PREPARATION AND PROPERTIES OF THE CORNER-SHARED DOUBLE CUBE [MO6PBS8(H2O)(18)](8-)() AS A DERIVATIVE OF [MO3S4(H2O)(9)](4)

The heterometallic corner-shared double-cuboidal cluster [Mo6PbS8(H2O) (18)](8+), with the lead atom common to both cubes, has been prepared for the first time by the reaction of [Mo3S4(H2O)(9)](4+) with lead sh ot, which requires up to 1 h to reach completion, and by addition of a solution mix of [Mo3S4(H2O)(9)](4+) and Pb-II to an excess of BH4-, w hen reaction is rapid. The air-sensitive blue-green product has UV/VIS absorbance bands at 387 and 757 nm in 2.0 M HClO4. Inductively couple d plasma atomic emission spectroscopy confirmed the Mo:Pb:S ratio as 6 :1:8. It was eluted from a cation-exchange column with 4 M Hpts (tolue ne-p-sulfonic acid), but not 2 M Hpts (or 4 M HClO4), consistent with a high charge, confirmed as 8+ from the 2:1 stoichiometries for the ox idation reactions with e.g. [Co(dipic)(2)](-) (dipic = pyridine-2,6-di carboxylate) or [Fe(H2O)(6)](3+), which yield [Mo3S4(H2O)(9)](4+). Kin etic studies on the oxidations with [Co(dipic)(2)](-) and [Fe(H2O)(6)] (3+) were also carried out as part of an overall appraisal of the reac tivity of the heterometallic clusters.