A Stable Bicyclic Compound with Two Si
Si Double Bonds
Takeaki Iwamoto,
Makoto Tamura,
Chizuko Kabuto,
Mitsuo Kira*
In contrast to carbon, silicon does not readily form double bonds,
and compounds containing silicon-silicon double bonds can usually be
stabilized only by protection with bulky substituents. We have isolated
a silicon analog of spiropentadiene 1, a carbon double-ring
compound that has not been isolated to date. In the crystal structure
of
tetrakis[tri(t-butyldimethylsilyl)silyl]spiropentasiladiene 2, a substantial deviation from the perpendicular
arrangement of the two rings is observed, and the silicon-silicon
double bonds are shown to be distorted. Spectroscopic data indicate
pronounced interaction between two remote silicon-silicon double bonds
in the molecule. Silicon-silicon bonds may be more accessible to synthesis than previously assumed.
Department of Chemistry, Graduate School of Science, Tohoku
University, Aoba-ku, Sendai 980-8578, Japan.
*
To whom correspondence should be addressed. E-mail:
mkira{at}si.chem.tohoku.ac.jp
