Microwave spectrum of sulfuryl chloride fluoride, SO2ClF: structure, hyperfine constants and harmonic force field

Abstract

The pure rotational spectrum of sulfuryl chloride fluoride, SO₂ClF, has been investigated in the frequency range 5.6–24.0 GHz using a pulsed molecular beam microwave Fourier-transform spectrometer. Between 48 and 170 lines of 8 to 26 rotational transitions have been observed for the six isotopomers SO₂ClF, SO₂³⁷ClF, ³⁴SO₂ClF, ³⁴SO₂³⁷ClF, SO ¹⁸OClF and SO ¹⁸O ³⁷ClF (unlabelled atoms indicate ¹⁶O, ¹⁹F, ³²S, and ³⁵Cl) in natural isotopic abundance. The rotational and quartic centrifugal distortion constants have been determined. r₀, r_ΔP and r_s-type structural parameters have been evaluated. A harmonic force field has been calculated to derive ground-state average and estimated equilibrium geometries. The description of the normal modes in terms of internal coordinates is discussed. Chlorine and fluorine hyperfine structures have been resolved, allowing quadrupole coupling (including χ_bc for the isotopomers containing ¹⁸O) and spin–rotation constants to be determined. Variations in the chlorine quadrupole coupling constants with different isotopomers have allowed the Cl quadrupole tensor to be diagonalized and indicate that its z-axis coincides with the SCl bond.