Microwave Spectrum and Force Constants of SiF2: Centrifugal Distortion

Over 70 rotational transitions of SiF2 ranging up to J=37 have been measured and assigned in the region 8–40 Gc/sec. The microwave spectrum of the v2=1 state of 28SiF2, and the ground vibrational states of 29SiF2 and 30SiF2 have been assigned. A centrifugal-distortion analysis of the spectrum of ground state 28SiF2 has been carried out. It was found that force constants are not determined by the centrifugal-distortion effect alone. Graphical solutions utilizing centrifugal-distortion data expressing the force constants in terms of the harmonic frequencies ω1 and ω3 are presented.