Bis[bis(trimethylsilyl)amino]silylene,an unstable divalent silicon compound

The title compound, (Me3Si)2N]2Si: (1), was prepared by the reduction of (Me3Si)2N]2SiBr2 (2) with potassium graphite at -78 degrees C. Unlike the corresponding germanium and tin compounds, 1 is unstable, but it can be studied in solution at low temperatures. The 29Si NMR chemical shift of 1 measured at -20 degrees C was 223.9 ppm, in good agreement with a value obtained from model calculations of 233 ppm. Reaction of solutions of 1 with methanol or phenol gave the trapping products expected for the silylene, (Me3Si)2N]2Si(H)OR (R = CH3, C6H5).