1
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Hejda M, Doležal L, Blahut J, Hupf E, Tydlitát J, Jambor R, Růžička A, Beckmann J, Dostál L. N-Coordinated tellurenium(II) and telluronium(IV) cations: synthesis, structure and hydrolysis. Dalton Trans 2023; 52:16235-16248. [PMID: 37853810 DOI: 10.1039/d3dt02404k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RNCH)C6H4, R = tBu or Dipp; Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RNCH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann-Beckett method using Et3PO as the probing agent. The Te-N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators.
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Affiliation(s)
- Martin Hejda
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic.
| | - Lukáš Doležal
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic.
| | - Jan Blahut
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Science, Flemingovo nám. 2, 16610, Prague, Czech Republic
| | - Emanuel Hupf
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany.
| | - Jiří Tydlitát
- Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic
| | - Roman Jambor
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic.
| | - Aleš Růžička
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic.
| | - Jens Beckmann
- Institut für Anorganische Chemie und Kristallographie, Universität Bremen, Leobener Straße 7, 28359 Bremen, Germany.
| | - Libor Dostál
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10 Pardubice, Czech Republic.
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2
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Zhou B, Gabbaï FP. Four-Electron Reduction of O 2 Using Distibines in the Presence of ortho-Quinones. J Am Chem Soc 2023; 145:13758-13767. [PMID: 37306561 PMCID: PMC10863049 DOI: 10.1021/jacs.3c02223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Indexed: 06/13/2023]
Abstract
This study, which aims to identify atypical platforms for the reduction of dioxygen, describes the reaction of O2 with two distibines, namely, 4,5-bis(diphenylstibino)-2,7-di-tert-butyl-9,9-dimethylxanthene and 4,5-bis(diphenylstibino)-2,7-di-tert-butyl-9,9-dimethyldihydroacridine, in the presence of an ortho-quinone such as phenanthraquinone. The reaction proceeds by oxidation of the two antimony atoms to the + V state in concert with reductive cleavage of the O2 molecule. As confirmed by 18O labeling experiments, the two resulting oxo units combine with the ortho-quinone to form an α,α,β,β-tetraolate ligand that bridges the two antimony(V) centers. This process, which has been studied both experimentally and computationally, involves the formation of asymmetric, mixed-valent derivatives featuring a stibine as well as a catecholatostiborane formed by oxidative addition of the quinone to only one of the antimony centers. Under aerobic conditions, the catecholatostiborane moiety reacts with O2 to form a semiquinone/peroxoantimony intermediate, as supported by NMR spectroscopy in the case of the dimethyldihydroacridine derivative. These intermediates swiftly evolve into the symmetrical bis(antimony(V)) α,α,β,β-tetraolate complexes via low barrier processes. Finally, the controlled protonolysis and reduction of the bis(antimony(V)) α,α,β,β-tetraolate complex based on the 9,9-dimethylxanthene platform have been investigated and shown to regenerate the starting distibine and the ortho-quinone. More importantly, these last reactions also produce two equivalents of water as the product of O2 reduction.
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Affiliation(s)
- Benyu Zhou
- Texas A&M University, Department of Chemistry, College
Station, Texas 77843, United States
| | - François P. Gabbaï
- Texas A&M University, Department of Chemistry, College
Station, Texas 77843, United States
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3
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Tanimura K, Gon M, Tanaka K. Effects of Hypervalent Bismuth on Electronic Properties of the Azobenzene Tridentate Ligand and Roles of Lewis Acidity in Controlling Optical Properties. Inorg Chem 2023; 62:4590-4597. [PMID: 36867889 DOI: 10.1021/acs.inorgchem.2c04478] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2023]
Abstract
Organobismuth compounds have been studied in various fields, including electronic states, pnictogen bonds, and catalysis. Among them, one of the unique electronic states of the element is the hypervalent state. So far, many issues regarding the electronic structures of bismuth in hypervalent states have been revealed; meanwhile, the influence of hypervalent bismuth on the electronic properties of π-conjugated scaffolds is still vailed. Here, we synthesized the hypervalent bismuth compound, BiAz, by introducing hypervalent bismuth into the azobenzene tridentate ligand as a π-conjugated scaffold. The influence of hypervalent bismuth on the electronic properties of the ligand was evaluated from optical measurements and quantum chemical calculations. The introduction of hypervalent bismuth revealed three significant electronic effects: first, hypervalent bismuth shows position-dependent electron-donating and electron-accepting effects. Second, BiAz can have a larger effective Lewis acidity than the hypervalent tin compound derivatives reported in our previous research. Finally, the coordination of dimethyl sulfoxide transformed the electronic properties of BiAz, similar to the hypervalent tin compounds. The data from quantum chemical calculations showed that the optical properties of the π-conjugated scaffold were able to be changed by introducing hypervalent bismuth. To the best of our knowledge, we first demonstrate that the introduction of hypervalent bismuth should be a new methodology for controlling the electronic properties of π-conjugated molecules and developing sensing materials.
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Affiliation(s)
- Kazuya Tanimura
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Masayuki Gon
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kazuo Tanaka
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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4
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Zapf L, Riethmann M, Föhrenbacher SA, Finze M, Radius U. An easy-to-perform evaluation of steric properties of Lewis acids. Chem Sci 2023; 14:2275-2288. [PMID: 36873848 PMCID: PMC9977453 DOI: 10.1039/d3sc00037k] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 02/04/2023] [Indexed: 02/08/2023] Open
Abstract
Steric and electronic effects play a very important role in chemistry, as these effects influence the shape and reactivity of molecules. Herein, an easy-to-perform approach to assess and quantify steric properties of Lewis acids with differently substituted Lewis acidic centers is reported. This model applies the concept of the percent buried volume (%V Bur) to fluoride adducts of Lewis acids, as many fluoride adducts are crystallographically characterized and are frequently calculated to judge fluoride ion affinities (FIAs). Thus, data such as cartesian coordinates are often easily available. A list of 240 Lewis acids together with topographic steric maps and cartesian coordinates of an oriented molecule suitable for the SambVca 2.1 web application is provided, together with different FIA values taken from the literature. Diagrams of %V Bur as a scale for steric demand vs. FIA as a scale for Lewis acidity provide valuable information about stereo-electronic properties of Lewis acids and an excellent evaluation of steric and electronic features of the Lewis acid under consideration. Furthermore, a novel LAB-Rep model (Lewis acid/base repulsion model) is introduced, which judges steric repulsion in Lewis acid/base pairs and helps to predict if an arbitrary pair of Lewis acid and Lewis base can form an adduct with respect to their steric properties. The reliability of this model was evaluated in four selected case studies, which demonstrate the versatility of this model. For this purpose, a user-friendly Excel spreadsheet was developed and is provided in the ESI, which works with listed buried volumes of Lewis acids %V Bur_LA and of Lewis bases %V Bur_LB, and no results from experimental crystal structures or quantum chemical calculations are necessary to evaluate steric repulsion in these Lewis acid/base pairs.
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Affiliation(s)
- Ludwig Zapf
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Melanie Riethmann
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Steffen A Föhrenbacher
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group
| | - Maik Finze
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group.,Institute for Sustainable Chemistry & Catalysis with Boron (ICB), Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany
| | - Udo Radius
- Institute of Inorganic Chemistry, Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Germany https://www.ak-radius.de https://go.uniwue.de/finze-group
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5
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Warring LS, Walley JE, Dickie DA, Tiznado W, Pan S, Gilliard RJ. Lewis Superacidic Heavy Pnictaalkene Cations: Comparative Assessment of Carbodicarbene-Stibenium and Carbodicarbene-Bismuthenium Ions. Inorg Chem 2022; 61:18640-18652. [DOI: 10.1021/acs.inorgchem.2c03135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Levi S. Warring
- Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
| | - Jacob E. Walley
- Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
| | - Diane A. Dickie
- Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
| | - William Tiznado
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 270, Santiago 8370146, Chile
| | - Sudip Pan
- Philipps-Universität Marburg Hans-Meerwein-Straße, Marburg 35032, Germany
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Robert J. Gilliard
- Department of Chemistry, University of Virginia, McCormick Road, P.O. Box 400319, Charlottesville, Virginia 22904, United States
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6
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Ramler J, Stoy A, Preitschopf T, Kettner J, Fischer I, Roling B, Fantuzzi F, Lichtenberg C. Dihalo bismuth cations: unusual coordination properties and inverse solvent effects in Lewis acidity. Chem Commun (Camb) 2022; 58:9826-9829. [PMID: 35975673 DOI: 10.1039/d2cc04017d] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of well-defined cationic hepta-coordinate bismuth halides [BiX2(py)5][B(3,5-(CF3)2-C6H3)4] (X = Cl, Br, I), stabilized only by substitutionally labile solvent molecules, were synthesized and fully characterized. Their apparent D5h symmetry with a lone pair at the central atom is unprecedented for main group compounds. The potential of BiX3 to show unexpectedly high Lewis acidities in moderately polar solvents is likely due to the formation of [BiX2(solv)5]+ and related ionic species.
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Affiliation(s)
- Jacqueline Ramler
- Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Andreas Stoy
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany.
| | - Tobias Preitschopf
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Janosch Kettner
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany.
| | - Ingo Fischer
- Institute of Physical and Theoretical Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Bernhard Roling
- Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany.
| | - Felipe Fantuzzi
- School of Physical Sciences, Ingram Building, University of Kent, Park Wood Rd, Canterbury, CT2 7NH, UK.
| | - Crispin Lichtenberg
- Institute of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany.,Department of Chemistry, Philipps-University Marburg, Hans-Meerwein-Str. 4, 35032, Marburg, Germany.
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7
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Hanft A, Rottschäfer D, Müller V, Weinberger P, Radacki K, Xie X, Lichtenberg C. Sulfinyl-aminotroponiminates: alkali- (Li, Na, K) and heavy-metal (Bi) complexes. Dalton Trans 2022; 51:10809-10817. [PMID: 35818977 DOI: 10.1039/d2dt01802k] [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
The installation of electron-withdrawing functional groups at the carbocyclic backbone of aminotroponiminate (ATI) ligands is a versatile method for influencing the electronic properties of the resulting ATI complexes. We report here Li, Na, and K salts of an ATI ligand with a phenylsulfinyl substituent in the backbone. It is demonstrated that the sulfinyl group actively contributes to the coordination chemistry of these complexes, effectively competing with neutral donor ligands such as thf or pyridine in the solid state (XRD), in solution (DOSY NMR spectroscopy), and in the gas phase (DFT). The impact of the phenylsulfinyl group on the redox properties of the complexes have been investigated and access to sodium sodiate species through ligand-induced disproportionation has been studied. Transfer of the ATI ligand to the heavy p-block element bismuth has been demonstrated. Analytical techniques applied in this work include multinuclear and DOSY NMR spectroscopy, cyclic voltammetry, DFT calculations, and single-crystal X-ray diffraction analysis.
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Affiliation(s)
- Anna Hanft
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Dennis Rottschäfer
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
| | - Victoria Müller
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Pascal Weinberger
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-98074 Würzburg, Germany
| | - Xiulan Xie
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
| | - Crispin Lichtenberg
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Str. 4, D-35032 Marburg, Germany.
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8
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Tidwell JR, Martin CD. Investigating the Reactions of BiCl 3, a Diiminopyridine Ligand, and Trimethylsilyl Trifluoromethanesulfonate. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- John R. Tidwell
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Caleb D. Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
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9
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Oberdorf K, Grenzer P, Wieprecht N, Ramler J, Hanft A, Rempel A, Stoy A, Radacki K, Lichtenberg C. CH Activation of Cationic Bismuth Amides: Heteroaromaticity, Derivatization, and Lewis Acidity. Inorg Chem 2021; 60:19086-19097. [PMID: 34818003 DOI: 10.1021/acs.inorgchem.1c02911] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cationization of Bi(NPh2)3 has recently been reported to allow access to single- and double-CH activation reactions, followed by selective transformation of Bi-C into C-X functional groups (X = electrophile). Here we show that this approach can successfully be transferred to a range of bismuth amides with two aryl groups at the nitrogen, Bi(NRaryl2)3. Exchange of one nitrogen-bound aryl group for an alkyl substituent gave the first example of a homoleptic bismuth amide with a mixed aryl/alkyl substitution pattern at the nitrogen, Bi(NPhiPr)3. This compound is susceptible to selective N-N radical coupling in its neutral form and also undergoes selective CH activation when transformed into a cationic species. The second CH activation is blocked due to the absence of a second aryl moiety at nitrogen. The Lewis acidity of neutral bismuth amides is compared with that of cationic species "[Bi(aryl)(amide)(L)n]+" and "[Bi(aryl)2(L)n]+" based on the (modified) Gutmann-Beckett method (L = tetrahydrofuran or pyridine). The heteroaromatic character of [Bi(C6H3R)2NH(triflate)] compounds, which are iso-valence-electronic with anthracene, is investigated by theoretical methods. Analytical methods used in this work include nuclear magnetic resonance spectroscopy, single-crystal X-ray diffraction, mass spectrometry, and density functional theory calculations.
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Affiliation(s)
- Kai Oberdorf
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.,Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Patrick Grenzer
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Nele Wieprecht
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Jacqueline Ramler
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Anna Hanft
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Anna Rempel
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Andreas Stoy
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.,Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Krzysztof Radacki
- Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
| | - Crispin Lichtenberg
- Department of Chemistry, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany.,Department of Inorganic Chemistry, Julius-Maximilians-Universität, Würzburg Am Hubland, 97074 Würzburg, Germany
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10
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Hanft A, Rottschäfer D, Wieprecht N, Geist F, Radacki K, Lichtenberg C. Aminotroponiminates: Impact of the NO 2 Functional Group on Coordination, Isomerisation, and Backbone Substitution. Chemistry 2021; 27:14250-14262. [PMID: 34314083 PMCID: PMC8597084 DOI: 10.1002/chem.202102324] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Indexed: 01/17/2023]
Abstract
Aminotroponiminate (ATI) ligands are a versatile class of redox-active and potentially cooperative ligands with a rich coordination chemistry that have consequently found a wide range of applications in synthesis and catalysis. While backbone substitution of these ligands has been investigated in some detail, the impact of electron-withdrawing groups on the coordination chemistry and reactivity of ATIs has been little investigated. We report here Li, Na, and K salts of an ATI ligand with a nitro-substituent in the backbone. It is demonstrated that the NO2 group actively contributes to the coordination chemistry of these complexes, effectively competing with the N,N-binding pocket as a coordination site. This results in an unprecedented E/Z isomerisation of an ATI imino group and culminates in the isolation of the first "naked" (i. e., without directional bonding to a metal atom) ATI anion. Reactions of sodium ATIs with silver(I) and tritylium salts gave the first N,N-coordinated silver ATI complexes and unprecedented backbone substitution reactions. Analytical techniques applied in this work include multinuclear (VT-)NMR spectroscopy, single-crystal X-ray diffraction analysis, and DFT calculations.
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Affiliation(s)
- Anna Hanft
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Dennis Rottschäfer
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Nele Wieprecht
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Felix Geist
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Crispin Lichtenberg
- Institut für Anorganische Chemie, Fakultät für Chemie und Pharmazie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
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11
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Hanft A, Radacki K, Lichtenberg C. Cationic Bismuth Aminotroponiminates: Charge Controls Redox Properties. Chemistry 2021; 27:6230-6239. [PMID: 33326650 PMCID: PMC8048980 DOI: 10.1002/chem.202005186] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Indexed: 01/03/2023]
Abstract
The behavior of the redox‐active aminotroponiminate (ATI) ligand in the coordination sphere of bismuth has been investigated in neutral and cationic compounds, [Bi(ATI)3] and [Bi(ATI)2Ln][A] (L=neutral ligand; n=0, 1; A=counteranion). Their coordination chemistry in solution and in the solid state has been analyzed through (variable‐temperature) NMR spectroscopy, line‐shape analysis, and single‐crystal X‐ray diffraction analyses, and their Lewis acidity has been evaluated by using the Gutmann–Beckett method (and modifications thereof). Cyclic voltammetry, in combination with DFT calculations, indicates that switching between ligand‐ and metal‐centered redox events is possible by altering the charge of the compounds from 0 in neutral species to +1 in cationic compounds. This adds important facets to the rich redox chemistry of ATIs and to the redox chemistry of bismuth compounds, which is, so far, largely unexplored.
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Affiliation(s)
- Anna Hanft
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Krzysztof Radacki
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Crispin Lichtenberg
- Department of Inorganic Chemistry, Julius-Maximilians-University Würzburg, Am Hubland, 97074, Würzburg, Germany
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12
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Lichtenberg C. Molecular bismuth(iii) monocations: structure, bonding, reactivity, and catalysis. Chem Commun (Camb) 2021; 57:4483-4495. [DOI: 10.1039/d1cc01284c] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Structurally defined, molecular bismuth(iii) cations show remarkable properties in coordination chemistry, Lewis acidity, and redox chemistry, allowing for unique applications in synthetic chemistry.
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Affiliation(s)
- Crispin Lichtenberg
- Julius-Maximilians-University Würzburg
- Institute of Inorganic Chemistry Am Hubland
- 97074 Würzburg
- Germany
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