Syntheses and characterization of cubane-type clusters with molybdenum-iron-sulfur (Mo3FeS4) or molybdenum-nickel-sulfur (Mo3NiS4) cores. X-ray structures of [Mo3FeS4(H2O)10](CH3C6H4SO3)4.7H2O and [Mo3FeS4(H2O)(NH3)9]Cl4, and discrete variational (DV)-Xα calculation of the electronic structures of [Mo3FeS4(H2O)10]4+, [Mo3FeS4(H2O)(NH3)9]4+, and [Mo3NiS4(H2O)10]4+

Shibahara, Takashi; Sakane, Genta; Naruse, Yoshiyuki; Taya, Kazuhisa; Akashi, Haruo; Ichimura, Akio; Adachi, Hirohiko

crystal structure iron molybdenum sulfur cubane; molybdenum iron sulfur aqua cubane cluster; electronic structure molybdenum iron nickel cubane; ammine molybdenum iron sulfur aqua cubane; structure molybdenum iron sulfur aqua cubane; nickel molybdenum sulfur cubane electronic structure; XPS molybdenum iron nickel sulfur cubane
Reaction of the incomplete cubane-type cluster [Mo3S4(H2O)9]6+ (A) with iron gives a novel cubane-type aqua cluster [Mo3FeS4(H2O)10](MeC6H4SO3)4.7H2O (B').  An ammonia coordinated deriv. cluster [Mo3FeS4(H2O)(NH3)9]Cl4 (C') is also synthesized.  X-ray structural analyses of B' and C' revealed that the clusters, [Mo3FeS4(H2O)10]4+ (B) and [Mo3FeS4(H2O)(NH3)9]4+ (C), have an approx. symmetry of C3v.  The iron atom has fairly regular tetrahedral geometry in both clusters.  The effective magnetic moments of B' at 2.16 K and 269.95 K are 2.78 and 3.26 B.M., resp.  57Fe-Moessbauer spectroscopy showed that the oxidn. states of iron in B' and C' were assignable to be +2.39 and +2.54, resp., which indicates that the reaction is a reductive addn. of an iron atom to the Mo3S4 core in A.  The cyclic voltammograms of A, B, and [Me3NiS4(H2O)10]4+ (D) show three consecutive one electron reductive steps, resp., and the oxidn. states of metals in B and D are assigned as MoIVMo2IIIMII (M = Fe, Ni).  Discrete variational (DV)-Xa calcn. of B, C, and D explains the magnetic behavior, XPS spectra, and reactivity toward CO, C2H2, and C2H4.

Bulletin of the Chemical Society of Japan

Chemical Society of Japan

68

10

2769

2782