Chapter 11. Binuclear Ethylene-Bridged Silicon Chelates: Equilibrium between Neutral Hexacoordinate and Ionic Pentacoordinate Siliconium Complexes

  1. Prof. Dr. Norbert Auner3 and
  2. Prof. Dr. Johann Weis4
  1. Inna Kalikhman1,
  2. Vijeyakumar Kingston1,
  3. Daniel Kost1,
  4. Dietmar Stalke2 and
  5. Bernhard Walfort2

Published Online: 5 MAY 2008

DOI: 10.1002/9783527619924.ch11

Organosilicon Chemistry V: From Molecules to Materials

Organosilicon Chemistry V: From Molecules to Materials

How to Cite

Kalikhman, I., Kingston, V., Kost, D., Stalke, D. and Walfort, B. (2003) Binuclear Ethylene-Bridged Silicon Chelates: Equilibrium between Neutral Hexacoordinate and Ionic Pentacoordinate Siliconium Complexes, in Organosilicon Chemistry V: From Molecules to Materials (eds N. Auner and J. Weis), Wiley-VCH Verlag GmbH, Weinheim, Germany. doi: 10.1002/9783527619924.ch11

Editor Information

  1. 3

    Department of Inorganic Chemistry, University of Frankfurt, Marie-Curie-Straße 11, 60439 Frankfurt am Main, Germany

  2. 4

    Consortium of Electrochemical Industry GmbH, Zielstattstraße 20, 81379 Munich, Germany

Author Information

  1. 1

    Department of Chemistry, Ben-Gurion University of the Negev Beer-Sheva 84105, Israel Tel: +972 8 646 1192 — Fax: +972 8 647 2943

  2. 2

    Institut für Anorganische Chemie, Universität Würzburg, D-97074 Würzburg, Germany Tel.: +49 931 888 4783 — Fax: +49 931 888 4619

Publication History

  1. Published Online: 5 MAY 2008
  2. Published Print: 26 SEP 2003

ISBN Information

Print ISBN: 9783527306701

Online ISBN: 9783527619924

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Keywords:

  • siliconium cations;
  • hexacoordinate silicon;
  • binuclear silicon complexes

Summary

Binuclear hexacoordinate silicon complexes with two N[RIGHTWARDS ARROW]Si dative bonds (per Si atom) have been prepared. The crystal structure conforms to a distorted octahedron, with the N[RIGHTWARDS ARROW]Si bonds trans to each other. The binuclear complex undergoes Si-Cl dissociation of one Si–Cl bond in CD2Cl2 and CDCl3 solution, to form a binuclear, monosiliconium chloride salt, in reversible equilibrium with its precursor. The dissociation and equilibrium reactions are observed by variable-temperature 29Si NMR spectra. The extent of ionic dissociation increases as the temperature is decreased. The equilibrium population ratio is shifted completely to the di-ionic side at room temperature, by replacement of the chloride by the less nucleophilic triflate anion. The crystal structure of a disiliconium ditriflate shows a) well separated ions, b) that the geometry about silicon is almost an exact square pyramid, and c) that the N[RIGHTWARDS ARROW]Si bonds are among the shortest coordination bonds of this kind.