The trigonal–bipyramidal triiodo­thallium(III) complex [TlI3{(CH3)2SO}2]

The title compound, bis(dimethyl sulfoxide)triiodo­thallium(III), TlI₃(C₂H₆OS)₂], was crystallized from equimolar amounts of Tl^II and I₂ in a dimethyl sulfoxide (DMSO) solution. After the initial redox reaction, the thallium(III)–iodo complex forms and precipitates as a DMSO solvate. In the crystal structure, Tl is surrounded by three iodide ligands in the equatorial plane and two O‐coordinated DMSO mol­ecules in the axial positions, forming a slightly distorted trigonal bipyramid. The complex lies on a twofold rotation axis, making the DMSO mol­ecules and two of the I atoms crystallographically equivalent.