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Kühn S, Köstler B, True C, Albers L, Wagner M, Müller T, Marschner C. Selective synthesis of germasila-adamantanes through germanium-silicon shift processes. Chem Sci 2023; 14:8956-8961. [PMID: 37621423 PMCID: PMC10445437 DOI: 10.1039/d3sc03301e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 07/28/2023] [Indexed: 08/26/2023] Open
Abstract
The regioselective synthesis of germasila-adamantanes with the germanium atoms in the bridgehead positions is described starting from cyclic precursors by a cationic sila-Wagner-Meerwein (SWM) rearrangement reaction. The SWM rearrangement allows also a deliberate shift of germanium atoms from the periphery and within the cage structures into the bridgehead positions. This opens the possibility for a synthesis of germasila-adamantanes of defined germanium content and controlled regiochemistry. In the same way that sila-adamantane can be regarded as a molecular building block of elemental silicon, the germasila-adamantane molecules represent cutouts of silicon/germanium alloys.
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Affiliation(s)
- Steffen Kühn
- Institut für Anorganische Chemie, Technische Universität Graz Stremayrgasse 9 8010 Graz Austria
- Institut für Chemie, Carl Ossietzky Universität Oldenburg Carl von Ossietzky-Str. 9-11 26129 Oldenburg Germany
| | - Benedikt Köstler
- Institut für Anorganische und Analytische Chemie, Goethe Universität Frankfurt am Main Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Celine True
- Institut für Chemie, Carl Ossietzky Universität Oldenburg Carl von Ossietzky-Str. 9-11 26129 Oldenburg Germany
| | - Lena Albers
- Institut für Chemie, Carl Ossietzky Universität Oldenburg Carl von Ossietzky-Str. 9-11 26129 Oldenburg Germany
| | - Matthias Wagner
- Institut für Anorganische und Analytische Chemie, Goethe Universität Frankfurt am Main Max-von-Laue-Str. 7 60438 Frankfurt am Main Germany
| | - Thomas Müller
- Institut für Chemie, Carl Ossietzky Universität Oldenburg Carl von Ossietzky-Str. 9-11 26129 Oldenburg Germany
| | - Christoph Marschner
- Institut für Anorganische Chemie, Technische Universität Graz Stremayrgasse 9 8010 Graz Austria
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2
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Siu TC, Imex Aguirre Cardenas M, Seo J, Boctor K, Shimono MG, Tran IT, Carta V, Su TA. Site‐Selective Functionalization of Sila‐Adamantane and Its Ensuing Optical Effects. Angew Chem Int Ed Engl 2022; 61:e202206877. [DOI: 10.1002/anie.202206877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Timothy C. Siu
- Department of Chemistry University of California Riverside CA 92521 USA
| | | | - Jacob Seo
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Kirllos Boctor
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Miku G. Shimono
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Isabelle T. Tran
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Veronica Carta
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Timothy A. Su
- Department of Chemistry University of California Riverside CA 92521 USA
- Materials Science and Engineering Program University of California Riverside CA 92521 USA
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3
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Siu TC, Imex Aguirre Cardenas M, Seo J, Boctor K, Shimono MG, Tran IT, Carta V, Su TA. Site‐Selective Functionalization of Sila‐Adamantane and Its Ensuing Optical Effects. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202206877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Timothy C. Siu
- Department of Chemistry University of California Riverside CA 92521 USA
| | | | - Jacob Seo
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Kirllos Boctor
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Miku G. Shimono
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Isabelle T. Tran
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Veronica Carta
- Department of Chemistry University of California Riverside CA 92521 USA
| | - Timothy A. Su
- Department of Chemistry University of California Riverside CA 92521 USA
- Materials Science and Engineering Program University of California Riverside CA 92521 USA
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4
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Nimoth JP, Müller T. Hydrogen-Bridged Oligosilanylsilyl Mono- and Oligosilanylsilyl Dications. Chemistry 2021; 28:e202104318. [PMID: 34882861 PMCID: PMC9305540 DOI: 10.1002/chem.202104318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Indexed: 11/24/2022]
Abstract
Hydrogen‐bridged oligosilanylsilyl borates 8 [B(C6F5)4], 9[B(C6F5)4] and diborates 10 [B(C6F5)4]2 have been prepared by hydride transfer between α‐ω‐dihydrido‐ (11) and branched tetrahydrido‐oligosilanes (13) and trityl cation. The obtained cyclic intramolecularly stabilized silylium ions 8, 9 and bissilylium ion 10 were characterized by low temperature NMR spectroscopy supported by the results of density functional calculations. The branched Si−H−Si monocation 9 undergoes at low temperatures a fast degenerate rearrangement, which exchanges the Si−H groups with a barrier of 31 kJ mol−1 via an antarafacial transition state. Reaction of the branched monocation 9 with a second equivalent of trityl cation or of the branched oligosilane 13 with two equivalents of trityl cation, gives at −80 °C the corresponding bissilylium ion 10, an example for a new class of highly reactive poly‐Lewis acids.
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Affiliation(s)
- Jelte P Nimoth
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129, Oldenburg, Germany, European Union
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky-Str. 9-11, 26129, Oldenburg, Germany, European Union
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5
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Nimoth JP, Müller T. The influence of ring strain on the formation of Si-H-Si stabilised oligosilanylsilyl cations. Dalton Trans 2021; 50:16509-16513. [PMID: 34761782 DOI: 10.1039/d1dt03375a] [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
Hydride transfer between Si(SiMe2H)4 (2) and [Ph3C][B(C6F5)4] in 3-fluorotoluene yields the intermolecularly silane-stabilised silylium ion [((HMe2Si)3SiSiMe2)2H]+ ([5]+), independently of the amount of [Ph3C][B(C6F5)4] (0.5, 1.0 or 2.0 equiv.) used. The cyclic silane-stabilised silylium ion [4]+ is not detected by NMR spectroscopy. This result demonstrates the influence of ring strain effects on the formation of intra- ([4]+) or intermolecularly ([5]+) Si-H-Si bridged silyl cations.
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Affiliation(s)
- Jelte P Nimoth
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Federal Republic of Germany, European Union.
| | - Thomas Müller
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, 26129 Oldenburg, Federal Republic of Germany, European Union.
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6
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Matsuo T, Yamaguchi T, Hirohata T, Nakamoto M, Yamamoto Y, Maeda Y, Kawachi A. Synthesis of Alkoxy‐Substituted Oligosilanes using [
β
‐(Alkoxy)disilanyl]lithium. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202100668] [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)
- Takumi Matsuo
- Major in Applied Chemistry Graduate School of Science and Engineering Hosei University 3-7-2 Kajino-cho Koganei Tokyo 184-8584 Japan
| | - Tatsuya Yamaguchi
- Major in Applied Chemistry Graduate School of Science and Engineering Hosei University 3-7-2 Kajino-cho Koganei Tokyo 184-8584 Japan
| | - Tomoki Hirohata
- Department of Chemical Science and Technology Faculty of Bioscience and Applied Chemistry Hosei University 3-7-2 Kajino-cho Koganei Tokyo 184-8584 Japan
| | - Masaaki Nakamoto
- Basic Chemistry Program Graduate School of Advanced Science and Engineering Hiroshima University 1-3-1 Kagamiyama Higashi Hiroshima 739-8526 Japan
| | - Yohsuke Yamamoto
- Basic Chemistry Program Graduate School of Advanced Science and Engineering Hiroshima University 1-3-1 Kagamiyama Higashi Hiroshima 739-8526 Japan
| | - Yutaka Maeda
- Department of Chemistry Tokyo Gakugei University 4-1-1 Nukuikita-machi Koganei Tokyo 184-8501 Japan
| | - Atsushi Kawachi
- Department of Chemical Science and Technology Faculty of Bioscience and Applied Chemistry Hosei University 3-7-2 Kajino-cho Koganei Tokyo 184-8584 Japan
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7
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Klare HFT, Albers L, Süsse L, Keess S, Müller T, Oestreich M. Silylium Ions: From Elusive Reactive Intermediates to Potent Catalysts. Chem Rev 2021; 121:5889-5985. [PMID: 33861564 DOI: 10.1021/acs.chemrev.0c00855] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The history of silyl cations has all the makings of a drama but with a happy ending. Being considered reactive intermediates impossible to isolate in the condensed phase for decades, their actual characterization in solution and later in solid state did only fuel the discussion about their existence and initially created a lot of controversy. This perception has completely changed today, and silyl cations and their donor-stabilized congeners are now widely accepted compounds with promising use in synthetic chemistry. This review provides a comprehensive summary of the fundamental facts and principles of the chemistry of silyl cations, including reliable ways of their preparation as well as their physical and chemical properties. The striking features of silyl cations are their enormous electrophilicity and as such reactivity as super Lewis acids as well as fluorophilicity. Known applications rely on silyl cations as reactants, stoichiometric reagents, and promoters where the reaction success is based on their steady regeneration over the course of the reaction. Silyl cations can even be discrete catalysts, thereby opening the next chapter of their way into the toolbox of synthetic methodology.
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Affiliation(s)
- Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Lena Albers
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Lars Süsse
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Sebastian Keess
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17 Juni 115, 10623 Berlin, Germany
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8
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Wu Q, Roy A, Wang G, Irran E, Klare HFT, Oestreich M. Synthese eines gegenanionstabilisierten Bis(silylium)ions. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202003799] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Qian Wu
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Avijit Roy
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Guoqiang Wang
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Elisabeth Irran
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Hendrik F. T. Klare
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Martin Oestreich
- Institut für Chemie Technische Universität Berlin Straße des 17. Juni 115 10623 Berlin Deutschland
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9
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Wu Q, Roy A, Wang G, Irran E, Klare HFT, Oestreich M. Synthesis of a Counteranion-Stabilized Bis(silylium) Ion. Angew Chem Int Ed Engl 2020; 59:10523-10526. [PMID: 32216163 PMCID: PMC7317492 DOI: 10.1002/anie.202003799] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Indexed: 11/12/2022]
Abstract
The preparation of a molecule with two alkyl‐tethered silylium‐ion sites from the corresponding bis(hydrosilanes) by two‐fold hydride abstraction is reported. The length of the conformationally flexible alkyl bridge is crucial as otherwise the hydride abstraction stops at the stage of a cyclic bissilylated hydronium ion. With an ethylene tether, the open form of the hydronium‐ion intermediate is energetically accessible and engages in another hydride abstraction. The resulting bis(silylium) ion has been NMR spectroscopically and structurally characterized. Related systems based on rigid naphthalen‐n,m‐diyl platforms can only be converted into the dications when the positively charged silylium‐ion units are remote from each other (1,8 versus 1,5 and 2,6).
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Affiliation(s)
- Qian Wu
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Avijit Roy
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Guoqiang Wang
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Elisabeth Irran
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, Strasse des 17. Juni 115, 10623, Berlin, Germany
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10
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Wu Q, Irran E, Müller R, Kaupp M, Klare HFT, Oestreich M. Characterization of hydrogen-substituted silylium ions in the condensed phase. SCIENCE (NEW YORK, N.Y.) 2020; 365:168-172. [PMID: 31296768 DOI: 10.1126/science.aax9184] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Accepted: 06/17/2019] [Indexed: 11/02/2022]
Abstract
Hydrogen-substituted silylium ions are long-sought reactive species. We report a protolysis strategy that chemoselectively cleaves either an Si-C(sp2) or an Si-H bond using a carborane acid to access the full series of [CHB11H5Br6]--stabilized R2SiH+, RSiH2 +, and SiH3 + cations, where bulky tert-butyl groups at the silicon atom (R = tBu) were crucial to avoid substituent redistribution. The crystallographically characterized molecular structures of [CHB11H5Br6]--stabilized tBu2HSi+ and tBuH2Si+ feature pyramidalization at the silicon atom, in accordance with that of tBu3Si+[CHB11H5Br6]- Conversely, the silicon atom in the H3Si+ cation adopts a trigonal-planar structure and is stabilized by two counteranions. This solid-state structure resembles that of the corresponding Brønsted acid.
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Affiliation(s)
- Qian Wu
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
| | - Elisabeth Irran
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
| | - Robert Müller
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
| | - Martin Kaupp
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany
| | - Hendrik F T Klare
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany.
| | - Martin Oestreich
- Institut für Chemie, Technische Universität Berlin, 10623 Berlin, Germany.
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11
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Fischer M, Schmidtmann M. B(C 6F 5) 3- and HB(C 6F 5) 2-mediated transformations of isothiocyanates. Chem Commun (Camb) 2020; 56:6205-6208. [PMID: 32364554 DOI: 10.1039/d0cc02626c] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This contribution reports on the reactivity of isothiocyanates towards the boranes B(C6F5)3 and HB(C6F5)2. The reactions of alkyl-substituted isothiocyanates with B(C6F5)3 were found to result in rearrangement reactions to yield stable thiocyanate-B(C6F5)3 adducts. Treatment of isothiocyanates with HB(C6F5)2 leads to 1,2-hydroboration and thus, B,N,C,S heterocycles are formed, which react further under non-inert conditions. Hydrolysis of the hydroboration products leads to a new access to thioformamides.
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Affiliation(s)
- Malte Fischer
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
| | - Marc Schmidtmann
- Institute of Chemistry, Carl von Ossietzky University Oldenburg, Carl von Ossietzky Straße 9-11, D-26129 Oldenburg, Germany.
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12
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Sturm AG, Santowski T, Schweizer JI, Meyer L, Lewis KM, Felder T, Auner N, Holthausen MC. Making Use of the Direct Process Residue: Synthesis of Bifunctional Monosilanes. Chemistry 2019; 25:8499-8502. [PMID: 31026105 DOI: 10.1002/chem.201901881] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Indexed: 11/08/2022]
Abstract
The industrial production of monosilanes Men SiCl4-n (n=1-3) through the Müller-Rochow Direct Process generates disilanes Men Si2 Cl6-n (n=2-6) as unwanted byproducts ("Direct Process Residue", DPR) by the thousands of tons annually, large quantities of which are usually disposed of by incineration. Herein we report a surprisingly facile and highly effective protocol for conversion of the DPR: hydrogenation with complex metal hydrides followed by Si-Si bond cleavage with HCl/ether solutions gives (mostly bifunctional) monosilanes in excellent yields. Competing side reactions are efficiently suppressed by the appropriate choice of reaction conditions.
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Affiliation(s)
- Alexander G Sturm
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Tobias Santowski
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Julia I Schweizer
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Lioba Meyer
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Kenrick M Lewis
- Momentive Performance Materials, 769 Old Saw Mill River Rd., Tarrytown, NY, 10591, USA
| | - Thorsten Felder
- Momentive Performance Materials, Chempark, 51368, Leverkusen, Germany
| | - Norbert Auner
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
| | - Max C Holthausen
- Institut für Anorganische Chemie, Goethe-Universität, Max-von-Laue-Strasse 7, 60438, Frankfurt/Main, Germany
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13
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14
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Omatsu Y, Mizuhata Y, Tokitoh N. Synthesis of Dodecaallylhexasilacyclohexane and Its Convertibility. Z Anorg Allg Chem 2018. [DOI: 10.1002/zaac.201800171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Yamato Omatsu
- Institute for Chemical Research; Kyoto University; 611-0011 Kyoto Gokasho, Uji Japan
| | - Yoshiyuki Mizuhata
- Institute for Chemical Research; Kyoto University; 611-0011 Kyoto Gokasho, Uji Japan
- Integrated Research Consortium on Chemical Sciences; 611-0011 Kyoto Gokasho, Uji Japan
| | - Norihiro Tokitoh
- Institute for Chemical Research; Kyoto University; 611-0011 Kyoto Gokasho, Uji Japan
- Integrated Research Consortium on Chemical Sciences; 611-0011 Kyoto Gokasho, Uji Japan
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15
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Wu Q, Qu ZW, Omann L, Irran E, Klare HFT, Oestreich M. Cleavage of Unactivated Si−C(sp3) Bonds with Reed's Carborane Acids: Formation of Known and Unknown Silylium Ions. Angew Chem Int Ed Engl 2018; 57:9176-9179. [DOI: 10.1002/anie.201805637] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Indexed: 11/12/2022]
Affiliation(s)
- Qian Wu
- Institut für Chemie; Technische Universität Berlin; Strasse des 17. Juni 115 10623 Berlin Germany
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry; Institut für Physikalische und Theoretische Chemie; Rheinische Friedrich-Wilhelms-Universität Bonn; Beringstrasse 4 53115 Bonn Germany
| | - Lukas Omann
- Institut für Chemie; Technische Universität Berlin; Strasse des 17. Juni 115 10623 Berlin Germany
| | - Elisabeth Irran
- Institut für Chemie; Technische Universität Berlin; Strasse des 17. Juni 115 10623 Berlin Germany
| | - Hendrik F. T. Klare
- Institut für Chemie; Technische Universität Berlin; Strasse des 17. Juni 115 10623 Berlin Germany
| | - Martin Oestreich
- Institut für Chemie; Technische Universität Berlin; Strasse des 17. Juni 115 10623 Berlin Germany
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16
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Wu Q, Qu ZW, Omann L, Irran E, Klare HFT, Oestreich M. Spaltung nicht aktivierter Si-C(sp3)-Bindungen mit Reedschen Carboransäuren: Bildung bekannter und unbekannter Silyliumionen. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201805637] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- Qian Wu
- Institut für Chemie; Technische Universität Berlin; Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Zheng-Wang Qu
- Mulliken Center for Theoretical Chemistry; Institut für Physikalische und Theoretische Chemie; Rheinische Friedrich-Wilhelms-Universität Bonn; Beringstraße 4 53115 Bonn Deutschland
| | - Lukas Omann
- Institut für Chemie; Technische Universität Berlin; Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Elisabeth Irran
- Institut für Chemie; Technische Universität Berlin; Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Hendrik F. T. Klare
- Institut für Chemie; Technische Universität Berlin; Straße des 17. Juni 115 10623 Berlin Deutschland
| | - Martin Oestreich
- Institut für Chemie; Technische Universität Berlin; Straße des 17. Juni 115 10623 Berlin Deutschland
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17
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Zaitsev KV, Lam K, Poleshchuk OK, Kuz'mina LG, Churakov AV. Oligothienyl catenated germanes and silanes: synthesis, structure, and properties. Dalton Trans 2018; 47:5431-5444. [PMID: 29594275 DOI: 10.1039/c8dt00256h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The synthesis of two new groups of oligothienyl catenated silanes and germanes, Me5M2Thn (1a-b), Me5M2ThnM2Me5 (2a-c) (terminal), and ThnM2Me4Thn (3a-d) (internal) (M = Si, Ge; n = 2, 3; Th = 2- or 2,5-thienyl), is reported. The study of their structural parameters as well as of their spectral (NMR), electrochemical (CV) and optical (UV/vis absorbance, luminescence) properties has been performed in detail; in addition, the unexpected compound [Th2Si2Me4Th]2 (3a') is also studied. Theoretical investigations have been performed for model compounds in order to establish structure-property relationships. The molecular structures of 2a (Me5Si2Th2Si2Me5), 2b (Me5Ge2Th2Ge2Me5), 3a (Th2Si2Me4Th2) and 3b (Th2Ge2Me4Th2) have been investigated by X-ray diffraction analysis. An effective conjugation with flattening of both Th planes in terminal 2a and 2b was observed. The main trends in the dependence of the optical and electrochemical properties on the structural parameters have been established. All of the compounds studied exhibit a strong emission within the 378-563 nm range, and the maximal quantum yield (up to 77%) is observed for the Si derivative 3a'. For the majority of the compounds, the quantum yields (20-30%) are significantly larger than for 2,2'-bi- and 2,2':5',5''-terthiophenes. Due to their good emission properties, these compounds could be used to develop new materials with specific spectral properties.
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Affiliation(s)
- Kirill V Zaitsev
- Department of Chemistry, Moscow State University, Leninskye Gory 1, 3, Moscow 119991, Russia.
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18
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Musgrave RA, Hailes RLN, Schäfer A, Russell AD, Gates PJ, Manners I. New reactivity at the silicon bridge in sila[1]ferrocenophanes. Dalton Trans 2018; 47:2759-2768. [PMID: 29417116 DOI: 10.1039/c7dt04593j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We describe two new types of reactivity involving silicon-bridged [1]ferrocenophanes. In an attempt to form a [1]ferrocenophane with a bridging silyl cation, the reaction of sila[1]ferrocenophane [Fe(η-C5H4)2Si(H)TMP] (12) (TMP = 2,2,6,6-tetramethylpiperidyl) towards the hydride-abstraction reagent trityl tetrakis(pentafluorophenyl)borate ([CPh3][B(C6F5)4]) was explored. This yielded the unusual dinuclear species [Fe(η-C5H4)2Si(TMP·H)(η-C5H3)Fe(η-C5H4)Si(H)TMP][B(C6F5)4] [13][B(C6F5)4] in low yield. The formation of [13]+ is proposed to involve abstraction of hydride from the silicon bridge in 12 with subsequent C-H bond cleavage of a cyclopentadienyl group by the resulting electrophilic transient silyl cation intermediate. We also explored the reaction of dimethylsila[1]ferrocenophane [Fe(η-C5H4)2SiMe2] (1) with the Au(i) species AuCl(PMe3). This was found to result in addition of the Au-Cl bond across the Cpipso-Si bond to yield the ring-opened species [1'-(chlorodimethylsilyl)-ferrocenyl](trimethylphosphine)gold(i), [Fe(C5H4SiMe2Cl){C5H4Au(PMe3)}] (14). This represents the first example of ring-opening addition of a metallocenophane with a reagent possessing a transition metal-halogen bond.
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Affiliation(s)
- Rebecca A Musgrave
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK.
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Biggs MJP, Fernandez M, Thomas D, Cooper R, Palma M, Liao J, Fazio T, Dahlberg C, Wheadon H, Pallipurath A, Pandit A, Kysar J, Wind SJ. The Functional Response of Mesenchymal Stem Cells to Electron-Beam Patterned Elastomeric Surfaces Presenting Micrometer to Nanoscale Heterogeneous Rigidity. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:10.1002/adma.201702119. [PMID: 28861921 PMCID: PMC7391933 DOI: 10.1002/adma.201702119] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 07/03/2017] [Indexed: 05/13/2023]
Abstract
Cells directly probe and respond to the physicomechanical properties of their extracellular environment, a dynamic process which has been shown to play a key role in regulating both cellular adhesive processes and differential cellular function. Recent studies indicate that stem cells show lineage-specific differentiation when cultured on substrates approximating the stiffness profiles of specific tissues. Although tissues are associated with a range of Young's modulus values for bulk rigidity, at the subcellular level, tissues are comprised of heterogeneous distributions of rigidity. Lithographic processes have been widely explored in cell biology for the generation of analytical substrates to probe cellular physicomechanical responses. In this work, it is shown for the first time that that direct-write e-beam exposure can significantly alter the rigidity of elastomeric poly(dimethylsiloxane) substrates and a new class of 2D elastomeric substrates with controlled patterned rigidity ranging from the micrometer to the nanoscale is described. The mechanoresponse of human mesenchymal stem cells to e-beam patterned substrates was subsequently probed in vitro and significant modulation of focal adhesion formation and osteochondral lineage commitment was observed as a function of both feature diameter and rigidity, establishing the groundwork for a new generation of biomimetic material interfaces.
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Affiliation(s)
- Manus J. P. Biggs
- Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, Newcastle Road, Dangan, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Marc Fernandez
- Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, Newcastle Road, Dangan, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Dilip Thomas
- Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, Newcastle Road, Dangan, National University of Ireland, Galway, Ireland
| | - Ryan Cooper
- Department of Mechanical Engineering, Columbia University, 500 West 120 St., New York, NY, USA 10027
| | - Matteo Palma
- The School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Jinyu Liao
- Department of Electrical Engineering, Columbia University, 500 West 120th St. New York, NY, USA 10027
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120 St., New York, NY, USA 10027
| | - Teresa Fazio
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120 St., New York, NY, USA 10027
| | - Carl Dahlberg
- Department of Mechanical Engineering, Columbia University, 500 West 120 St., New York, NY, USA 10027
| | - Helen Wheadon
- Leukaemia Research Centre, Gartnavel General Hospital, Glasgow G11 0YN, UK
| | | | - Abhay Pandit
- Centre for Research in Medical Devices (CÚRAM), Biosciences Research Building, Newcastle Road, Dangan, National University of Ireland, Galway, Ireland
- Department of Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland
| | - Jeffrey Kysar
- Department of Mechanical Engineering, Columbia University, 500 West 120 St., New York, NY, USA 10027
| | - Shalom J. Wind
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 West 120 St., New York, NY, USA 10027
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Albers L, Baumgartner J, Marschner C, Müller T. Cationic Si-H-Si Bridges in Polysilanes: Their Detection and Targeted Formation in Stable Ion Studies. Chemistry 2016; 22:7970-7. [PMID: 27105609 PMCID: PMC5074309 DOI: 10.1002/chem.201600116] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Indexed: 11/24/2022]
Abstract
The ionization of 1,1-dihydridocyclopentasilane 7 has been found to yield the cyclic polysilanylsilyl cation 8 instead of the expected hydrogen-substituted silylium ion 6. The silyl cation 8 is stabilized by the formation of an intramolecular Si-H-Si bridge, which also provides the thermodynamic driving force for its formation. In general, the preference for the formation of Si-H-Si bridges can be used to scavenge and identify transient intermediates in the Lewis acid induced rearrangement of polysilanes. The validity of this concept has been demonstrated for one central step in this chemistry, the ring-contraction reaction of cyclohexasilanes to form silylcyclopentasilanes.
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Affiliation(s)
- Lena Albers
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Str. 9-11, 26111, Oldenburg, Germany
| | - Judith Baumgartner
- Institut für Chemie, Universität Graz, Stremayrgasse 9, 8010, Graz, Austria.
| | - Christoph Marschner
- Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, 8010, Graz, Austria.
| | - Thomas Müller
- Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Str. 9-11, 26111, Oldenburg, Germany.
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