Research Abstract |
The sulfur-bridged incomplete cubane-type aqua ion, [Mo_3S_4(H_2O)_9]^<4+> (A), reacts with metals to give three types of cubane-type mixed-metal aqua ions: Single, [Mo_3MS_4(H_2O)_<10>]^<4+> (M=Fe, Ni); Double, [(H_2O)_9Mo_3S_4MMS_4Mo_3(H_2O)_0]^<8+> (M=Co, Cu); Sandwich, [(H_2O)_9Mo_3S_4MS_4Mo_3(H_2O)_0]^<8+> (M=Sn, Hg). Metals with high reducing power such as Al or Zn cause reformation of the incomplete cubane-type core to give a cluster with a sandwich type core, [(H_2O)_9Mo_3S_4MoS_4Mo_3(H_2O)_0]^<8+>. A mixed metal aqua ion, Mo_3SnS_4(aq)^<6+>, has also been obtained by the reaction of the aqua ion A with tin(II) ion. Incomplete cubane-type molybdenum(IV) and tungsten(IV) mixed-metal clusters with Mo_2WS_4 and MoW2S_4 cores have been prepared and characterized, and their X-ray structures determined. Cubane-type sulfur/oxygen-bridged and sulfur-bridged aqua ions, [Mo_4OS_3(H_2O)_<12>]^<5+> and [Mo_4S_4(H_2O)_<12>]^<5+> have been prepared and characterized, and their X-ray structures determined. A new tungsten(V) complex, [W_2O_2S_2(cys)_2] has been prepared and the X-ray structure determined. A facile preparative method of (NH_4)_3[MoCl_6] has been developed and the X-ray structure determined. Kinetic studies on the oxidation of cubane-type cluster, [Mo_4S_4(edta)_2]^<3-> by Fe(aq)^<3+>, VO^+_, and quinone gave kinetic parameters.
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