Synthesis of a linear-type pentanuclear (Rh^III-W^VI-Cu^I-W^VI-Rh^III) sulfide cluster predicted by fast atom bombardment mass spectrometry

The positive ion FAB mass spectrum of a linear trinuclear sulfide cluster, [Cp^*RhP(OEt)₃(μ-WS₄CuCl] (1; Cp^* = η⁵-C₅Me₅), shows many ions heavier than the molecular ion. One of the envelopes corresponds to a pentanuclear cationic cluster of [{Cp^*RhP(OEt)₃(WS₄)}₂Cu]⁺. It has been synthesized by a reaction between [Cp^*RhP(OEt)₃WS₄] and Cu⁺ in a 2:1 molar ratio as the PF₆ salt [{Cp^*RhP(OEt)₃(μ-WS₄)}₂Cu][PF₆] (2 · PF₆), which is characterized by a single-crystal X-ray diffraction, EXAFS, and IR measurements.