title: A stable fused bicyclic disilene as a model for silicon surface.
abstract: We synthesized the first fused bicyclic disilene 1 representing topologically a partial structure of the Si(001) surface up to the third layer. In the solid state, the five-membered rings adopt the envelope conformation, and the Si=Si double bond in 1 exists in the slightly cis-bent form (bent angle theta is 3.6 degrees ) compared to that of the highly cis-bent dimer on the Si(001) surface. Highly symmetric 1H NMR spectral pattern of 1 remains even at -80 degrees C, indicating the facile ring flipping of the bicyclic skeleton in solution. While syn-adduct was obtained in the reaction of 1 with water, anti-addition of chlorine atoms across the Si=Si double bond in 1 was observed in the reaction with carbon tetrachloride. The structural characteristics of the 9,10-phenanthrenequinone adduct 7 are in good accord with those of the proposed structure of the 9,10-phenanthrenequinone molecule adsorbed on the Si(001) surface.
authors.affiliation: PRESTO, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Takeaki
authors.initials: T
authors.lastname: Iwamoto
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Kira