Trichlates, an Unattended Class of Compounds: Characterization of Cl3 CSO2 Cl, and (H5 O2 )[Cl3 CSO3 ]

Chlorination of CS2 leads to trichloromethanesulfenyl chloride, Cl3 CSCl, in moderate yields. The oxidation of Cl3 CSCl with H2 O2 gives Cl3 CSO2 Cl, the chloride of trichloromethanesulfonic acid. Cl3 CSO2 Cl is the crucial product for the preparation of trichloromethanesulfonates ("trichlates") and has been characterized by IR spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction measurements (P-1, a=609.99(5) pm, b=727.45(6) pm, c=782.49(7) pm, α=80.644(3)°, β=85.175(3)°, γ=88.311(3)°. The acid Cl3 CSO3 H can be gained in form of the hydrate (H5 O2 )[Cl3 CSO3 ] in two different modifications (I: monoclinic, P21 /n, Z=8, a=1292.47(7) pm, b=605.89(2) pm, c=2661.1(1) pm, β=98.708(4)°, V=1672.8(1) Å3 ; II: monoclinic, Cc, Z=4, a=699.80(5) pm, b=1054.72(8) pm, c=1139.88(8) pm, β=95.303(3)°, V=837.7(1) Å3 . Both modifications have been investigated by IR spectroscopy, thermal analyses and theoretical calculations.