EXPERIMENTALLY DETERMINED STRUCTURE OF H2SIO BY ROTATIONAL SPECTROSCOPY AND ISOTOPIC-SUBSTITUTION

The rotational submillimeter-wave spectra of four isotopomers of silan one, H-2 (SiO)-Si-29-O-16, H-2 (SiO)-Si-30-O-16, H-2 (SiO)-Si-28-O-18, and D-2 (SiO)-Si-28-O-16, have been measured for the first time. Thes e reactive species were produced by a low-power ''abnormal'' glow disc harge in a mixture of silane and oxygen. The observation of the deuter ated species required the prior synthesis of SiD4. Anomalies in the sp ectrum of the parent species, measured previously, were shown to be du e to a Stark splitting caused by the discharge. The fitted rotational constants were used to determine the r(m)(r)ho structure of silanone. The bond lengths and angles have been determined as Si=O 1.515 Angstro m, Si-H 1.472 Angstrom, <HSiH 112.0 degrees. The precision of these re sults is expected to be better than 0.002 Angstrom for the bond length s and 0.2 degrees for the bond angle. (C) 1996 Academic Press, Inc.