Trithiotungsten(VI) Complexes Having Phosphine-Thiolate Hybrid Ligands: Synthesis and Cluster Forming Reactions with CuBr, FeCl₂, and [Fe(CH₃CN)₆](ClO₄)₂

Five-coordinated trithiotungsten complexes (PPh4)[(dmsp)W(S)3] (1a) and (PPh4)[(dpsp)W(S)3] (1b) (R2PCH2CH2S-; R = Me (dmsp-), Ph (dpsp-)) were synthesized by addition of Hdmsp and Hdpsp to a THF solution of (PPh4)[(EtS)W(S)3]. Treatment of 1a with CuBr in the presence of PPh3 in CH3CN afforded a WCu2 cluster (dmsp)WS3Cu2(PPh3)2Br (2). The reaction of 1a with 1 equiv of FeCl2 went smoothly to generate a 1:1 adduct (PPh4)[(dmsp)WS3(FeCl2)] (3), while 3 did not react further with excess FeCl2. On the other hand, 3 was found to react with [Fe(CH3CN)6](ClO4)2, giving rise to an unusual tetranuclear cluster, [(dmsp)WS3]2Fe2Cl (4), while the reaction of 1a with 2 equiv of [Fe(CH3CN)6](ClO4)2 led to a cyclic octanuclear cluster [(dmsp)WS3Fe]4 (5). Although the oxidation states of W(VI), Cu(I), and Fe(II) are retained in 2 and 3, reduction of the metal ions occurs in the formation of 4 and 5. All the complexes reported in this paper were structurally characterized by X-ray analysis. It is anticipated that the new type of trithiotungsten complexes, 1a and 1b, will serve as potential synthons for various heterometallic sulfide clusters.