Syntheses and Electrochemistry of Incomplete Cubane-Type Clusters with M3S4 Cores (M=Mo,W). X-ray Structures of [W3S4(H2O)9](CH3C6H4SO3)4･9H2O, Na2[W3S4(Hnta)3]･5H2O, and (bpyH)5[W3S4(NCS)9]･3H2O

Shibahara, Takashi; Yamasaki, Mikio; Sakane, Genta; Minami, Ken'ichi; Yabuki, Toru; Ichimura, Akio

electrochem redn molybdate tungstate sulfido trinuclear; nitrilotriacetato molybdate tungstate sulfido trinuclear complex; crystal structure tungstate sulfido trinuclear complex
Facile synthetic methods for [Mo3(μ3-S)(μ-S)3(H2O)9]4+ and [W3(m3-S)(m-S)3(H2O)9]4+ are described, (NH4)2MoS4 (or Na2[Mo2O2S2(cys)2].4H2O; H2cys = cysteine) and (NH4)2WS4 being used for starting materials, resp. Synthetic methods for deriv. clusters with M3S4 cores (M = Mo, W), [W3S4(Hnta)3]2-, [W3S4(NCS)9]5-, and [Mo3S4(Hnta)3]2- (H3nta = nitrilotriacetic acid) are described. Crystal structures of [W3S4(H2O)9](CH3C6H4SO3)4.9H2O (1), Na2[W3S4(Hnta)3].5H2O (2), and (bpyH)5[W3S4(NCS)9].3H2O (3; bpy = 2,2'-bipyridine) were detd. 1 Crystd. as triclinic, space group P1-, Z = 2, R = 0.0468, Rw = 0.0596. 2 Crystd. as monoclinic, space group P21/a, Z = 4, R = 0.0428, Rw = 0.0725. 3 Crystd. as triclinic, space group P.hivin.1, Z = 2, R = 0.0536, Rw = 0.0737. The cluster cation and anions have an approx. symmetry of C3v. Current-sampled d.c. polarograms and cyclic voltammograms of [M3S4(Hnta)3]2- (4; M = Mo, W) show 3 consecutive 1-electron reductive steps in alk. soln. (pH 11-12): E1/2 (V vs Ag/AgCl) = -0.64, -1.08, -1.39; -1.12, -1.41, -1.88, resp.  These steps correspond to the change of oxidn. states of the 3 metals in each cluster: (IV,IV,IV) -> (IV,IV,III) -> (IV,III,III) -> (III,III,III).  Electronic spectra of 1-electron redn. products, the oxidn. state being (IV,IV,III), obtained by bulk electrolyses of 4 and are reported, and the absorption max. are 400, 620, and 720sh nm for [Mo3S4(Hnta)3]3- and 557, 597, and 708 nm for [W3S4(Hnta)3]3-.

Syntheses and Electrochemistry of Incomplete Cubane-Type Clusters with M3S4 Cores (M=Mo,W). X-ray Structures of [W3S4(H2O)9](CH3C6H4SO3)4･9H2O, Na2[W3S4(Hnta)3]･5H2O, and (bpyH)5[W3S4(NCS)9]･3H2O

Inorganic Chemistry

American Chemical Society

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