Chapter 28. The Rotational Isomerism of the Disilanes tBuX2SiSiX2tBu (X = Cl, Br and I): A Combined Raman Spectroscopic, X-Ray Diffraction and Ab Initio Study

  1. Prof. Norbert Auner2 and
  2. Prof. Johann Weis3
  1. Robert Zink,
  2. Harald Siegl and
  3. Karl Hassler

Published Online: 28 APR 2008

DOI: 10.1002/9783527619917.ch28

Organosilicon Chemistry IV: From Molecules to Materials

Organosilicon Chemistry IV: From Molecules to Materials

How to Cite

Zink, R., Siegl, H. and Hassler, K. (2000) The Rotational Isomerism of the Disilanes tBuX2SiSiX2tBu (X = Cl, Br and I): A Combined Raman Spectroscopic, X-Ray Diffraction and Ab Initio Study, in Organosilicon Chemistry IV: From Molecules to Materials (eds N. Auner and J. Weis), Wiley-VCH Verlag GmbH, Weinheim, Germany. doi: 10.1002/9783527619917.ch28

Editor Information

  1. 2

    Inst. für Anorganische Chemie, der Universität Frankfurt, Marie-Curie-Strasse 11, D-60439 Frankfurt am Main, Germany, Phone: 0 69/7 98-29180, -29591, Fax: 069/798-29188

  2. 3

    Wacker-Chemie GmbH, Geschäftsbereich S, Werk Burghausen, Johannes-Hess-Strasse 24, D-84489 Burghausen, Germany

Author Information

  1. Institut für Anorganische Chemie Technische Universität Graz Stremayrgasse 16, A-8010 Graz, Austria

Publication History

  1. Published Online: 28 APR 2008
  2. Published Print: 17 JAN 2000

ISBN Information

Print ISBN: 9783527298549

Online ISBN: 9783527619917

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Keywords:

  • tert-butyldisilane;
  • rotational isomerism;
  • raman spectroscopy;
  • ab initio calculations;
  • X-ray diffraction

Summary

Ab initio calculations predict the existence of anti and gauche rotamers for the disilanes tBuX2SiSiX2tBu (X = Br and I). For the chloro compound a third backbone conformer with a CSiSiC dihedral angle of 95° (ortho) was located on the potential energy surface. Due to the fact that the vibrational spectra of these disilanes are hardly sensitive to the conformation around the Si-Si bond we have not been able to determine energy differences between conformers from variable-temperature Raman spectra. Infrared and Raman spectroscopy suggest that anti and twisted conformers are present in liquid and solid tBuCl2SiSiCl2tBu. For X = Br and I the anti conformation is adopted in the solid state, as proven by X-ray diffraction and vibrational spectroscopy.