FOURIER-TRANSFORM MICROWAVE-SPECTRUM, STRUCTURE, HARMONIC FORCE-FIELD, AND HYPERFINE CONSTANTS OF SULFUR CHLORIDE FLUORIDE, CLSF

The rotational spectrum of sulfur choride fluoride, ClSF, has been obs erved for the first time in the frequency range 8-26 GHz by means of a pulsed molecular jet Fourier-transform microwave spectrometer. The un stable sample molecule has been prepared using a pulsed electrical dis charge in jets containing a mixture of SF6 and SCl2 in Ne. Besides the parent species (ClSF)-Cl-35-S-32-F-19, the isotopomers (ClSF)-Cl-37-S -32-F-19 and (ClSF)-Cl-35-S-34-F-19 could be observed in natural abund ance. Rotational constants and quartic centrifugal distortion constant s as well as nuclear quadrupole coupling constants due to Cl-35 and Cl -37 and spin-rotation constants due to Cl-35, Cl-37, and F-19 are give n. The data were used for the determination of r(0), r(Delta P), r(s) structural parameters. Additionally, the new data were used for the re finement of the molecular harmonic force field. Results from those har monic force field calculations were applied in the evaluation of the g round-state average structure, r(z), and the estimation of the equilib rium structure, r(e). The r(s) structure is r(SF)=160.653(162) pm, r(S Cl)=199.437(65) pm, and angle(ClSF)=100.732(81)degrees. The diagonal e lements of the Cl-35/Cl-37 quadrupole coupling tensors have been obtai ned, and are interpreted in terms of the bonding at Cl-35/Cl-37. Negat ive F-19 spin-rotation constants suggest a close analogy of the electr onic structures of CISF and SF2. (C) 1997 American Institute of Physic s.