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Pham HL, Rajeshkumar T, Wang LUH, Ng YH, Wong KH, So YM, Sung HHY, Lortz R, Williams ID, Maron L, Leung WH. Synthesis and Reactivity of Redox-Active Cerium(IV) Aryloxide Complexes. Organometallics 2023. [DOI: 10.1021/acs.organomet.2c00569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Affiliation(s)
- Hoang-Long Pham
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | | | - Lily Ueh-hsi Wang
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yat Hei Ng
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Kai-Hong Wong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yat-Ming So
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Herman H. Y. Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Rolf Lortz
- Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Ian D. Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | | | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
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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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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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Wong KH, Cheung WM, Pham HL, So YM, Sung HHY, Williams ID, Leung WH. Oxidizing Cerium(IV) Alkoxide Complexes Supported by the Kläui Ligand [Co(η 5-C 5H 5){P(O)(OEt) 2} 3] -: Synthesis, Structure, and Redox Reactivity. Inorg Chem 2021; 60:2261-2270. [PMID: 33499604 DOI: 10.1021/acs.inorgchem.0c03105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Tetravalent cerium alkoxide complexes supported by the Kläui tripodal ligand [Co(η5-C5H5){P(O)(OEt)2}3]- (LOEt-) have been synthesized, and their nucleophilic and redox reactivity have been studied. Treatment of the Ce(IV) oxo complex [CeIV(LOEt)2(O)(H2O)]·MeCONH2 (1) with iPrOH or reaction of [CeIV(LOEt)2Cl2] (2) with Ag2O in iPrOH afforded the Ce(IV) dialkoxide complex [CeIV(LOEt)2(OiPr)2] (3-iPr). The methoxide and ethoxide analogues [CeIV(LOEt)2(OR)2] (R = Me (3-Me), Et (3-Et)) have been prepared similarly from 2 and Ag2O in ROH. Reaction of 3-iPr with an equimolar amount of 2 yielded a new Ce(IV) complex that was formulated as the chloro-alkoxide complex [CeIV(LOEt)2(OiPr)Cl] (4). Treatment of 3-iPr with HX and methyl triflate (MeOTf) afforded [Ce(LOEt)2X2] (X- = Cl-, NO3-, PhO-) and [CeIV(LOEt)2(OTf)2], respectively, whereas treatment with excess CO2 in hexane led to isolation of the Ce(IV) carbonate [CeIV(LOEt)2(CO3)]. 3-iPr reacted with water in hexane to give a Ce(III) complex and a Ce(IV) species, presumably the reported tetranuclear oxo cluster [CeIV4(LOEt)4(O)5(OH)2]. The Ce(IV) alkoxide complexes are capable of oxidizing substituted phenols, possibly via a proton-coupled electron transfer pathway. Treatment of 3-iPr with ArOH afforded the Ce(III) aryloxide complexes [CeIII(LOEt)2(OAr)] (Ar = 2,4,6-tri-tert-butylphenyl (5), 2,6-diphenylphenyl (6)). On the other hand, a Ce(III) complex containing a monodeprotonated 2,2'-biphenol ligand, [CeIII(LOEt)2(tBu4C12H4O2H)] (7) (tBu4C12H4O2H2 = 4,4',6,6'-tetra-tert-butyl-2,2'-biphenol), was isolated from the reaction of 3-iPr with 2,4-di-tert-butylphenol. The crystal structures of complexes 3-iPr, 3-Me, 3-Et, and 5-7 have been determined.
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Affiliation(s)
- Kai-Hong Wong
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wai-Man Cheung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Hoang-Long Pham
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Yat-Ming So
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Herman H-Y Sung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Ian D Williams
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
| | - Wa-Hung Leung
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P. R. China
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Cheung WM, Au-Yeung KC, Wong KH, So YM, Sung HHY, Williams ID, Leung WH. Reactions of cerium complexes with transition metal nitrides: synthesis and structure of heterometallic cerium complexes containing bridging catecholate ligands. Dalton Trans 2019; 48:13458-13465. [DOI: 10.1039/c9dt02959a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Heterometallic cerium complexes containing bridging catecholate ligands have been synthesized from cerium complexes with Kläui's tripodal ligand and metal catecholates.
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Affiliation(s)
- Wai-Man Cheung
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Ka-Chun Au-Yeung
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Kai-Hong Wong
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Yat-Ming So
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Herman H. Y. Sung
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Ian D. Williams
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
| | - Wa-Hung Leung
- Department of Chemistry
- The Hong Kong University of Science and Technology
- Kowloon
- P. R. China
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