The Trimethylsulfonium Ion, [(CH3)3S]⊕, in Hexachlorometallate(IV) Complexes, [(CH3)3S]2MCl6 (M = Pt, Se, Te, Sn). 1H NMR, 35Cl NQR, and X‐Ray Diffraction Studies

The measurements of 35Cl NQR spectra and X-ray powder diffraction patterns were carried out in a series of the complexes of trimethylsulfonium hexachlorometallates(IV), (triMS)2MCl6 (M = Pt, Se, Te, Sn). For (triMS)2TeCl6 and (triMS)2SnCl6, 1H NMR second moments were determined at various temperatures between 77 K and 370 K. The temperature dependence of 1H NMR spin-lattice relaxation times was observed for (triMS)2PtCl6, (triMS)2TeCl6, and (triMS)3SnCl6. From X-ray powder patterns, it was found that the complexes studied are isomorphous with each other and form cubic crystals belonging to the space group T-Pa3. The unit cell dimensions were determined. A single 35Cl NQR line was observed for all of the complexes in agreement with the crystal symmetry. From 1H NMR studies, two kinds of motions of (triMS)⊕, namely, the intracationic CH3 group reorientation and the reorientation of the whole cation about its C3 axis, were observed separately in the above three complexes. The activation energies of these motions were evaluated and compared with those of trimethylammonium ions in hexahalometallate(IV) complexes previously reported.