STRUCTURE OF SILOXENE AND LAYERED POLYSILANE (SI6H6)

Powder-x-ray-diffraction measurements on siloxene and calculations of the diffraction patterns for the three commonly proposed structures of siloxene (Si6H6O3) clearly show that only a structure with silicon la yers is ever:observed. The formation of siloxene from CaSi2 is topotac tic, with the Si layers remaining intact and with no oxygen insertion into these layers. Siloxene prepared at 0 degrees C has very little ox ygen incorporated into the interlayer gaps, and can be described as hy drogen terminated silicon layers (Si6H6), which we call layered polysi lane. Layered polysilane can be purified by reaction with aqueous HF a nd is pyrophoric on contact with air. In some sense, layered polysilan e can be considered the silicon equivalent of graphite.