Electron diffraction study on the molecular structure of methane sulphonyl fluoride

The molecular structure of methane sulphonyl fluoride in the vapour state was studied by electron diffraction. Assuming a value of 2.480A?for the distance between the oxygen atoms from a microwave determination, the following geometrical parameters (r_a structure) have been obtained: r(C-H) = 1.093±0.010Å, r(S-O) = 1.410±0.003Å, r(S-F) = 1.561 ±0.004Å, r(S-C) = 1.759±0.006Å, ∠F-S-C = 98.2±1.5°, ∠-S-F = 106.2±0.4°, ∠-O-S-O = 123.1 ±1.5° and ∠H-C-H = 112.9±1.9°. All the observed variations in the molecular geometries of (CH₃)₂SO₂, CH₃SO₂Cl, CH₃SO₂F and SO₂F₂ may be accounted for by the valence shell electron pair repulsion theory. It is particularly advantageous to combine electron diffraction and microwave data in studying sulphone molecular geometries.