1
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Uhlmann C, Münzfeld L, Hauser A, Ruan TT, Kumar Kuppusamy S, Jin C, Ruben M, Fink K, Moreno-Pineda E, Roesky PW. Unique Double and Triple Decker Arrangements of Rare-Earth 9,10-Diborataanthracene Complexes Featuring Single-Molecule Magnet Characteristics. Angew Chem Int Ed Engl 2024; 63:e202401372. [PMID: 38390783 DOI: 10.1002/anie.202401372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/07/2024] [Accepted: 02/09/2024] [Indexed: 02/24/2024]
Abstract
Herein, we present the first report on the synthesis of rare-earth complexes featuring a 9,10-diborataanthracene ligand. This 14-π-electron ligand is highly reductive and was previously used in small-molecule activation. Salt elimination reactions between dipotassium 9,10-diethyl-9,10-diborataanthracene [K2(DEDBA)] and [LnIII(η8-CotTIPS)(BH4)(thf)x] (CotTIPS=1,4-(iPr3Si)2C8H6) in a 1 : 1 ratio yielded heteroleptic sandwich complexes [K(η8-CotTIPS)LnIII(η6-DEDBA)] (Ln=Y, Dy, Er). These compounds form Lewis-base-free one-dimensional coordination polymers when crystallised from toluene. In contrast, reaction of [K2(DEDBA)] and [LnIII(η8-CotTIPS)(BH4)(thf)x] in a 1 : 2 ratio led to the formation of heteroleptic triple-decker complexes [(η8-CotTIPS)LnIII(μ-η6:η6-DEDBA)LnIII(η8-CotTIPS)] (Ln=Y, Dy, Er). Notably, these are not only the first lanthanide triple-decker compounds featuring a six-membered ring as a deck but also the first trivalent lanthanide triple-decker featuring a heterocycle in the coordination sphere. Magnetic investigations reveal that [K(η8-CotTIPS)LnIII(η6-DEDBA)] (Ln=Dy, Er) and [(η8-CotTIPS)ErIII(μ-η6:η6-DEDBA)ErIII(η8-CotTIPS)] exhibit Single-Molecule Magnet (SMM) behaviour. In the case of [(η8-CotTIPS)LnIII(μ-η6:η6-DEDBA)LnIII(η8-CotTIPS)] (Ln=Dy, Er), the introduction of a second near lanthanide ion results in strong antiferromagnetic interactions, allowing the enhancement of the magnetic characteristic of the system, compared to the quasi isolated counterpart. This research renews the overlooked coordination chemistry of the DBA ligand and expands it to encompass rare-earth elements.
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Affiliation(s)
- Cedric Uhlmann
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Luca Münzfeld
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Adrian Hauser
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
| | - Ting-Ting Ruan
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Senthil Kumar Kuppusamy
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Chengyu Jin
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Mario Ruben
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
- Institute of Quantum Materials and Technologies (IQMT), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
- Centre Européen de Science Quantique (CESQ), Institut de Science et d'Ingénierie Supramoléculaires (ISIS, UMR 7006), CNRS-Université de Strasbourg, 8 allée Gaspard Monge BP, 70028 67083, Strasbourg Cedex, France
| | - Karin Fink
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131, Karlsruhe, Germany
| | - Eufemio Moreno-Pineda
- Universidad de Panamá, Facultad de Ciencias Naturales, Exactas y Tecnología, Depto. de Química-Física, Panamá, 0824, Panamá
- Universidad de Panamá, Facultad de Ciencias Naturales, Exactas y Tecnología, Grupo de Investigación de Materiales, Panamá, 0824, Panamá
| | - Peter W Roesky
- Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstraße 15, 76131, Karlsruhe
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2
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Grewelinger P, Wiesmeier T, Präsang C, Morgenstern B, Scheschkewitz D. Diboriranide σ-Complexes of d- and p-Block Metals. Angew Chem Int Ed Engl 2023; 62:e202308678. [PMID: 37522813 DOI: 10.1002/anie.202308678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Diboriranides are the smallest conceivable monoanionic aromatic cycles, yet only limited examples have been reported and their reactivity and complexation behavior remain completely unexplored. We report a straightforward synthesis of the first peraryl diboriranide c-(DurB)2 CPh- as its lithium salt in three steps via the corresponding non-classical diborirane from a readily available 1,2-dichlorodiborane(4) (Dur=2,3,5,6-tetramethylphenyl). With the preparation and complete characterization of representative complexes with tin, copper, gold and zinc, we demonstrate the strong preference of the diboriranide for σ-type coordination modes towards main group and transition metal centers under unperturbed retention of the three-membered B2 C-ring's 2e- π-system.
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Affiliation(s)
- Philipp Grewelinger
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Tim Wiesmeier
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Carsten Präsang
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Bernd Morgenstern
- Service Center X-ray diffraction, Saarland University, 66123, Saarbrücken, Germany
| | - David Scheschkewitz
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
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3
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Liu X, Heinz M, Wang J, Tan L, Holthausen MC, Ye Q. A Journey from Benzoborirene to Benzoborole-Supported 1,2-Diimine and Antiaromatic Borolediide. Angew Chem Int Ed Engl 2023:e202312608. [PMID: 37758684 DOI: 10.1002/anie.202312608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 09/27/2023] [Accepted: 09/27/2023] [Indexed: 09/29/2023]
Abstract
The reaction of benzoborirene with one equivalent of isocyanides leads to benzene-fused boretes bearing one imine function, while the reaction with two equivalents of isocyanide affords 2,3-dihydro-2,3-diiminoboroles with perfect regioselectivity. The isocyanide double insertion products represent a novel type of 1,2-diimine with a benzoborole backbone. The reduction chemistry of the benzoborole-supported 1,2-diimine was investigated. Single- and two-electron reduction allow for the isolation and full characterization of a radical anion and a dianion, respectively. In stark contrast to the ordinary boroles, which should turn aromatic by accepting two electrons, the antiaromatic character of the benzoborole backbone is highlighted upon reduction, thus presenting a rare example of antiaromatic borole dianion. Detailed quantum chemical calculations provide a rationale for the observed regioselectivity and the electronic structure of the reduced borole diimine species.
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Affiliation(s)
- Xiaocui Liu
- State Key Laboratory of Traditional Chinese Medicine Syndromes, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, 510000, Guangzhou, P. R. China
- Department of Chemistry, Southern University of Science and Technology, 518055, Shenzhen, P. R. China
| | - Myron Heinz
- Institute of Inorganic and Analytical Chemistry, Goethe-Universität, 60438, Frankfurt am Main, Germany
| | - Junyi Wang
- Department of Chemistry, Southern University of Science and Technology, 518055, Shenzhen, P. R. China
| | - Leibo Tan
- Institute für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, 97074, Würzburg, Germany
| | - Max C Holthausen
- Institute of Inorganic and Analytical Chemistry, Goethe-Universität, 60438, Frankfurt am Main, Germany
| | - Qing Ye
- Institute für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, 97074, Würzburg, Germany
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4
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Vincent A, Whyatt YL, Chilton NF, Long JR. Strong Axiality in a Dysprosium(III) Bis(borolide) Complex Leads to Magnetic Blocking at 65 K. J Am Chem Soc 2023; 145:1572-1579. [PMID: 36629382 PMCID: PMC9923674 DOI: 10.1021/jacs.2c08568] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Substituted dysprosocenium complexes of the type [Dy(CpR)2]+ exhibit slow magnetic relaxation at cryogenic temperatures and have emerged as top-performing single-molecule magnets. The remarkable properties of these compounds derive in part from the strong axial ligand field afforded by the cyclopentadiene anions, and the design of analogous compounds with even stronger ligand fields is one promising route toward identifying new single-molecule magnets that retain a magnetic memory at even higher temperatures. Here, we report the synthesis and characterization of a dysprosium bis(borolide) compound, [K(18-crown-6)][Dy(BC4Ph5)2] (1), featuring the dysprosocenate anion [Dy(BC4Ph5)2]- with a pseudoaxial coordination environment afforded by two dianionic pentaphenyl borolide ligands. Variable-field magnetization data reveal open magnetic hysteresis up to 66 K, establishing 1 as a top-performing single-molecule magnet among its dysprosocenium analogues. Ac magnetic susceptibility data indicate that 1 relaxes via an Orbach mechanism above ∼80 K with Ueff = 1500(100) cm-1 and τ0 = 10-12.0(9) s, whereas Raman relaxation and quantum tunneling of the magnetization dominate at lower temperatures. Compound 1 exhibits a 100 s blocking temperature of 65 K, among the highest reported for dysprosium-based single-molecule magnets. Ab initio spin dynamics calculations support the experimental Ueff and τ0 values and enable a quantitative comparison of the relaxation dynamics of 1 and two representative dysprosocenium cations, yielding additional insights into the impact of the crystal field splitting and vibronic coupling on the observed relaxation behavior. Importantly, compound 1 represents a step toward the development of alternatives to substituted dysprosocenium single-molecule magnets with increased axiality.
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Affiliation(s)
- Alexandre
H. Vincent
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California94720, United States
| | - Yasmin L. Whyatt
- Department
of Chemistry, The University of Manchester, Oxford Road, ManchesterM13 9PL, U.K.
| | - Nicholas F. Chilton
- Department
of Chemistry, The University of Manchester, Oxford Road, ManchesterM13 9PL, U.K.,
| | - Jeffrey R. Long
- Department
of Chemistry, University of California,
Berkeley, Berkeley, California94720, United States,Department
of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley, California94720, United States,Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California94720, United States,
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5
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Vanjak JC, Wilkins BO, Vieru V, Bhuvanesh NS, Reibenspies JH, Martin CD, Chibotaru LF, Nippe M. A High-Performance Single-Molecule Magnet Utilizing Dianionic Aminoborolide Ligands. J Am Chem Soc 2022; 144:17743-17747. [PMID: 36162057 DOI: 10.1021/jacs.2c06698] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first example of a homoleptic f-block borolide sandwich complex is presented and shown to be a high-performance single-molecule magnet (SMM). The bis(borolide) complex [K(2.2.2)][[1-(piperidino)-2,3,4,5-tetraphenylborolyl]2Dy] (1) features an unusual example of an anionic Ln3+ metallocene that supports short metal-ligand bonds and a high degree of linearity around the central Dy3+ ion, resulting in comparatively large barriers to magnetization reversal (Ueff = 1600 cm-1 for the most linear orientation) and, importantly, a high blocking temperature (TB, defined as T(τ100s)) of 66 K. These metrics put complex 1 among the very best performing SMMs reported to date and highlight the potential of dianionic borolide ligands to increase ligand field axiality, compared to monoanionic cyclic ligands, to ultimately maximize magnetic anisotropy in f-block-based SMMs.
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Affiliation(s)
- James C Vanjak
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Branford O Wilkins
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Veacheslav Vieru
- Maastricht Science Programme, Faculty of Science and Engineering, Maastricht University, Paul-Henri Spaaklaan 1, 6229 EN Maastricht, The Netherlands
| | - Nattamai S Bhuvanesh
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Joseph H Reibenspies
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Caleb D Martin
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Liviu F Chibotaru
- Theory of Nanomaterials Group, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Leuven, Belgium
| | - Michael Nippe
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
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6
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Golfmann M, Sindlinger CP. Assessing an Elusive 3,4‐Dimethyl‐Chloroborole. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Maxim Golfmann
- Institut für Anorganische Chemie Georg-August Universität Göttingen Tammannstr. 4 37077 Göttingen Germany
- Present address: Institut für Organische und Biomolekulare Chemie Georg-August Universität Göttingen Tammannstr. 2 37077 Göttingen Germany
| | - Christian P. Sindlinger
- Institut für Anorganische Chemie RWTH Aachen University Landoltweg 1a D-52074 Aachen Germany
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7
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Lindl FD, Fantuzzi F, Mailänder L, Hörl C, Bélanger-Chabot G, Braunschweig H. Azidoborolate anions and azidoborole adducts: isolable forms of an unstable borole azide. Chem Commun (Camb) 2022; 58:4735-4738. [DOI: 10.1039/d2cc00543c] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Boroles are well known to undergo ring expansion reactions with organic azides to yield 1,2-azaborinines. A synthon featuring both azide and borole moieties within the same molecule, 1-azido-2,3,4,5-tetraphenylborole, was found...
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8
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Pearce KG, Canham EPF, Nixon JF, Crossley IR. A Benzodiphosphaborolediide. Chemistry 2021; 27:16342-16346. [PMID: 34586681 DOI: 10.1002/chem.202103427] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Indexed: 01/06/2023]
Abstract
The first example of a diphosphaborolediide, the benzo-fused [C6 H4 P2 BPh]2- (12- ), is prepared from ortho-bis(phosphino)benzene (C6 H4 {PH2 }) and dichlorophenylborane, via a sequential lithiation approach. The dilithio-salt can be obtained as an oligomeric THF solvate or discrete TMEDA adduct, both of which are fully characterized, including by X-ray diffraction. Alongside NICS calculations, data strongly suggest some aromaticity within 12- , which is further supported by preliminary coordination studies that demonstrate η5 -coordination to a zerovalent molybdenum center, as observed crystallographically for the oligomeric [{Mo(CO)3 (η5 -1)}{μ-η1 -Mo(CO)3 (TMEDA)}2 ] ⋅ [μ-Li(THF)][μ-Li(TMEDA)].
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Affiliation(s)
- Kyle G Pearce
- Department of Chemistry, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
| | - Elinor P F Canham
- Department of Chemistry, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
| | - John F Nixon
- Department of Chemistry, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
| | - Ian R Crossley
- Department of Chemistry, University of Sussex, Falmer, Brighton, BN1 9QJ, UK
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9
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Yruegas S, Tang H, Bornovski GZ, Su X, Sung S, Hall MB, Nippe M, Martin CD. Nickel-Borolide Complexes and Their Complex Electronic Structure. Inorg Chem 2021; 60:16160-16167. [PMID: 34637613 DOI: 10.1021/acs.inorgchem.1c01845] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Borolides (BC42-) can be considered as dianionic heterocyclic analogues of monoanionic cyclopentadienides. Although both are formally six-π-electron donors, we herein demonstrate that the electronic structure of their corresponding transition metal complexes differs significantly, leading to altered properties. Specifically, the 18-electron sandwich complex Ni(iPr2NBC4Ph2)2 (1) features an ∼90° angle between the Ni-B-N planes and is best described as a combination of three limiting resonance structures with the major contribution stemming from a formally Ni2+ species bound to two monoanionic radical (BC4•-) ligands. Compound 1 displays two sequential one-electron oxidation events over a small potential range of <0.2 V, which strikingly contrasts the large potential separations between redox partners in the family of metallocenes, and the potential reasons for this unusual observation are discussed.
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Affiliation(s)
- Sam Yruegas
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Hao Tang
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Gayle Z Bornovski
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Xiaojun Su
- Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Siyoung Sung
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Michael B Hall
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, United States
| | - Michael Nippe
- Department of Chemistry, Texas A&M University, 3255 TAMU, College Station, Texas 77843, 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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10
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Zhu D, Wang M, Guo L, Shi W, Li J, Cui C. Synthesis, Structure, and Magnetic Properties of Rare-Earth Benzoborole Complexes. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Dezhao Zhu
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
| | - Mengmeng Wang
- Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
| | - Lulu Guo
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
| | - Wei Shi
- Key Laboratory of Advanced Energy Materials Chemistry (MOE), College of Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
| | - Jianfeng Li
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
| | - Chunming Cui
- State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071, People’s Republic of China
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11
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Zhu D, Guo L, Li J, Cui C. From BN-Naphthalenes to Benzoborole Dianions. Chemistry 2021; 27:9514-9518. [PMID: 33909296 DOI: 10.1002/chem.202101178] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Indexed: 01/02/2023]
Abstract
The synthesis of benzoborole dianions by alkali metal reduction of BN-naphthalene derivatives via a ring-contraction strategy has been developed. Reduction of 1-alkynyl 2,1-benzazaborine 1 a in Et2 O led to the elimination of alkynyllithium with the formation of 1-amino-1-benzoborole trilithium salt 2 a, whereas reduction of 1-phenyl 2,1-benzazaborine 1 c in THF yielded 1-phenyl-1-benzoborole dilithium salt 2 c with the elimination of ArNHLi. The trilithium and dilithium salts 2 a and 2 c have been fully characterized. Treatment of trilithium salt 2 a with Et3 NHCl led to the selective protonation of the amino lithium to afford the dilithium salt 2 aH, which could be cleanly oxidized to 1-amino-1-benzoborole 3 in an excellent yield. Reaction of 1-phenyl-1-benzoborole dilithium salt 2 c with MeI yielded the lithium borate 4 c, which is luminescent both in solution and in the solid state.
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Affiliation(s)
- Dezhao Zhu
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Lulu Guo
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Jianfeng Li
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin, 300071, China
| | - Chunming Cui
- State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin, 300071, China
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12
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Heitkemper T, Sarcevic J, Sindlinger CP. A Neutral Silicon(II) Half-Sandwich Compound. J Am Chem Soc 2020; 142:21304-21309. [PMID: 33315393 DOI: 10.1021/jacs.0c11904] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metathesis reaction of a dilithio borole dianion, a cyclic π-ligand isoelectronic to ubiquitous cyclopentadienyls, with two equivalents of "silicocenium" cation [Cp*Si]+ as a source of low-valent Si(II), cleanly gives a borole half-sandwich π-complex of Si(II) and silicocene. The resulting half-sandwich complex is a neutral isoelectronic analogue to the iconic silicocenium cation and features the rare structural motif of an apical silicon(II) atom with an energetically high lying lone pair of electrons that is shown to be accessible for coordination chemistry toward tungsten carbonyl. Protonation at the Si(II) atom with [H(OEt2)2][Al{OC(CF3)3}4] induces formal oxidation, and the compound rearranges to incorporate the Si atom into the carbocyclic base to give an unprecedented cationic 5-sila-6-borabicyclo[2.1.1]hex-2-ene. This rearrangement is accompanied by drastic changes in the 11B and 29Si NMR chemical shifts.
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Affiliation(s)
- Tobias Heitkemper
- Institut für Anorganische Chemie, Georg-August Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Julijan Sarcevic
- Institut für Anorganische Chemie, Georg-August Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Christian P Sindlinger
- Institut für Anorganische Chemie, Georg-August Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
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13
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Budy H, Gilmer J, Trageser T, Wagner M. Anionic Organoboranes: Delicate Flowers Worth Caring for. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000786] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Hendrik Budy
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Jannik Gilmer
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Timo Trageser
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
| | - Matthias Wagner
- Institut für Anorganische Chemie Goethe‐Universität Frankfurt Max‐von‐Laue‐Str. 7 60438 Frankfurt (Main) Germany
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14
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Abstract
This work describes the synthesis and characterization of a highly reactive cationic borole. Halide abstraction with Li{Al[OC(CF3 )3 ]4 } from the NHC-chloroborole adduct yields the first stable NHC-supported 1-(Me NHC)-2,5-(SiMe3 )2 -3,4-(Ph*)2 -borole cation. Electronically, it features both a five-membered cyclic conjugated 4 π-electron system and a cationic charge and thus resembles the yet elusive cyclopentadienyl cation. The borole cation was characterized crystallographically, spectroscopically (NMR, UV/Vis), by cyclovoltammetry, microanalysis and mass-spectrometry and its electronic structure was probed computationally. The cation reacts with tolane and reversibly binds carbon monoxide. Direct comparison with the structurally related, yet neutral, 1-mesityl borole reveals strong Lewis acidity, reduced HOMO-LUMO gaps, and increased anti-aromatic character.
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Affiliation(s)
- Tobias Heitkemper
- Institut für Anorganische ChemieGeorg-August-Universität GöttingenTammannstr. 437077GöttingenGermany
| | - Christian P. Sindlinger
- Institut für Anorganische ChemieGeorg-August-Universität GöttingenTammannstr. 437077GöttingenGermany
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15
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Paprocki V, Hrobárik P, Harriman KLM, Luff MS, Kupfer T, Kaupp M, Murugesu M, Braunschweig H. Ein neutrales 1,4‐Diborabenzol als π‐Ligand in Actinoidkomplexen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202004501] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Valerie Paprocki
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Peter Hrobárik
- Institut für Chemie Theoretische Chemie/Quantenchemie, Sekr. C7 Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Deutschland
- Department of Inorganic Chemistry Faculty of Natural Sciences Comenius University 84215 Bratislava Slowakei
| | - Katie L. M. Harriman
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Kanada
| | - Martin S. Luff
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Thomas Kupfer
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
| | - Martin Kaupp
- Institut für Chemie Theoretische Chemie/Quantenchemie, Sekr. C7 Technische Universität Berlin Straße des 17. Juni 135 10623 Berlin Deutschland
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular Sciences University of Ottawa 10 Marie Curie Ottawa Ontario K1N 6N5 Kanada
| | - Holger Braunschweig
- Institut für Anorganische Chemie Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
- Institute for Sustainable Chemistry & Catalysis with Boron Julius-Maximilians-Universität Würzburg Am Hubland 97074 Würzburg Deutschland
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16
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Paprocki V, Hrobárik P, Harriman KLM, Luff MS, Kupfer T, Kaupp M, Murugesu M, Braunschweig H. Stable Actinide π Complexes of a Neutral 1,4-Diborabenzene. Angew Chem Int Ed Engl 2020; 59:13109-13115. [PMID: 32329111 PMCID: PMC7496575 DOI: 10.1002/anie.202004501] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Indexed: 11/25/2022]
Abstract
The π coordination of arene and anionic heteroarene ligands is a ubiquitous bonding motif in the organometallic chemistry of d-block and f-block elements. By contrast, related π interactions of neutral heteroarenes including neutral bora-π-aromatics are less prevalent particularly for the f-block, due to less effective metal-to-ligand backbonding. In fact, π complexes with neutral heteroarene ligands are essentially unknown for the actinides. We have now overcome these limitations by exploiting the exceptionally strong π donor capabilities of a neutral 1,4-diborabenzene. A series of remarkably robust, π-coordinated thorium(IV) and uranium(IV) half-sandwich complexes were synthesized by simply combining the bora-π-aromatic with ThCl4 (dme)2 or UCl4 , representing the first examples of actinide complexes with a neutral boracycle as sandwich-type ligand. Experimental and computational studies showed that the strong actinide-heteroarene interactions are predominately electrostatic in nature with distinct ligand-to-metal π donation and without significant π/δ backbonding contributions.
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Affiliation(s)
- Valerie Paprocki
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Peter Hrobárik
- Institut für ChemieTheoretische Chemie/Quantenchemie, Sekr. C7Technische Universität BerlinStraße des 17. Juni 13510623BerlinGermany
- Department of Inorganic ChemistryFaculty of Natural SciencesComenius University84215BratislavaSlovakia
| | - Katie L. M. Harriman
- Department of Chemistry and Biomolecular SciencesUniversity of Ottawa10 Marie CurieOttawaOntarioK1N 6N5Canada
| | - Martin S. Luff
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Thomas Kupfer
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
| | - Martin Kaupp
- Institut für ChemieTheoretische Chemie/Quantenchemie, Sekr. C7Technische Universität BerlinStraße des 17. Juni 13510623BerlinGermany
| | - Muralee Murugesu
- Department of Chemistry and Biomolecular SciencesUniversity of Ottawa10 Marie CurieOttawaOntarioK1N 6N5Canada
| | - Holger Braunschweig
- Institut für Anorganische ChemieJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
- Institute for Sustainable Chemistry & Catalysis with BoronJulius-Maximilians-Universität WürzburgAm Hubland97074WürzburgGermany
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17
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Heitkemper T, Naß L, Sindlinger CP. 2,5-Bis-trimethylsilyl substituted boroles. Dalton Trans 2020; 49:2706-2714. [PMID: 32049092 DOI: 10.1039/d0dt00393j] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This manuscript includes a comprehensive study of the synthesis and spectroscopic features of 2,5-disilyl boroles.
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Affiliation(s)
| | - Leonard Naß
- Institut für Anorganische Chemie
- 37077 Göttingen
- Germany
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18
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Su X, Baker JJ, Martin CD. Dimeric boroles: effective sources of monomeric boroles for heterocycle synthesis. Chem Sci 2019; 11:126-131. [PMID: 32110363 PMCID: PMC7012074 DOI: 10.1039/c9sc04053f] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Accepted: 10/27/2019] [Indexed: 11/23/2022] Open
Abstract
Dimeric boroles as thermal sources of monomers.
Monomeric boroles have been gaining attention as reagents for the synthesis of heterocycles due to their ability to insert atoms into the BC4 ring in a single step. Although unique boron frameworks can be accessed via this methodology, the products feature aryl substitution on the carbon centers as steric bulk is required to preclude borole dimerization. This work demonstrates that insertion chemistry is possible with Diels–Alder dimeric boroles and that such reactivity is not exclusive to monomeric boroles with bulky groups. With 1-phenyl-2,3,4,5-tetramethylborole dimer, the formal 1,1-insertion of a nitrene and sulfur generate the six-membered aromatic 1,2-azaborine and 1,2-thiaborine, respectively. The isolation of the 1,2-thiaborine enabled the synthesis of an η6-chromium complex. Benzophenone and diphenylketene readily insert a CO unit to generate BOC5 seven-membered rings confirming dimeric boroles can serve as monomeric synthons in 1,2-insertion reactions. An epoxide did not furnish the anticipated eight-membered BOC6 ring, instead provided a bicyclic system with a BOC3 ring. The insertion chemistry was demonstrated with two other borole dimers featuring different substitution with diphenylketene as a substrate. This work elevates borole insertion chemistry to a new level to access products that do not require bulky substitution.
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Affiliation(s)
- Xiaojun Su
- Department of Chemistry and Biochemistry , Baylor University , One Bear Place #97348 , Waco , TX 76798 , USA .
| | - J J Baker
- Department of Chemistry and Biochemistry , Baylor University , One Bear Place #97348 , Waco , TX 76798 , USA .
| | - Caleb D Martin
- Department of Chemistry and Biochemistry , Baylor University , One Bear Place #97348 , Waco , TX 76798 , USA .
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19
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Sindlinger CP, Ruth PN. A Neutral "Aluminocene" Sandwich Complex: η 1 - versus η 5 -Coordination Modes of a Pentaarylborole with ECp* (E=Al, Ga; Cp*=C 5 Me 5 ). Angew Chem Int Ed Engl 2019; 58:15051-15056. [PMID: 31390132 PMCID: PMC6856865 DOI: 10.1002/anie.201907749] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Indexed: 11/07/2022]
Abstract
The pentaaryl borole (Ph*C)4 BXylF [Ph*=3,5-tBu2 (C6 H3 ); XylF =3,5-(CF3 )2 (C6 H3 )] reacts with low-valent Group 13 precursors AlCp* and GaCp* by two divergent routes. In the case of [AlCp*]4 , the borole reacts as an oxidising agent and accepts two electrons. Structural, spectroscopic, and computational analysis of the resulting unprecedented neutral η5 -Cp*,η5 -[(Ph*C)4 BXylF ] complex of AlIII revealed a strong, ionic bonding interaction. The formation of the heteroleptic borole-cyclopentadienyl "aluminocene" leads to significant changes in the 13 C NMR chemical shifts within the borole unit. In the case of the less-reductive GaCp*, borole (Ph*C)4 BXylF reacts as a Lewis acid to form a dynamic adduct with a dative 2-center-2-electron Ga-B bond. The Lewis adduct was also studied structurally, spectroscopically, and computationally.
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Affiliation(s)
- Christian P Sindlinger
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Paul Niklas Ruth
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
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20
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Sindlinger CP, Ruth PN. Ein neutraler “Aluminocen”‐Sandwich‐Komplex: η
1
‐ vs. η
5
‐Koordination eines Pentaarylborols mit ECp* (E=Al, Ga; Cp*=C
5
Me
5
). Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Christian P. Sindlinger
- Institut für Anorganische Chemie Georg-August-Universität Göttingen Tammannstr. 4 37077 Göttingen Deutschland
| | - Paul Niklas Ruth
- Institut für Anorganische Chemie Georg-August-Universität Göttingen Tammannstr. 4 37077 Göttingen Deutschland
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21
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Taylor JW, McSkimming A, Essex LA, Harman WH. CO 2 reduction with protons and electrons at a boron-based reaction center. Chem Sci 2019; 10:9084-9090. [PMID: 31827750 PMCID: PMC6889837 DOI: 10.1039/c9sc02792k] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 07/30/2019] [Indexed: 11/21/2022] Open
Abstract
Borohydrides are widely used reducing agents in chemical synthesis and have emerging energy applications as hydrogen storage materials and reagents for the reduction of CO2. Unfortunately, the high energy cost associated with the multistep preparation of borohydrides starting from alkali metals precludes large scale implementation of these latter uses. One potential solution to this issue is the direct synthesis of borohydrides from the protonation of reduced boron compounds. We herein report reactions of the redox series [Au(B2P2)] n (n = +1, 0, -1) (B2P2, 9,10-bis(2-(diisopropylphosphino)phenyl)-9,10-dihydroboranthrene) and their conversion into corresponding mono- and diborohydride complexes. Crucially, the monoborohydride can be accessed via protonation of [Au(B2P2)]-, a masked borane dianion equivalent accessible at relatively mild potentials (-2.05 V vs. Fc/Fc+). This species reduces CO2 to produce the corresponding formate complex. Cleavage of the formate complex can be achieved by reduction (ca. -1.7 V vs. Fc/Fc+) or by the addition of electrophiles including H+. Additionally, direct reaction of [Au(B2P2)]- with CO2 results in reductive disproportion to release CO and generate a carbonate complex. Together, these reactions constitute a synthetic cycle for CO2 reduction at a boron-based reaction center that proceeds through a B-H unit generated via protonation of a reduced borane with weak organic acids.
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Affiliation(s)
- Jordan W Taylor
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - Alex McSkimming
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - Laura A Essex
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
| | - W Hill Harman
- Department of Chemistry , University of California , Riverside , California 92521 , USA .
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22
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Heitkemper T, Sindlinger CP. Electronic Push-Pull Modulation by Peripheral Substituents in Pentaaryl Boroles. Chemistry 2019; 25:6628-6637. [PMID: 30861220 DOI: 10.1002/chem.201900826] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 03/07/2019] [Indexed: 11/06/2022]
Abstract
Establishing access to a bulky tetraaryl dilithiobutadiene (Ph*C)4 Li2 (Ph*=3,5-tBu2 (C6 H3 )) allowed for the synthesis of five-membered heterocycles with incorporated main-group elements. Along with an amino borole, a set of substituted pentaaryl boroles (Ph*C)4 BAr has been synthesized. The examination of their absorption spectra and computational studies by means of DFT granted insight into the influence of peripheral substituents on the electronic features of the parent pentaphenyl borole (PhC)4 BPh. Introduction of the more electron-rich Ph* residue at the carbon atoms increases the HOMO energy, redshifting the visible π/π*-absorption bands compared with the parent pentaphenyl borole. The influence on the frontier orbitals of three different boron-bound aryls with electronically modulating substituents in the remote 3,5-positions Ar=3,5-R2 -C6 H3 (R=Me, H, CF3 ) was studied. The substituents were found to increase (+I effect, Me) or decrease (-I effect, CF3 ) the LUMO energy, thus directly affecting the visible absorption spectra. This represents the first study on HOMO-LUMO-gap adjustments by a combined push-pull approach of a substituted pentaphenylborole.
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Affiliation(s)
- Tobias Heitkemper
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
| | - Christian P Sindlinger
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, 37077, Göttingen, Germany
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23
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Tholen P, Dong Z, Schmidtmann M, Albers L, Müller T. A Neutral η 5 -Aminoborole Complex of Germanium(II). Angew Chem Int Ed Engl 2018; 57:13319-13324. [PMID: 30070743 DOI: 10.1002/anie.201808271] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 08/01/2018] [Indexed: 11/09/2022]
Abstract
The synthesis of two η5 -aminoborole complexes of germanium(II) from the reaction of a germole dianion with aminoboron dichlorides is reported. This reaction constitutes a remarkable example of a germole-to-borole transformation. The two aminoborole complexes of germanium(II) were fully characterized by multinuclear NMR spectroscopy, IR spectroscopy, HRMS, and, in one case, by X-ray crystallography. The results of quantum-mechanical calculations favor the electronic structure of a half-sandwich complex of GeII over an ionic representation with a germanium dication stabilized by an aromatic aminoborole dianion.
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Affiliation(s)
- Patrik Tholen
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Straße 9-11, 26129, Oldenburg, Germany
| | - Zhaowen Dong
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Straße 9-11, 26129, Oldenburg, Germany
| | - Marc Schmidtmann
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Straße 9-11, 26129, Oldenburg, Germany
| | - Lena Albers
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Straße 9-11, 26129, Oldenburg, Germany
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Straße 9-11, 26129, Oldenburg, Germany
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24
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Tholen P, Dong Z, Schmidtmann M, Albers L, Müller T. Ein neutraler η
5
‐Aminoborol‐Germanium(II)‐Komplex. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201808271] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Patrik Tholen
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Zhaowen Dong
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Marc Schmidtmann
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Lena Albers
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
| | - Thomas Müller
- Institut für ChemieCarl von Ossietzky Universität Oldenburg Carl von Ossietzky-Straße 9–11 26129 Oldenburg Deutschland
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25
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Wang Z, Zhou Y, Lee KH, Lam WH, Dewhurst RD, Braunschweig H, Marder TB, Lin Z. DFT Studies of Dimerization Reactions of Boroles. Chemistry 2017. [PMID: 28627022 DOI: 10.1002/chem.201701737] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Boroles undergo dimerization reactions to give Diels-Alder (DA) dimers, bridged-bicyclic (BB) dimers or spiro dimers (SD) depending on the substituents on the borole. We performed DFT calculations to investigate how different substituents at the carbon atoms of the butadiene backbone as well as at the boron atom influence the dimerization reaction pathways. The DFT results show that, in general, both the DA and BB dimers are easily accessible kinetically, and the DA dimers are thermodynamically more stable than the BB dimers. When the substituent-substituent repulsive steric interactions are alleviated to a certain extent, the BB dimers are more stable than the DA dimer, and become accessible. The SD dimers are generally kinetically difficult to obtain. However, we found that aryl substituents promote the formation of the SD dimers.
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Affiliation(s)
- Zheng Wang
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong
| | - Yu Zhou
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong
| | - Ka-Ho Lee
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong
| | - Wai Han Lam
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong
| | - Rian D Dewhurst
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Holger Braunschweig
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Todd B Marder
- Institut für Anorganische Chemie and Institute for Sustainable Chemistry & Catalysis with Boron, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074, Würzburg, Germany
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Hong Kong
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26
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Huang K, Couchman SA, Wilson DJD, Dutton JL, Martin CD. Reactions of Imines, Nitriles, and Isocyanides with Pentaphenylborole: Coordination, Ring Expansion, C–H Bond Activation, and Hydrogen Migration Reactions. Inorg Chem 2015; 54:8957-68. [DOI: 10.1021/acs.inorgchem.5b01040] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Kexuan Huang
- Department
of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
| | - Shannon A. Couchman
- Department
of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia, 3086
| | - David J. D. Wilson
- Department
of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia, 3086
| | - Jason L. Dutton
- Department
of Chemistry and Physics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria, Australia, 3086
| | - Caleb D. Martin
- Department
of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, Texas 76798, United States
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27
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Jimenez-Halla JOC, Matito E, Solà M, Braunschweig H, Hörl C, Krummenacher I, Wahler J. A theoretical study of the aromaticity in neutral and anionic borole compounds. Dalton Trans 2015; 44:6740-7. [DOI: 10.1039/c4dt03445g] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A theoretical assessment of the degree of (anti)aromaticity in various borole compounds reveals distinct substituent effects.
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Affiliation(s)
| | - Eduard Matito
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química
- Universitat de Girona
- 17071 Girona (Catalonia)
- Spain
| | - Miquel Solà
- Institut de Química Computacional i Catàlisi (IQCC) and Departament de Química
- Universitat de Girona
- 17071 Girona (Catalonia)
- Spain
| | - Holger Braunschweig
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Christian Hörl
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Ivo Krummenacher
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
| | - Johannes Wahler
- Institut für Anorganische Chemie
- Julius-Maximilians-Universität Würzburg
- 97074 Würzburg
- Germany
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28
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Ge F, Kehr G, Daniliuc CG, Erker G. Reactions of Boroles Formed by 1,1-Carboboration. Organometallics 2014. [DOI: 10.1021/om501085j] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Fang Ge
- Organisch-Chemisches
Institut, Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Gerald Kehr
- Organisch-Chemisches
Institut, Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches
Institut, Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
| | - Gerhard Erker
- Organisch-Chemisches
Institut, Universität Münster, Corrensstrasse 40, D-48149 Münster, Germany
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29
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Bissinger P, Braunschweig H, Damme A, Hörl C, Krummenacher I, Kupfer T. Bor als überaus starkes Reduktionsmittel: Synthese eines Bor‐ zentrierten Radikalanionen‐Radikalkationen‐Paares. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201409513] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Philipp Bissinger
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
| | - Alexander Damme
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
| | - Christian Hörl
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
| | - Ivo Krummenacher
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
| | - Thomas Kupfer
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Deutschland)
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30
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Bissinger P, Braunschweig H, Damme A, Hörl C, Krummenacher I, Kupfer T. Boron as a Powerful Reductant: Synthesis of a Stable Boron‐Centered Radical‐Anion Radical‐Cation Pair. Angew Chem Int Ed Engl 2014; 54:359-62. [DOI: 10.1002/anie.201409513] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Indexed: 11/07/2022]
Affiliation(s)
- Philipp Bissinger
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Holger Braunschweig
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Alexander Damme
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Christian Hörl
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Ivo Krummenacher
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
| | - Thomas Kupfer
- Institut für Anorganische Chemie, Julius‐Maximilians‐Universität Würzburg, Am Hubland, 97074 Würzburg (Germany)
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Bertermann R, Braunschweig H, Dewhurst RD, Hörl C, Kramer T, Krummenacher I. Deutliche Belege für Ein-Elektronen-Übertragungen in der Boryl-Anionenchemie: Isolierung und Reaktivität eines neutralen Borolradikals. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201402556] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Bertermann R, Braunschweig H, Dewhurst RD, Hörl C, Kramer T, Krummenacher I. Evidence for extensive single-electron-transfer chemistry in boryl anions: isolation and reactivity of a neutral borole radical. Angew Chem Int Ed Engl 2014; 53:5453-7. [PMID: 24719250 DOI: 10.1002/anie.201402556] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Indexed: 11/10/2022]
Abstract
Despite the synthesis of a boryl anion by Yamashita et al. in 2006, compounds that show boron-centered nucleophilicity are still rare and sought-after synthetic goals. A number of such boryl anions have since been prepared, two of which were reported to react with methyl iodide in apparent nucleophilic substitution reactions. One of these, a borolyl anion based on the borole framework, has now been found to display single-electron-transfer (SET) reactivity in its reaction with triorganotetrel halides, which was confirmed by the isolation of the first neutral borole-based radical. The radical was characterized by elemental analysis, single-crystal X-ray crystallography, and EPR spectroscopy, and has implications for the understanding of boron-based nucleophilic behavior and the emergent role of boron radicals in synthesis. This radical reactivity was also exploited in the synthesis of compounds with rare B-Sn and B-Pb bonds, the latter of which was the first isolated and structurally characterized compound with a "noncluster" B-Pb bond.
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Affiliation(s)
- Rüdiger Bertermann
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, 97074 Würzburg (Germany) http://www-anorganik.chemie.uni-wuerzburg.de/Braunschweig/
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Seven Ö, Bolte M, Lerner HW, Wagner M. High-Yield Syntheses and Reactivity Studies of 1,2-Diborylated and 1,2,4,5-Tetraborylated Benzenes. Organometallics 2014. [DOI: 10.1021/om500104w] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Ömer Seven
- Institut für Anorganische
und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse
7, D-60438 Frankfurt (Main), Germany
| | - Michael Bolte
- Institut für Anorganische
und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse
7, D-60438 Frankfurt (Main), Germany
| | - Hans-Wolfram Lerner
- Institut für Anorganische
und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse
7, D-60438 Frankfurt (Main), Germany
| | - Matthias Wagner
- Institut für Anorganische
und Analytische Chemie, J. W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse
7, D-60438 Frankfurt (Main), Germany
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Abstract
Bis(trimethylsilylethynyl)diphenylaminoborane was reacted with the strong Lewis acid B(C6F5)3 at ambient temperature to give the borole 9 admixed with a small amount of its thermal follow-up product 12. Compound 9 was subsequently stabilized by adduct formation with pyridine (10). Treatment of bis(trimethylsilylethynyl)phenylborane with B(C6F5)3 gave the borole 14, which reacted with 3-hexyne to give the [4 + 2] cycloaddition product 15.
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Affiliation(s)
- Fang Ge
- Organisch-Chemisches Institut, Universität Münster , Corrensstrasse 40, D-48149 Münster, Germany
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Bauer J, Braunschweig H, Hörl C, Radacki K, Wahler J. Synthesis of Zwitterionic Cobaltocenium Borate and Borata-alkene Derivatives from a Borole-Radical Anion. Chemistry 2013; 19:13396-401. [DOI: 10.1002/chem.201302201] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Indexed: 11/11/2022]
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Braunschweig H, Chiu CW, Gamon D, Gruß K, Hörl C, Kupfer T, Radacki K, Wahler J. Lewis Acid-Base Adducts of 1-Mesityl- and 1-Chloro-2,3,4,5-tetraphenylborole. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201201383] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Braunschweig H, Chiu CW, Gamon D, Kaupp M, Krummenacher I, Kupfer T, Müller R, Radacki K. Synthesis, Structure, and Reactivity of Borole-Functionalized Ferrocenes. Chemistry 2012; 18:11732-46. [DOI: 10.1002/chem.201201317] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Indexed: 11/06/2022]
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Khafizova LO, Khusainova LI, Tyumkina TV, Dzhemilev UM. One-pot synthesis of borolanes by reaction of aluminacyclopentanes with BF3·Et2O. RUSSIAN JOURNAL OF ORGANIC CHEMISTRY 2012. [DOI: 10.1134/s1070428012060012] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Braunschweig H, Damme A, Gamon D, Kelch H, Krummenacher I, Kupfer T, Radacki K. Synthesis, Coordination Behavior, and Reduction Chemistry of Cymantrenyl‐1,3‐bis(2,3,4,5‐tetraphenyl)borole. Chemistry 2012; 18:8430-6. [DOI: 10.1002/chem.201200284] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2012] [Indexed: 11/10/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Alexander Damme
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Daniela Gamon
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Hauke Kelch
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Ivo Krummenacher
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Thomas Kupfer
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Julius–Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg (Germany), Fax: (+49) 931‐31‐84623
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Braunschweig H, Dyakonov V, Jimenez-Halla JOC, Kraft K, Krummenacher I, Radacki K, Sperlich A, Wahler J. An Isolable Radical Anion Based on the Borole Framework. Angew Chem Int Ed Engl 2012; 51:2977-80. [DOI: 10.1002/anie.201108632] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Indexed: 11/07/2022]
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Braunschweig H, Dyakonov V, Jimenez-Halla JOC, Kraft K, Krummenacher I, Radacki K, Sperlich A, Wahler J. Ein isolierbares Borol-basiertes Radikalanion. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108632] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Biswas S, Maichle-Mössmer C, Bettinger HF. Rearrangement from the heteroantiaromatic borole to the heteroaromatic azaborine motif. Chem Commun (Camb) 2012; 48:4564-6. [DOI: 10.1039/c2cc30914a] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Lorbach A, Hübner A, Wagner M. Aryl(hydro)boranes: versatile building blocks for boron-doped π-electron materials. Dalton Trans 2012; 41:6048-63. [DOI: 10.1039/c2dt30118k] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Braunschweig H, Chiu CW, Damme A, Ferkinghoff K, Kraft K, Radacki K, Wahler J. Unwinding Antiaromaticity in 1-Bromo-2,3,4,5-tetraphenylborole. Organometallics 2011. [DOI: 10.1021/om200315p] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Ching-Wen Chiu
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Alexander Damme
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Katharina Ferkinghoff
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Katharina Kraft
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Johannes Wahler
- Institut für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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Braunschweig H, Chiu CW, Kupfer T, Radacki K. NHC-Stabilized 1-Hydro-1H-borole and Its Nondegenerate Sigmatropic Isomers. Inorg Chem 2011; 50:4247-9. [DOI: 10.1021/ic200533e] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Holger Braunschweig
- Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Ching-Wen Chiu
- Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Thomas Kupfer
- Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
| | - Krzysztof Radacki
- Institut für Anorganische Chemie, Julius-Maximilians Universität Würzburg, Am Hubland, 97074 Würzburg, Germany
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Braunschweig H, Kupfer T. Recent developments in the chemistry of antiaromatic boroles. Chem Commun (Camb) 2011; 47:10903-14. [DOI: 10.1039/c1cc13071d] [Citation(s) in RCA: 209] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Braunschweig H, Breher F, Chiu CW, Gamon D, Nied D, Radacki K. The Reduction Chemistry of Ferrocenylborole. Angew Chem Int Ed Engl 2010; 49:8975-8. [DOI: 10.1002/anie.201003611] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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49
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Braunschweig H, Breher F, Chiu CW, Gamon D, Nied D, Radacki K. Reduktion von Ferrocenylborol. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201003611] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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50
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Braunschweig H, Chiu CW, Wahler J, Radacki K, Kupfer T. Chemical Reduction and Dimerization of 1-Chloro-2,3,4,5-tetraphenylborole. Chemistry 2010; 16:12229-33. [DOI: 10.1002/chem.201001556] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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