Diphenylsilylene.
Lamp or pulsed laser photolysis of 1,1,3,3-tetramethyl-2,2-diphenyl-1,2,3-trisilacycloheptane affords diphenylsilylene (SiPh2) with significantly higher selectivity than that reported previously from other SiPh2 precursors, allowing the direct detection of SiPh2 in solution for the first time. The UV/vis spectrum of the silylene in anhydrous hexane at 25 degrees C, determined by laser flash photolysis methods, agrees well with that obtained in frozen hydrocarbon matrixes, and that of the dimerization product, tetraphenyldisilene, is tentatively assigned. Absolute rate constants measured for the reaction of SiPh2 with a number of characteristic silylene scavengers correspond closely to those reported previously for SiMe2 with the same or similar substrates.
Moiseev
Andrey G
AG
Department of Chemistry, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1.
Leigh
William J
WJ