1
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Tricoire M, Hsueh FC, Keener M, Rajeshkumar T, Scopelliti R, Zivkovic I, Maron L, Mazzanti M. Siloxide tripodal ligands as a scaffold for stabilizing lanthanides in the +4 oxidation state. Chem Sci 2024; 15:6874-6883. [PMID: 38725506 PMCID: PMC11077534 DOI: 10.1039/d4sc00051j] [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: 01/03/2024] [Accepted: 03/21/2024] [Indexed: 05/12/2024] Open
Abstract
Synthetic strategies to isolate molecular complexes of lanthanides, other than cerium, in the +4 oxidation state remain elusive, with only four complexes of Tb(iv) isolated so far. Herein, we present a new approach for the stabilization of Tb(iv) using a siloxide tripodal trianionic ligand, which allows the control of unwanted ligand rearrangements, while tuning the Ln(iii)/Ln(iv) redox-couple. The Ln(iii) complexes, [LnIII((OSiPh2Ar)3-arene)(THF)3] (1-LnPh) and [K(toluene){LnIII((OSiPh2Ar)3-arene)(OSiPh3)}] (2-LnPh) (Ln = Ce, Tb, Pr), of the (HOSiPh2Ar)3-arene ligand were prepared. The redox properties of these complexes were compared to those of the Ln(iii) analogue complexes, [LnIII((OSi(OtBu)2Ar)3-arene)(THF)] (1-LnOtBu) and [K(THF)6][LnIII((OSi(OtBu)2Ar)3-arene)(OSiPh3)] (2-LnOtBu) (Ln = Ce, Tb), of the less electron-donating siloxide trianionic ligand, (HOSi(OtBu)2Ar)3-arene. The cyclic voltammetry studies showed a cathodic shift in the oxidation potential for the cerium and terbium complexes of the more electron-donating phenyl substituted scaffold (1-LnPh) compared to those of the tert-butoxy (1-LnOtBu) ligand. Furthermore, the addition of the -OSiPh3 ligand further shifts the potential cathodically, making the Ln(iv) ion even more accessible. Notably, the Ce(iv) complexes, [CeIV((OSi(OtBu)2Ar)3-arene)(OSiPh3)] (3-CeOtBu) and [CeIV((OSiPh2Ar)3-arene)(OSiPh3)(THF)2] (3-CePh), were prepared by chemical oxidation of the Ce(iii) analogues. Chemical oxidation of the Tb(iii) and Pr(iii) complexes (2-LnPh) was also possible, in which the Tb(iv) complex, [TbIV((OSiPh2Ar)3-arene)(OSiPh3)(MeCN)2] (3-TbPh), was isolated and crystallographically characterized, yielding the first example of a Tb(iv) supported by a polydentate ligand. The versatility and robustness of these siloxide arene-anchored platforms will allow further development in the isolation of more oxidizing Ln(iv) ions, widening the breadth of high-valent Ln chemistry.
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Affiliation(s)
- Maxime Tricoire
- Group of Coordiantion Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Fang-Che Hsueh
- Group of Coordiantion Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Megan Keener
- Group of Coordiantion Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Thayalan Rajeshkumar
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées Cedex 4 31077 Toulouse France
| | - Rosario Scopelliti
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Ivica Zivkovic
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL) CH-1015 Lausanne Switzerland
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées Cedex 4 31077 Toulouse France
| | - Marinella Mazzanti
- Group of Coordiantion Chemistry, Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
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2
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Ouellette ET, Brackbill IJ, Kynman AE, Christodoulou S, Maron L, Bergman RG, Arnold J. Triple Inverse Sandwich versus End-On Diazenido: Bonding Motifs across a Series of Rhenium-Lanthanide and -Actinide Complexes. Inorg Chem 2024; 63:7177-7188. [PMID: 38598523 DOI: 10.1021/acs.inorgchem.3c04248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
While synthesizing a series of rhenium-lanthanide triple inverse sandwich complexes, we unexpectedly uncovered evidence for rare examples of end-on lanthanide dinitrogen coordination for certain heavy lanthanide elements as well as for uranium. We begin our report with the synthesis and characterization of a series of trirhenium triple inverse sandwich complexes with the early lanthanides, Ln[(μ-η5:η5-Cp)Re(BDI)]3(THF) (1-Ln, Ln = La, Ce, Pr, Nd, Sm; Cp = cyclopentadienide, BDI = N,N'-bis(2,6-diisopropylphenyl)-3,5-dimethyl-β-diketiminate). However, as we moved across the lanthanide series, we ran into an unexpected result for gadolinium in which we structurally characterized two products for gadolinium, namely, 1-Gd (analogous to 1-Ln) and a diazenido dirhenium double inverse sandwich complex Gd[(μ-η1:η1-N2)Re(η5-Cp)(BDI)][(μ-η5:η5-Cp)Re(BDI)]2(THF)2 (2-Gd). Evidence for analogues of 2-Gd was spectroscopically observed for other heavy lanthanides (2-Ln, Ln = Tb, Dy, Er), and, in the case of 2-Er, structurally authenticated. These complexes represent the first observed examples of heterobimetallic end-on lanthanide dinitrogen coordination. Density functional theory (DFT) calculations were utilized to probe relevant bonding interactions and reveal energetic differences between both the experimental and putative 1-Ln and 2-Ln complexes. We also present additional examples of novel end-on heterobimetallic lanthanide and actinide diazenido moieties in the erbium-rhenium complex (η8-COT)Er[(μ-η1:η1-N2)Re(η5-Cp)(BDI)](THF)(Et2O) (3-Er) and uranium-rhenium complex [Na(2.2.2-cryptand)][(η5-C5H4SiMe3)3U(μ-η1:η1-N2)Re(η5-Cp)(BDI)] (4-U). Finally, we expand the scope of rhenium inverse sandwich coordination by synthesizing divalent double inverse sandwich complex Yb[(μ-η5:η5-Cp)Re(BDI)]2(THF)2 (5-Yb), as well as base-free, homoleptic rhenium-rare earth triple inverse sandwich complex Y[(μ-η5:η5-Cp)Re(BDI)]3 (6-Y).
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Affiliation(s)
- Erik T Ouellette
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - I Joseph Brackbill
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Amy E Kynman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Stella Christodoulou
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Robert G Bergman
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John Arnold
- 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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3
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Tateyama H, Boggiano AC, Liao C, Otte KS, Li X, La Pierre HS. Tetravalent Cerium Alkyl and Benzyl Complexes. J Am Chem Soc 2024; 146:10268-10273. [PMID: 38564671 PMCID: PMC11027143 DOI: 10.1021/jacs.4c01964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/22/2024] [Accepted: 03/25/2024] [Indexed: 04/04/2024]
Abstract
High-valent cerium complexes of alkyl and benzyl ligands are unprecedented due to the incompatibility of the typically highly oxidizing Ce4+ ion and the reducing alkyl or benzyl ligand. Herein we report the synthesis and isolation of the first tetravalent cerium alkyl and benzyl complexes supported by the tri-tert-butyl imidophosphorane ligand, [NP(tBu)3]1-. The Ce4+ monoiodide complex, [Ce4+I(NP(tert-butyl)3)3] (1-CeI), serves as a precursor to the alkyl and benzyl complexes, [Ce4+(Npt)(NP(tert-butyl)3)3] (2-CeNpt) (Npt = neopentyl, CH2C(CH3)3) and [Ce4+(Bn)(NP(tert-butyl)3)3] (2-CeBn) (Bn = benzyl, CH2Ph). The bonding and structure of these complexes are characterized by single-crystal XRD, NMR and UV-vis-NIR spectroscopy, cyclic voltammetry, and DFT studies.
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Affiliation(s)
- Haruko Tateyama
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332-0400, United States
| | - Andrew C. Boggiano
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332-0400, United States
| | - Can Liao
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Kaitlyn S. Otte
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332-0400, United States
| | - Xiaosong Li
- Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
| | - Henry S. La Pierre
- School
of Chemistry and Biochemistry, Georgia Institute
of Technology, Atlanta, Georgia 30332-0400, United States
- Nuclear
and Radiological Engineering and Medical Physics Program, School of
Mechanical Engineering, Georgia Institute
of Technology, Atlanta, Georgia 30332-0400, United States
- Physical
Sciences Division, Pacific Northwest National
Laboratory, Richland, Washington 99352, United States
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4
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Xue T, Ding YS, Zheng Z. A tetravalent praseodymium complex with field-induced slow magnetic relaxation. Dalton Trans 2024; 53:5779-5783. [PMID: 38482700 DOI: 10.1039/d4dt00052h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Herein the synthesis, structural characterization, and magnetic properties of a Pr(IV) complex [Pr(OSiPh3)4(L)] (1, L = 4,4'-dimethoxy-2,2'-bipyridine) are reported. The stability of the Pr(IV) complex significantly enhanced with the use of the bidentate ligand L. Slow magnetic relaxation was observed at low temperatures, indicating that the complex may be the first single-ion magnet with a tetravalent lanthanide ion being the magnetic center.
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Affiliation(s)
- Tianjiao Xue
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
- Key University Laboratory of Rare Earth Chemistry of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - You-Song Ding
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
- Key University Laboratory of Rare Earth Chemistry of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Zhiping Zheng
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
- Key University Laboratory of Rare Earth Chemistry of Guangdong, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
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5
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Xu H, Wang QY, Jiang M, Li SS. Application of valence-variable transition-metal-oxide-based nanomaterials in electrochemical analysis: A review. Anal Chim Acta 2024; 1295:342270. [PMID: 38355227 DOI: 10.1016/j.aca.2024.342270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 01/18/2024] [Accepted: 01/19/2024] [Indexed: 02/16/2024]
Abstract
The construction of materials with rapid electron transfer is considered an effective method for enhancing electrochemical activity in electroanalysis. It has been widely demonstrated that valence changes in transition metal ions can promote electron transfer and thus increase electrochemical activity. Recently, valence-variable transition metal oxides (TMOs) have shown popular application in electrochemical analysis by using their abundant valence state changes to accelerate electron transfer during electrochemical detection. In this review, we summarize recent research advances in valence changes of TMOs and their application in electrochemical analysis. This includes the definition and mechanism of valence change, the association of valence changes with electronic structure, and their applications in electrochemical detection, along with the use of density functional theory (DFT) to simulate the process of electron transfer during valence changes. Finally, the challenges and opportunities for developing and applying valence changes in electrochemical analysis are also identified.
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Affiliation(s)
- Huan Xu
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Anhui Province Industrial Generic Technology Research Center for Alumics Materials, School of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000, China
| | - Qiu-Yu Wang
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Anhui Province Industrial Generic Technology Research Center for Alumics Materials, School of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000, China
| | - Min Jiang
- School of Land Resources and Environment, Jiangxi Agricultural University, Nanchang, 330045, China.
| | - Shan-Shan Li
- Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Anhui Province Industrial Generic Technology Research Center for Alumics Materials, School of Physics and Electronic Information, Huaibei Normal University, Huaibei 235000, China.
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6
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Flosbach NT, Bykov M, Bykova E, Rasche B, Mezouar M, Fedotenko T, Chariton S, Prakapenka VB, Wickleder MS. Stabilization of Pr 4+ in Silicates─High-Pressure Synthesis of PrSi 3O 8 and Pr 2Si 7O 18. Inorg Chem 2024; 63:4875-4882. [PMID: 38412505 DOI: 10.1021/acs.inorgchem.3c03948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/29/2024]
Abstract
The reaction between PrO2 and SiO2 was investigated at various pressure points up to 29 GPa in a diamond anvil cell using laser heating and in situ single-crystal structure analysis. The pressure points at 5 and 10 GPa produced Pr2III(Si2O7), whereas Pr4IIISi3O12 and Pr2IV(O2)O3 were obtained at 15 GPa. Pr4IIISi3O12 can be interpreted as a high-pressure modification of the still unknown orthosilicate Pr4III(SiO4)3. PrIVSi3O8 and Pr2IVSi7O18 that contain praseodymium in its rare + IV oxidation state were identified at 29 GPa. After the pressure was released from the reaction chamber, the Pr(IV) silicates could be recovered, indicating that they are metastable at ambient pressure. Density functional theory calculations of the electronic structure corroborate the oxidation state of praseodymium in both PrIVSi3O8 and Pr2IVSi7O18. Both silicates are the first structurally characterized representatives of Pr4+-containing salts with oxoanions. All three silicates contain condensed networks of [SiO6] octahedra which is unprecedented in the rich chemistry of lanthanoid silicates.
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Affiliation(s)
- Niko T Flosbach
- Institute of Inorganic Chemistry, University of Cologne, Greinstraße 6, 50939 Cologne, Germany
| | - Maxim Bykov
- Institute of Inorganic Chemistry, University of Cologne, Greinstraße 6, 50939 Cologne, Germany
- Institute of Inorganic and Analytical Chemistry, Goethe University Frankfurt, Max-von-Laue-Straße 7, 60438 Frankfurt am Main, Germany
| | - Elena Bykova
- Institute of Geosciences, Goethe University Frankfurt, Altenhöferallee 1, 60438 Frankfurt am Main, Germany
| | - Bertold Rasche
- Institute of Inorganic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany
| | - Mohamed Mezouar
- European Synchrotron Radiation Facility (ESRF), Avenue des Martyrs 71, 38000 Grenoble, France
| | - Timofey Fedotenko
- Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg, Germany
| | - Stella Chariton
- Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637, United States
| | - Vitali B Prakapenka
- Center for Advanced Radiation Sources, University of Chicago, Chicago, Illinois 60637, United States
| | - Mathias S Wickleder
- Institute of Inorganic Chemistry, University of Cologne, Greinstraße 6, 50939 Cologne, Germany
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7
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Guo H, Hong D, Cui P. Tripodal tris(siloxide) ligand supported trivalent rare-earth metal complexes and redox reactivity. Dalton Trans 2023; 52:15672-15676. [PMID: 37882247 DOI: 10.1039/d3dt02519e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2023]
Abstract
Tripodal tris(siloxide) ligand supported rare-earth metal complexes LLn(III) (Ln = Ce, Pr, Tb, Y, Lu) were synthesized. The Ce(III) complex was oxidized with [N(C6H4Br)3][SbCl6] to a Ce(IV) chloride complex, which reacted with tBuONa to form a Ce(IV) tert-butoxide complex, one displaying a reduction potential cathodically shifted relative to that of Ce(IV) chloride complex.
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Affiliation(s)
- Hui Guo
- Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials; College of Chemistry and Materials Science; Anhui Normal University, S 189, Jiuhua Road, Wuhu, Anhui 241002, P. R. China.
| | - Dongjing Hong
- Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials; College of Chemistry and Materials Science; Anhui Normal University, S 189, Jiuhua Road, Wuhu, Anhui 241002, P. R. China.
| | - Peng Cui
- Key Laboratory of Functional Molecular Solids, Ministry of Education; Anhui Laboratory of Molecule-Based Materials; College of Chemistry and Materials Science; Anhui Normal University, S 189, Jiuhua Road, Wuhu, Anhui 241002, P. R. China.
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8
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Boggiano AC, Studvick CM, Steiner A, Bacsa J, Popov IA, La Pierre HS. Structural distortion by alkali metal cations modulates the redox and electronic properties of Ce 3+ imidophosphorane complexes. Chem Sci 2023; 14:11708-11717. [PMID: 37920331 PMCID: PMC10619540 DOI: 10.1039/d3sc04262f] [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: 08/14/2023] [Accepted: 09/15/2023] [Indexed: 11/04/2023] Open
Abstract
A series of Ce3+ complexes with counter cations ranging from Li to Cs are presented. Cyclic voltammetry data indicate a significant dependence of the oxidation potential on the alkali metal identity. Analysis of the single-crystal X-ray diffraction data indicates that the degree of structural distortion of the secondary coordination sphere is linearly correlated with the measured oxidation potential. Solution electronic absorption spectroscopy confirms that the structural distortion is reflected in the solution structure. Computational studies further validate this analysis, deciphering the impact of alkali metal cations on the Ce atomic orbital contributions, differences in energies of Ce-dominant molecular orbitals, energy shift of the 4f-5d electronic transitions, and degree of structural distortions. In sum, the structural impact of the alkali metal cation is demonstrated to modulate the redox and electronic properties of the Ce3+ complexes, and provides insight into the rational tuning of the Ce3+ imidophosphorane complex oxidation potential through alkali metal identity.
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Affiliation(s)
- Andrew C Boggiano
- School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
| | - Chad M Studvick
- Department of Chemistry, The University of Akron Akron Ohio 44325-3601 USA
| | - Alexander Steiner
- Department of Chemistry, University of Liverpool Liverpool L69 7ZD UK
| | - John Bacsa
- School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
| | - Ivan A Popov
- Department of Chemistry, The University of Akron Akron Ohio 44325-3601 USA
| | - Henry S La Pierre
- School of Chemistry and Biochemistry, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
- Nuclear and Radiological Engineering and Medical Physics Program, School of Mechanical Engineering, Georgia Institute of Technology Atlanta Georgia 30332-0400 USA
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9
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Wang Y, Liang J, Deng C, Sun R, Fu PX, Wang BW, Gao S, Huang W. Two-Electron Oxidations at a Single Cerium Center. J Am Chem Soc 2023; 145:22466-22474. [PMID: 37738079 DOI: 10.1021/jacs.3c06613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Two-electron oxidations are ubiquitous and play a key role in the synthesis and catalysis. For transition metals and actinides, two-electron oxidation often takes place at a single-metal site. However, redox reactions at rare-earth metals have been limited to one-electron processes due to the lack of accessible oxidation states. Despite recent advancements in nontraditional oxidation state chemistry, the low stability of low-valent compounds and large disparity among different oxidation states prevented the implementation of two-electron processes at a single rare-earth metal center. Here we report two-electron oxidations at a cerium(II) center to yield cerium(IV) terminal oxo and imido complexes. A series of cerium(II-IV) complexes supported by a tripodal tris(amido)arene ligand were synthesized and characterized. Experimental and theoretical studies revealed that the cerium(II) complex is best described as a 4f2 ion stabilized by δ-backdonation to the anchoring arene, while the cerium(IV) oxo and imido complexes exhibit multiple bonding characters. The accomplishment of two-electron oxidations at a single cerium center brings a new facet to molecular rare-earth metal chemistry.
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Affiliation(s)
- Yi Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Jiefeng Liang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Chong Deng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Rong Sun
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
- Beijing Key Laboratory for Magnetoelectric Materials and Devices, Beijing 100871, P. R. China
| | - Peng-Xiang Fu
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Bing-Wu Wang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
- Beijing Key Laboratory for Magnetoelectric Materials and Devices, Beijing 100871, P. R. China
| | - Song Gao
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
- Spin-X Institute, School of Chemistry and Chemical Engineering, State Key Laboratory of Luminescent Materials and Devices, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, South China University of Technology, Guangzhou 510641, P. R. China
| | - Wenliang Huang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
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10
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Otte KS, Niklas JE, Studvick CM, Boggiano AC, Bacsa J, Popov IA, La Pierre HS. Divergent Stabilities of Tetravalent Cerium, Uranium, and Neptunium Imidophosphorane Complexes. Angew Chem Int Ed Engl 2023; 62:e202306580. [PMID: 37327070 DOI: 10.1002/anie.202306580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/15/2023] [Accepted: 06/16/2023] [Indexed: 06/18/2023]
Abstract
The study of the redox chemistry of mid-actinides (U-Pu) has historically relied on cerium as a model, due to the accessibility of trivalent and tetravalent oxidation states for these ions. Recently, dramatic shifts of lanthanide 4+/3+ non-aqueous redox couples have been established within a homoleptic imidophosphorane ligand framework. Herein we extend the chemistry of the imidophosphorane ligand (NPC=[N=Pt Bu(pyrr)2 ]- ; pyrr=pyrrolidinyl) to tetrahomoleptic NPC complexes of neptunium and cerium (1-M, 2-M, M=Np, Ce) and present comparative structural, electrochemical, and theoretical studies of these complexes. Large cathodic shifts in the M4+/3+ (M=Ce, U, Np) couples underpin the stabilization of higher metal oxidation states owing to the strongly donating nature of the NPC ligands, providing access to the U5+/4+ , U6+/5+ , and to an unprecedented, well-behaved Np5+/4+ redox couple. The differences in the chemical redox properties of the U vs. Ce and Np complexes are rationalized based on their redox potentials, degree of structural rearrangement upon reduction/oxidation, relative molecular orbital energies, and orbital composition analyses employing density functional theory.
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Affiliation(s)
- Kaitlyn S Otte
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Julie E Niklas
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Chad M Studvick
- Department of Chemistry, The University of Akron, Akron, OH, 44325-3601, USA
| | - Andrew C Boggiano
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - John Bacsa
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
| | - Ivan A Popov
- Department of Chemistry, The University of Akron, Akron, OH, 44325-3601, USA
| | - Henry S La Pierre
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
- Nuclear and Radiological Engineering Program, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA
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11
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Shiau AA, Lee HB, Oyala PH, Agapie T. Mn IV4O 4 Model of the S 3 Intermediate of the Oxygen-Evolving Complex: Effect of the Dianionic Disiloxide Ligand. Inorg Chem 2023; 62:1791-1796. [PMID: 35829634 DOI: 10.1021/acs.inorgchem.2c01612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Synthetic complexes provide useful models to study the interplay between the structure and spectroscopy of the different Sn-state intermediates of the oxygen-evolving complex (OEC) of photosystem II (PSII). Complexes containing the MnIV4 core corresponding to the S3 state, the last observable intermediate prior to dioxygen formation, remain very rare. Toward the development of synthetic strategies to stabilize highly oxidized tetranuclear complexes, ligands with increased anion charge were pursued. Herein, we report the synthesis, electrochemistry, SQUID magnetometry, and electron paramagnetic resonance spectroscopy of a stable MnIV4O4 cuboidal complex supported by a disiloxide ligand. The substitution of an anionic acetate or amidate ligand with a dianionic disiloxide ligand shifts the reduction potential of the MnIIIMnIV3/MnIV4 redox couple by up to ∼760 mV, improving stability. The S = 3 spin ground state of the siloxide-ligated MnIV4O4 complex matches the acetate and amidate variants, in corroboration with the MnIV4 assignment of the S3 state of the OEC.
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Affiliation(s)
- Angela A Shiau
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Heui Beom Lee
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Paul H Oyala
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
| | - Theodor Agapie
- Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard, MC 127-72, Pasadena, California 91125, United States
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12
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Lu JB, Jiang XL, Wang JQ, Hu HS, Schwarz WHE, Li J. On the highest oxidation states of the actinoids in AnO 4 molecules (An = Ac - Cm): A DMRG-CASSCF study. J Comput Chem 2023; 44:190-198. [PMID: 35420170 DOI: 10.1002/jcc.26856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/18/2022] [Accepted: 03/23/2022] [Indexed: 12/31/2022]
Abstract
Actinoid tetroxide molecules AnO4 (An = Ac - Cm) are investigated with the ab initio density matrix renormalization group (DMRG) approach. Natural orbital shapes are used to read out the oxidation state (OS) of the f-elements, and the atomic orbital energies and radii are used to explain the trends. The highest OSs reveal a "volcano"-type variation: For An = Ac - Np, the OSs are equal to the number of available valence electrons, that is, AcIII , ThIV , PaV , UVI , and NpVII . Starting with plutonium as the turning point, the highest OSs in the most stable AnO4 isomers then decrease as PuV , AmV , and CmIII , indicating that the 5f-electrons are hard to be fully oxidized off from Pu onward. The variations are related to the actinoid contraction and to the 5f-covalency characteristics. Combined with previous work on OSs, we review their general trends throughout the periodic table, providing fundamental understanding of OS-relevant phenomena.
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Affiliation(s)
- Jun-Bo Lu
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen.,Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - Xue-Lian Jiang
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen
| | - Jia-Qi Wang
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - Han-Shi Hu
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
| | - W H Eugen Schwarz
- Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing.,Theoretische Chemie, Fachbereich Chemie und Biologie, Universität Siegen, Siegen, Germany
| | - Jun Li
- Departmentof Chemistry, Southern University of Science and Technology, Shenzhen.,Department of Chemistry and Key Laboratory of Organic Optoelectronics and Molecular Engineering, Ministry of Education, Tsinghua University, Beijing
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13
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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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14
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Lu JB, Jiang XL, Hu HS, Li J. Norm-Conserving 4f-in-Core Pseudopotentials and Basis Sets Optimized for Trivalent Lanthanides (Ln = Ce-Lu). J Chem Theory Comput 2023; 19:82-96. [PMID: 36512750 DOI: 10.1021/acs.jctc.2c00922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
We present here a set of scalar-relativistic norm-conserving 4f-in-core pseudopotentials, together with complementary valence-shell Gaussian basis sets, for the lanthanide (Ln) series (Ce-Lu). The Goedecker, Teter, and Hutter (GTH) formalism is adopted with the generalized gradient approximation (GGA) for the exchange-correlation Perdew-Burke-Ernzerhof (PBE) functional. The 4f-in-core pseudopotentials are built through attributing 4f-subconfiguration 4fn (n = 1-14) for Ln (Ln = Ce-Lu) into the atomic core region, making it possible to circumvent the difficulty of the description of the open 4fn valence shell. A wide variety of computational benchmarks and tests have been carried out on lanthanide systems including Ln3+-containing molecular complexes, aqueous solutions, and bulk solids to validate the accuracy, reliability, and efficiency of the optimized 4f-in-core GTH pseudopotentials and basis sets. The 4f-in-core GTH pseudopotentials successfully replicate the main features of lanthanide structural chemistry and reaction energetics, particularly for nonredox reactions. The chemical bonding features and solvation shells, hydrolysis energetics, acidity constants, and solid-state properties of selected lanthanide systems are also discussed in detail by utilizing these new 4f-in-core GTH pseudopotentials. This work bridges the idea of keeping highly localized 4f electrons in the atomic core and efficient pseudopotential formalism of GTH, thus providing a highly efficient approach for studying lanthanide chemistry in multi-scale modeling of constituent-wise and structurally complicated systems, including electronic structures of the condensed phase and first-principles molecular dynamics simulations.
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Affiliation(s)
- Jun-Bo Lu
- Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xue-Lian Jiang
- Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Han-Shi Hu
- Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Jun Li
- Department of Chemistry and Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Chemistry and Engineering Research Center of Advanced Rare-Earth Materials of Ministry of Education, Tsinghua University, Beijing 100084, China
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15
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Zhang J, Yang X, Wang W, Jia D. Highly-visible-light-driven photocatalysts based on terbium(III) complexes with tetraselenidoantimonate and polyamine mixed ligands. INORG CHEM COMMUN 2022. [DOI: 10.1016/j.inoche.2022.110185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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16
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Barluzzi L, Giblin SR, Mansikkamäki A, Layfield RA. Identification of Oxidation State +1 in a Molecular Uranium Complex. J Am Chem Soc 2022; 144:18229-18233. [PMID: 36169550 PMCID: PMC9562434 DOI: 10.1021/jacs.2c06519] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The concept of oxidation state plays a fundamentally
important
role in defining the chemistry of the elements. In the f block of
the periodic table, well-known oxidation states in compounds of the
lanthanides include 0, +2, +3 and +4, and oxidation states for the
actinides range from +7 to +2. Oxidation state +1 is conspicuous by
its absence from the f-block elements. Here we show that the uranium(II)
metallocene [U(η5-C5iPr5)2] and the uranium(III) metallocene
[IU(η5-C5iPr5)2] can be reduced by potassium graphite
in the presence of 2.2.2-cryptand to the uranium(I) metallocene [U(η5-C5iPr5)2]− (1) (C5iPr5 = pentaisopropylcyclopentadienyl)
as the salt of [K(2.2.2-cryptand)]+. An X-ray crystallographic
study revealed that 1 has a bent metallocene structure,
and theoretical studies and magnetic measurements confirmed that the
electronic ground state of uranium(I) adopts a 5f3(7s/6dz2)1(6dx2–y2/6dxy)1 configuration. The
metal–ligand bonding in 1 consists of contributions
from uranium 5f, 6d, and 7s orbitals, with the 6d orbitals engaging
in weak but non-negligible covalent interactions. Identification of
the oxidation state +1 for uranium expands the range of isolable oxidation
states for the f-block elements and potentially signposts a synthetic
route to this elusive species for other actinides and the lanthanides.
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Affiliation(s)
- Luciano Barluzzi
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9JQ, U.K
| | - Sean R Giblin
- School of Physics and Astronomy, Cardiff University, Cardiff CF24 3AA, U.K
| | - Akseli Mansikkamäki
- NMR Research Group, University of Oulu, P.O. Box 8000, FI-90014 Oulu, Finland
| | - Richard A Layfield
- Department of Chemistry, School of Life Sciences, University of Sussex, Brighton BN1 9JQ, U.K
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17
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Rice NT, Dalodière E, Adelman SL, Jones ZR, Kozimor SA, Mocko V, Root HD, Stein BW. Oxidizing Americium(III) with Sodium Bismuthate in Acidic Aqueous Solutions. Inorg Chem 2022; 61:12948-12953. [PMID: 35939562 DOI: 10.1021/acs.inorgchem.2c01596] [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
Historic perspectives describing f-elements as being redox "inactive" are fading. Researchers continue to discover new oxidation states that are not as inaccessible as once assumed for actinides and lanthanides. Inspired by those contributions, we studied americium(III) oxidation in aqueous media under air using NaBiO3(s). We identified selective oxidation of Am3+(aq) to AmO22+(aq) or AmO21+(aq) could be achieved by changing the aqueous matrix identity. AmO22+(aq) formed in H3PO4(aq) (1 M) and AmO21+(aq) formed in dilute HCl(aq) (0.1 M). These americyl products were stable for weeks in solution. Also included is a method to recover 243Am from the americium and bismuth mixtures generated during these studies.
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Affiliation(s)
- Natalie T Rice
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Elodie Dalodière
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Sara L Adelman
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Zachary R Jones
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Stosh A Kozimor
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Veronika Mocko
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Harrison D Root
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Benjamin W Stein
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
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18
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Rice NT, Popov IA, Carlson RK, Greer SM, Boggiano AC, Stein BW, Bacsa J, Batista ER, Yang P, La Pierre HS. Spectroscopic and electrochemical characterization of a Pr 4+ imidophosphorane complex and the redox chemistry of Nd 3+ and Dy 3+ complexes. Dalton Trans 2022; 51:6696-6706. [PMID: 35412547 DOI: 10.1039/d2dt00758d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The molecular tetravalent oxidation state for praseodymium is observed in solution via oxidation of the anionic trivalent precursor [K][Pr3+(NP(1,2-bis-tBu-diamidoethane)(NEt2))4] (1-Pr(NP*)) with AgI at -35 °C. The Pr4+ complex is characterized in solution via cyclic voltammetry, UV-vis-NIR electronic absorption spectroscopy, and EPR spectroscopy. Electrochemical analyses of [K][Ln3+(NP(1,2-bis-tBu-diamidoethane)(NEt2))4] (Ln = Nd and Dy) by cyclic voltammetry are reported and, in conjunction with theoretical modeling of electronic structure and oxidation potential, are indicative of principal ligand oxidations in contrast to the metal-centered oxidation observed for 1-Pr(NP*). The identification of a tetravalent praseodymium complex in in situ UV-vis and EPR experiments is further validated by theoretical modeling of the redox chemistry and the UV-vis spectrum. The latter study was performed by extended multistate pair-density functional theory (XMS-PDFT) and implicates a multiconfigurational ground state for the tetravalent praseodymium complex.
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Affiliation(s)
- Natalie T Rice
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
| | - Ivan A Popov
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA. .,Department of Chemistry, The University of Akron, Akron, OH 44325-3601, USA
| | - Rebecca K Carlson
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Samuel M Greer
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Andrew C Boggiano
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
| | - Benjamin W Stein
- Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - John Bacsa
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
| | - Enrique R Batista
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Ping Yang
- Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
| | - Henry S La Pierre
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA. .,Nuclear and Radiological Engineering and Medical Physics Program, School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA
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19
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Isolation and crystal structure of the first Pr(IV) coordination polymer and the complex anti-proliferative activity evaluation against seven cancer cell lines. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.132508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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20
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Shafi Z, Gibson JK. Lanthanide Complexes Containing a Terminal Ln═O Oxo Bond: Revealing Higher Stability of Tetravalent Praseodymium versus Terbium. Inorg Chem 2022; 61:7075-7087. [PMID: 35476904 DOI: 10.1021/acs.inorgchem.2c00525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report on the reactivity of gas-phase lanthanide-oxide nitrate complexes, [Ln(O)(NO3)3]- (denoted LnO2+), produced via elimination of NO2• from trivalent [LnIII(NO3)4]- (Ln = Ce, Pr, Nd, Sm, Tb, Dy). These complexes feature a LnIII-O• oxyl, a LnIV═O oxo, or an intermediate LnIII/IV oxyl/oxo bond, depending on the accessibility of the tetravalent LnIV state. Hydrogen atom abstraction reactivity of the LnO2+ complexes to form unambiguously trivalent [LnIII(OH)(NO3)3]- reveals the nature of the oxide bond. The result of slower reactivity of PrO2+ versus TbO2+ is considered to indicate higher stability of the tetravalent praseodymium-oxo, PrIV═O, versus TbIV═O. This is the first report of PrIV as more stable than TbIV, which is discussed with respect to ionization potentials, standard electrode potentials, atomic promotion energies, and oxo bond covalency via 4f- and/or 5d-orbital participation.
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Affiliation(s)
- Ziad Shafi
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John K Gibson
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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21
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Wang Z, Lu JB, Dong X, Yan Q, Feng X, Hu HS, Wang S, Chen J, Li J, Xu C. Ultra-Efficient Americium/Lanthanide Separation through Oxidation State Control. J Am Chem Soc 2022; 144:6383-6389. [PMID: 35353513 DOI: 10.1021/jacs.2c00594] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Lanthanide/actinide separation is a worldwide challenge for atomic energy and nuclear waste treatment. Separation of americium (Am), a critical actinide element in the nuclear fuel cycle, from lanthanides (Ln) is highly desirable for minimizing the long-term radiotoxicity of nuclear waste, yet it is extremely challenging given the chemical similarity between trivalent Am(III) and Ln(III). Selective oxidation of Am(III) to a higher oxidation state (OS) could facilitate this separation, but so far, it is far from satisfactory for practical application as a result of the unstable nature of Am in a high OS. Herein, we find a novel strategy to generate stable pentavalent Am (Am(V)) through coordination of Am(III) with a diglycolamide ligand and oxidation with Bi(V) species in the presence of an organic solvent. This strategy leads to efficient stabilization of Am(V) and an extraordinarily high separation factor (>104) of Am from Ln through one single contact in solvent extraction, thereby opening a new avenue to study the high-OS chemistry of Am and fulfill the crucial task of Ln/Am separation in the nuclear fuel cycle. The synergistic coordination and oxidation process is found to occur in the organic solvent, and the mechanism has been well elucidated by quantum-theoretical modeling.
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Affiliation(s)
- Zhipeng Wang
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jun-Bo Lu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xue Dong
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Qiang Yan
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Xiaogui Feng
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Han-Shi Hu
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Shuao Wang
- State Key Laboratory of Radiation Medicine and Protection, School for Radiological and Interdisciplinary Sciences, Soochow University, Suzhou 215123, China
| | - Jing Chen
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
| | - Jun Li
- Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China.,Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Chao Xu
- Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China
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22
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Abstract
The number of rare earth (RE) starting materials used in synthesis is staggering, ranging from simple binary metal-halide salts to borohydrides and "designer reagents" such as alkyl and organoaluminate complexes. This review collates the most important starting materials used in RE synthetic chemistry, including essential information on their preparations and uses in modern synthetic methodologies. The review is divided by starting material category and supporting ligands (i.e., metals as synthetic precursors, halides, borohydrides, nitrogen donors, oxygen donors, triflates, and organometallic reagents), and in each section relevant synthetic methodologies and applications are discussed.
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Affiliation(s)
- Fabrizio Ortu
- School of Chemistry, University of Leicester, LE1 7RH Leicester, U.K.
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23
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Boyle TJ, Guerrero F, Cramer RE, Reuel PC, Boye DM, Brooks HL. Synthesis and Characterization of Solvated Lanthanide Tris(trimethylsilyl)siloxides. Inorg Chem 2022; 61:5048-5059. [PMID: 35286077 DOI: 10.1021/acs.inorgchem.1c03997] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In an effort to develop precursors for the production of lanthanide silicate (LnSiOx) materials, the reactions of [Ln(NR2)3] (R = SiMe3) with three equivalents of tris(trimethylsilyl)silanol (H-OSi(SiMe3)3) or H-SST) in tetrahydrofuran (THF) were undertaken. The products were crystallographically characterized as [Ln(SST)3(THF)2] (where Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). In general, these compounds are similar to the previously reported [Gd(SST)3(THF)2] complex, where each metal center of the monomeric species is found to adopt a trigonal bipyramidal (TBP; τ = av 0.95) geometry; however, the crystallographic structure solutions for these crystals invoke a much larger unit cell that reveals the complex disorder of the axial THF ligands. Using incompletely washed H-SST, the tetrahedrally (T-4) bound [Ln(SST)3(NEt3)] (Ln-NEt3 = Pr-NEt3, Ho-NEt3; NEt3 = triethylamine) compounds were isolated from the same reaction run in toluene. Rational syntheses of amine derivatives were realized by performing the same reaction with pure H-SST in toluene containing the appropriate amine and [Ln(NR2)3] with the final products identified as [Tm(SST)3(NEt3)] (Tm-NEt3) or [Tm(SST)3(NHPr2i)] (NHPr2i = di-iso-propylamine; Tm-NHPr2i). The products isolated from reactions undertaken in pyridine (py) were identified as [Ln(SST)3(py)2] (Ln-py = Ce-py, Eu-py, and Tm-py). The Ln-py structures exhibit the larger unit cell noted for the THF derivatives with each Ln adopting a TBP (τ = av 0.98) metal center possessing equatorial SST and axial py ligands. The same reaction run in toluene led to the isolation of [(η6-tol)Tm(SST)3] (Tm-tol). Multinuclear NMR (1H and 29Si) data support the retention of the solid-state structures of all of these compounds in solution. Photoluminescent measurements of Tb, Sm, Dy, and Eu were found to display emission and lifetime profiles in the visible range due to f-f transitions, consistent with trivalent lanthanide metal centers.
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Affiliation(s)
- Timothy J Boyle
- Advanced Materials Laboratory, Sandia National Laboratories, 1001 University Boulevard, SE, Albuquerque, New Mexico 87106, United States
| | - Fernando Guerrero
- Advanced Materials Laboratory, Sandia National Laboratories, 1001 University Boulevard, SE, Albuquerque, New Mexico 87106, United States
| | - Roger E Cramer
- Department of Chemistry, University of Hawaii─Manoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822-2275, United States
| | - Paris C Reuel
- Advanced Materials Laboratory, Sandia National Laboratories, 1001 University Boulevard, SE, Albuquerque, New Mexico 87106, United States
| | - Daniel M Boye
- Physics Department, Davidson College, 209 Ridge Rd., Davidson, North Carolina 28035, United States
| | - Henry L Brooks
- Physics Department, Davidson College, 209 Ridge Rd., Davidson, North Carolina 28035, United States
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24
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Willauer AR, Douair I, Chauvin AS, Fadaei-Tirani F, Bünzli JCG, Maron L, Mazzanti M. Structure, reactivity and luminescence studies of triphenylsiloxide complexes of tetravalent lanthanides. Chem Sci 2022; 13:681-691. [PMID: 35173932 PMCID: PMC8769062 DOI: 10.1039/d1sc05517h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/15/2021] [Indexed: 12/03/2022] Open
Abstract
Among the 14 lanthanide elements (Ce–Lu), until recently, the tetravalent oxidation state was readily accessible in solution only for cerium while Pr(iv), Nd(iv), Dy(iv) and Tb(iv) had only been detected in the solid state. The triphenylsiloxide ligand recently allowed the isolation of molecular complexes of Tb(iv) and Pr(iv) providing an unique opportunity of investigating the luminescent properties of Ln(iv) ions. Here we have expanded the coordination studies of the triphenylsiloxide ligand with Ln(iii) and Ln(iv) ions and we report the first observed luminescence emission spectra of Pr(iv) complexes which are assigned to a ligand-based emission on the basis of the measured lifetime and computational studies. Binding of the ligand to the Pr(iv) ion leads to an unprecedented large shift of the ligand triplet state which is relevant for future applications in materials science. The first observed luminescence emission spectra of Pr(iv) complexes are assigned to a ligand-based emission. Binding of the triphenylsiloxide ligand to the Pr(iv) ion leads to an unprecedented large red shift of its triplet state.![]()
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Affiliation(s)
- Aurélien R Willauer
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Iskander Douair
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées 31077 Toulouse France
| | - Anne-Sophie Chauvin
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Farzaneh Fadaei-Tirani
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
| | - Jean-Claude G Bünzli
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland .,Department of Biomedical Engineering, Southern University of Science and Technology (SUSTech) Shenzhen China
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées 31077 Toulouse France
| | - Marinella Mazzanti
- Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL) 1015 Lausanne Switzerland
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25
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Arman MO, Geboes B, Van Hecke K, Binnemans K, Cardinaels T. Electrochemical oxidation of terbium(III) in aqueous media: influence of supporting electrolyte on oxidation potential and stability. J APPL ELECTROCHEM 2022. [DOI: 10.1007/s10800-021-01651-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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26
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Wytrych P, Utko J, Kłak J, Ptak M, Stefanski M, Lis T, Ejfler J, John Ł. Synthesis, Crystal Structures, and Spectroscopic Properties of Novel Gadolinium and Erbium Triphenylsiloxide Coordination Entities. MOLECULES (BASEL, SWITZERLAND) 2021; 27:molecules27010147. [PMID: 35011379 PMCID: PMC8746333 DOI: 10.3390/molecules27010147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/20/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022]
Abstract
In alkali metal and lanthanide coordination chemistry, triphenylsiloxides seem to be unduly underappreciated ligands. This is as surprising as that such substituents play a crucial role, among others, in stabilizing rare oxidation states of lanthanide ions, taking a part of intramolecular and molecular interactions stabilizing metal-oxygen cores and many others. This paper reports the synthesis and characterization of new lithium [Li4(OSiPh3)4(THF)2] (1), and sodium [Na4(OSiPh3)4] (2) species, which were later used in obtaining novel gadolinium [Gd(OSiPh3)3(THF)3]·THF (3), and erbium [Er(OSiPh3)3(THF)3]·THF (4) configuration, it can result in res were determined for all 1-4 compounds, and in addition, IR, Raman, absorption spectroscopy studies were conducted for 3 and 4 lanthanide compounds. Furthermore, direct current (dc) variable-temperature magnetic susceptibility measurements on polycrystalline samples of 3 and 4 were carried out in the temperature range 1.8-300 K. The 3 shows behavior characteristics for the paramagnetism of the Gd3+ ion. In contrast, the magnetic properties of 4 are dominated by the crystal field effect on the Er3+ ion, masking the magnetic interaction between magnetic centers of neighboring molecules.
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Affiliation(s)
- Patrycja Wytrych
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
| | - Józef Utko
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
| | - Julia Kłak
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
| | - Maciej Ptak
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna, 50-422 Wrocław, Poland; (M.P.); (M.S.)
| | - Mariusz Stefanski
- Institute of Low Temperature and Structure Research, Polish Academy of Sciences, 2 Okólna, 50-422 Wrocław, Poland; (M.P.); (M.S.)
| | - Tadeusz Lis
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
| | - Jolanta Ejfler
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
| | - Łukasz John
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland; (P.W.); (J.U.); (J.K.); (T.L.); (J.E.)
- Correspondence:
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27
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Hirneise L, Maichle-Mössmer C, Anwander R. Pentamethylcyclopentadienyl Complexes of Cerium(IV): Synthesis, Reactivity, and Electrochemistry. Inorg Chem 2021; 60:18211-18224. [PMID: 34779192 DOI: 10.1021/acs.inorgchem.1c02851] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Treatment of Cp*2CeCl2K(THF) with alkali-metal alkoxides and siloxides in the presence of hexachloroethane generates the monomeric bis(pentamethylcyclopentadienyl) cerium(IV) complexes Cp*2Ce(OR)2 (Cp* = C5Me5; R = Et, iPr, CH2tBu, tBu, SiMe3, or SiPh3). Large substituents R trigger ligand scrambling to half-sandwich complexes Cp*Ce(OR)3, which could be isolated for R = tBu and SiPh3. Similar reactions with sodium aryloxide NaOAr (OAr = OC6H3iPr2-2,6) led to Cp*2Ce(OAr)Cl. Treatment of tris(cyclopentadienyl) complexes CpR3CeCl (CpH = Cp = C5H5; CpMe = C5H4Me) with NaOAr afforded CpMe2Ce(OAr)2 and Cp3Ce(OAr). The cerium(IV) complexes display a pseudotetrahedral geometry in the solid state. Cyclic voltammetry revealed mostly chemically reversible as well as electrochemically quasi-reversible redox processes with potentials ranging from -0.84 to -1.61 V versus Fc/Fc+. Switching from sandwich to half-sandwich complexes decreased the electrochemical potentials drastically, showing better stabilization of the cerium(IV) center in the case of Cp*Ce(OR)3 than in the case of Cp*2Ce(OR)2. Enhanced stabilization of the cerium +IV oxidation state could be further demonstrated in the series alkoxy > siloxy > aryloxy as well as C5Me5 > C5HMe4.
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Affiliation(s)
- Lars Hirneise
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Cäcilia Maichle-Mössmer
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
| | - Reiner Anwander
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen, Auf der Morgenstelle 18, 72076 Tübingen, Germany
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28
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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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29
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MacInnes MM, Jones ZR, Li B, Anderson NH, Batista ER, DiMucci IM, Eiroa-Lledo C, Knope KE, Livshits MY, Kozimor SA, Mocko V, Pace KA, Rocha FR, Stein BW, Wacker JN, Yang P. Using molten salts to probe outer-coordination sphere effects on lanthanide(III)/(II) electron-transfer reactions. Dalton Trans 2021; 50:15696-15710. [PMID: 34693951 DOI: 10.1039/d1dt02708e] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Controlling structure and reactivity by manipulating the outer-coordination sphere around a given reagent represents a longstanding challenge in chemistry. Despite advances toward solving this problem, it remains difficult to experimentally interrogate and characterize outer-coordination sphere impact. This work describes an alternative approach that quantifies outer-coordination sphere effects. It shows how molten salt metal chlorides (MCln; M = K, Na, n = 1; M = Ca, n = 2) provided excellent platforms for experimentally characterizing the influence of the outer-coordination sphere cations (Mn+) on redox reactions accessible to lanthanide ions; Ln3+ + e1- → Ln2+ (Ln = Eu, Yb, Sm; e1- = electron). As a representative example, X-ray absorption spectroscopy and cyclic voltammetry results showed that Eu2+ instantaneously formed when Eu3+ dissolved in molten chloride salts that had strongly polarizing cations (like Ca2+ from CaCl2) via the Eu3+ + Cl1- → Eu2+ + ½Cl2 reaction. Conversely, molten salts with less polarizing outer-sphere M1+ cations (e.g., K1+ in KCl) stabilized Ln3+. For instance, the Eu3+/Eu2+ reduction potential was >0.5 V more positive in CaCl2 than in KCl. In accordance with first-principle molecular dynamics (FPMD) simulations, we postulated that hard Mn+ cations (high polarization power) inductively removed electron density from Lnn+ across Ln-Cl⋯Mn+ networks and stabilized electron-rich and low oxidation state Ln2+ ions. Conversely, less polarizing Mn+ cations (like K1+) left electron density on Lnn+ and stabilized electron-deficient and high-oxidation state Ln3+ ions.
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Affiliation(s)
- Molly M MacInnes
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Zachary R Jones
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Bo Li
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Nickolas H Anderson
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Enrique R Batista
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Ida M DiMucci
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Cecilia Eiroa-Lledo
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Karah E Knope
- Department of Chemistry, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, USA
| | - Maksim Y Livshits
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Stosh A Kozimor
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Veronika Mocko
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Kristen A Pace
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Francisca R Rocha
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Benjamin W Stein
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
| | - Jennifer N Wacker
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA. .,Department of Chemistry, Georgetown University, 37th and O Streets NW, Washington, D.C. 20057, USA
| | - Ping Yang
- Los Alamos National Laboratory (LANL), P.O. Box 1663, Los Alamos, New Mexico, 87545, USA.
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30
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Abstract
Lanthanide (Ln) elements are generally found in the oxidation state +II or +III, and a few examples of +IV and +V compounds have also been reported. In contrast, monovalent Ln(+I) complexes remain scarce. Here we combine photoelectron spectroscopy and theoretical calculations to study Ln-doped octa-boron clusters (LnB8−, Ln = La, Pr, Tb, Tm, Yb) with the rare +I oxidation state. The global minimum of the LnB8− species changes from Cs to C7v symmetry accompanied by an oxidation-state change from +III to +I from the early to late lanthanides. All the C7v-LnB8− clusters can be viewed as a monovalent Ln(I) coordinated by a η8-B82− doubly aromatic ligand. The B73−, B82−, and B9− series of aromatic boron clusters are analogous to the classical aromatic hydrocarbon molecules, C5H5−, C6H6, and C7H7+, respectively, with similar trends of size and charge state and they are named collectively as “borozenes”. Lanthanides with variable oxidation states and magnetic properties may be formed with different borozenes. The most common oxidation state for lanthanides is +3. Here the authors use photoelectron spectroscopy and theoretical calculations to study half-sandwich complexes where a lanthanide center in the oxidation state +1 is bound to an aromatic wheel-like B82- ligand.
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31
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Wytrych P, Utko J, Lis T, John Ł. Polyoxometalate-like structure of new potassium triphenylsiloxides: [K 6(OSiPh 3) 6(C 3H 7OH)(H 2O)]·2C 6H 5CH 3 and [K 6(OSiPh 3) 6(H 2O) 2]. Acta Crystallogr C 2021; 77:522-528. [PMID: 34482295 DOI: 10.1107/s2053229621008160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 08/09/2021] [Indexed: 11/10/2022] Open
Abstract
The synthesis and structural characterization of two new potassium triphenylsiloxides, namely, aqua(propan-2-ol)hexakis(triphenylsilanolato)hexapotassium toluene disolvate, [K6(C18H15OSi)6(C3H8O)(H2O)]·2C7H8, and diaquahexakis(triphenylsilanolato)hexapotassium, [K6(C18H15OSi)6(H2O)2], are reported. Both compounds crystallize in the triclinic space group P-1. The structure in each case resembles an alkali metal polyoxometalate-like structure, in which electrostatic interactions are observed in the metal-oxygen core. Furthermore, both compounds also resemble a reverse micelles-like architecture, in which the hydrophilic core is enclosed in a hydrophobic shell. The cores of the complexes are flanked by hydrophobic aromatic rings derived from Ph3SiO- anions, where intramolecular π-interactions between the aromatic rings and potassium cations stabilize the cores of the crystals. Moreover, in both structures, the presence of hydrogen bonds is observed; until now, no crystal structures have been described containing K atoms and triphenylsiloxide molecules in which the presence of hydrogen bonds was confirmed. Thus, these coordination entities could be considered as attractive reagents for further synthetic protocols towards heterometallic complexes.
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Affiliation(s)
- Patrycja Wytrych
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland
| | - Józef Utko
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland
| | - Tadeusz Lis
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland
| | - Łukasz John
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland
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33
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Gompa TP, Greer SM, Rice NT, Jiang N, Telser J, Ozarowski A, Stein BW, La Pierre HS. High-Frequency and -Field Electron Paramagnetic Resonance Spectroscopic Analysis of Metal-Ligand Covalency in a 4f 7 Valence Series (Eu 2+, Gd 3+, and Tb 4+). Inorg Chem 2021; 60:9064-9073. [PMID: 34106710 DOI: 10.1021/acs.inorgchem.1c01062] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The recent isolation of molecular tetravalent lanthanide complexes has enabled renewed exploration of the effect of oxidation state on the single-ion properties of the lanthanide ions. Despite the isotropic nature of the 8S ground state in a tetravalent terbium complex, [Tb(NP(1,2-bis-tBu-diamidoethane)(NEt2))4], preliminary X-band electron paramagnetic resonance (EPR) measurements on tetravalent terbium complexes show rich spectra with broad resonances. The complexity of these spectra highlights the limits of conventional X-band EPR for even qualitative determination of zero-field splitting (ZFS) in these complexes. Therefore, we report the synthesis and characterization of a novel valence series of 4f7 molecular complexes spanning three oxidation states (Eu2+, Gd3+, and Tb4+) featuring a weak-field imidophosphorane ligand system, and employ high-frequency and -field electron paramagnetic resonance (HFEPR) to obtain quantitative values for ZFS across this valence series. The series was designed to minimize deviation in the first coordination sphere from the pseudotetrahedral geometry in order to directly interrogate the role of metal identity and charge on the complexes' electronic structures. These HFEPR studies are supported by crystallographic analysis and quantum-chemical calculations to assess the relative covalent interactions in each member of this valence series and the effect of the oxidation state on the splitting of the ground state and first excited state.
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Affiliation(s)
| | - Samuel M Greer
- Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, United States
| | | | | | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois 60605, United States
| | - Andrew Ozarowski
- National High Magnetic Field Laboratory (NHMFL), Florida State University, Tallahassee, Florida 32310, United States
| | - Benjamin W Stein
- Los Alamos National Laboratory (LANL), Los Alamos, New Mexico 87545, United States
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34
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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: 13] [Impact Index Per Article: 4.3] [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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35
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Kovacs D, Kocsi D, Wells JAL, Kiraev SR, Borbas KE. Electron transfer pathways in photoexcited lanthanide(iii) complexes of picolinate ligands. Dalton Trans 2021; 50:4244-4254. [PMID: 33688904 DOI: 10.1039/d1dt00616a] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
A series of luminescent lanthanide(iii) complexes consisting of 1,4,7-triazacyclononane frameworks and three secondary amide-linked carbostyril antennae were synthesised. The metal binding sites were augmented with two pyridylcarboxylate donors yielding octadentate ligands. The antennae carried methyl, methoxymethyl or trifluoromethyl substituents in their 4-positions, allowing for a range of excited state energies and antenna electronic properties. The 1H NMR spectra of the Eu(iii) complexes were found to be analogous to each other. Similar results were obtained in the solid-state by single-crystal X-ray crystallography, which showed the structures to have nine-coordinate metal ions with heavily distorted tricapped trigonal prismatic geometries. Steady-state and time-resolved luminescence spectroscopy showed that the antennae could sensitize both Tb(iii) and Eu(iii), however, quantum yields were lower than in other octadentate complexes lacking pyridylcarboxylate. Complexes with more electron-poor pyridines were less emissive even when equipped with the same antenna. The oxidation and reduction potentials of the antennae and the pyridinecarboxylates, respectively, were determined by cyclic voltammetry. The obtained values were consistent with electron transfer from the excited antenna to the pyridine providing a previously unexplored quenching pathway that could efficiently compete with energy transfer to the lanthanide. These results show the crucial impact that photophysically innocent ligand binding sites can have on lanthanide luminescence.
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Affiliation(s)
- Daniel Kovacs
- Department of Chemistry, Ångström Laboratory, Box 523, Uppsala University, 75120, Uppsala, Sweden.
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36
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Gao Y, Chen N, Tian Y, Zhang J, Jia D. Polymeric Iodoargentate Hybrids Incorporating Octakis- or Heptakis-Solvated Lanthanide Complexes: Syntheses, Crystal Structures, and Photocatalysis. Inorg Chem 2021; 60:3761-3772. [DOI: 10.1021/acs.inorgchem.0c03528] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Yan Gao
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Niannian Chen
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Yiming Tian
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Jiahua Zhang
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
| | - Dingxian Jia
- College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People’s Republic of China
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37
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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: 17] [Impact Index Per Article: 5.7] [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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Yang Q, Qiao Y, McSkimming A, Moreau LM, Cheisson T, Booth CH, Lapsheva E, Carroll PJ, Schelter EJ. A hydrolytically stable Ce( iv) complex of glutarimide-dioxime. Inorg Chem Front 2021. [DOI: 10.1039/d0qi00969e] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Glutarimide-dioxime, a proligand known for its strongly electron-donating properties that has been studied for applications in uranium-sequestration from seawater, is considered here for stabilization of the cerium(iv) cation.
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Affiliation(s)
- Qiaomu Yang
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Yusen Qiao
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Alex McSkimming
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Liane M. Moreau
- Chemical Sciences Division
- Lawerence Berkeley National Laboratory
- Berkeley
- USA
| | - Thibault Cheisson
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Corwin H. Booth
- Chemical Sciences Division
- Lawerence Berkeley National Laboratory
- Berkeley
- USA
| | - Ekaterina Lapsheva
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Patrick J. Carroll
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
| | - Eric J. Schelter
- P. Roy and Diana T. Vagelos Laboratories
- Department of Chemistry
- University of Pennsylvania
- Philadelphia
- USA
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39
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Klamm BE, Windorff CJ, Celis-Barros C, Beltran-Leiva MJ, Sperling JM, Albrecht-Schönzart TE. Exploring the Oxidation States of Neptunium with Schiff Base Coordination Complexes. Inorg Chem 2020; 59:18035-18047. [PMID: 33238091 DOI: 10.1021/acs.inorgchem.0c02455] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A pair of neptunium Schiff base coordination complexes, NpVIO2L(MeOH) and NpIVL2 {H2L = N,N'-bis[(4,4'-diethylamino)salicylidene]-1,2-phenylenediamine}, have been synthesized and analyzed by several characterization methods including single-crystal X-ray diffraction, electronic absorption, 1H NMR, cyclic voltammetry, and theoretical interpretation. Structural analysis reveals that NpVIO2L(MeOH) and NpIVL2 are isomorphous with the previously reported UVIO2L(MeOH) and MIVL2 (M = Pu, Ce, U, Th) complexes, respectively, allowing for a direct comparison across the series. The reduction of NpVIO2L(MeOH) in situ or direct synthesis from a (NpVO2)+ source shows evidence of a pentavalent neptunyl (NpVO2L)xn- species as determined by UV/vis/NIR and 1H NMR spectroscopy. The synthesis of (NpVO2L)xn- directly from a (NpVO2)+ starting material gives a similar spectrum. Theoretical analysis offers insight into the electronic structure for a better understanding of the bonding patterns and relative stability of the different oxidation states. Computational results show that the Np-L covalent interactions in NpIVL2 are similar to those in the NpVIO2L(MeOH) complex, indicating that neither the presence of the axial oxo ligands nor the oxidation state significantly modify the nature of the Np-L bonds.
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Affiliation(s)
- Bonnie E Klamm
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States.,Chemistry Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States
| | - Cory J Windorff
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States
| | - Cristian Celis-Barros
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States
| | - Maria J Beltran-Leiva
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States
| | - Joseph M Sperling
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States
| | - Thomas E Albrecht-Schönzart
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftan Way, Room 118 DLC, Tallahassee, Florida 32306, United States
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40
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Qiao Y, Yin H, Moreau LM, Feng R, Higgins RF, Manor BC, Carroll PJ, Booth CH, Autschbach J, Schelter EJ. Cerium(iv) complexes with guanidinate ligands: intense colors and anomalous electronic structures. Chem Sci 2020; 12:3558-3567. [PMID: 34163629 PMCID: PMC8179493 DOI: 10.1039/d0sc05193d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A series of cerium(iv) mixed-ligand guanidinate–amide complexes, {[(Me3Si)2NC(NiPr)2]xCeIV[N(SiMe3)2]3−x}+ (x = 0–3), was prepared by chemical oxidation of the corresponding cerium(iii) complexes, where x = 1 and 2 represent novel complexes. The Ce(iv) complexes exhibited a range of intense colors, including red, black, cyan, and green. Notably, increasing the number of the guanidinate ligands from zero to three resulted in significant redshift of the absorption bands from 503 nm (2.48 eV) to 785 nm (1.58 eV) in THF. X-ray absorption near edge structure (XANES) spectra indicated increasing f occupancy (nf) with more guanidinate ligands, and revealed the multiconfigurational ground states for all Ce(iv) complexes. Cyclic voltammetry experiments demonstrated less stabilization of the Ce(iv) oxidation state with more guanidinate ligands. Moreover, the Ce(iv) tris(guanidinate) complex exhibited temperature independent paramagnetism (TIP) arising from the small energy gap between the ground- and excited states with considerable magnetic moments. Computational analysis suggested that the origin of the low energy absorption bands was a charge transfer between guanidinate π orbitals that were close in energy to the unoccupied Ce 4f orbitals. However, the incorporation of sterically hindered guanidinate ligands inhibited optimal overlaps between Ce 5d and ligand N 2p orbitals. As a result, there was an overall decrease of ligand-to-metal donation and a less stabilized Ce(iv) oxidation state, while at the same time, more of the donated electron density ended up in the 4f shell. The results indicate that incorporating guanidinate ligands into Ce(iv) complexes gives rise to intense charge transfer bands and noteworthy electronic structures, providing insights into the stabilization of tetravalent lanthanide oxidation states. A series of cerium(iv) mixed-ligand guanidinate-amide complexes, {[(Me3Si)2NC(NiPr)2]xCeIV[N(SiMe3)2]3−x}+ (x = 0−3), was prepared by chemical oxidation and studied spectroscopically and computationally, revealing trends in 4f/5d orbital occupancies.![]()
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Affiliation(s)
- Yusen Qiao
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA .,Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Haolin Yin
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA
| | - Liane M Moreau
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Rulin Feng
- Department of Chemistry, University at Buffalo, State University of New York Buffalo New York 14260 USA
| | - Robert F Higgins
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA
| | - Brian C Manor
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA
| | - Patrick J Carroll
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA
| | - Corwin H Booth
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley California 94720 USA
| | - Jochen Autschbach
- Department of Chemistry, University at Buffalo, State University of New York Buffalo New York 14260 USA
| | - Eric J Schelter
- P. Roy and Diana T. Vagelos Laboratories, Department of Chemistry, University of Pennsylvania 231 South 34 Street Philadelphia Pennsylvania 19104 USA
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41
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Bayer U, Werner D, Berkefeld A, Maichle-Mössmer C, Anwander R. Cerium-quinone redox couples put under scrutiny. Chem Sci 2020; 12:1343-1351. [PMID: 34163897 PMCID: PMC8179043 DOI: 10.1039/d0sc04489j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Homoleptic cerous complexes Ce[N(SiMe3)2]3, [Ce{OSi(OtBu)3}3]2 and [Ce{OSiiPr3}3]2 were employed as thermally robust, weakly nucleophilic precursors to assess their reactivity towards 1,4-quinones in non-aqueous solution. The strongly oxidizing quinones 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) or tetrachloro-1,4-benzoquinone (Cl4BQ) readily form hydroquinolato-bridged ceric complexes of the composition [(CeIVL3)2(μ2-O2C6R4)]. Less oxidising quinones like 2,5-di-tert-butyl-1,4-benzoquinone (tBu2BQ) tend to engage in redox equilibria with the ceric hydroquinolato-bridged form being stable only in the solid state. Even less oxidising quinones such as tetramethyl-1,4-benzoquinone (Me4BQ) afford cerous semiquinolates of the type [(CeIIIL2(thf)2)(μ2-O2C6Me4)]2. All complexes were characterised by X-ray diffraction, 1H, 13C{1H} and 29Si NMR spectroscopy, DRIFT spectroscopy, UV-Vis spectroscopy and CV measurements. The species putatively formed during the electrochemical reduction of [CeIV{N(SiMe3)2}3]2(μ2-O2C6H4) could be mimicked by chemical reduction with CoIICp2 yielding [(CeIII{N(SiMe3)2}3)2(μ2-O2C6H4)][CoIIICp2]2.
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Affiliation(s)
- Uwe Bayer
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen (EKUT) Auf der Morgenstelle 18 72076 Tübingen Germany [http://uni-tuebingen.de/syncat-anwander]
| | - Daniel Werner
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen (EKUT) Auf der Morgenstelle 18 72076 Tübingen Germany [http://uni-tuebingen.de/syncat-anwander]
| | - Andreas Berkefeld
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen (EKUT) Auf der Morgenstelle 18 72076 Tübingen Germany [http://uni-tuebingen.de/syncat-anwander]
| | - Cäcilia Maichle-Mössmer
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen (EKUT) Auf der Morgenstelle 18 72076 Tübingen Germany [http://uni-tuebingen.de/syncat-anwander]
| | - Reiner Anwander
- Institut für Anorganische Chemie, Eberhard Karls Universität Tübingen (EKUT) Auf der Morgenstelle 18 72076 Tübingen Germany [http://uni-tuebingen.de/syncat-anwander]
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42
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Aguirre Quintana LM, Jiang N, Bacsa J, La Pierre HS. Homoleptic cerium tris(dialkylamido)imidophosphorane guanidinate complexes. Dalton Trans 2020; 49:14908-14913. [PMID: 33078808 DOI: 10.1039/d0dt03472j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We report the synthesis of a new potassium tris(piperdino)imidophosphorane N,N'-dicyclohexylguanidinate, K[CyGNP(pip)3], and describe the synthesis and characterization of the tris-homoleptic compounds, [Ce(CyGNP(pip)3)3], 1-Ce, and [Ce(CyGNP(pip)3)3][BPh4], 2-Ce. The latter is an unusual cationic tetravalent cerium complex. Cyclic voltammetry studies of 1-Ce and 2-Ce revealed Epc potentials of -1.56 V and -1.81 V, and Epa potentials of -0.78 V and -0.66 V (200 mV s-1; THF, vs. Fc0/+), respectively. Compounds 1-Ce and 2-Ce were studied by L3-edge X-ray absorption near-edge spectroscopy (XANES), and the fit of the spectrum of 2-Ce revealed a white-line multiplet with an nf value of 0.50(2).
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Affiliation(s)
- Luis M Aguirre Quintana
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
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43
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Kloditz R, Fichter S, Kaufmann S, Brunner TS, Kaden P, Patzschke M, Stumpf T, Roesky PW, Schmidt M, März J. Series of Tetravalent Actinide Amidinates: Structure Determination and Bonding Analysis. Inorg Chem 2020; 59:15670-15680. [PMID: 33030346 DOI: 10.1021/acs.inorgchem.0c01969] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Two series of isostructural tetravalent actinide amidinates [AnX((S)-PEBA)3] (An = Th, U, Np; X = Cl, N3) bearing the chiral (S,S)-N,N'-bis(1-phenylethyl)benzamidinate ((S)-PEBA) ligand have been synthesized and thoroughly characterized in solid and in solution. This study expands the already reported tetravalent neptunium complexes to the lighter actinides thorium and uranium. Furthermore, a rare Ce(IV) amidinate [CeCl((S)-PEBA)3] was synthesized to compare its properties to those of the analogous tetravalent actinide complexes. All compounds were characterized in the solid state using single-crystal XRD and infrared spectroscopy and in solution using NMR spectroscopy. Quantum chemical bonding analysis including also the isostructural Pa and Pu complexes was used to characterize the covalent contributions to any bond involving the metal cation. Th shows the least covalent character throughout the series, even substantially smaller than for the Ce complex. For U, Np, and Pu, similar covalent bonding contributions are found, but a natural population analysis reveals different origins. The 6d participation is the highest for U and decreases afterward, whereas the 5f participation increases continuously from Pa to Pu.
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Affiliation(s)
- Roger Kloditz
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Sebastian Fichter
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Sebastian Kaufmann
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, 76131 Karlsruhe, Germany
| | - Tobias S Brunner
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, 76131 Karlsruhe, Germany
| | - Peter Kaden
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Michael Patzschke
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Thorsten Stumpf
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Peter W Roesky
- Institute for Inorganic Chemistry, Karlsruhe Institute of Technology, Engesserstraße 15, 76131 Karlsruhe, Germany
| | - Moritz Schmidt
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
| | - Juliane März
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, Bautzner Landstraße 400, 01328 Dresden, Germany
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44
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Xiao Y, Zhao XK, Wu T, Miller JT, Hu HS, Li J, Huang W, Diaconescu PL. Distinct electronic structures and bonding interactions in inverse-sandwich samarium and ytterbium biphenyl complexes. Chem Sci 2020; 12:227-238. [PMID: 34168742 PMCID: PMC8179684 DOI: 10.1039/d0sc03555f] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Inverse-sandwich samarium and ytterbium biphenyl complexes were synthesized by the reduction of their trivalent halide precursors with potassium graphite in the presence of biphenyl. While the samarium complex had a similar structure as previously reported rare earth metal biphenyl complexes, with the two samarium ions bound to the same phenyl ring, the ytterbium counterpart adopted a different structure, with the two ytterbium ions bound to different phenyl rings. Upon the addition of crown ether to encapsulate the potassium ions, the inverse-sandwich samarium biphenyl structure remained intact; however, the ytterbium biphenyl structure fell apart with the concomitant formation of a divalent ytterbium crown ether complex and potassium biphenylide. Spectroscopic and computational studies were performed to gain insight into the electronic structures and bonding interactions of these samarium and ytterbium biphenyl complexes. While the ytterbium ions were found to be divalent with a 4f14 electron configuration and form a primarily ionic bonding interaction with biphenyl dianion, the samarium ions were in the trivalent state with a 4f5 electron configuration and mainly utilized the 5d orbitals to form a δ-type bonding interaction with the π* orbitals of the biphenyl tetraanion, showing covalent character. Inverse-sandwich samarium and ytterbium biphenyl complexes were synthesized and characterized by X-ray crystallography. Combined experimental and computational studies indicated that they have distinct electronic structures and bonding interactions.![]()
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Affiliation(s)
- Yuyuan Xiao
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 P. R. China
| | - Xiao-Kun Zhao
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University Beijing 100084 P. R. China
| | - Tianpin Wu
- Chemical Sciences and Engineering Division, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Jeffrey T Miller
- Chemical Sciences and Engineering Division, Argonne National Laboratory Argonne Illinois 60439 USA
| | - Han-Shi Hu
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University Beijing 100084 P. R. China
| | - Jun Li
- Department of Chemistry and Key Laboratory of Organic Optoelectronics & Molecular Engineering of the Ministry of Education, Tsinghua University Beijing 100084 P. R. China
| | - Wenliang Huang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Material Chemistry and Application, College of Chemistry and Molecular Engineering, Peking University Beijing 100871 P. R. China
| | - Paula L Diaconescu
- Department of Chemistry and Biochemistry, University of California Los Angeles California 90095 USA
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45
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Affiliation(s)
- Nan Li
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University Beijing 100871 China
- Henan Key Laboratory of Function‐Oriented Porous Materials, College of Chemistry and Chemical Engineering, Luoyang Normal University Luoyang 471934 China
| | - Wen‐Xiong Zhang
- Beijing National Laboratory for Molecular Sciences (BNLMS), Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry, Peking University Beijing 100871 China
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46
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Rice NT, Popov IA, Russo DR, Gompa TP, Ramanathan A, Bacsa J, Batista ER, Yang P, La Pierre HS. Comparison of tetravalent cerium and terbium ions in a conserved, homoleptic imidophosphorane ligand field. Chem Sci 2020; 11:6149-6159. [PMID: 32832060 PMCID: PMC7422963 DOI: 10.1039/d0sc01414a] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 05/16/2020] [Indexed: 01/10/2023] Open
Abstract
A redox pair of Ce4+ and Ce3+ complexes has been prepared that is stabilized by the [(NP(1,2-bis- t Bu-diamidoethane)(NEt2))]1- ligand. Since these complexes are isostructural to the recently reported isovalent terbium analogs, a detailed structural and spectroscopic comparative analysis was pursued via Voronoi-Dirichlet polyhedra analysis, UV-vis-NIR, L3-edge X-ray absorption near edge spectroscopy (XANES), cyclic voltammetry, and natural transitions orbital (NTO) analysis and natural bond orbital (NBO) analysis. The electrochemical studies confirm previous theoretical studies of the redox properties of the related complex [K][Ce3+(NP(pip)3)4] (pip = piperidinyl), 1-Ce(PN). Complex 1-Ce(PN*) presents the most negative E pc of -2.88 V vs. Fc/Fc+ in THF of any cerium complex studied electrochemically. Likewise 1-Tb(PN*) has the most negative E pc for electrochemically interrogated terbium complexes at -1.79 V vs. Fc/Fc+ in THF. Complexes 1-Ce(PN*) and 2-Ce(PN*) were also studied by L3-edge X-ray absorption near edges spectroscopy (XANES) and a comparison to previously reported spectra for 1-Tb(PN*), 2-Tb(PN*), 1-Ce(PN), and, [Ce4+(NP(pip)3)4], 2-Ce(PN), demonstrates similar n f values for all the tetravalent lanthanide complexes. According to the natural bond orbital analysis, a greater covalent character of the M-L bonds is found in 2-Ce(PN*) than in 1-Ce(PN*), in agreement with the shorter Ce-N bonds in the tetravalent counterpart. The greater contribution of Ce orbitals in the Ce-N bonding and, specifically, the higher participation of 4f electrons accounts for the stronger covalent interactions in 2-Ce(PN*) as compared to 2-Tb(PN*).
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Affiliation(s)
- Natalie T Rice
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
| | - Ivan A Popov
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , USA . ;
| | - Dominic R Russo
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
| | - Thaige P Gompa
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
| | - Arun Ramanathan
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
| | - John Bacsa
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
| | - Enrique R Batista
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , USA . ;
| | - Ping Yang
- Theoretical Division , Los Alamos National Laboratory , Los Alamos , New Mexico 87545 , USA . ;
| | - Henry S La Pierre
- School of Chemistry and Biochemistry , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA .
- Nuclear and Radiological Engineering and Medical Physics Program , School of Mechanical Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332-0400 , USA
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47
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Aguirre Quintana LM, Jiang N, Bacsa J, La Pierre HS. Coinage metal tris(dialkylamido)imidophosphorane complexes as transmetallation reagents for cerium complexes. Dalton Trans 2020; 49:5420-5423. [PMID: 32266907 DOI: 10.1039/d0dt00842g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We report the synthesis of tetrameric Cu(i) and Ag(i) homoleptic complexes supported by the tris(piperidinyl)imidophosphorane [NP(pip)3]1- and [NP(1,2-bis-tBu-diamidoethane)(NEt2)]1- ligands. These complexes demonstrate the redox stability of the imidophosphorane ligands to oxidizing salts, and the silver complexes can, in turn, serve as oxidative transmetallation reagents for the isolation of tetravalent cerium complexes from cerium metal or trivalent cerium precursors.
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Affiliation(s)
- Luis M Aguirre Quintana
- Department of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, USA.
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48
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Willauer AR, Palumbo CT, Fadaei-Tirani F, Zivkovic I, Douair I, Maron L, Mazzanti M. Accessing the +IV Oxidation State in Molecular Complexes of Praseodymium. J Am Chem Soc 2020; 142:5538-5542. [PMID: 32134644 DOI: 10.1021/jacs.0c01204] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Out of the 14 lanthanide (Ln) ions, molecular complexes of Ln(IV) were known only for cerium and more recently terbium. Here we demonstrate that the +IV oxidation state is also accessible for the large praseodymium (Pr) cation. The oxidation of the tetrakis(triphenysiloxide) Pr(III) ate complex, [KPr(OSiPh3)4(THF)3], 1-PrPh, with [N(C6H4Br)3][SbCl6], affords the Pr(IV) complex [Pr(OSiPh3)4(MeCN)2], 2-PrPh, which is stable once isolated. The solid state structure, UV-visible spectroscopy, magnetometry, and cyclic voltammetry data along with the DFT computations of the 2-PrPh complex unambiguously confirm the presence of Pr(IV).
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Affiliation(s)
- Aurélien R Willauer
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Chad T Palumbo
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Farzaneh Fadaei-Tirani
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Ivica Zivkovic
- Laboratory for Quantum Magnetism, Institute of Physics, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Iskander Douair
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées, 31077 Toulouse, Cedex 4, France
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nano-objets, Institut National des Sciences Appliquées, 31077 Toulouse, Cedex 4, France
| | - Marinella Mazzanti
- Institut des Sciences et Ingénierie Chimiques, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland
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49
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Gompa TP, Ramanathan A, Rice NT, La Pierre HS. The chemical and physical properties of tetravalent lanthanides: Pr, Nd, Tb, and Dy. Dalton Trans 2020; 49:15945-15987. [DOI: 10.1039/d0dt01400a] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The thermochemistry, descriptive chemistry, spectroscopy, and physical properties of the tetravalent lanthanides (Pr, Nd, Tb and Dy) in extended phases, gas phase, solution, and as isolable molecular complexes are presented.
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Affiliation(s)
- Thaige P. Gompa
- Department of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Arun Ramanathan
- Department of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Natalie T. Rice
- Department of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
| | - Henry S. La Pierre
- Department of Chemistry and Biochemistry
- Georgia Institute of Technology
- Atlanta
- USA
- Nuclear and Radiological Engineering Program
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