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Lainer T, Leypold M, Kugler C, Fischer RC, Haas M. Dodecamethoxyneopentasilane as a New Building Block for Defined Silicon Frameworks. Eur J Inorg Chem 2021. [DOI: 10.1002/ejic.202001112] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Thomas Lainer
- Institute of Inorganic Chemistry Graz University of Technology Stremayrgasse 9/IV 8010 Graz Austria
| | - Mario Leypold
- Institute of Inorganic Chemistry Graz University of Technology Stremayrgasse 9/IV 8010 Graz Austria
| | - Christoph Kugler
- Institute of Inorganic Chemistry Graz University of Technology Stremayrgasse 9/IV 8010 Graz Austria
| | - Roland C. Fischer
- Institute of Inorganic Chemistry Graz University of Technology Stremayrgasse 9/IV 8010 Graz Austria
| | - Michael Haas
- Institute of Inorganic Chemistry Graz University of Technology Stremayrgasse 9/IV 8010 Graz Austria
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2
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Pinchuk D, Kratish Y, Mathew J, Zborovsky L, Bravo-Zhivotovskii D, Tumanskii B, Apeloig Y. Generation and EPR Spectroscopy of the First Silenyl Radicals, R 2 C=Si . -R: Experiment and Theory. Angew Chem Int Ed Engl 2019; 58:7435-7439. [PMID: 30912602 DOI: 10.1002/anie.201901772] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Revised: 03/17/2019] [Indexed: 11/09/2022]
Abstract
The first two persistent silenyl radicals (R2 C=Si. -R), with a half-life (t1/2 ) of about 30 min, were generated and characterized by electron paramagnetic resonance (EPR) spectroscopy. The large hyperfine coupling constants (hfccs) (a(29 Siα )=137.5-148.0 G) indicate that the unpaired electron has substantial s character. DFT calculations, which are in good agreement with the experimentally observed hfccs, predict a strongly bent structure (∡C=Si-R=134.7-140.7°). In contrast, the analogous vinyl radical, R2 C=C. -R (t1/2 ≈3 h), exhibits a small hfcc (a(13 Cα )=26.6 G) and has a nearly linear geometry (∡C=C-R=168.7°).
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Affiliation(s)
- Daniel Pinchuk
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Yosi Kratish
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Jomon Mathew
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Lieby Zborovsky
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Dmitry Bravo-Zhivotovskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Boris Tumanskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
| | - Yitzhak Apeloig
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel
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3
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Pinchuk D, Kratish Y, Mathew J, Zborovsky L, Bravo‐Zhivotovskii D, Tumanskii B, Apeloig Y. Generation and EPR Spectroscopy of the First Silenyl Radicals, R
2
C=Si
.
−R: Experiment and Theory. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201901772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Daniel Pinchuk
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Yosi Kratish
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Jomon Mathew
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Lieby Zborovsky
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Dmitry Bravo‐Zhivotovskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Boris Tumanskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
| | - Yitzhak Apeloig
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum ChemistryTechnion-Israel Institute of Technology Haifa 32000 Israel
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4
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Kratish Y, Molev G, Kostenko A, Sheberla D, Tumanskii B, Botoshansky M, Shimada S, Bravo-Zhivotovskii D, Apeloig Y. Activation of Homolytic Si-Zn and Si-Hg Bond Cleavage, Mediated by a Pt(0) Complex, via Novel Pt-Zn and Pt-Hg Compounds. Angew Chem Int Ed Engl 2015; 54:11817-21. [PMID: 26288342 DOI: 10.1002/anie.201505805] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Indexed: 11/11/2022]
Abstract
The thermally stable [(tBuMe2 Si)2 M] (M=Zn, Hg) generate R3 Si(.) radicals in the presence of [(dmpe)Pt(PEt3 )2 ] at 60-80 °C. The reaction proceeds via hexacoordinate Pt complexes, (M=Zn (2 a and 2 b), M=Hg (3 a and 3 b)) which were isolated and characterized. Mild warming or photolysis of 2 or 3 lead to homolytic dissociation of the Pt-MSiR3 bond generating silyl radicals and novel unstable pentacoordinate platinum paramagnetic complexes (M=Zn (5), Hg (6)) whose structures were determined by EPR spectroscopy and DFT calculations.
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Affiliation(s)
- Yosi Kratish
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Gregory Molev
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Arseni Kostenko
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Dennis Sheberla
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Boris Tumanskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Mark Botoshansky
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel)
| | - Shigeru Shimada
- Interdisciplinary Research Center for Catalytic Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan)
| | - Dmitry Bravo-Zhivotovskii
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel).
| | - Yitzhak Apeloig
- Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000 (Israel).
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5
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Kratish Y, Molev G, Kostenko A, Sheberla D, Tumanskii B, Botoshansky M, Shimada S, Bravo-Zhivotovskii D, Apeloig Y. Activation of Homolytic SiZn and SiHg Bond Cleavage, Mediated by a Pt0Complex, via Novel PtZn and PtHg Compounds. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201505805] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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6
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Lee VY, Sekiguchi A. 1,1-Dilithiosilanes, 1,1-dilithiogermanes, 1,1-dilithiostannanes and related compounds: Organometallic reagents of the new generation. MENDELEEV COMMUNICATIONS 2015. [DOI: 10.1016/j.mencom.2015.05.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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7
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Saito M, Nakada M, Kuwabara T, Minoura M. A reversible two-electron redox system involving a divalent lead species. Chem Commun (Camb) 2015; 51:4674-6. [DOI: 10.1039/c4cc09856k] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A reversible interconversion between Pb(ii) and its dianionic species bearing organic substituents is described.
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Affiliation(s)
- Masaichi Saito
- Department of Chemistry
- Graduate School of Science and Engineering
- Saitama University
- Saitama-city
- Japan
| | - Marisa Nakada
- Department of Chemistry
- Graduate School of Science and Engineering
- Saitama University
- Saitama-city
- Japan
| | - Takuya Kuwabara
- Department of Chemistry
- Graduate School of Science and Engineering
- Saitama University
- Saitama-city
- Japan
| | - Mao Minoura
- Department of Chemistry
- Graduate School of Science
- Rikkyo University
- Toshima-ku
- Japan
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8
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9
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10
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Dobrovetsky R, Kratish Y, Tumanskii B, Botoshansky M, Bravo-Zhivotovskii D, Apeloig Y. Radical Activation of SiH Bonds by Organozinc and Silylzinc Reagents: Synthesis of Geminal Dizinciosilanes and Zinciolithiosilanes. Angew Chem Int Ed Engl 2012; 51:4671-5. [DOI: 10.1002/anie.201200126] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/16/2012] [Indexed: 11/11/2022]
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11
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Dobrovetsky R, Kratish Y, Tumanskii B, Botoshansky M, Bravo-Zhivotovskii D, Apeloig Y. Radical Activation of SiH Bonds by Organozinc and Silylzinc Reagents: Synthesis of Geminal Dizinciosilanes and Zinciolithiosilanes. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201200126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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12
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Lee VY, Sekiguchi A. Novel Organometallic Reagents: Geminal Dianionic Derivatives of the Heavy Group 14 Elements. Inorg Chem 2011; 50:12303-14. [PMID: 21630690 DOI: 10.1021/ic2006106] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Vladimir Ya. Lee
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Akira Sekiguchi
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
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13
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Corey JY. Reactions of hydrosilanes with transition metal complexes and characterization of the products. Chem Rev 2011; 111:863-1071. [PMID: 21250634 DOI: 10.1021/cr900359c] [Citation(s) in RCA: 353] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Joyce Y Corey
- Department of Chemistry and Biochemistry, University of Missouri-St. Louis, 63121, USA.
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14
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Dobrovetsky R, Bravo-Zhivotovskii D, Tumanskii B, Botoshansky M, Apeloig Y. Synthesis, Isolation, and Characterization of 1,1-DiGrignard and 1,1-Dizincio Silanes. Angew Chem Int Ed Engl 2010; 49:7086-8. [DOI: 10.1002/anie.201002876] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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15
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Dobrovetsky R, Bravo-Zhivotovskii D, Tumanskii B, Botoshansky M, Apeloig Y. Synthesis, Isolation, and Characterization of 1,1-DiGrignard and 1,1-Dizincio Silanes. Angew Chem Int Ed Engl 2010. [DOI: 10.1002/ange.201002876] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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16
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Bravo-Zhivotovskii D, Dobrovetsky R, Nemirovsky D, Molev V, Bendikov M, Molev G, Botoshansky M, Apeloig Y. The Synthesis and Isolation of a Metal-Substituted Bis-silene. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200800973] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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17
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Bravo-Zhivotovskii D, Dobrovetsky R, Nemirovsky D, Molev V, Bendikov M, Molev G, Botoshansky M, Apeloig Y. The Synthesis and Isolation of a Metal-Substituted Bis-silene. Angew Chem Int Ed Engl 2008; 47:4343-5. [PMID: 18446914 DOI: 10.1002/anie.200800973] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Dmitry Bravo-Zhivotovskii
- Schulich Faculty of Chemistry and The Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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18
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Inoue S, Ichinohe M, Sekiguchi A. Isolable Alkali-Metal-Substituted Silyl Radicals (tBu2MeSi)2SiM (M = Li, Na, K): Electronically and Sterically Accessible Planar Silyl Radicals. Organometallics 2008. [DOI: 10.1021/om8000185] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shigeyoshi Inoue
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Masaaki Ichinohe
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
| | - Akira Sekiguchi
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
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19
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Lee VY, Nakamoto M, Sekiguchi A. Making Stable Radicals of Heavy Elements of Groups 14 and 13: The Might of Silyl Substitution. CHEM LETT 2008. [DOI: 10.1246/cl.2008.128] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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20
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Chatgilialoglu C, Timokhin VI. Silyl Radicals in Chemical Synthesis. ADVANCES IN ORGANOMETALLIC CHEMISTRY 2008. [DOI: 10.1016/s0065-3055(08)00002-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
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21
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Inoue S, Ichinohe M, Sekiguchi A. Isolable Silylene Anion Radical: Structural Characteristics in the Solid State and in Solution. J Am Chem Soc 2007; 129:6096-7. [PMID: 17441724 DOI: 10.1021/ja0711314] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shigeyoshi Inoue
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan
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22
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Kira M, Iwamoto T, Ishida S. A Helmeted Dialkylsilylene. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2007. [DOI: 10.1246/bcsj.80.258] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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23
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Bravo-Zhivotovskii D, Ruderfer I, Melamed S, Botoshansky M, Tumanskii B, Apeloig Y. Nonsolvated, aggregated 1,1-dilithiosilane and the derived silyl radicals. Angew Chem Int Ed Engl 2006; 44:739-43. [PMID: 15612070 DOI: 10.1002/anie.200461765] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Dmitry Bravo-Zhivotovskii
- Department of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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24
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25
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Bravo-Zhivotovskii D, Ruderfer I, Yuzefovich M, Kosa M, Botoshansky M, Tumanskii B, Apeloig Y. Mercury-Substituted Silyl Radical Intermediates in Formation and Fragmentation of Geminal Dimercury Silyl Compounds. Organometallics 2005. [DOI: 10.1021/om050118u] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Dmitry Bravo-Zhivotovskii
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Ilya Ruderfer
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Michael Yuzefovich
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Monica Kosa
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Mark Botoshansky
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Boris Tumanskii
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
| | - Yitzhak Apeloig
- Department of Chemistry and Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion−Israel Institute of Technology, Haifa 32000, Israel
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26
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Lee VY, Sekiguchi A. Si‐, Ge‐, and Sn‐Centered Free Radicals: From Phantom Species toGrams‐Order‐Scale Materials. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400999] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Vladimir Ya. Lee
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305–8571, Japan
| | - Akira Sekiguchi
- Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305–8571, Japan
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28
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Kira M, Ishida S, Iwamoto T. Comparative chemistry of isolable divalent compounds of silicon, germanium, and tin. CHEM REC 2004; 4:243-53. [PMID: 15340909 DOI: 10.1002/tcr.20019] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Recent studies of the synthesis, structures, spectroscopic properties, and reactions of a series of isolable metallylenes (R2E:, E = Si (1), Ge (2), and Sn (3); R2 = 1,1,4,4-tetrakis(trimethylsilyl)butane-1,4-diyl) are summarized. Because these group-14 metallylenes bear the same helmet-like ligand, a straightforward discussion of the element-dependence of the intrinsic properties of the group-14 element divalent compounds is possible. All these metallylenes were monomeric both in solution and in the solid state, indicating the effective steric protection by the ligand against dimerization. A small sigma-pi conjugation between C-Si(substituent) sigma orbitals and the vacant npz orbitals of divalent atoms in R2E: exists and the extent decreases in the order E = Si > Ge > Sn, as evidenced by UV-vis and NMR spectroscopies and X-ray crystallography. However, the extent of the sigma-pi conjugation in metallylenes 1-3 was much smaller than the electron-donating effects of neighboring nitrogen atoms in known stable cyclic diamino-substituted metallylenes, and hence metallylenes 1-3 are regarded as the least electronically perturbed. Comparative studies of the unique reactions among these metallylenes are also discussed.
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Affiliation(s)
- Mitsuo Kira
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
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29
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Abstract
By the reduction of an isolable dialkylsilylene, 2,2,5,5-[tetrakis(trimethylsilyl)]-1-silacyclopentane-1,1-diyl (1), with cesium, rubidium, potassium, sodium, and lithium 4,4'-di(tert-butyl)biphenylide in DME at low temperatures, the corresponding silylene radical anion 2 was generated as the first persistent silylene radical anion in solution and characterized by ESR spectroscopy. Radical anion 2 is rather stable at -70 degrees C in DME but decomposes rapidly at room temperature with a half-life time of ca. 20 min. The g-factor and 29Si hyperfine splitting constants (hfs's) of 2 are almost independent of the countercations, indicating that 2 exists as a free ion or a solvent-separated ion pair in a polar DME solution. A very small hfs due to the 29Si nucleus of the divalent silicon (3.0 mT) as well as a very large g-factor (2.0077) indicates that an unpaired electron is accommodated in the vacant 3ppi orbital of silylene 1.
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Affiliation(s)
- S Ishida
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku, Sendai 980-8578, Japan
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