Synthesis, characterization and luminescence property of heterobimetallic trinuclear Mo(W)–Ag–S clusters containing 1,2-bis(diphenylphosphino)-1,2-dicarba- closo-dodecaborane

Abstract

Reactions of (NH 4) 2MS 4 or (NH 4) 2MOS 3 (M = Mo, W) with AgSCN and closo carborane diphosphine ligand 1,2-(PPh 2) 2-1,2-C 2B 10H 10 (L) in CH 2Cl 2 yielded four heterobimetallic trinuclear Mo(W)–Ag–S clusters: [Ag 2MoS 4L 2] ( 1), [Ag 2WS 4L 2] ( 2), [Ag 2MoOS 3L 2] ( 3) and [Ag 2WS 4L 2] ( 4), respectively. All the new clusters have been characterized by elemental analysis, FT-IR, UV–Vis, 1H and 13C NMR spectroscopy and their molecular structures (except for 3) were further confirmed by single-crystal X-ray diffraction. X-ray crystal structure analysis showed that the closo carborane diphosphine ligand was coordinated bidentately to Ag(I) atom through its two phosphorus atoms, resulting in a stable five-member chelating ring between the diphosphine ligand and the metal. The coordination sphere of the central M atom, as well as all the Ag atoms, was tetrahedron. The skeletons of these clusters could be classified into two types: with (NH 4) 2MS 4, the three metal atoms (two Ag atoms and one M atom) are in a linear conformation, while with (NH 4) 2MOS 3, the conformation of the heterobimetallic trinuclear cluster is butterfly shaped. The luminescence properties of the clusters were investigated in CH 2Cl 2 solution at room temperature and for the first time the butterfly-shaped Ag–W–S cluster containing the Ag 2WS 4 core has been proved to show luminescence property.