Summary: J. Am. Chem. SOC.1995,117, 5363-5364 5363
Do Silylenes Always Dimerize to Disilenes? Novel
Silylene Dimers with Unusual Structures'
Yitzhak Apeloig* and Thomas Muller
Department of Chemist?
Technion-Ismel Institute of Technology
Haifn 32000, Israel
Received December 28 1994
The isolation of the first indefinitely stable disilene by West,
Fink. and Michl in 19x1I has prompted substantial experimental'
and theoreticalZ activity, leading to the isolation of stable
disilenes 1 with aryl.l.' alkyl,' amino,' and silyl' substituents.
All of these disilenes 1 were synthesized via the dimerization
of the corresponding silylenes (Scheme 1, path a). However,
in principle the dimerization of two silylenes can lead also to
the bridged isomer 2 (Scheme 1. path b). Are unconventional
isomers of disilenes such as 2 thermodynamically and kinetically
stable? Can they be observed?
In this paper we study silylene dimers of type 2 using high
level ab initio calculations. We find that for Y = NH2 the