Switzerland.
| | - Guido Pintacuda
- Université de Lyon, Centre de RMN à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, Université Claude Bernard Lyon 1), F-69100 Villeurbanne, France.
| | - Richard A Andersen
- Department of Chemistry, University of California, Berkeley, CA 94720, USA
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4
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Nodaraki LE, Liu J, Ariciu AM, Ortu F, Oakley MS, Birnoschi L, Gransbury GK, Cobb PJ, Emerson-King J, Chilton NF, Mills DP, McInnes EJL, Tuna F. Metal-carbon bonding in early lanthanide substituted cyclopentadienyl complexes probed by pulsed EPR spectroscopy. Chem Sci 2024; 15:3003-3010. [PMID: 38404384 PMCID: PMC10882510 DOI: 10.1039/d3sc06175b] [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: 11/17/2023] [Accepted: 01/12/2024] [Indexed: 02/27/2024] Open
Abstract
We examine lanthanide (Ln)-ligand bonding in a family of early Ln3+ complexes [Ln(Cptt)3] (1-Ln, Ln = La, Ce, Nd, Sm; Cptt = C5H3tBu2-1,3) by pulsed electron paramagnetic resonance (EPR) methods, and provide the first characterization of 1-La and 1-Nd by single crystal XRD, multinuclear NMR, IR and UV/Vis/NIR spectroscopy. We measure electron spin T1 and Tm relaxation times of 12 and 0.2 μs (1-Nd), 89 and 1 μs (1-Ce) and 150 and 1.7 μs (1-Sm), respectively, at 5 K: the T1 relaxation of 1-Nd is more than 102 times faster than its valence isoelectronic uranium analogue. 13C and 1H hyperfine sublevel correlation (HYSCORE) spectroscopy reveals that the extent of covalency is negligible in these Ln compounds, with much smaller hyperfine interactions than observed for equivalent actinide (Th and U) complexes. This is corroborated by ab initio calculations, confirming the predominant electrostatic nature of the metal-ligand bonding in these complexes.
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Affiliation(s)
- Lydia E Nodaraki
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
- Photon Science Institute, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Jingjing Liu
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Ana-Maria Ariciu
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
- Photon Science Institute, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Fabrizio Ortu
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Meagan S Oakley
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Letitia Birnoschi
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Gemma K Gransbury
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Philip J Cobb
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Jack Emerson-King
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Nicholas F Chilton
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - David P Mills
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Eric J L McInnes
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
- Photon Science Institute, The University of Manchester Oxford Road Manchester M13 9PL UK
| | - Floriana Tuna
- Department of Chemistry, The University of Manchester Oxford Road Manchester M13 9PL UK
- Photon Science Institute, The University of Manchester Oxford Road Manchester M13 9PL UK
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5
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Rajabi A, Grotjahn R, Rappoport D, Furche F. A DFT perspective on organometallic lanthanide chemistry. Dalton Trans 2024; 53:410-417. [PMID: 38013481 DOI: 10.1039/d3dt03221c] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Computational studies of the coordination chemistry and bonding of lanthanides have grown in recent decades as the need for understanding the distinct physical, optical, and magnetic properties of these compounds increased. Density functional theory (DFT) methods offer a favorable balance of computational cost and accuracy in lanthanide chemistry and have helped to advance the discovery of novel oxidation states and electronic configurations. This Frontier article examines the scope and limitations of DFT in interpreting structural and spectroscopic data of low-valent lanthanide complexes, elucidating periodic trends, and predicting their properties and reactivity, presented through selected examples.
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Affiliation(s)
- Ahmadreza Rajabi
- Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025, USA.
| | - Robin Grotjahn
- Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025, USA.
| | - Dmitrij Rappoport
- Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025, USA.
| | - Filipp Furche
- Department of Chemistry, University of California Irvine, 1102 Natural Sciences II, Irvine, CA 92697-2025, USA.
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6
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Tarannum I, Moorthy S, Singh SK. Understanding electrostatics and covalency effects in highly anisotropic organometallic sandwich dysprosium complexes [Dy(C mR m) 2] (where R = H, SiH 3, CH 3 and m = 4 to 9): a computational perspective. Dalton Trans 2023; 52:15576-15589. [PMID: 37786345 DOI: 10.1039/d3dt01646c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
In this article, we have thoroughly studied the electronic structure and 4f-ligand covalency of six mononuclear dysprosium organometallic sandwich complexes [Dy(CmRm)2]n+/- (where R = H, SiH3, CH3; m = 4 to 9; n = 1, 3) using both the scalar relativistic density functional and complete active space self-consistent field (CASSCF) and N-electron valence perturbation theory (NEVPT2) method to shed light on the ligand field effects in fine-tuning the magnetic anisotropy of these complexes. Energy decomposition analysis (EDA) and ab initio-based ligand field theory AILFT calculations predict the sizable 4f-ligand covalency in all these complexes. The analysis of CASSCF/NEVPT2 computed spin-Hamiltonian (SH) parameters indicates the stabilization of mJ |±15/2〉 for [Dy(C4(SiH3)4)2]- (1), [Dy(C5(CH3)5)2]+ (2) and [Dy(C6H6)2]3+ (3) complexes with the Ucal value of 1867.5, 1621.5 and 1070.8 cm-1, respectively. On the other hand, we observed mJ |±9/2〉 as the ground state for [Dy(C7H7)2]3- (4) and [Dy(C8H8)2]- (5) complexes with significantly smaller Ucal values of 237.1 and 38.6 cm-1 respectively. For the nine-membered ring [Dy(C9H9)2]+ (6) complex, we observed the stabilization of the mJ |±1/2〉 ground state, with the first excited state being located ∼29 cm-1 higher in energy. AILFT-NEVPT2 ligand field splitting analysis indicates that the presence of π-type 4f-ligand interactions in complexes 1-3 help generate the axial-ligand field, while the δ-type interactions in complexes 4-5 generate the equatorial ligand field despite the ligands approaching from the axial direction. As the ring size increases, φ-type interactions dominate, generating a pure equatorial ligand field stabilising mJ |±1/2〉 as the ground state for 6. Calculations suggest that the nature of the ligand field mainly governs the Ucal values in the following order: 4f-Lσ > 4f-Lπ > 4f-Lδ > 4f-Lφ. Calculations were performed by replacing ligands with CHELPG charges to access the crystal field (CF) effects which suggests the stabilization of pure mJ |±15/2〉 in all the charge-embedded models (1Q-6Q). Our findings point out that the crystal field and ligand field effects complement each other and generate a giant barrier for magnetic relaxation in the small ring complexes 1-3, while a relatively weak crystal field and adverse 4f-Lδ/4f-Lφ interactions diminish the SMM behaviour in the large ring complexes 4-6.
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Affiliation(s)
- Ibtesham Tarannum
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Shruti Moorthy
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
| | - Saurabh Kumar Singh
- Department of Chemistry, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Telangana, 502285, India.
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7
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Mahieu N, Piątkowski J, Simler T, Nocton G. Back to the future of organolanthanide chemistry. Chem Sci 2023; 14:443-457. [PMID: 36741512 PMCID: PMC9848160 DOI: 10.1039/d2sc05976b] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 11/29/2022] [Indexed: 12/02/2022] Open
Abstract
At the dawn of the development of structural organometallic chemistry, soon after the discovery of ferrocene, the description of the LnCp3 complexes, featuring large and mostly trivalent lanthanide ions, was rather original and sparked curiosity. Yet, the interest in these new architectures rapidly dwindled due to the electrostatic nature of the bonding between π-aromatic ligands and 4f-elements. Almost 70 years later, it is interesting to focus on how the discipline has evolved in various directions with the reports of multiple catalytic reactivities, remarkable potential in small molecule activation, and the development of rich redox chemistry. Aside from chemical reactivity, a better understanding of their singular electronic nature - not precisely as simplistic as anticipated - has been crucial for developing tailored compounds with adapted magnetic anisotropy or high fluorescence properties that have witnessed significant popularity in recent years. Future developments shall greatly benefit from the detailed reactivity, structural and physical chemistry studies, particularly in photochemistry, electro- or photoelectrocatalysis of inert small molecules, and manipulating the spins' coherence in quantum technology.
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Affiliation(s)
- Nolwenn Mahieu
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Jakub Piątkowski
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Thomas Simler
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
| | - Grégory Nocton
- LCM, CNRS, Ecole Polytechnique, Institut Polytechnique de Paris, Route de Saclay91120 PalaiseauFrance
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8
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Rousset E, Piccardo M, Gable RW, Massi M, Sorace L, Soncini A, Boskovic C. Elucidation of LMCT Excited States for Lanthanoid Complexes: A Theoretical and Solid-State Experimental Framework. Inorg Chem 2022; 61:14004-14018. [PMID: 35998349 DOI: 10.1021/acs.inorgchem.2c01985] [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
Photophysical and magnetic properties arising from both ground and excited states of lanthanoid ions are relevant for numerous applications. These properties can be substantially affected, both adversely and beneficially, by ligand-to-metal charge-transfer (LMCT) states. However, probing LMCT states remains a significant challenge in f-block chemistry, particularly in the solid state. Intriguingly, the europium compounds [EuIII(18-c-6)(X4Cat)(NO3)]·MeCN (18-c-6 = 18-crown-6; X = Cl (tetrachlorocatecholate, 1-Eu) or Br (tetrabromocatecholate, 2-Eu) are distinctly darkly-colored, in marked contrast to the analogues with other lanthanoid ions in the 1-Ln and 2-Ln series (Ln = La, Ce, Nd, Gd, Tb, and Dy). Herein, we report a multi-technique investigation of these compounds that has allowed elucidation of the LMCT character of the relevant absorption bands using magnetometry, absorption and emission spectroscopies, and solid-state electrochemistry. To support experimental observations, we present a semi-quantitative multireference ab initio model that (i) captures the anomalously low-lying LMCT excited state observed in the visible spectrum of 1-Eu (and its absence in the other 1-Ln analogues); (ii) elucidates the contribution of the LMCT excitation to the crystal field split 7FJ ground-state wave functions; and (iii) identifies the crucial role played by radial dynamical correlation of the EuIII 4f electrons in the description of the LMCT excited state, modeled by the inclusion of 4f → 5f excitations in the optimized wave function. By providing a set of experimental and theoretical tools, this work establishes a framework for the elucidation of LMCT excited states in lanthanoid compounds in the solid state.
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Affiliation(s)
- Elodie Rousset
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Matteo Piccardo
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Robert W Gable
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Massimiliano Massi
- School of Molecular and Life Sciences─Curtin Institute for Functional Materials and Interfaces, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Lorenzo Sorace
- UdR INSTM and Department of Chemistry "U. Schiff", University of Florence, Sesto Fiorentino, FI 50019, Italy
| | - Alessandro Soncini
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
| | - Colette Boskovic
- School of Chemistry, University of Melbourne, Parkville, VIC 3010, Australia
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9
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Stetsiuk O, La Droitte L, Goudy V, Le Guennic B, Cador O, Nocton G. Synthesis and Structures of Tris(cyclononatetraenyl) Rare-Earth Complexes [Ln(C9H9)3] (Ln = Y, Gd, Tb, Dy, Ho, Er, Tm). Organometallics 2022. [DOI: 10.1021/acs.organomet.1c00590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Oleh Stetsiuk
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91120 Palaiseau, France
| | - Léo La Droitte
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)−UMR 6226, F-35000 Rennes, France
| | - Violaine Goudy
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91120 Palaiseau, France
| | - Boris Le Guennic
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)−UMR 6226, F-35000 Rennes, France
| | - Olivier Cador
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes)−UMR 6226, F-35000 Rennes, France
| | - Grégory Nocton
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91120 Palaiseau, France
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10
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Moreau LM, Lapsheva E, Amaro-Estrada JI, Gau MR, Carroll PJ, Manor BC, Qiao Y, Yang Q, Lukens WW, Sokaras D, Schelter EJ, Maron L, Booth CH. Electronic structure studies reveal 4f/5d mixing and its effect on bonding characteristics in Ce-imido and -oxo complexes. Chem Sci 2022; 13:1759-1773. [PMID: 35282640 PMCID: PMC8827158 DOI: 10.1039/d1sc06623d] [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] [Received: 11/27/2021] [Accepted: 01/06/2022] [Indexed: 11/23/2022] Open
Abstract
This study presents the role of 5d orbitals in the bonding, and electronic and magnetic structure of Ce imido and oxo complexes synthesized with a tris(hydroxylaminato) [((2-tBuNO)C6H4CH2)3N]3− (TriNOx3−) ligand framework, including the reported synthesis and characterization of two new alkali metal-capped Ce oxo species. X-ray spectroscopy measurements reveal that the imido and oxo materials exhibit an intermediate valent ground state of the Ce, displaying hallmark features in the Ce LIII absorption of partial f-orbital occupancy that are relatively constant for all measured compounds. These spectra feature a double peak consistent with other formal Ce(iv) compounds. Magnetic susceptibility measurements reveal enhanced levels of temperature-independent paramagnetism (TIP). In contrast to systems with direct bonding to an aromatic ligand, no clear correlation between the level of TIP and f-orbital occupancy is observed. CASSCF calculations defy a conventional van Vleck explanation of the TIP, indicating a single-reference ground state with no low-lying triplet excited state, despite accurately predicting the measured values of f-orbital occupancy. The calculations do, however, predict strong 4f/5d hybridization. In fact, within these complexes, despite having similar f-orbital occupancies and therefore levels of 4f/5d hybridization, the d-state distributions vary depending on the bonding motif (Ce
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O vs. CeN) of the complex, and can also be fine-tuned based on varying alkali metal cation capping species. This system therefore provides a platform for understanding the characteristic nature of Ce multiple bonds and potential impact that the associated d-state distribution may have on resulting reactivity. Ce(iv) complexes with multiple bonds display similar f0 fractions, but different f/d hybridization, 5d-orbital energies, and TIP levels.![]()
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Affiliation(s)
- Liane M. Moreau
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Ekaterina Lapsheva
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | | | - Michael R. Gau
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Patrick J. Carroll
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Brian C. Manor
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Yusen Qiao
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Qiaomu Yang
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Wayne W. Lukens
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Dimosthenis Sokaras
- Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Eric J. Schelter
- Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Laurent Maron
- LPCNO, UMR 5215, CNRS, INSA, UPS, Université de Toulouse, 31000 Toulouse, France
| | - Corwin H. Booth
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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11
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Wedal JC, Evans WJ. A Rare-Earth Metal Retrospective to Stimulate All Fields. J Am Chem Soc 2021; 143:18354-18367. [PMID: 34677044 DOI: 10.1021/jacs.1c08288] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Formulating insightful questions and experiments is crucial to the advancement of science. The purpose of this Perspective is to encourage scientists in all areas of chemistry to ask more "What if?" questions: What if we tried this experiment? What if we used these conditions? What if that idea is not correct? To stimulate this thinking, a retrospective analysis of a specific field, in this case rare-earth metal chemistry, is presented that describes the "What if?" questions that could have and should have been asked earlier based on our current knowledge. The goal is to provide scientists with a historical perspective of discovery that exemplifies how previous views in chemistry were often narrowed by predominant beliefs in principles that were incorrect. The same situation is likely to exist today, but we do not realize the limitations! Hopefully, this analysis can be used as a springboard for posing important "What if?" questions that should be asked right now in every area of chemical research.
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Affiliation(s)
- Justin C Wedal
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - William J Evans
- Department of Chemistry, University of California, Irvine, California 92697, United States
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12
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Celis-Barros C, Albrecht-Schönzart T, Windorff CJ. Computational Investigation of the Bonding in [(η 5–Cp′) 3(η 1–Cp′)M] 1– (M = Pu, U, Ce). Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00803] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Cristian Celis-Barros
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, RM. 118 DLC, Tallahassee, Florida 32306, United States
| | - Thomas Albrecht-Schönzart
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, RM. 118 DLC, Tallahassee, Florida 32306, United States
| | - Cory J. Windorff
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, RM. 118 DLC, Tallahassee, Florida 32306, United States
- Department of Chemistry and Biochemistry, New Mexico State University, MSC 3C, PO Box 3001, Las Cruces, New Mexico 88003, United States
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13
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14
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Tricoire M, Mahieu N, Simler T, Nocton G. Intermediate Valence States in Lanthanide Compounds. Chemistry 2021; 27:6860-6879. [PMID: 33340383 PMCID: PMC7610675 DOI: 10.1002/chem.202004735] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Indexed: 12/31/2022]
Abstract
Over more than 50 years, intermediate valence states in lanthanide compounds have often resulted in unexpected or puzzling spectroscopic and magnetic properties. Such experimental singularities could not be rationalised until new theoretical models involving multiconfigurational electronic ground states were established. In this minireview, the different singularities that have been observed among lanthanide complexes are highlighted, the models used to rationalise them are detailed and how such electronic effects may be adjusted depending on energy and symmetry considerations is considered. Understanding and tuning the ground-state multiconfigurational behaviour in lanthanide complexes may open new doors to modular and unusual reactivities.
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Affiliation(s)
- Maxime Tricoire
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128, Palaiseau, cedex, France
| | - Nolwenn Mahieu
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128, Palaiseau, cedex, France
| | - Thomas Simler
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128, Palaiseau, cedex, France
| | - Grégory Nocton
- LCM, CNRS, Ecole polytechnique, Institut Polytechnique de Paris, Route de Saclay, 91128, Palaiseau, cedex, France
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15
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Lukens WW, Booth CH, Walter MD. Experimental evaluation of the stabilization of the COT orbitals by 4f orbitals in COT 2Ce using a Hubbard model. Dalton Trans 2021; 50:2530-2535. [PMID: 33522542 DOI: 10.1039/d0dt03897k] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Significant orbital mixing is rare in lanthanide complexes because of the limited radial extent of the 4f orbitals, which results in a generally small stabilization due to 4f orbital interactions. Nevertheless, even a small amount of additional stabilization could enhance lanthanide separations. One lanthanide complex in which orbital mixing has been extensively studied both experimentally and computationally is cerocene, COT2Ce, where COT is cyclooctatetraene. This compound has a singlet ground state with a low-lying, triplet excited state. Previous fluorescence studies on trimethylsilyl-substituted cerocenes indicate the triplet state is 0.4 eV higher in energy than the singlet state. In addition, computational studies predict that the triplet is 0.3 to 1 eV higher in energy than the singlet. The synthesis of highly pure COT2Ce by Walter and Andersen allowed its physical properties to be accurately measured. Using these measurements, we evaluate the stabilization of the 4f orbitals using two, independent approaches. A Hubbard model is used to evaluate the stabilization of the ground state due to orbital mixing. This stabilization, which is also the singlet-triplet gap, is -0.29 eV using this model. This gap was also from the temperature independent paramagnetism of COT2Ce, which yielded a value of -0.32 eV.
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Affiliation(s)
- Wayne W Lukens
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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16
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Hay MA, Boskovic C. Lanthanoid Complexes as Molecular Materials: The Redox Approach. Chemistry 2021; 27:3608-3637. [PMID: 32965741 DOI: 10.1002/chem.202003761] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Indexed: 11/05/2022]
Abstract
The development of molecular materials with novel functionality offers promise for technological innovation. Switchable molecules that incorporate redox-active components are enticing candidate compounds due to their potential for electronic manipulation. Lanthanoid metals are most prevalent in their trivalent state and usually redox-activity in lanthanoid complexes is restricted to the ligand. The unique electronic and physical properties of lanthanoid ions have been exploited for various applications, including in magnetic and luminescent materials as well as in catalysis. Lanthanoid complexes are also promising for applications reliant on switchability, where the physical properties can be modulated by varying the oxidation state of a coordinated ligand. Lanthanoid-based redox activity is also possible, encompassing both divalent and tetravalent metal oxidation states. Thus, utilization of redox-active lanthanoid metals offers an attractive opportunity to further expand the capabilities of molecular materials. This review surveys both ligand and lanthanoid centered redox-activity in pre-existing molecular systems, including tuning of lanthanoid magnetic and photophysical properties by modulating the redox states of coordinated ligands. Ultimately the combination of redox-activity at both ligands and metal centers in the same molecule can afford novel electronic structures and physical properties, including multiconfigurational electronic states and valence tautomerism. Further targeted exploration of these features is clearly warranted, both to enhance understanding of the underlying fundamental chemistry, and for the generation of a potentially important new class of molecular material.
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Affiliation(s)
- Moya A Hay
- School of Chemistry, University of Melbourne, Victoria, 3010, Australia
| | - Colette Boskovic
- School of Chemistry, University of Melbourne, Victoria, 3010, Australia
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17
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Amoza M, Gómez-Coca S, Ruiz E. Magnetic anisotropy in Yb III complex candidates for molecular qubits: a theoretical analysis. Phys Chem Chem Phys 2021; 23:1976-1983. [PMID: 33433544 DOI: 10.1039/d0cp05422d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
The magnetic properties of mononuclear YbIII complexes have been explored by using multiconfigurational CASPT2/RASSI calculations. Such complexes, in particular the case of [Yb(trensal)] complex, have been proposed as molecular qubits due to their spin dynamics properties. We have verified the accuracy of the theoretical approach to study such systems by comparing with experimental magnetic data. In order to have a wide overview of the magnetic properties of mononuclear YbIII complexes, we have considered simple charged and neutral models, [Yb(H2O)n]3+ and [Yb(OH)3(H2O)n-3], for many coordination modes. Thus, the results for more than 100 models allow extraction of some conclusions about the best ligand distributions in the coordination sphere to tailor the magnetic properties. Some low coordination, between 3 and 5, complexes that have no experimental magnetic data have been studied computationally to check if they can present high magnetic anisotropy.
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Affiliation(s)
- Martín Amoza
- Departament de Química Inorgànica i Orgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
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18
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Smiles DE, Batista ER, Booth CH, Clark DL, Keith JM, Kozimor SA, Martin RL, Minasian SG, Shuh DK, Stieber SCE, Tyliszczak T. The duality of electron localization and covalency in lanthanide and actinide metallocenes. Chem Sci 2020; 11:2796-2809. [PMID: 34084340 PMCID: PMC8157540 DOI: 10.1039/c9sc06114b] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 02/04/2020] [Indexed: 12/14/2022] Open
Abstract
Previous magnetic, spectroscopic, and theoretical studies of cerocene, Ce(C8H8)2, have provided evidence for non-negligible 4f-electron density on Ce and implied that charge transfer from the ligands occurs as a result of covalent bonding. Strong correlations of the localized 4f-electrons to the delocalized ligand π-system result in emergence of Kondo-like behavior and other quantum chemical phenomena that are rarely observed in molecular systems. In this study, Ce(C8H8)2 is analyzed experimentally using carbon K-edge and cerium M5,4-edge X-ray absorption spectroscopies (XAS), and computationally using configuration interaction (CI) calculations and density functional theory (DFT) as well as time-dependent DFT (TDDFT). Both spectroscopic approaches provide strong evidence for ligand → metal electron transfer as a result of Ce 4f and 5d mixing with the occupied C 2p orbitals of the C8H8 2- ligands. Specifically, the Ce M5,4-edge XAS and CI calculations show that the contribution of the 4f1, or Ce3+, configuration to the ground state of Ce(C8H8)2 is similar to strongly correlated materials such as CeRh3 and significantly larger than observed for other formally Ce4+ compounds including CeO2 and CeCl6 2-. Pre-edge features in the experimental and TDDFT-simulated C K-edge XAS provide unequivocal evidence for C 2p and Ce 4f covalent orbital mixing in the δ-antibonding orbitals of e2u symmetry, which are the unoccupied counterparts to the occupied, ligand-based δ-bonding e2u orbitals. The C K-edge peak intensities, which can be compared directly to the C 2p and Ce 4f orbital mixing coefficients determined by DFT, show that covalency in Ce(C8H8)2 is comparable in magnitude to values reported previously for U(C8H8)2. An intuitive model is presented to show how similar covalent contributions to the ground state can have different impacts on the overall stability of f-element metallocenes.
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Affiliation(s)
- Danil E Smiles
- Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | | | - Corwin H Booth
- Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - David L Clark
- Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
| | | | - Stosh A Kozimor
- Los Alamos National Laboratory Los Alamos New Mexico 87545 USA
| | | | | | - David K Shuh
- Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | | | - Tolek Tyliszczak
- Lawrence Berkeley National Laboratory Berkeley California 94720 USA
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19
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Giansiracusa MJ, Al-Badran S, Kostopoulos AK, Whitehead GFS, McInnes EJL, Collison D, Winpenny REP, Chilton NF. Magnetic exchange interactions in symmetric lanthanide dimetallics. Inorg Chem Front 2020. [DOI: 10.1039/d0qi00854k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multi-frequency EPR spectra and CASSCF-SO calculations on two symmetric homo-dimetallic lanthanide complexes are used to determine the magnetic exchange coupling in the low-lying states.
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Affiliation(s)
| | - Susan Al-Badran
- Department of Chemistry
- The University of Manchester
- Manchester
- UK
- Chemistry Department
| | | | | | | | - David Collison
- Department of Chemistry
- The University of Manchester
- Manchester
- UK
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20
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Nicholas HM, Vonci M, Goodwin CAP, Loo SW, Murphy SR, Cassim D, Winpenny REP, McInnes EJL, Chilton NF, Mills DP. Electronic structures of bent lanthanide(III) complexes with two N-donor ligands. Chem Sci 2019; 10:10493-10502. [PMID: 32110338 PMCID: PMC7020784 DOI: 10.1039/c9sc03431e] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 09/17/2019] [Indexed: 01/19/2023] Open
Abstract
Low coordinate metal complexes can exhibit superlative physicochemical properties, but this chemistry is challenging for the lanthanides (Ln) due to their tendency to maximize electrostatic contacts in predominantly ionic bonding regimes. Although a handful of Ln2+ complexes with only two monodentate ligands have been isolated, examples in the most common +3 oxidation state have remained elusive due to the greater electrostatic forces of Ln3+ ions. Here, we report bent Ln3+ complexes with two bis(silyl)amide ligands; in the solid state the Yb3+ analogue exhibits a crystal field similar to its three coordinate precursor rather than that expected for an axial system. This unanticipated finding is in opposition to the predicted electronic structure for two-coordinate systems, indicating that geometries can be more important than the Ln ion identity for dictating the magnetic ground states of low coordinate complexes; this is crucial transferable information for the construction of systems with enhanced magnetic properties.
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Affiliation(s)
- Hannah M Nicholas
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Michele Vonci
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Conrad A P Goodwin
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Song Wei Loo
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Siobhan R Murphy
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Daniel Cassim
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Richard E P Winpenny
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Eric J L McInnes
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - Nicholas F Chilton
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
| | - David P Mills
- Department of Chemistry , School of Natural Sciences , The University of Manchester , Oxford Road , Manchester , M13 9PL , UK .
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21
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Semenov SG, Bedrina ME, Buzin AE, Titov AV. Structural Parameters and Electron Transfer in Ytterbium, Lutetium, and Cerium Compounds with Hydrocarbon Monocycles. RUSS J GEN CHEM+ 2019. [DOI: 10.1134/s1070363219070120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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22
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Vonci M, Mason K, Neil ER, Yufit DS, McInnes EJL, Parker D, Chilton NF. Sensitivity of Magnetic Anisotropy in the Solid State for Lanthanide Complexes with Small Crystal Field Splitting. Inorg Chem 2019; 58:5733-5745. [DOI: 10.1021/acs.inorgchem.9b00060] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Michele Vonci
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Kevin Mason
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, U.K
| | - Emily R. Neil
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, U.K
| | - Dmitry S. Yufit
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, U.K
| | - Eric J. L. McInnes
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - David Parker
- Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, U.K
| | - Nicholas F. Chilton
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
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23
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Periodic Trends Revealed by Photoelectron Studies of Transition Metal and Lanthanide Compounds. STRUCTURE AND BONDING 2019. [DOI: 10.1007/430_2019_37] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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24
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25
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Jenkins TF, Woen DH, Mohanam LN, Ziller JW, Furche F, Evans WJ. Tetramethylcyclopentadienyl Ligands Allow Isolation of Ln(II) Ions across the Lanthanide Series in [K(2.2.2-cryptand)][(C5Me4H)3Ln] Complexes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00557] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tener F. Jenkins
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - David H. Woen
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Luke N. Mohanam
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Joseph W. Ziller
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J. Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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26
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Halbach RL, Nocton G, Booth CH, Maron L, Andersen RA. Cerium Tetrakis(tropolonate) and Cerium Tetrakis(acetylacetonate) Are Not Diamagnetic but Temperature-Independent Paramagnets. Inorg Chem 2018; 57:7290-7298. [PMID: 29863340 DOI: 10.1021/acs.inorgchem.8b00928] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new synthesis of cerium tetrakis(tropolonate), Ce(trop)4, where trop is deprotonated 2-hydroxy-2,4,6-cycloheptatrienone) or Ce(O2C7H5)4, is developed that results in dark-purple crystals whose X-ray crystal structure shows that the geometry of the eight-coordinate compound closely resembles a D2 d dodecahedron, based on shape parameters. The magnetic susceptibility as a function of the temperature (4-300 K) shows that it is a temperature-independent paramagnet, χ = 1.2(3) × 10-4 emu/mol, and the LIII-edge X-ray absorption near-edge structure spectrum shows that the molecule is multiconfigurational, comprised of a f1:f0 configuration mixture in a 50:50 ratio. Ce(acac)4 and Ce(tmtaa)2 (where acac is acetylacetonate and tmtaaH2 is tetramethyldibenzotetraaza[14]annulene) have similar physical properties, as does the solid-state compound CeO2. The concept is advanced that trop-, acac-, tmtaa2-, cot2-, and O2- are redox-active ligands that function as electron donors, rendering the classification of these compounds according to their oxidation numbers misleading because their magnetic susceptibilities, χ, are positive and their effective magnetic moments, μeff, lie in the range of 0.1-0.7 μB at 300 K.
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Affiliation(s)
- Robert L Halbach
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
| | - Grégory Nocton
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,LCM, CNRS , Ecole Polytechnique, Université Paris Saclay , 91128 Palaiseau , France
| | - Corwin H Booth
- Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Laurent Maron
- LPCNO, UMR 5215, CNRS, INSA, UPS , Université de Toulouse , 31000 Toulouse , France
| | - Richard A Andersen
- Department of Chemistry , University of California , Berkeley , California 94720 , United States.,Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
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27
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Giansiracusa MJ, Moreno-Pineda E, Hussain R, Marx R, Martínez Prada M, Neugebauer P, Al-Badran S, Collison D, Tuna F, van Slageren J, Carretta S, Guidi T, McInnes EJL, Winpenny REP, Chilton NF. Measurement of Magnetic Exchange in Asymmetric Lanthanide Dimetallics: Toward a Transferable Theoretical Framework. J Am Chem Soc 2018; 140:2504-2513. [DOI: 10.1021/jacs.7b10714] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
| | - Eufemio Moreno-Pineda
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Riaz Hussain
- Dipartimento di Scienze Matematiche, Fisiche ed Informatiche, Università di Parma, Parco Area delle Scienze 7/a, Parma 43124, Italy
| | - Raphael Marx
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - María Martínez Prada
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Petr Neugebauer
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Susan Al-Badran
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - David Collison
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Floriana Tuna
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | - Joris van Slageren
- Institut für Physikalische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Stefano Carretta
- Dipartimento di Scienze Matematiche, Fisiche ed Informatiche, Università di Parma, Parco Area delle Scienze 7/a, Parma 43124, Italy
| | - Tatiana Guidi
- ISIS Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Didcot OX11 0QX, U.K
| | - Eric J. L. McInnes
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
| | | | - Nicholas F. Chilton
- School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, U.K
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28
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Goodwin CAP, Reta D, Ortu F, Chilton NF, Mills DP. Synthesis and Electronic Structures of Heavy Lanthanide Metallocenium Cations. J Am Chem Soc 2017; 139:18714-18724. [DOI: 10.1021/jacs.7b11535] [Citation(s) in RCA: 83] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Conrad A. P. Goodwin
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Daniel Reta
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Fabrizio Ortu
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - Nicholas F. Chilton
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
| | - David P. Mills
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, U.K
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29
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Fieser ME, Ferrier MG, Su J, Batista E, Cary SK, Engle JW, Evans WJ, Lezama Pacheco JS, Kozimor SA, Olson AC, Ryan AJ, Stein BW, Wagner GL, Woen DH, Vitova T, Yang P. Evaluating the electronic structure of formal Ln II ions in Ln II(C 5H 4SiMe 3) 31- using XANES spectroscopy and DFT calculations. Chem Sci 2017; 8:6076-6091. [PMID: 28989638 PMCID: PMC5625586 DOI: 10.1039/c7sc00825b] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 06/05/2017] [Indexed: 12/15/2022] Open
Abstract
The isolation of [K(2.2.2-cryptand)][Ln(C5H4SiMe3)3], formally containing LnII, for all lanthanides (excluding Pm) was surprising given that +2 oxidation states are typically regarded as inaccessible for most 4f-elements. Herein, X-ray absorption near-edge spectroscopy (XANES), ground-state density functional theory (DFT), and transition dipole moment calculations are used to investigate the possibility that Ln(C5H4SiMe3)31- (Ln = Pr, Nd, Sm, Gd, Tb, Dy, Y, Ho, Er, Tm, Yb and Lu) compounds represented molecular LnII complexes. Results from the ground-state DFT calculations were supported by additional calculations that utilized complete-active-space multi-configuration approach with second-order perturbation theoretical correction (CASPT2). Through comparisons with standards, Ln(C5H4SiMe3)31- (Ln = Sm, Tm, Yb, Lu, Y) are determined to contain 4f6 5d0 (SmII), 4f13 5d0 (TmII), 4f14 5d0 (YbII), 4f14 5d1 (LuII), and 4d1 (YII) electronic configurations. Additionally, our results suggest that Ln(C5H4SiMe3)31- (Ln = Pr, Nd, Gd, Tb, Dy, Ho, and Er) also contain LnII ions, but with 4f n 5d1 configurations (not 4f n+1 5d0). In these 4f n 5d1 complexes, the C3h-symmetric ligand environment provides a highly shielded 5d-orbital of a' symmetry that made the 4f n 5d1 electronic configurations lower in energy than the more typical 4f n+1 5d0 configuration.
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Affiliation(s)
| | | | - Jing Su
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Enrique Batista
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Samantha K Cary
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Jonathan W Engle
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
- University of Wisconsin , Madison , Wisconsin 53711 , USA
| | | | | | - Stosh A Kozimor
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Angela C Olson
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Austin J Ryan
- University of California , Irvine , CA 92697 , USA .
| | - Benjamin W Stein
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - Gregory L Wagner
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
| | - David H Woen
- University of California , Irvine , CA 92697 , USA .
| | - Tonya Vitova
- Karlsruhe Institute of Technology , Institute for Nuclear Waste Disposal , P.O. Box 3640 , 76021 Karlsruhe , Germany
| | - Ping Yang
- Los Alamos National Laboratory , Los Alamos , NM 87545 , USA . ; ;
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30
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Xémard M, Jaoul A, Cordier M, Molton F, Cador O, Le Guennic B, Duboc C, Maury O, Clavaguéra C, Nocton G. Divalent Thulium Triflate: A Structural and Spectroscopic Study. Angew Chem Int Ed Engl 2017; 56:4266-4271. [DOI: 10.1002/anie.201700576] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Indexed: 11/08/2022]
Affiliation(s)
- Mathieu Xémard
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Arnaud Jaoul
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Marie Cordier
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Florian Molton
- Département de Chimie Moléculaire; Grenoble Université, CNRS; Avenue de la Chimie Saint Martin d'Hères France
| | - Olivier Cador
- Institut des Sciences Chimique de Rennes, UMR 6226 CNRS; Université de Rennes 1; 263 avenue du Général Leclerc 35042 Rennes cedex France
| | - Boris Le Guennic
- Institut des Sciences Chimique de Rennes, UMR 6226 CNRS; Université de Rennes 1; 263 avenue du Général Leclerc 35042 Rennes cedex France
| | - Carole Duboc
- Département de Chimie Moléculaire; Grenoble Université, CNRS; Avenue de la Chimie Saint Martin d'Hères France
| | - Olivier Maury
- Univ Lyon, ENS Lyon, CNRS; Université Claude Bernard Lyon 1, UMR 5182, Laboratoire de Chimie; 69342 Lyon France
| | - Carine Clavaguéra
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
- Laboratoire de Chimie Physique, CNRS; Université Paris Sud, Université Paris-Saclay; 15 avenue Jean Perrin 91405 Orsay cedex France
| | - Grégory Nocton
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
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31
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Xémard M, Jaoul A, Cordier M, Molton F, Cador O, Le Guennic B, Duboc C, Maury O, Clavaguéra C, Nocton G. Divalent Thulium Triflate: A Structural and Spectroscopic Study. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201700576] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Mathieu Xémard
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Arnaud Jaoul
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Marie Cordier
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
| | - Florian Molton
- Département de Chimie Moléculaire; Grenoble Université, CNRS; Avenue de la Chimie Saint Martin d'Hères France
| | - Olivier Cador
- Institut des Sciences Chimique de Rennes, UMR 6226 CNRS; Université de Rennes 1; 263 avenue du Général Leclerc 35042 Rennes cedex France
| | - Boris Le Guennic
- Institut des Sciences Chimique de Rennes, UMR 6226 CNRS; Université de Rennes 1; 263 avenue du Général Leclerc 35042 Rennes cedex France
| | - Carole Duboc
- Département de Chimie Moléculaire; Grenoble Université, CNRS; Avenue de la Chimie Saint Martin d'Hères France
| | - Olivier Maury
- Univ Lyon, ENS Lyon, CNRS; Université Claude Bernard Lyon 1, UMR 5182, Laboratoire de Chimie; 69342 Lyon France
| | - Carine Clavaguéra
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
- Laboratoire de Chimie Physique, CNRS; Université Paris Sud, Université Paris-Saclay; 15 avenue Jean Perrin 91405 Orsay cedex France
| | - Grégory Nocton
- LCM, Ecole polytechnique, CNRS; Université Paris-Saclay; Route de Saclay 91128 Palaiseau cedex France
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32
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Dutkiewicz MS, Apostolidis C, Walter O, Arnold PL. Reduction chemistry of neptunium cyclopentadienide complexes: from structure to understanding. Chem Sci 2017; 8:2553-2561. [PMID: 28553487 PMCID: PMC5431675 DOI: 10.1039/c7sc00034k] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 01/27/2017] [Indexed: 12/31/2022] Open
Abstract
Structural investigation on neptunium cyclopentadienyl organometallic complexes in the formal oxidation states II, III, and IV: similarities and differences between Np and U.
Neptunium complexes in the formal oxidation states II, III, and IV supported by cyclopentadienyl ligands are explored, and significant differences between Np and U highlighted as a result. A series of neptunium(iii) cyclopentadienyl (Cp) complexes [Np(Cp)3], its bis-acetonitrile adduct [Np(Cp)3(NCMe)2], and its KCp adduct K[Np(Cp)4] and [Np(Cp′)3] (Cp′ = C5H4SiMe3) have been made and characterised providing the first single crystal X-ray analyses of NpIII Cp complexes. In all NpCp3 derivatives there are three Cp rings in η5-coordination around the NpIII centre; additionally in [Np(Cp)3] and K[Np(Cp)4] one Cp ring establishes a μ-η1-interaction to one C atom of a neighbouring Np(Cp)3 unit. The solid state structure of K[Np(Cp)4] is unique in containing two different types of metal–Cp coordination geometries in the same crystal. NpIII(Cp)4 units are found exhibiting four units of η5-coordinated Cp rings like in the known complex [NpIV(Cp)4], the structure of which is now reported. A detailed comparison of the structures gives evidence for the change of ionic radii of ca. –8 pm associated with change in oxidation state between NpIII and NpIV. The rich redox chemistry associated with the syntheses is augmented by the reduction of [Np(Cp′)3] by KC8 in the presence of 2.2.2-cryptand to afford a neptunium(ii) complex that is thermally unstable above –10 °C like the UII and ThII complexes K(2.2.2-cryptand)[Th/U(Cp′)3]. Together, these spontaneous and controlled redox reactions of organo-neptunium complexes, along with information from structural characterisation, show the relevance of organometallic Np chemistry to understanding fundamental structure and bonding in the minor actinides.
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Affiliation(s)
- Michał S Dutkiewicz
- European Commission , Directorate for Nuclear Safety and Security , Joint Research Centre , Postfach 2340 , D-76125 , Karlsruhe , Germany . .,EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK .
| | - Christos Apostolidis
- European Commission , Directorate for Nuclear Safety and Security , Joint Research Centre , Postfach 2340 , D-76125 , Karlsruhe , Germany .
| | - Olaf Walter
- European Commission , Directorate for Nuclear Safety and Security , Joint Research Centre , Postfach 2340 , D-76125 , Karlsruhe , Germany .
| | - Polly L Arnold
- EaStCHEM School of Chemistry , The University of Edinburgh , Joseph Black Building, David Brewster Road , Edinburgh , EH9 3FJ , UK .
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33
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Actinide covalency measured by pulsed electron paramagnetic resonance spectroscopy. Nat Chem 2016; 9:578-583. [PMID: 28537586 DOI: 10.1038/nchem.2692] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 11/10/2016] [Indexed: 12/20/2022]
Abstract
Our knowledge of actinide chemical bonds lags far behind our understanding of the bonding regimes of any other series of elements. This is a major issue given the technological as well as fundamental importance of f-block elements. Some key chemical differences between actinides and lanthanides-and between different actinides-can be ascribed to minor differences in covalency, that is, the degree to which electrons are shared between the f-block element and coordinated ligands. Yet there are almost no direct measures of such covalency for actinides. Here we report the first pulsed electron paramagnetic resonance spectra of actinide compounds. We apply the hyperfine sublevel correlation technique to quantify the electron-spin density at ligand nuclei (via the weak hyperfine interactions) in molecular thorium(III) and uranium(III) species and therefore the extent of covalency. Such information will be important in developing our understanding of the chemical bonding, and therefore the reactivity, of actinides.
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34
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Evans WJ. Tutorial on the Role of Cyclopentadienyl Ligands in the Discovery of Molecular Complexes of the Rare-Earth and Actinide Metals in New Oxidation States. Organometallics 2016. [DOI: 10.1021/acs.organomet.6b00466] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- William J. Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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35
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Duignan TJ, Autschbach J. Impact of the Kohn–Sham Delocalization Error on the 4f Shell Localization and Population in Lanthanide Complexes. J Chem Theory Comput 2016; 12:3109-21. [DOI: 10.1021/acs.jctc.6b00238] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas J. Duignan
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, United States
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36
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Blackburn OA, Edkins RM, Faulkner S, Kenwright AM, Parker D, Rogers NJ, Shuvaev S. Electromagnetic susceptibility anisotropy and its importance for paramagnetic NMR and optical spectroscopy in lanthanide coordination chemistry. Dalton Trans 2016; 45:6782-800. [DOI: 10.1039/c6dt00227g] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Electromagnetic susceptibility anisotropy can explain the spectroscopy and magnetism of lanthanide containing systems, but current theories have limitations.
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Affiliation(s)
| | | | | | | | - David Parker
- Department of Chemistry
- Durham University
- Durham
- UK
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37
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Altman AB, Pacold JI, Wang J, Lukens WW, Minasian SG. Evidence for 5d-σ and 5d-π covalency in lanthanide sesquioxides from oxygen K-edge X-ray absorption spectroscopy. Dalton Trans 2016; 45:9948-61. [DOI: 10.1039/c6dt00358c] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The electronic structure in the complete series of stable lanthanide sesquioxides, Ln2O3 (Ln = La to Lu, except radioactive Pm), has been evaluated using oxygen K-edge X-ray absorption spectroscopy with a scanning transmission X-ray microscope (STXM).
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Affiliation(s)
- Alison B. Altman
- Department of Chemistry
- University of California
- Berkeley CA 94720
- USA
- Chemical Sciences Division
| | - Joseph I. Pacold
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley CA 94720
- USA
| | - Jian Wang
- Canadian Light Source
- Saskatoon
- Canada
| | - Wayne W. Lukens
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley CA 94720
- USA
| | - Stefan G. Minasian
- Chemical Sciences Division
- Lawrence Berkeley National Laboratory
- Berkeley CA 94720
- USA
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38
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Kotyk CM, Fieser ME, Palumbo CT, Ziller JW, Darago LE, Long JR, Furche F, Evans WJ. Isolation of +2 rare earth metal ions with three anionic carbocyclic rings: bimetallic bis(cyclopentadienyl) reduced arene complexes of La 2+ and Ce 2+ are four electron reductants. Chem Sci 2015; 6:7267-7273. [PMID: 29861961 PMCID: PMC5947538 DOI: 10.1039/c5sc02486b] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Accepted: 09/18/2015] [Indexed: 12/30/2022] Open
Abstract
A new option for stabilizing unusual Ln2+ ions has been identified in the reaction of Cp'3Ln, 1-Ln (Ln = La, Ce; Cp' = C5H4SiMe3), with potassium graphite (KC8) in benzene in the presence of 2.2.2-cryptand. This generates [K(2.2.2-cryptand)]2[(Cp'2Ln)2(μ-η6:η6-C6H6)], 2-Ln, complexes that contain La and Ce in the formal +2 oxidation state. These complexes expand the range of coordination environments known for these ions beyond the previously established examples, (Cp''3Ln)1- and (Cp'3Ln)1- (Cp'' = C5H3(SiMe3)2-1,3), and generalize the viability of using three anionic carbocyclic rings to stabilize highly reactive Ln2+ ions. In 2-Ln, a non-planar bridging (C6H6)2- ligand shared between two metals takes the place of a cyclopentadienyl ligand in (Cp'3Ln)1-. The intensely colored (ε = ∼8000 M-1 cm-1) 2-Ln complexes react as four electron reductants with two equiv. of naphthalene to produce two equiv. of the reduced naphthalenide complex, [K(2.2.2-cryptand)][Cp'2Ln(η4-C10H8)].
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Affiliation(s)
- Christopher M Kotyk
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
| | - Megan E Fieser
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
| | - Chad T Palumbo
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
| | - Joseph W Ziller
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
| | - Lucy E Darago
- Department of Chemistry , University of California , Berkeley , California 94720 , USA .
| | - Jeffrey R Long
- Department of Chemistry , University of California , Berkeley , California 94720 , USA .
| | - Filipp Furche
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
| | - William J Evans
- Department of Chemistry , University of California , Irvine , California 92697 , USA . ; ; ; Tel: +1-949-824-5174
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39
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Blackburn OA, Chilton NF, Keller K, Tait CE, Myers WK, McInnes EJL, Kenwright AM, Beer PD, Timmel CR, Faulkner S. Spectroscopic and Crystal Field Consequences of Fluoride Binding by [Yb⋅DTMA](3+) in Aqueous Solution. Angew Chem Int Ed Engl 2015; 54:10783-6. [PMID: 26223970 PMCID: PMC4611957 DOI: 10.1002/anie.201503421] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/11/2015] [Indexed: 11/05/2022]
Abstract
Yb⋅DTMA forms a ternary complex with fluoride in aqueous solution by displacement of a bound solvent molecule from the lanthanide ion. [Yb⋅DTMA⋅F](2+) and [Yb⋅DTMA⋅OH2 ](3+) are in slow exchange on the relevant NMR timescale (<2000 s(-1) ), and profound differences are observed in their respective NMR and EPR spectra of these species. The observed differences can be explained by drastic modification of the ligand field states due to the fluoride binding. This changes the magnetic anisotropy of the Yb(III) ground state from easy-axis to easy-plane type, and this change is easily detected in the observed magnetic anisotropy despite thermal population of more than just the ground state. The spectroscopic consequences of such drastic changes to the ligand field represent important new opportunities in developing fluoride-responsive complexes and contrast agents.
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Affiliation(s)
- Octavia A Blackburn
- Chemistry Research Laboratory, University of OxfordMansfield Road, Oxford OX1 3TA (UK) E-mail:
| | - Nicholas F Chilton
- School of Chemistry, and Photon Science Institute, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | - Katharina Keller
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of OxfordSouth Parks Road, Oxford, OX1 3QR (UK)
| | - Claudia E Tait
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of OxfordSouth Parks Road, Oxford, OX1 3QR (UK)
| | - William K Myers
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of OxfordSouth Parks Road, Oxford, OX1 3QR (UK)
| | - Eric J L McInnes
- School of Chemistry, and Photon Science Institute, University of ManchesterOxford Road, Manchester M13 9PL (UK)
| | - Alan M Kenwright
- Department of Chemistry, University of DurhamSouth Road, Durham DH1 3LE (UK)
| | - Paul D Beer
- Chemistry Research Laboratory, University of OxfordMansfield Road, Oxford OX1 3TA (UK) E-mail:
| | - Christiane R Timmel
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of OxfordSouth Parks Road, Oxford, OX1 3QR (UK)
| | - Stephen Faulkner
- Chemistry Research Laboratory, University of OxfordMansfield Road, Oxford OX1 3TA (UK) E-mail:
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40
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Blackburn OA, Chilton NF, Keller K, Tait CE, Myers WK, McInnes EJL, Kenwright AM, Beer PD, Timmel CR, Faulkner S. Spectroscopic and Crystal Field Consequences of Fluoride Binding by [Yb⋅DTMA] 3+ in Aqueous Solution. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2015; 127:10933-10936. [PMID: 27478267 PMCID: PMC4955232 DOI: 10.1002/ange.201503421] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/11/2015] [Indexed: 11/12/2022]
Abstract
Yb⋅DTMA forms a ternary complex with fluoride in aqueous solution by displacement of a bound solvent molecule from the lanthanide ion. [Yb⋅DTMA⋅F]2+ and [Yb⋅DTMA⋅OH2]3+ are in slow exchange on the relevant NMR timescale (<2000 s-1), and profound differences are observed in their respective NMR and EPR spectra of these species. The observed differences can be explained by drastic modification of the ligand field states due to the fluoride binding. This changes the magnetic anisotropy of the YbIII ground state from easy-axis to easy-plane type, and this change is easily detected in the observed magnetic anisotropy despite thermal population of more than just the ground state. The spectroscopic consequences of such drastic changes to the ligand field represent important new opportunities in developing fluoride-responsive complexes and contrast agents.
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Affiliation(s)
- Octavia A. Blackburn
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA (UK)
| | - Nicholas F. Chilton
- School of Chemistry, and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Katharina Keller
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR (UK)
| | - Claudia E. Tait
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR (UK)
| | - William K. Myers
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR (UK)
| | - Eric J. L. McInnes
- School of Chemistry, and Photon Science Institute, University of Manchester, Oxford Road, Manchester M13 9PL (UK)
| | - Alan M. Kenwright
- Department of Chemistry, University of Durham, South Road, Durham DH1 3LE (UK)
| | - Paul D. Beer
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA (UK)
| | - Christiane R. Timmel
- Centre for Advanced ESR (CÆSR), Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR (UK)
| | - Stephen Faulkner
- Chemistry Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA (UK)
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41
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Corbey JF, Woen DH, Palumbo CT, Fieser ME, Ziller JW, Furche F, Evans WJ. Ligand Effects in the Synthesis of Ln2+ Complexes by Reduction of Tris(cyclopentadienyl) Precursors Including C–H Bond Activation of an Indenyl Anion. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00500] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jordan F. Corbey
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - David H. Woen
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Chad T. Palumbo
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Megan E. Fieser
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Joseph W. Ziller
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J. Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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42
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Langeslay RR, Fieser ME, Ziller JW, Furche F, Evans WJ. Synthesis, structure, and reactivity of crystalline molecular complexes of the {[C 5H 3(SiMe 3) 2] 3Th} 1- anion containing thorium in the formal +2 oxidation state. Chem Sci 2015; 6:517-521. [PMID: 29560172 PMCID: PMC5811171 DOI: 10.1039/c4sc03033h] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 10/15/2014] [Indexed: 11/21/2022] Open
Abstract
Reduction of the Th3+ complex Cp''3Th, 1 [Cp'' = C5H3(SiMe3)2], with potassium graphite in THF in the presence of 2.2.2-cryptand generates [K(2.2.2-cryptand)][Cp''3Th], 2, a complex containing thorium in the formal +2 oxidation state. Reaction of 1 with KC8 in the presence of 18-crown-6 generates the analogous Th2+ compound, [K(18-crown-6)(THF)2][Cp''3Th], 3. Complexes 2 and 3 form dark green solutions in THF with ε = 23 000 M-1 cm-1, but crystallize as dichroic dark blue/red crystals. X-ray crystallography revealed that the anions in 2 and 3 have trigonal planar coordination geometries, with 2.521 and 2.525 Å Th-(Cp'' ring centroid) distances, respectively, equivalent to the 2.520 Å distance measured in 1. Density functional theory analysis of (Cp''3Th)1- is consistent with a 6d2 ground state, the first example of this transition metal electron configuration. Complex 3 reacts as a two-electron reductant with cyclooctatetraene to make Cp''2Th(C8H8), 4, and [K(18-crown-6)]Cp''.
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Affiliation(s)
- Ryan R Langeslay
- Department of Chemistry , University of California , Irvine , California 92697-2025 , USA . ; ; ; Tel: +1-949-824-5174
| | - Megan E Fieser
- Department of Chemistry , University of California , Irvine , California 92697-2025 , USA . ; ; ; Tel: +1-949-824-5174
| | - Joseph W Ziller
- Department of Chemistry , University of California , Irvine , California 92697-2025 , USA . ; ; ; Tel: +1-949-824-5174
| | - Filipp Furche
- Department of Chemistry , University of California , Irvine , California 92697-2025 , USA . ; ; ; Tel: +1-949-824-5174
| | - William J Evans
- Department of Chemistry , University of California , Irvine , California 92697-2025 , USA . ; ; ; Tel: +1-949-824-5174
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Fieser ME, MacDonald MR, Krull BT, Bates JE, Ziller JW, Furche F, Evans WJ. Structural, Spectroscopic, and Theoretical Comparison of Traditional vs Recently Discovered Ln2+ Ions in the [K(2.2.2-cryptand)][(C5H4SiMe3)3Ln] Complexes: The Variable Nature of Dy2+ and Nd2+. J Am Chem Soc 2014; 137:369-82. [DOI: 10.1021/ja510831n] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Megan E. Fieser
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Matthew R. MacDonald
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Brandon T. Krull
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Jefferson E. Bates
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Joseph W. Ziller
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J. Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
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Jacquot L, Xémard M, Clavaguéra C, Nocton G. Multiple One-Electron Transfers in Bipyridine Complexes of Bis(phospholyl) Thulium. Organometallics 2014. [DOI: 10.1021/om500607r] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Léa Jacquot
- Laboratoire de Chimie Moléculaire, CNRS, Ecole Polytechnique, Route de Saclay, Palaiseau 91128, France
| | - Mathieu Xémard
- Laboratoire de Chimie Moléculaire, CNRS, Ecole Polytechnique, Route de Saclay, Palaiseau 91128, France
| | - Carine Clavaguéra
- Laboratoire de Chimie Moléculaire, CNRS, Ecole Polytechnique, Route de Saclay, Palaiseau 91128, France
| | - Grégory Nocton
- Laboratoire de Chimie Moléculaire, CNRS, Ecole Polytechnique, Route de Saclay, Palaiseau 91128, France
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45
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Nocton G, Ricard L. N-aromatic heterocycle adducts of bulky [1,2,4-(Me3C)3C5H2]2Sm: synthesis, structure and solution analysis. Dalton Trans 2014; 43:4380-7. [DOI: 10.1039/c3dt52641k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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46
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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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47
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Nocton G, Booth CH, Maron L, Andersen RA. Influence of the Torsion Angle in 3,3′-Dimethyl-2,2′-bipyridine on the Intermediate Valence of Yb in (C5Me5)2Yb(3,3′-Me2-bipy). Organometallics 2013. [DOI: 10.1021/om400528d] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Grégory Nocton
- Laboratoire Hétéroéléments
et Coordination, CNRS, Ecole Polytechnique, Route de Saclay, 91128 Palaiseau, France
- Department of Chemistry, University of California—Berkeley, Berkeley, California 94720, United States
| | - Corwin H. Booth
- Chemical Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Laurent Maron
- LPCNO, UMR 5215,
Université de Toulouse-CNRS, INSA, UPS, Toulouse, France
| | - Richard A. Andersen
- Department of Chemistry, University of California—Berkeley, Berkeley, California 94720, United States
- LPCNO, UMR 5215,
Université de Toulouse-CNRS, INSA, UPS, Toulouse, France
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48
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Bogart JA, Lewis AJ, Medling SA, Piro NA, Carroll PJ, Booth CH, Schelter EJ. Homoleptic Cerium(III) and Cerium(IV) Nitroxide Complexes: Significant Stabilization of the 4+ Oxidation State. Inorg Chem 2013; 52:11600-7. [DOI: 10.1021/ic401974t] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Justin A. Bogart
- P. Roy and Diana T. Vagelos
Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Andrew J. Lewis
- P. Roy and Diana T. Vagelos
Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Scott A. Medling
- Chemical Sciences
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nicholas A. Piro
- P. Roy and Diana T. Vagelos
Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Patrick J. Carroll
- P. Roy and Diana T. Vagelos
Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Corwin H. Booth
- Chemical Sciences
Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Eric J. Schelter
- P. Roy and Diana T. Vagelos
Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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MacDonald MR, Bates JE, Ziller JW, Furche F, Evans WJ. Completing the series of +2 ions for the lanthanide elements: synthesis of molecular complexes of Pr2+, Gd2+, Tb2+, and Lu2+. J Am Chem Soc 2013; 135:9857-68. [PMID: 23697603 DOI: 10.1021/ja403753j] [Citation(s) in RCA: 255] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The first examples of crystallographically characterizable complexes of Tb(2+), Pr(2+), Gd(2+), and Lu(2+) have been isolated, which demonstrate that Ln(2+) ions are accessible in soluble molecules for all of the lanthanides except radioactive promethium. The first molecular Tb(2+) complexes have been obtained from the reaction of Cp'3Ln (Cp' = C5H4SiMe3, Ln = rare earth) with potassium in the presence of 18-crown-6 in Et2O at -35 °C under argon: [(18-crown-6)K][Cp'3Tb], {[(18-crown-6)K][Cp'3Tb]}n, and {[K(18-crown-6)]2(μ-Cp')}{Cp'3Tb}. The first complex is analogous to previously isolated Y(2+), Ho(2+), and Er(2+) complexes, the second complex shows an isomeric structural form of these Ln(2+) complexes, and the third complex shows that [(18-crown-6)K](1+) alone is not the only cation that will stabilize these reactive Ln(2+) species, a result that led to further exploration of cation variants. With 2.2.2-cryptand in place of 18-crown-6 in the Cp'3Ln/K reaction, a more stable complex of Tb(2+) was produced as well as more stable Y(2+), Ho(2+), and Er(2+) analogs: [K(2.2.2-cryptand)][Cp'3Ln]. Exploration of this 2.2.2-cryptand-based reaction with the remaining lanthanides for which Ln(2+) had not been observed in molecular species provided crystalline Pr(2+), Gd(2+), and Lu(2+) complexes. These Ln(2+) complexes, [K(2.2.2-cryptand)][Cp'3Ln] (Ln = Y, Pr, Gd, Tb, Ho, Er, Lu), all have similar UV-vis spectra and exhibit Ln-C(Cp') bond distances that are ~0.03 Å longer than those in the Ln(3+) precursors, Cp'3Ln. These data, as well as density functional theory calculations and EPR spectra, suggest that a 4f(n)5d(1) description of the electron configuration in these Ln(2+) ions is more appropriate than 4f(n+1).
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Affiliation(s)
- Matthew R MacDonald
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA
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50
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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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