Abstract

The vibration-rotation spectrum of silicon monosulfide, an important astrophysical molecule, has been observed in emission between 640 and 800 cm^–1 using the Fourier-transform spectrometer associated with the McMath Solar Telescope at Kitt Peak. Gas-phase SiS was produced by the reaction of solid silicon with silicon disulfide, SiS₂, in an alumina heat pipe oven. More than 2400 lines were assigned to four isotopomers (²⁸Si³²S, ²⁸Si³⁴S, ²⁹Si³²S and ³⁰Si³²S). The data for all the isotopomers series were fitted together using the mass-reduced Dunham expression including Watson's Born-Oppenheimer breakdown coefficients. The infrared spectrum of the antisymmetric stretching mode, v3, of BeF₂ has been observed in emission near 1530 cm^-1. Gas-phase BeF₂ was produced by heating solid beryllium difluoride to about 800°C in a heat pipe oven. The spectra were recorded at a resolution of 0.005 cm^–1 using a KC1 beam splitter and Si:As detectors.

© 1990 Optical Society of America