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Leitner D, Wittwer B, Neururer FR, Seidl M, Wurst K, Tambornino F, Hohloch S. Expanding the Utility of β-Diketiminate Ligands in Heavy Group VI Chemistry of Molybdenum and Tungsten. Organometallics 2023; 42:1411-1424. [PMID: 37388273 PMCID: PMC10302891 DOI: 10.1021/acs.organomet.3c00056] [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: 01/27/2023] [Indexed: 07/01/2023]
Abstract
We report the synthesis of 17 molybdenum and tungsten complexes supported by the ubiquitous BDI ligand framework (BDI = β-diketiminate). The focal entry point is the synthesis of four molybdenum and tungsten(V) BDI complexes of the general formula [MO(BDIR)Cl2] [M = Mo, R = Dipp (1); M = W, R = Dipp (2); M = Mo, R = Mes (3); M = W, R = Mes (4)] synthesized by the reaction between MoOCl3(THF)2 or WOCl3(THF)2 and LiBDIR. Reactivity studies show that the BDIDipp complexes are excellent precursors toward adduct formation, reacting smoothly with dimethylaminopyridine (DMAP) and triethylphosphine oxide (OPEt3). No reaction with small phosphines has been observed, strongly contrasting the chemistry of previously reported rhenium(V) complexes. Additionally, the complexes 1 and 2 are good precursors for salt metathesis reactions. While 1 can be chemically reduced to the first stable example of a Mo(IV) BDI complex 15, reduction of 2 resulted in degradation of the BDI ligand via a nitrene transfer reaction, leading to MAD (4-((2,6-diisopropylphenyl)imino)pent-2-enide) supported tungsten(V) and tungsten(VI) complexes 16 and 17. All reported complexes have been thoroughly studied by VT-NMR and (heteronuclear) NMR spectroscopy, as well as UV-vis and EPR spectroscopy, IR spectroscopy, and X-ray diffraction analysis.
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Affiliation(s)
- Daniel Leitner
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
| | - Benjamin Wittwer
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
| | - Florian R. Neururer
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
| | - Michael Seidl
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
| | - Klaus Wurst
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
| | - Frank Tambornino
- Fachbereich
Chemie and Wissenschaftlichen Zentrum für Materialwissenschaften
(WZMW), Phillips-University Marburg, Hans-Meerwein-Straße 4, 35043 Marburg, Germany
| | - Stephan Hohloch
- Faculty
of Chemistry and Pharmacy, Institute for General, Inorganic and Theoretical
Chemistry, University of Innsbruck, Innrain 80−82, Innsbruck 6020 Austria
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Bae DY, Lee G, Lee E. Reduction of highly bulky triphenolamine molybdenum nitrido and chloride complexes. Dalton Trans 2021; 50:14139-14143. [PMID: 34635894 DOI: 10.1039/d1dt02375f] [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
Transition metal nitrides are key intermediates in the catalytic reduction of dinitrogen to ammonia. To date, transition metal nitride complexes with the triphenolamine (TPA) ligand have not been reported and the system with the ligand has been much less studied for ammonia formation compared with other systems. Herein, we report a series of molybdenum complexes supported by a sterically demanding TPA ligand, including a nitrido complex NMo(TPA). We achieved the stoichiometric conversion of the nitride moiety into ammonia under ambient conditions by adding proton and electron sources to NMo(TPA). However, the catalytic turnover for N2 reduction to ammonia was not observed in the triphenolamine ligand system unlike the Schrock system-triamidoamine ligand. Density functional theory calculation revealed that the molybdenum center favors binding NH3 over N2 by 16.9 kcal mol-1 and the structural lability of the trigonal bipyramidal (TBP) molybdenum complex seems to prevent catalytic turnover. Our systematic study showed that the electronegativity and bond length of ancillary ligands determine the preference between N2 and NH3, suggesting a systematic design strategy for improvement.
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Affiliation(s)
- Dae Young Bae
- Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-Ro, 37673, Pohang, Republic of Korea.
| | - Gunhee Lee
- Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-Ro, 37673, Pohang, Republic of Korea.
| | - Eunsung Lee
- Department of Chemistry, Pohang University of Science and Technology, 77 Cheongam-Ro, 37673, Pohang, Republic of Korea.
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Tanabe Y, Nishibayashi Y. Comprehensive insights into synthetic nitrogen fixation assisted by molecular catalysts under ambient or mild conditions. Chem Soc Rev 2021; 50:5201-5242. [PMID: 33651046 DOI: 10.1039/d0cs01341b] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
N2 is fixed as NH3 industrially by the Haber-Bosch process under harsh conditions, whereas biological nitrogen fixation is achieved under ambient conditions, which has prompted development of alternative methods to fix N2 catalyzed by transition metal molecular complexes. Since the early 21st century, catalytic conversion of N2 into NH3 under ambient conditions has been achieved by using molecular catalysts, and now H2O has been utilized as a proton source with turnover frequencies reaching the values found for biological nitrogen fixation. In this review, recent advances in the development of molecular catalysts for synthetic N2 fixation under ambient or mild conditions are summarized, and potential directions for future research are also discussed.
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Affiliation(s)
- Yoshiaki Tanabe
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
| | - Yoshiaki Nishibayashi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
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Liu S, Amaro-Estrada JI, Baltrun M, Douair I, Schoch R, Maron L, Hohloch S. Catalytic Deoxygenation of Nitroarenes Mediated by High-Valent Molybdenum(VI)–NHC Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.0c00352] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shenyu Liu
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | | | - Marc Baltrun
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Iskander Douair
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Roland Schoch
- Paderborn University, Faculty of Science, Department of Chemistry, Warburger Straße 100, 33098 Paderborn, Germany
| | - Laurent Maron
- LPCNO, Université de Toulouse, INSA Toulouse, 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Stephan Hohloch
- University of Innsbruck, Faculty of Chemistry and Pharmacy, Institute of General, Inorganic and Theoretical Chemistry, Innrain 80-82, 6020 Innsbruck, Austria
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A hemilabile diphosphine pyridine pincer ligand: σ- and π-binding in molybdenum coordination complexes. Polyhedron 2020. [DOI: 10.1016/j.poly.2020.114631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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