The microwave spectrum, structure and dipole moment of thiocarbonyl fluoride, F2CS

The microwave spectrum of thiocarbonyl fluoride, F2CS, has been investigated in the region 26.5-40.0 GHz. Transitions of the F-19(2) (CS)-C-12-S-32 and F-19(2) (CS)-C-12-S-34 isotopic species have been observed and the derived rotational constants yield the following ground state structural parameters r(CF) = 1.315 angstrom +/- 0.01, r(CS) = 1.589 angstrom +/- 0.01, angle FCF = 107.1 degrees +/- 1.0. The ground state rotational constants of the normal species am (in MHz) A(o) = 11892.6 +/- 0.5, B-o = 5133.03 +/- 0.03, C-o = 3580.32 +/- 0.03. The asymmetry parameter, kappa = -0.62640, and the inertial defect Delta(o) = 0.203 u angstrom(2) which is consistent with that expected for this type of molecule. if planar. The dipole moment was determined from the Stark effect of two Lines, and was found to be mu(A) = 0.080 D.