Hexakis (trialkylsilyl) cyclotrisilanes 1a (trialkylsilyl= tert-butyldimethylsilyl) and 1b (trialkylsilyl= diisopropylmethylsilyl) were synthesized by the reductive coupling of the corresponding 2, 2-dibromotrisilanes. Their molecular structures were confirmed by X-ray crystallography. In the absence of trapping reagents, photolysis of cyclotrisilanes 1a and 1b gave the corresponding stable tetrakis (trialkylsilyl) disilenes quantitatively. Irradiation of ...