2,3,4-Tricarba-nido-hexaboranes(7) with a Bridging B−Ethyl−B Moiety
1998; Wiley; Volume: 1998; Issue: 5 Linguagem: Inglês
10.1002/(sici)1099-0682(199805)1998
ISSN1099-0682
AutoresBernd Wrackmeyer, Hans‐Jörg Schanz, Matthias Hofmann, Paul von Ragué Schleyer,
Tópico(s)Luminescence and Fluorescent Materials
ResumoEuropean Journal of Inorganic ChemistryVolume 1998, Issue 5 p. 633-637 Full Paper 2,3,4-Tricarba-nido-hexaboranes(7) with a Bridging B−Ethyl−B Moiety Bernd Wrackmeyer, Bernd Wrackmeyer [email protected] Search for more papers by this authorHans-Jörg Schanz, Hans-Jörg Schanz Laboratorium für Anorganische Chemie, Universität Bayreuth, D-95440 Bayreuth, Fax: Int. code +49(0)921/552157Search for more papers by this authorMatthias Hofmann, Matthias Hofmann Institut für Organische Chemie, Universität Erlangen-Nürnberg, Henkestr. 42, D-91054 Erlangen, Fax: Int. code +49(0)9131/859132Search for more papers by this authorPaul von R. Schleyer, Paul von R. Schleyer [email protected] Institut für Organische Chemie, Universität Erlangen-Nürnberg, Henkestr. 42, D-91054 Erlangen, Fax: Int. code +49(0)9131/859132Search for more papers by this author Bernd Wrackmeyer, Bernd Wrackmeyer [email protected] Search for more papers by this authorHans-Jörg Schanz, Hans-Jörg Schanz Laboratorium für Anorganische Chemie, Universität Bayreuth, D-95440 Bayreuth, Fax: Int. code +49(0)921/552157Search for more papers by this authorMatthias Hofmann, Matthias Hofmann Institut für Organische Chemie, Universität Erlangen-Nürnberg, Henkestr. 42, D-91054 Erlangen, Fax: Int. code +49(0)9131/859132Search for more papers by this authorPaul von R. Schleyer, Paul von R. Schleyer [email protected] Institut für Organische Chemie, Universität Erlangen-Nürnberg, Henkestr. 42, D-91054 Erlangen, Fax: Int. code +49(0)9131/859132Search for more papers by this author First published: May 1998 https://doi.org/10.1002/(SICI)1099-0682(199805)1998:5 3.0.CO;2-DCitations: 14AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat Abstract Hydroboration of diethyl(1-propynyl)borane 1 with tetraethyldiborane(6) in the presence of a catalytic amount of trimethyl- or tributyltin chloride gave two new organo-substituted carboranes 6 and 7 with 2,3,5-tricarba-nido-hexaborane(7) and 2,3,4-tricarba-nido-hexaborane(7) skeletons, respectively, along with polymeric material and the known organo-substituted 1-carba-arachno-pentaborane(10) (3) and pentaethyl-1,5-dicarba-closo-pentaborane(5) (4). Selective 11B(5,6) decoupled 13C-NMR spectra indicate an unprecedented B(5)−ethyl−B(6) bridge in 7. This structure is supported by the agreement between experimental and calculated 11B- and 13C-chemical shifts on a model compound 7d with methyl groups in the 1,2,3,5,6-positions and an ethyl group bridging B(5) and B(6). References 1(1a) R. N. Grimes, Carboranes, Academic Press, London, 1970. Google Scholar(1b) – C. L. Bramlett, R. N. Grimes, J. Am. 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Trucks, H. B. Schlegel, P. M. W. Gill, B. G. Johnson, M. A. Robb, J. R. Cheeseman, T. Keith, G. A. Petersson, J. A. Montgomery, K. Raghavachari, M. A. Al-Laham, V. G. Zakrzewski, J. V. Ortiz, J. B. Foresman, J. Cioslowski, B. B. Stefanov, A. Nanayakkara, M. Challacombe, C. Y. Peng, P. Y. Ayala, W. Chen, M. W. Wong, J. L. Andres, E. S. Replogle, R. Gomperts, R. L. Martin, D. J. Fox, J. S. Binkley, D. J. Defrees, J. Baker, J. P. Stewart, M. Head-Gordon, C. Gonzalez, and J. A. Pople, Gaussian, Inc., Pittsburgh PA, 1995). Google Scholar 18 For the parent 2,3,4-C3B3H7 we get IGLO/DZ/MP2(fu)/6-31G* chemical shifts of –52.9 (B1), 0.7 (B5,6), 87.6 (C2,4) and 120.0 (C3); experimental δ11B data :[2b] –57.9 [B(1)), –0.3 (B(5,6)]. Google Scholar 19 Geometric effects can be shown to be less important: A structure based on 7d but with the methyl groups at C(2), C(3) and the bridging methylene group replaced by H (i.e. 7c in the geometry of 7d) gave computed chemical shifts [B(1): –42.3, B(5): 4.0, B(6): –3.1, C(2): 88.4, C(3): 138.0, C(4): –75.1, C(μ-CH2): –9.7] close to those for the optimized 7c geometry. Google Scholar 20 W. Koch, P. v. R. Schleyer, P. Buzek, B. Liu, Croat. Chim. Acta 1992, 65, 655–672 and literature cited. CASWeb of Science®Google Scholar Citing Literature Volume1998, Issue5May 1998Pages 633-637 ReferencesRelatedInformation
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