1
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Tamhankar A, Wensien M, Jannuzzi SAV, Chatterjee S, Lassalle-Kaiser B, Tittmann K, DeBeer S. In Solution Identification of the Lysine-Cysteine Redox Switch with a NOS Bridge in Transaldolase by Sulfur K-Edge X-ray Absorption Spectroscopy. J Phys Chem Lett 2024; 15:4263-4267. [PMID: 38607253 DOI: 10.1021/acs.jpclett.4c00484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
A novel covalent post-translational modification (lysine-NOS-cysteine) was discovered in proteins, initially in the enzyme transaldolase of Neisseria gonorrhoeae (NgTAL) [Nature 2021, 593, 460-464], acting as a redox switch. The identification of this novel linkage in solution was unprecedented until now. We present detection of the NOS redox switch in solution using sulfur K-edge X-ray absorption spectroscopy (XAS). The oxidized NgTAL spectrum shows a distinct shoulder on the low-energy side of the rising edge, corresponding to a dipole-allowed transition from the sulfur 1s core to the unoccupied σ* orbital of the S-O group in the NOS bridge. This feature is absent in the XAS spectrum of reduced NgTAL, where Lys-NOS-Cys is absent. Our experimental and calculated XAS data support the presence of a NOS bridge in solution, thus potentially facilitating future studies on enzyme activity regulation mediated by the NOS redox switches, drug discovery, biocatalytic applications, and protein design.
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Affiliation(s)
- Ashish Tamhankar
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Marie Wensien
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermonotowa-Weg 3, 37077 Göttingen, Germany
- Max Planck Institute for Multidisciplinary Sciences Göttingen, 37075 Göttingen, Germany
| | - Sergio A V Jannuzzi
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Sayanti Chatterjee
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
- Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee, 247667 Uttarakhand, India
| | | | - Kai Tittmann
- Department of Molecular Enzymology, Göttingen Center of Molecular Biosciences, Georg-August University Göttingen, Julia-Lermonotowa-Weg 3, 37077 Göttingen, Germany
- Max Planck Institute for Multidisciplinary Sciences Göttingen, 37075 Göttingen, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
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2
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Keilwerth M, Mao W, Malischewski M, Jannuzzi SAV, Breitwieser K, Heinemann FW, Scheurer A, DeBeer S, Munz D, Bill E, Meyer K. The synthesis and characterization of an iron(VII) nitrido complex. Nat Chem 2024; 16:514-520. [PMID: 38291260 PMCID: PMC10997499 DOI: 10.1038/s41557-023-01418-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 12/08/2023] [Indexed: 02/01/2024]
Abstract
Complexes of iron in high oxidation states are captivating research subjects due to their pivotal role as active intermediates in numerous catalytic processes. Structural and spectroscopic studies of well-defined model complexes often provide evidence of these intermediates. In addition to the fundamental molecular and electronic structure insights gained by these complexes, their reactivity also affects our understanding of catalytic reaction mechanisms for small molecule and bond-activation chemistry. Here, we report the synthesis, structural and spectroscopic characterization of a stable, octahedral Fe(VI) nitrido complex and an authenticated, unique Fe(VII) species, prepared by one-electron oxidation. The super-oxidized Fe(VII) nitride rearranges to an Fe(V) imide through an intramolecular amination mechanism and ligand exchange, which is characterized spectroscopically and computationally. This enables combined reactivity and stability studies on a single molecular system of a rare high-valent complex redox pair. Quantum chemical calculations complement the spectroscopic parameters and provide evidence for a diamagnetic (S = 0) d 2 Fe(VI) and a genuine S = 1/2, d 1 Fe(VII) configuration of these super-oxidized nitrido complexes.
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Affiliation(s)
- Martin Keilwerth
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Chemistry and Pharmacy, Inorganic Chemistry, Erlangen, Germany
| | - Weiqing Mao
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Chemistry and Pharmacy, Inorganic Chemistry, Erlangen, Germany
| | - Moritz Malischewski
- Freie Universität Berlin, Institute of Chemistry and Biochemistry, Inorganic Chemistry, Berlin, Germany
| | - Sergio A V Jannuzzi
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - Kevin Breitwieser
- Saarland University, Inorganic Chemistry, Coordination Chemistry, Saarbrücken, Germany
| | - Frank W Heinemann
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Chemistry and Pharmacy, Inorganic Chemistry, Erlangen, Germany
| | - Andreas Scheurer
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Chemistry and Pharmacy, Inorganic Chemistry, Erlangen, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany.
| | - Dominik Munz
- Saarland University, Inorganic Chemistry, Coordination Chemistry, Saarbrücken, Germany.
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Mülheim an der Ruhr, Germany
| | - Karsten Meyer
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Chemistry and Pharmacy, Inorganic Chemistry, Erlangen, Germany.
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3
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Porte V, Milunovic MNM, Knof U, Leischner T, Danzl T, Kaiser D, Gruene T, Zalibera M, Jelemenska I, Bucinsky L, Jannuzzi SAV, DeBeer S, Novitchi G, Maulide N, Arion VB. Chemical and Redox Noninnocence of Pentane-2,4-dione Bis( S-methylisothiosemicarbazone) in Cobalt Complexes and Their Application in Wacker-Type Oxidation. JACS Au 2024; 4:1166-1183. [PMID: 38559722 PMCID: PMC10976605 DOI: 10.1021/jacsau.4c00005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/09/2024] [Accepted: 02/15/2024] [Indexed: 04/04/2024]
Abstract
Cobalt complexes with multiproton- and multielectron-responsive ligands are of interest for challenging catalytic transformations. The chemical and redox noninnocence of pentane-2,4-dione bis(S-methylisothiosemicarbazone) (PBIT) in a series of cobalt complexes has been studied by a range of methods, including spectroscopy [UV-vis, NMR, electron paramagnetic resonance (EPR), X-ray absorption spectroscopy (XAS)], cyclic voltammetry, X-ray diffraction, and density functional theory (DFT) calculations. Two complexes [CoIII(H2LSMe)I]I and [CoIII(LSMe)I2] were found to act as precatalysts in a Wacker-type oxidation of olefins using phenylsilane, the role of which was elucidated through isotopic labeling. Insights into the mechanism of the catalytic transformation as well as the substrate scope of this selective reaction are described, and the essential role of phenylsilane and the noninnocence of PBIT are disclosed. Among the several relevant species characterized was an unprecedented Co(III) complex with a dianionic diradical PBIT ligand ([CoIII(LSMe••)I]).
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Affiliation(s)
- Vincent Porte
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Miljan N. M. Milunovic
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Ulrich Knof
- Novartis
Pharma AG, CH-4056 Basel, Switzerland
| | - Thomas Leischner
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Tobias Danzl
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Daniel Kaiser
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Tim Gruene
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
| | - Michal Zalibera
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Ingrid Jelemenska
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Lukas Bucinsky
- Institute
of Physical Chemistry and Chemical Physics, Faculty of Chemical and
Food Technology, Slovak University of Technology
in Bratislava, Radlinského 9, SK-81237 Bratislava, Slovak Republic
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | | | - Nuno Maulide
- University
of Vienna, Institute of Organic Chemistry, Währinger Strasse 38, A-1090 Vienna, Austria
| | - Vladimir B. Arion
- University
of Vienna, Institute of Inorganic Chemistry, Währinger Strasse 42, A-1090 Vienna, Austria
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4
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Hall K, Joseph C, Ayuso-Fernández I, Tamhankar A, Rieder L, Skaali R, Golten O, Neese F, Røhr ÅK, Jannuzzi SAV, DeBeer S, Eijsink VGH, Sørlie M. A Conserved Second Sphere Residue Tunes Copper Site Reactivity in Lytic Polysaccharide Monooxygenases. J Am Chem Soc 2023; 145:18888-18903. [PMID: 37584157 PMCID: PMC10472438 DOI: 10.1021/jacs.3c05342] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Indexed: 08/17/2023]
Abstract
Lytic polysaccharide monooxygenases (LPMOs) are powerful monocopper enzymes that can activate strong C-H bonds through a mechanism that remains largely unknown. Herein, we investigated the role of a conserved glutamine/glutamate in the second coordination sphere. Mutation of the Gln in NcAA9C to Glu, Asp, or Asn showed that the nature and distance of the headgroup to the copper fine-tune LPMO functionality and copper reactivity. The presence of Glu or Asp close to the copper lowered the reduction potential and decreased the ratio between the reduction and reoxidation rates by up to 500-fold. All mutants showed increased enzyme inactivation, likely due to changes in the confinement of radical intermediates, and displayed changes in a protective hole-hopping pathway. Electron paramagnetic resonance (EPR) and X-ray absorption spectroscopic (XAS) studies gave virtually identical results for all NcAA9C variants, showing that the mutations do not directly perturb the Cu(II) ligand field. DFT calculations indicated that the higher experimental reoxidation rate observed for the Glu mutant could be reconciled if this residue is protonated. Further, for the glutamic acid form, we identified a Cu(III)-hydroxide species formed in a single step on the H2O2 splitting path. This is in contrast to the Cu(II)-hydroxide and hydroxyl intermediates, which are predicted for the WT and the unprotonated glutamate variant. These results show that this second sphere residue is a crucial determinant of the catalytic functioning of the copper-binding histidine brace and provide insights that may help in understanding LPMOs and LPMO-inspired synthetic catalysts.
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Affiliation(s)
- Kelsi
R. Hall
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Chris Joseph
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Iván Ayuso-Fernández
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ashish Tamhankar
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Lukas Rieder
- Institute
for Molecular Biotechnology, Graz University
of Technology, 8010, Graz, Austria
| | - Rannei Skaali
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Ole Golten
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Frank Neese
- Max-Planck-Institut
für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Åsmund K. Røhr
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Sergio A. V. Jannuzzi
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max
Planck Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Vincent G. H. Eijsink
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
| | - Morten Sørlie
- Faculty
of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1432, Ås, Norway
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5
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Mao W, Zhang Z, Fehn D, Jannuzzi SAV, Heinemann FW, Scheurer A, van Gastel M, DeBeer S, Munz D, Meyer K. Synthesis and Reactivity of a Cobalt-Supported Singlet Nitrene. J Am Chem Soc 2023. [PMID: 37310290 DOI: 10.1021/jacs.3c01478] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The synthesis, characterization, and reactivity of a series of cobalt terminal imido complexes supported by an N-anchored tripodal tris(carbene) chelate is described, including a Co-supported singlet nitrene. Reaction of the CoI precursor [(TIMMNmes)CoI](PF6) (TIMMNmes = tris-[2-(3-mesityl-imidazolin-2-ylidene)-methyl]amine) with p-methoxyphenyl azide yields a CoIII imide [(TIMMNmes)CoIII(NAnisole)](PF6) (1). Treatment of 1 with 1 equiv of [FeCp2](PF6) at -35 °C affords a formal CoIV imido complex [(TIMMNmes)Co(NAnisole)](PF6)2 (2), which features a bent Co-N(imido)-C(Anisole) linkage. Subsequent one-electron oxidation of 2 with 1 equiv of AgPF6 provides access to the tricationic cobalt imido complex [(TIMMNmes)Co(NAnisole)](PF6)3 (3). All complexes were fully characterized, including single-crystal X-ray diffraction (SC-XRD) analyses, infrared (IR) vibrational, ultraviolet/visible (UV/vis) electronic absorption, multinuclear NMR, X-band electron paramagnetic resonance (EPR), electron nuclear double resonance (ENDOR), and high-energy-resolution fluorescence-detected X-ray absorption spectroscopy (HERFD XAS). Quantum chemical calculations provide additional insight into the electronic structures of all compounds. The dicationic CoIV imido complex 2 exhibits a doublet ground state with considerable imidyl character as a result of covalent Co-NAnisole bonding. At room temperature, 2 readily converts to a CoII amine complex involving intramolecular C-H bond amination. Electronically, tricationic complex 3 can be understood as a singlet nitrene bound to CoIII with significant CoIV imidyl radical character. Verifying the pronounced electrophilicity, nucleophiles such as H2O and tBuNH2 add to 3─analogous to the parent free nitrene─in the para position of the aromatic substituent, thus, clearly corroborating singlet nitrene-type reactivity.
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Affiliation(s)
- Weiqing Mao
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Zihan Zhang
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Dominik Fehn
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Sergio A V Jannuzzi
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Frank W Heinemann
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Andreas Scheurer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim an der Ruhr, Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion, Stiftstr. 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Dominik Munz
- Inorganic Chemistry: Coordination Chemistry, Saarland University, Campus C4 1, 66123 Saarbrücken, Germany
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
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6
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Keilwerth M, Mao W, Jannuzzi SAV, Grunwald L, Heinemann FW, Scheurer A, Sutter J, DeBeer S, Munz D, Meyer K. From Divalent to Pentavalent Iron Imido Complexes and an Fe(V) Nitride via N-C Bond Cleavage. J Am Chem Soc 2023; 145:873-887. [PMID: 36583993 DOI: 10.1021/jacs.2c09072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
As key intermediates in metal-catalyzed nitrogen-transfer chemistry, terminal imido complexes of iron have attracted significant attention for a long time. In search of versatile model compounds, the recently developed second-generation N-anchored tris-NHC chelating ligand tris-[2-(3-mesityl-imidazole-2-ylidene)-methyl]amine (TIMMNMes) was utilized to synthesize and compare two series of mid- to high-valent iron alkyl imido complexes, including a reactive Fe(V) adamantyl imido intermediate en route to an isolable Fe(V) nitrido complex. The chemistry toward the iron adamantyl imides was achieved by reacting the Fe(I) precursor [(TIMMNMes)FeI(N2)]+ (1) with 1-adamantyl azide to yield the corresponding trivalent iron imide. Stepwise chemical reduction and oxidation lead to the isostructural series of low-spin [(TIMMNMes)Fe(NAd)]0,1+,2+,3+ (2Ad-5Ad) in oxidation states II to V. The Fe(V) imide [(TIMMNMes)Fe(NAd)]3+ (5Ad) is unstable under ambient conditions and converts to the air-stable nitride [(TIMMNMes)FeV(N)]2+ (6) via N-C bond cleavage. The stability of the pentavalent imide can be increased by derivatizing the nitride [(TIMMNMes)FeIV(N)]+ (7) with an ethyl group using the triethyloxonium salt Et3OPF6. This gives access to the analogous series of ethyl imides [(TIMMNMes)Fe(NEt)]0,1+,2+,3+ (2Et-5Et), including the stable Fe(V) ethyl imide. Iron imido complexes exist in a manifold of different electronic structures, ultimately controlling their diverse reactivities. Accordingly, these complexes were characterized by single-crystal X-ray diffraction analyses, SQUID magnetization, and electrochemical methods, as well as 57Fe Mössbauer, IR vibrational, UV/vis electronic absorption, multinuclear NMR, X-band EPR, and X-ray absorption spectroscopy. Our studies are complemented with quantum chemical calculations, thus providing further insight into the electronic structures of all complexes.
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Affiliation(s)
- Martin Keilwerth
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Weiqing Mao
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Sergio A V Jannuzzi
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Liam Grunwald
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany.,Department of Chemistry and Applied Biosciences (D-CHAB), ETH Zürich, 8093 Zürich, Switzerland
| | - Frank W Heinemann
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Andreas Scheurer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Jörg Sutter
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
| | - Serena DeBeer
- Max-Planck-Institute for Chemical Energy Conversion, Stiftstraße 34-36, 45470 Mülheim an der Ruhr, Germany
| | - Dominik Munz
- Inorganic Chemistry: Coordination Chemistry, Saarland University, Campus C4 1, 66123 Saarbrücken, Germany
| | - Karsten Meyer
- Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Egerlandstraße 1, 91058 Erlangen, Germany
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7
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Mao W, Fehn D, Heinemann FW, Scheurer A, van Gastel M, Jannuzzi SAV, DeBeer S, Munz D, Meyer K. Umpolung in a Pair of Cobalt(III) Terminal Imido/Imidyl Complexes. Angew Chem Int Ed Engl 2022; 61:e202206848. [PMID: 35674679 PMCID: PMC9541304 DOI: 10.1002/anie.202206848] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Indexed: 11/12/2022]
Abstract
Reaction of the CoI complex [(TIMMNmes)CoI](PF6) (1) (TIMMNmes=tris‐[2‐(3‐mesityl‐imidazolin‐2‐ylidene)‐methyl]amine) with mesityl azide yields the CoIII imide [(TIMMNmes)CoIII(NMes)](PF6) (2). Oxidation of 2 with [FeCp2](PF6) provides access to a rare CoIII imidyl [(TIMMNmes)Co(NMes)](PF6)2 (3). Single‐crystal X‐ray diffractometry and EPR spectroscopy confirm the molecular structure of 3 and its S=1/2
ground state. ENDOR, X‐ray absorption spectroscopy and computational analyses indicate a ligand‐based oxidation; thus, an imidyl‐radical electronic structure for 3. Migratory insertion of one ancillary NHC to the imido ligand in 2 gives the CoIN‐heterocyclic imine (4) within 12 h. Conversely, it takes merely 0.5 h for 3 to transform to the CoII congener (5). The migratory insertion in 2 occurs via a nucleophilic attack of the imido ligand at the NHC to give 4, whereas in 3, a nucleophilic attack of the NHC at the electrophilic imidyl ligand yields 5. The reactivity shunt upon oxidation of 2 to 3 confirms an umpolung of the imido ligand.
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Affiliation(s)
- Weiqing Mao
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
| | - Dominik Fehn
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
| | - Frank W. Heinemann
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
| | - Andreas Scheurer
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung Kaiser-Wilhelm-Platz 1 45470 Mülheim an der Ruhr Germany
| | - Sergio A. V. Jannuzzi
- Max Planck Institute for Chemical Energy Conversion Stiftstr. 34–36 45470 Mülheim an der Ruhr Germany
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion Stiftstr. 34–36 45470 Mülheim an der Ruhr Germany
| | - Dominik Munz
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
- Current address: Saarland University Inorganic Chemistry: Coordination Chemistry Campus C4.1 66123 Saarbrücken Germany
| | - Karsten Meyer
- Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) Inorganic Chemistry Egerlandstrasse 1 91058 Erlangen Germany
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8
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Mao W, Fehn D, Heinemann FW, Scheurer A, van Gastel M, Jannuzzi SAV, DeBeer S, Munz D, Meyer K. Umpolung in a Pair of Cobalt(III) Terminal Imido/Imidyl Complexes. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Weiqing Mao
- Friedrich-Alexander-Universität Erlangen-Nürnberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Department of Chemistry and Pharmacy GERMANY
| | - Dominik Fehn
- Friedrich-Alexander-Universität Erlangen-Nürnberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Department of Chemistry and Pharmacy GERMANY
| | - Frank W. Heinemann
- Friedrich-Alexander-Universität Erlangen-Nürnberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Department of Chemistry and Pharmacy GERMANY
| | - Andreas Scheurer
- Friedrich-Alexander-Universität Erlangen-Nürnberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Department of Chemistry and Pharmacy GERMANY
| | - Maurice van Gastel
- Max-Planck-Institut für Kohlenforschung: Max-Planck-Institut fur Kohlenforschung Spectroscopy GERMANY
| | | | - Serena DeBeer
- Max-Planck-Institut für chemische Energiekonversion: Max-Planck-Institut fur chemische Energiekonversion Spectroscopy GERMANY
| | - Dominik Munz
- Saarland University: Universitat des Saarlandes Inorganic Chemistry: Coordination Chemistry GERMANY
| | - Karsten Meyer
- Friedrich-Alexander-Universität Erlangen-Nürnberg: Friedrich-Alexander-Universitat Erlangen-Nurnberg Department Chemie und Pharmazie Anorganische ChemieEgerlandstr. 1 91058 Erlangen GERMANY
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9
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Souilah C, Jannuzzi SAV, Demirbas D, Ivlev S, Swart M, DeBeer S, Casitas A. Synthesis of Fe
III
and Fe
IV
Cyanide Complexes Using Hypervalent Iodine Reagents as Cyano‐Transfer One‐Electron Oxidants. Angew Chem Int Ed Engl 2022; 61:e202201699. [PMID: 35285116 PMCID: PMC9313551 DOI: 10.1002/anie.202201699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Indexed: 11/12/2022]
Affiliation(s)
- Charafa Souilah
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Sergio A. V. Jannuzzi
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Derya Demirbas
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Sergei Ivlev
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Marcel Swart
- ICREA Pg. Lluís Companys 23 08010 Barcelona Spain
- Institut de Química Computacional i Catàlisi, Facultat de Ciències Universitat de Girona c/ M.A. Capmany 69 17003 Girona Spain
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Alicia Casitas
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
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10
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Souilah C, Jannuzzi SAV, Demirbas D, Ivlev S, Swart M, DeBeer S, Casitas A. Synthesis of Fe
III
and Fe
IV
Cyanide Complexes Using Hypervalent Iodine Reagents as Cyano‐Transfer One‐Electron Oxidants. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202201699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Charafa Souilah
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Sergio A. V. Jannuzzi
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Derya Demirbas
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Sergei Ivlev
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
| | - Marcel Swart
- ICREA Pg. Lluís Companys 23 08010 Barcelona Spain
- Institut de Química Computacional i Catàlisi, Facultat de Ciències Universitat de Girona c/ M.A. Capmany 69 17003 Girona Spain
| | - Serena DeBeer
- Max Planck Institute for Chemical Energy Conversion (MPI CEC) Stiftstraße 34–36 45470 Mülheim an der Ruhr Germany
| | - Alicia Casitas
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35043 Marburg Germany
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11
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Jannuzzi SAV, de Arruda EGR, Lima FA, Ribeiro MA, Brinatti C, Formiga ALB. Enzyme-Like Selectivity on Metalloporphyrin-Catalyzed Oxidation by a Linear Homopolymer. ChemistrySelect 2016. [DOI: 10.1002/slct.201600597] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Sergio A. V. Jannuzzi
- Institute of Chemistry; University of Campinas - UNICAMP; P.O. Box 6154 13083-970 Campinas, SP Brazil
- Department of Chemistry; KU Leuven; Celestijnenlaan 200F B-3001 Leuven Belgium
| | - Eduardo G. R. de Arruda
- Institute of Chemistry; University of Campinas - UNICAMP; P.O. Box 6154 13083-970 Campinas, SP Brazil
| | - Frederico A. Lima
- Centro Nacional de Pesquisa em Energia e Materiais; Laboratório Nacional de Luz Síncrotron; Rua Giuseppe Máximo Scolfaro 10000, 1 3083-970 Campinas, SP Brazil
| | - Marcos A. Ribeiro
- Institute of Chemistry; University of Campinas - UNICAMP; P.O. Box 6154 13083-970 Campinas, SP Brazil
| | - César Brinatti
- Institute of Chemistry; University of Campinas - UNICAMP; P.O. Box 6154 13083-970 Campinas, SP Brazil
| | - André L. B. Formiga
- Institute of Chemistry; University of Campinas - UNICAMP; P.O. Box 6154 13083-970 Campinas, SP Brazil
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Jannuzzi SAV, Martins B, Huamaní LESC, Formiga ALB. Supramolecular Approach to Decorate Multi-Walled Carbon Nanotubes with Negatively Charged Iron(II) Complexes. J BRAZIL CHEM SOC 2016. [DOI: 10.5935/0103-5053.20160137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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13
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Linares EM, Jannuzzi SAV, Galembeck F. Electrostatic contributions in the increased compatibility of polymer blends. Langmuir 2011; 27:15199-15205. [PMID: 22008021 DOI: 10.1021/la2029998] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Successful blending of different polymers to make a structural or functional material requires overcoming limitations due to immiscibility and/or incompatibility that arise from large polymer-polymer interfacial tensions. In the case of latex blends, the combination of capillary adhesion during the blended dispersion drying stage with electrostatic adhesion in the final product is an effective strategy to avoid these limitations, which has been extended to a number of polymer blends and composites. This work shows that adhesion of polymer domains in blends made with natural rubber and synthetic latexes is enhanced by electrostatic adhesion that is in turn enhanced by ion migration, according to the results from scanning electric potential microscopy. The additional attractive force between domains improves blend stability and mechanical properties, broadening the possibilities and scope of latex blends, in consonance with the "green chemistry" paradigm. This novel approach based on electrostatic adhesion can be easily extended to multicomponent systems, including nonpolymers.
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Affiliation(s)
- Elisângela M Linares
- Institute of Chemistry, University of Campinas, P.O. Box 6154, 13083-970 Campinas, São Paulo, Brazil
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Abstract
Here we report chemically induced folding of thin graphene flakes. The folding occurs spontaneously when an intercalating species interrupts the adhesion between graphene and a supporting substrate. The morphology of induced folds suggests that the conjugated pi network is capable of extremely sharp curvature. Adjacent folds are often parallel, suggesting preferential deformation along certain crystallographic planes.
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Affiliation(s)
- Matthew J Allen
- Department of Chemistry and Biochemistry, University of California Los Angeles, LA, USA
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