Cationic Si-H-Si Bridges in Polysilanes: Their Detection and Targeted Formation in Stable Ion Studies.
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.
Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Str. 9-11, 26111, Oldenburg, Germany.
Lena
0000-0002-1853-0857
L
Albers
Institut für Chemie, Universität Graz, Stremayrgasse 9, 8010, Graz, Austria. baumgartner@tugraz.at.
Judith
0000-0002-9938-1813
J
Baumgartner
Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, 8010, Graz, Austria. christoph.marschner@tugraz.at.
Christoph
0000-0001-8586-2889
C
Marschner
Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Carl von Ossietzky Str. 9-11, 26111, Oldenburg, Germany. thomas.mueller@uni-oldenburg.de.
Thomas
0000-0002-4247-3776
T
Müller
cations; density functional calculations; polysilanes; reaction mechanisms; silicon