Synthesis, structural characterization, and crystal structure of bis(triphenylsulfonium)tetrachlorocuprate(II)

The synthesis and crystal structure of bis(triphenylsulfonium)tetrachlorocuprate(II) are reported. Single-crystal X-ray diffraction analysis revealed that the compound crystallizes in the monoclinic crystal system, space group Pn, with unit-cell parameters a = 10.4463(1) Å, b = 10.0143(1) Å, c = 16.0734(1) Å, β = 99.090(1)°, V = 1660.36(3) Å3, and Z = 2. The asymmetric unit consists of two crystallographically independent triphenylsulfonium cations and one tetrachlorocuprate(II) anion. Both sulfonium centers adopt distorted trigonal-pyramidal geometries, with S-C bond lengths ranging from 1.779(4) to 1.792(4) Å and C-S-C bond angles between 103.6(2) and 105.40(19)°. The [CuCl4]2- anion exhibits a significantly distorted tetrahedral geometry characterized by Cu-Cl bond lengths of 2.2364(13)-2.2723(11) Å, Cl-Cu-Cl bond angles of 96.15(5)-139.70(5)°, and a τ4 value of 0.59, indicative of a flattened tetrahedral (seesaw-like) coordination environment. The observed structural parameters are consistent with those reported for related triphenylsulfonium and tetrachlorocuprate(II) salts, confirming the characteristic distortion of the [CuCl4]2- unit in this class of compounds.