Trinuclear, tetranuclear and octanuclear chalcogenido clusters of molybdenum and tungsten supported by trimethylphosphine ligands

摘要

A variety of trinuclear, tetranuclear and octanuclear chalcogenido compounds of molybdenum and tungsten that are supported by PMe3 ligands has been synthesized and structurally characterized by X-ray diffraction. For example, the tetranuclear sulfido cluster, Mo4S6(SH)(2)(PMe3)(6), has been obtained by reaction of Mo(PMe3)(6) with H2S, while the trinuclear selenido and tellurido compounds, Mo3Se5(PMe3)(6) and Mo3Te3(PMe3)(6), may be obtained by thermolysis of Mo(PMe3)(4)Se-2 and Mo(PMe3)(4)Te-2, respectively. In contrast to the formation of a trinuclear compound analogous to Mo3E6(PMe3)(6) (E = Se, Te), thermolysis of the tungsten complex, W(PMe3)(4)S-2, produces the octanuclear sulfido cluster, W8S16(PMe3)(10). Of these compounds, Mo4S6(SH)(2)(PMe3)(6) and W8S16(PMe3)(10) possess M:S stoichiometries of 1:2 and so may be regarded as molecular derivatives of the respective disulfides, MS2, which are important components of hydrotreating catalysts. (C) 2014 Elsevier Ltd. All rights reserved.