Metal iodides in polyiodide networks - The structural chemistry of complexthallium iodides with excess iodine

The TII/(R3S)I-x systems (R = Me/Et, x = 3,5,7) have been investigated by m eans of Raman, far-IR, Tl-205 NMR spectroscopy and X-ray diffraction. The r eaction between (Me3S)I-7 and TII results in the polyiodide compound (Me3S) (3)I-26 Raman spectra also reveal the presence of a solid thallium- and iod ine-containing product. However, all attempts to structurally characterise this product were unsuccessful. The compound (Et3S)TlI4 is obtained from th e reaction between (Et3S)I-7 and TlI. Tl-205 NMR spectra show that Tl-III i s present in the reaction mixtures of TlI/(R3S)I-x and that the peak assign ed to TlI4- in the TlI/(Et3S)I-7 system splits upon heating. This effect is reversible and indicates an equilibrium between two Tl-III species.