The gas-phase structure of bis(fluorosulfonyl)difluoromethane, (SO2F)2CF2

New synthetic pathways and the infrared spectrum of bis(fluorosulfonyl)difluoromethane, (SO₂F)₂CF₂, are reported. The geometric structure and conformational properties of the title compound have been studied by gas electron diffraction. Depending on the rotational position of the two SO₂F groups, four conformers with different symmetries can occur in this compound: C_2v symmetry, if both S? F bonds stagger the CF₂ group. C₂ or C_s symmetry, if one S?O bond of each group staggers the CF₂ group. The experimental electron diffraction intensities can be fitted equally well with a C₁ conformer or with a mixture of C_2v, C₂ and C_s conformers, in a ratio of 3:2:5. The following geometric parameters (r_a distances, ∠_α angles with 3σ uncertainties) were derived: C? F = 1.340(6) Å, S?O = 1.412(2) Å, S? F = 1.550(3) Å, C? S = 1.848(4) Å, S? C? S = 113.6(7)°, F? C? F = 110.0(10)°, O?S?O = 124.6(18)°, C? S? F = 96.5(16)° and C? S?O = 108.4(14)°.