Syntheses and Structures of Mixed-Metal Sulfido Clusters Containing Trimetallic M<sub>2</sub>M‘S<sub>4</sub> (M = Mo, W; M‘ = Pd, Pt) and Tetrametallic Cubane-Type Mo<sub>2</sub>Pd<sub>2</sub>S<sub>4</sub> Cores

The reaction of the sulfido-bridged dimolybdenum or ditungsten complex [M<sub>2</sub>S<sub>2</sub>(μ<sub>2</sub>-S)<sub>2</sub>(S<sub>2</sub>CNEt<sub>2</sub>)<sub>2</sub>] (M = Mo (<b>1a</b>), W) with an equimolar amount of [M‘(PPh<sub>3</sub>)<sub>4</sub>] (M‘ = Pd, Pt) gave a series of mixed-metal sulfido clusters with a trimetallic M<sub>2</sub>M‘ core [M‘(PPh<sub>3</sub>)(μ<sub>2</sub>-S)<sub>2</sub>{M(S<sub>2</sub>CNEt<sub>2</sub>)}<sub>2</sub>(μ<sub>2</sub>-S)<sub>2</sub>]. The X-ray diffraction study for [Pt(PPh<sub>3</sub>)(μ<sub>2</sub>-S)<sub>2</sub>{W(S<sub>2</sub>CNEt<sub>2</sub>)}<sub>2</sub>(μ<sub>2</sub>-S)<sub>2</sub>] (<b>3b</b>) has disclosed the presence of a novel triangular framework, for which the two Pt−W edges are each bridged by one μ<sub>2</sub>-S ligand and the remaining W−W edge is supported by two μ<sub>2</sub>-S ligands. Cluster <b>3b</b> crystallized in the monoclinic system, space group <i>C</i>2/<i>c</i> with <i>a</i> = 13.718(3) Å, <i>b</i> = 12.795(2) Å, <i>c</i> = 43.798(2) Å, β = 95.24(1)°, and <i>Z</i> = 8. Refinement by full-matrix least-squares techniques gave final residuals <i>R</i> = 0.052 and <i>R</i><sub>w</sub> = 0.038. Treatment of [Pd(PPh<sub>3</sub>)(μ<sub>2</sub>-S)<sub>2</sub>{Mo(S<sub>2</sub>CNEt<sub>2</sub>)}<sub>2</sub>(μ<sub>2</sub>-S)<sub>2</sub>] with an additional amount of [Pd(PPh<sub>3</sub>)<sub>4</sub>] resulted in the formation of the cubane-type mixed-metal sulfido cluster [{Pd(PPh<sub>3</sub>)}<sub>2</sub>{Mo(S<sub>2</sub>CNEt<sub>2</sub>)}<sub>2</sub>(μ<sub>3</sub>-S)<sub>4</sub>], which was also obtained straightforwardly from the reaction of <b>1a</b> with 2 equiv of [Pd(PPh<sub>3</sub>)<sub>4</sub>].