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Werncke CG, Müller I, Weißer K, Limberg C. Divergent Interaction of (Iso)nitriles with a Linear Iron(I) Silylamide─A Combined Structural, Spectroscopic, and Computational Study. Inorg Chem 2024; 63:15236-15246. [PMID: 39066707 DOI: 10.1021/acs.inorgchem.4c02882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
Nitriles and isonitriles are important σ-donor ligands in coordination chemistry. Isonitriles also function in low-valent complexes as π-acceptor ligands similar to CO. Herein we present the unusual behavior of the highly reducing, high-spin iron(I) complex [Fe(hmds)2]- toward these compound classes. Rare examples of side-on coordination of nitriles to the metal center are observed. Insights gained by 57Fe Mössbauer spectroscopy as well as DFT and CASSCF calculations give an interplay between the resonance structures of not only an iron(I) π-complex and an iron(III) metallacycle but also point to the importance of an iron(II) nitrile radical anion. For an aromatic isonitrile end-on coordination is observed, which is best described as an iron(I) complex with only minor unpaired spin transfer onto the isonitrile. For aliphatic isonitriles, the selective R-CN bond cleavage occurs and yields stoichiometric mixtures of alkyl iron(II) and cyanido iron(II) complexes. Attempts to isolate presumed (iso)nitrile radical anions void of 3d-metal coordination give for the reaction of an aromatic isonitrile with KC8 facile reductive coupling to the corresponding diamido acetylene.
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Affiliation(s)
- C Gunnar Werncke
- Chemistry Department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35043 Marburg, Germany
| | - Igor Müller
- Chemistry Department, Philipps-University Marburg, Hans-Meerwein-Straße 4, D-35043 Marburg, Germany
| | - Kilian Weißer
- Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-13089 Berlin, Germany
| | - Christian Limberg
- Institute of Chemistry, Humboldt-University Berlin, Brook-Taylor-Str. 2, D-13089 Berlin, Germany
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2
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Errulat D, Harriman KLM, Gálico DA, Kitos AA, Mansikkamäki A, Murugesu M. A trivalent 4f complex with two bis-silylamide ligands displaying slow magnetic relaxation. Nat Chem 2023:10.1038/s41557-023-01208-y. [PMID: 37231297 DOI: 10.1038/s41557-023-01208-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Accepted: 04/17/2023] [Indexed: 05/27/2023]
Abstract
The best-performing single-molecule magnets (SMMs) have historically relied on pseudoaxial ligands delocalized across several coordinated atoms. This coordination environment has been found to elicit strong magnetic anisotropy, but lanthanide-based SMMs with low coordination numbers have remained synthetically elusive species. Here we report a cationic 4f complex bearing only two bis-silylamide ligands, Yb(III)[{N(SiMePh2)2}2][Al{OC(CF3)3}4], which exhibits slow relaxation of its magnetization. The combination of the bulky silylamide ligands and weakly coordinating [Al{OC(CF3)3}4]- anion provides a sterically hindered environment that suitably stabilizes the pseudotrigonal geometry necessary to elicit strong ground-state magnetic anisotropy. The resolution of the mJ states by luminescence spectroscopy is supported by ab initio calculations, which show a large ground-state splitting of approximately 1,850 cm-1. These results provide a facile route to access a bis-silylamido Yb(III) complex, and further underline the desirability of axially coordinated ligands with well-localized charges for high-performing SMMs.
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Affiliation(s)
- Dylan Errulat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Katie L M Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Diogo A Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | - Alexandros A Kitos
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario, Canada.
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Gonzalez A, Chen TY, Demeshko S, Meyer F, Werncke CG. Synthesis, Properties, and Reactivity of a Linear NHC-Based Chromium(I) Silylamide. Organometallics 2023. [DOI: 10.1021/acs.organomet.3c00013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023]
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Weller R, Atanasov M, Demeshko S, Chen TY, Mohelsky I, Bill E, Orlita M, Meyer F, Neese F, Werncke CG. On the Single-Molecule Magnetic Behavior of Linear Iron(I) Arylsilylamides. Inorg Chem 2023; 62:3153-3161. [PMID: 36744742 DOI: 10.1021/acs.inorgchem.2c04050] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The rational design of 3d-metal-based single-molecule magnets (SMM) requires a fundamental understanding of their intrinsic electronic and structural properties and how they translate into experimentally observable features. Here, we determined the magnetic properties of the linear iron(I) silylamides K{crypt}[FeL2] and [KFeL2] (L = -N(Dipp)SiMe3; crypt = 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosan). For the former, slow-relaxation of the magnetization with a spin reversal barrier of Ueff = 152 cm-1 as well as a closed-waist magnetic hysteresis and magnetic blocking below 2.5 K are observed. For the more linear [KFeL2], in which the potassium cation is encapsulated by the aryl substituents of the amide ligands, the relaxation barrier and the blocking temperature increase to Ueff = 184 cm-1 and TB = 4.5 K, respectively. The increase is rationalized by a more pronounced axial anisotropy in [KFeL2] determined by dc-SQUID magnetometry. The effective relaxation barrier of [KFeL2] is in agreement with the energy spacing between the ground and first-excited magnetic states, as obtained by field-dependent IR-spectroscopy (178 cm-1), magnetic measurements (208 cm-1), as well as theoretical analysis (212 cm-1). In comparison with the literature, the results show that magnetic coercivity in linear iron(I) silylamides is driven by the degree of linearity in conjunction with steric encumbrance, whereas the ligand symmetry is a marginal factor.
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Affiliation(s)
- Ruth Weller
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35043Marburg, Germany
| | - Mihail Atanasov
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany.,Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Akad.Georgi Bontchev Street, Bl.11, 1113Sofia, Bulgaria
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Ting-Yi Chen
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Ivan Mohelsky
- LAB National des Champs Magnétiques Intenses, LNCMI─CNRS, 25 Martyrs Avenue, BP 166, 38042Grenoble Cedex 9, France
| | - Eckhard Bill
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany
| | - Milan Orlita
- LAB National des Champs Magnétiques Intenses, LNCMI─CNRS, 25 Martyrs Avenue, BP 166, 38042Grenoble Cedex 9, France.,Institute of Physics, Charles University in Prague, Ke Karlovu 5, CZ-12116Prague, Czech Republic
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstr. 4, D-37077Göttingen, Germany
| | - Frank Neese
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470Mülheim an der Ruhr, Germany
| | - C Gunnar Werncke
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Straße 4, 35043Marburg, Germany
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Reith S, Demeshko S, Battistella B, Reckziegel A, Schneider C, Stoy A, Lichtenberg C, Meyer F, Munz D, Werncke CG. Between imide, imidyl and nitrene – an imido iron complex in two oxidation states. Chem Sci 2022; 13:7907-7913. [PMID: 35865905 PMCID: PMC9258327 DOI: 10.1039/d2sc01088g] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/28/2022] [Indexed: 01/11/2023] Open
Abstract
Imidyl and nitrene metal species play an important role in the N-functionalisation of unreactive C–H bonds as well as the aziridination of olefines. We report on the synthesis of the trigonal imido iron complexes [Fe(NMes)L2]0,− (L = –N{Dipp}SiMe3); Dipp = 2,6-diisopropyl-phenyl; Mes = (2,4,6-trimethylphenyl) via reaction of mesityl azide (MesN3) with the linear iron precursors [FeL2]0,−. UV-vis-, EPR-, 57Fe Mössbauer spectroscopy, magnetometry, and computational methods suggest for the reduced form an electronic structure as a ferromagnetically coupled iron(ii) imidyl radical, whereas oxidation leads to mixed iron(iii) imidyl and electrophilic iron(ii) nitrene character. Reactivity studies show that both complexes are capable of H atom abstraction from C–H bonds. Further, the reduced form [Fe(NMes)L2]− reacts nucleophilically with CS2 by inserting into the imido iron bond, as well as electrophilically with CO under nitrene transfer. The neutral [Fe(NMes)L2] complex shows enhanced electrophilic behavior as evidenced by nitrene transfer to a phosphine, yet in combination with an overall reduced reactivity. A pair of trigonal imido iron complexes ([Fe(NMes)L2]0,−) in two oxidation states is reported. The anionic complex K{crypt.222}[Fe(NMes)L2] is best described as an iron(ii) imide.![]()
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Affiliation(s)
- Sascha Reith
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
| | - Serhiy Demeshko
- University of Göttingen, Institute of Inorganic Chemistry, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Beatrice Battistella
- Humboldt-University, Berlin Institute for Chemistry, Brook-Taylor-Str. 2, D-12489 Berlin, Germany
| | - Alexander Reckziegel
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
| | - Christian Schneider
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
| | - Andreas Stoy
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
| | - Crispin Lichtenberg
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
| | - Franc Meyer
- University of Göttingen, Institute of Inorganic Chemistry, Tammannstr. 4, D-37077 Göttingen, Germany
| | - Dominik Munz
- Saarland University, Inorganic Chemistry: Coordination Chemistry, Campus C4.1, D-66123 Saarbrücken, Germany
- Friedrich-Alexander University Erlangen-Nürnberg, Inorganic Chemistry, Egerlandstr. 1, D-91058 Erlangen, Germany
| | - C. Gunnar Werncke
- Philipps-University Marburg, Department of Chemistry, Hans-Meerwein-Str. 4, D-35037 Marburg, Germany
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Weller R, Völlinger L, Werncke CG. On the Synthesis and Reduction of Trigonal Halido Bis(silylamido) Metalates of Chromium to Cobalt. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100716] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Ruth Weller
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Germany
| | - Lena Völlinger
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Germany
| | - C. Gunnar Werncke
- Fachbereich Chemie Philipps-Universität Marburg Hans-Meerwein-Straße 4 35032 Marburg Germany
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Errulat D, Harriman KLM, Gálico DA, Ovens JS, Mansikkamäki A, Murugesu M. Aufbau vs. non-Aufbau ground states in two-coordinate d7 single-molecule magnets. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00912e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Magnetic anisotropy is generated in two related d7 single-molecule magnets; (1) via 3d-4s orbital mixing in FeI; and (2) a non-Aufbau ground state in CoII, demonstrating that the electronic configurations are large retained independent of geometry.
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Affiliation(s)
- Dylan Errulat
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Katie L. M. Harriman
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Diogo A. Gálico
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Jeffrey S. Ovens
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Akseli Mansikkamäki
- A. Mansikkamäki, NMR Research Unit, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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