<
b>Mapped on the image
b> of the reactive differential cross section, the hitherto elusive disilavinylidene molecule (H
b>2b>SiSi) is found to
be initially formed in the gas-phase reaction of ground-state atomic silicon (Si) with silane (SiH
b>4b>) and in equili
brium with the mono-
bridged (Si(H)SiH) and di-
bridged (Si(H
b>2b>)Si) isomers. As shown
by R. I. Kaiser, A. H. H. Chang, J. F. Stanton et al. in their Communication on
page 1264 ff., the dynamics are distinct from those of the isovalent car
bon/methane system, and provide a rare glimpse of unusual silicon chemistry.