Phosphorescent Complexes of {Mo6I8}4+ and {W6I8}4+ with Perfluorinated Aryl Thiolates featuring Unusual Molecular Structures

A series of six novel cluster complexes [M6I8(SArf)(6)](2-) (M=Mo or W; SArf = p-SC6F4-C6F5, or p-SC6L4Cl, or p-SC6F4CF3) was prepared by exchange reactions between [Mo6I14](2-) or [W6I14](2-) and silver salts of the corresponding thiols and characterized by X-ray single-crystal diffraction and elemental analysis, NMR, ESI-MS, and CV techniques. In the crystal structures all the thiolate ligands adopt an idiosyncratic orientation along one of the idealized three-fold axes passing through two opposite mu(3)-I ligands and the centers of two opposite faces of the M-6 octahedra. This leads to shortened intramolecular distances inside the cluster below 3.5 angstrom. The clusters exhibit red photoluminescence with relatively high quantum yield, up to 0.42 in the case of (Bu4N)(2)[W6I8(SC6F4CF3)(6)]. Moreover, all the compounds exhibit X-ray luminescence; the close values of the maxima in the photo- and X-ray induced emission spectra indicate that the luminescence is cluster-centered.

Automated summary

In this study, a series of novel cluster complexes were synthesized and characterized. These clusters exhibit unique crystal structures and display efficient photoluminescence and X-ray luminescence properties.