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Mei T, Zhang P, Song Z, Wang B, Qu J, Ye S, Yang D. Unusual Hydrogenation Reactivities of a Thiolate-Bridged Dicobalt μ-Nitride Featuring a Bent {Co III-N-Co III} Core. J Am Chem Soc 2023; 145:20578-20587. [PMID: 37674257 DOI: 10.1021/jacs.3c07254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
Transition metal nitrides have received considerable attention owing to their crucial roles in nitrogen fixation and nitrogen atom transfer reactions. Compared to the early and middle transition metals, it is much more challenging to access late transition metal nitrides, especially cobalt in group 9. So far, only a handful of cobalt nitrides have been reported; consequently, their hydrogenation reactivity is largely unexplored. Herein, we present a structurally and spectroscopically well-characterized thiolate-bridged dicobalt μ-nitride [Cp*CoIII(μ-SAd)(μ-N)CoIIICp*] (2) featuring a bent {CoIII(μ-N)CoIII} core. Remarkably, complex 2 can realize not only direct hydrogenation of nitride to amide but also stepwise N-H bond formation from nitride to ammonia. Specifically, 2 can facilely activate dihydrogen (H2) at mild conditions to generate a dicobalt μ-amide [Cp*CoII(μ-SAd)(μ-NH2)CoIICp*] (4) via an unusual mechanism of two-electron oxidation of H2 as proposed by computational studies; in the presence of protons (H+) and electrons, nitride 2 can convert to dicobalt μ-imide [Cp*CoIII(μ-SAd)(μ-NH)CoIIICp*][BPh4] (3[BPh4]) and to CoIICoII μ-amide 4, and finally release ammonia. In contrast to 2, the only other structurally characterized dicobalt μ-nitride Na(THF)4{[(ketguan)CoIII(N3)]2(μ-N)} (ketguan = [(tBu2CN)C(NDipp)2]-, Dipp = 2,6-diisopropylphenyl) (e) that possesses a linear {CoIII(μ-N)CoIII} moiety cannot directly react with H2 or H+. Further in-depth electronic structure analyses shed light on how the varying geometries of the {CoIII(μ-N)CoIII} moieties in 2 and e, bent vs linear, impart their disparate reactivities.
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Affiliation(s)
- Tao Mei
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, P. R. China
| | - Peng Zhang
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Zihe Song
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, P. R. China
| | - Baomin Wang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, P. R. China
| | - Jingping Qu
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, P. R. China
- State Key Laboratory of Bioreactor Engineering, Collaborative Innovation Centre for Biomanufacturing, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Shengfa Ye
- State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China
| | - Dawei Yang
- State Key Laboratory of Fine Chemicals, Frontier Science Center for Smart Materials, Dalian University of Technology, Dalian 116024, P. R. China
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Mohar JS, Reinholdt A, Keller TM, Carroll PJ, Telser J, Mindiola DJ. A mononuclear, terminal titanium(III) imido. Chem Commun (Camb) 2023; 59:10101-10104. [PMID: 37417771 PMCID: PMC10777895 DOI: 10.1039/d3cc01758c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/08/2023]
Abstract
We report the first mononuclear TiIII complex possessing a terminal imido ligand. Complex [TptBu,MeTi{NSi(CH3)3}(THF)] (2) (TptBu,Me = hydridotris(3-tert-butyl-5-methylpyrazol-1-yl)borate) is prepared by reduction of [TptBu,MeTi{NSi(CH3)3}(Cl)] (1) with KC8 in high yield. The connectivity and metalloradical nature of 2 were confirmed by single crystal X-ray diffraction studies, Q- and X-band EPR, UV-Vis and 1H NMR spectroscopies. The d1 complex [(TptBu,Me)TiCl(OEt2)][B(C6F5)4] (3), was prepared to spectroscopically compare it to 2. Electrochemical studies of 1 and 2 reveal a reversible 1e- process, and chemical oxidants ClCPh3 or 1/2 eq. XeF2 react cleanly with 2 yielding 1 or the fluoride derivative [TptBu,MeTi{NSi(CH3)3}(F)] (4), respectively.
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Affiliation(s)
- Jacob S Mohar
- Department of Chemistry, University of Pennsylvania, 231 S 34th Street, Philadelphia, Pennsylvania, USA.
| | - Anders Reinholdt
- Department of Chemistry, University of Pennsylvania, 231 S 34th Street, Philadelphia, Pennsylvania, USA.
| | - Taylor M Keller
- Department of Chemistry, University of Pennsylvania, 231 S 34th Street, Philadelphia, Pennsylvania, USA.
| | - Patrick J Carroll
- Department of Chemistry, University of Pennsylvania, 231 S 34th Street, Philadelphia, Pennsylvania, USA.
| | - Joshua Telser
- Department of Biological, Physical and Health Sciences, Roosevelt University, Chicago, Illinois, USA.
| | - Daniel J Mindiola
- Department of Chemistry, University of Pennsylvania, 231 S 34th Street, Philadelphia, Pennsylvania, USA.
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