Silylenes photoextrusion

GENERATION OF SILYLENES BY THERMALLY INDUCED -ELIMINATION AND PHOTOEXTRUSION FROM OLIGOSILANES... 

Bond-order changes upon photoexcitation obtained from Sandorfy SCF-CI calculations have been employed to predict the ease of photoextrusion of a silylene from polysilane chains or rings236. Smaller bond-order changes with longer polysilane chains suggested that they are less efficient silylene sources. Similar conclusions were reached for branched and cyclic polysilanes. This approach focuses on a to a excitation without participation by Si 4s orbitals in descriptions of excited states237. 

Silylene complexes have been prepared by coordination of free silylene, extrusion of dihydrogen from a dihydrosilane, a-hydrogen elimination from a hydrosilyl complex, extraction of hydride, halide, or pseudo-haUde from a metal-silyl complex, and photoextrusion of silylene from a disilanyl complex. Examples of these reactions are shown in Equations 13.39-13.45. 

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