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With assistance of reactive and coordinative hydrazine, transition-metal telluromercurates [Mn(trien)(N2H4)2]2[Hg2Te4]2 (A), [Zn(trien)(N2H4)2]Hg2Te4 (B), [Mn(tepa)(N2H4)]2Hg4Te12 (C), [TM(trien)(Hg2Te4)] (TM = Mn (D), Zn (E)), and [Zn(atep)]2Hg5Te12 (atep = 4-(2-aminoethyl)triethylenetetramine) (F) were solvothermally prepared in triethylenetetramine (trien) or tetraethylenepentamine (tepa) solvents using elemental Te as precursor in lower temperature range. Compounds A and B consist of mixed coordination cations [TM(trien)(N2H4)2]2+ (TM = Mn, Zn) and one-dimensional polyanion [Hg2Te4]2– with the five-membered Hg2Te3 rings being coplanar. Compound C is composed of two [Mn(tepa)(N2H4)]2+ cations and a [Hg4Te12]4– cluster with a centrosymmetric structure. Compounds D and E consist of coordination polymer [TM(trien) (Hg2Te4)] containing novel doubled [Hg2Te4]n chain with tetrahedrally coordinated Hg(II) centers, which is quite different from the common single chain with the same composition of [Hg2Te4]n. D ...

We report a structural characterization of the molybdenum site of recombinant Escherichia coli trimethylamine N-oxide (TMAO) reductase using X-ray absorption spectroscopy. The enzyme active site shows considerable similarity to that of dimethyl sulfoxide (DMSO) reductase, in that, like DMSO reductase, the TMAO reductase active site can exist in multiple forms. Examination of the published crystal structure of TMAO oxidase from Shewanella massilia indicates that the postulated Mo coordination structure is chemically impossible. The presence of multiple active site structures provides a potential explanation for the anomalous features reported from the crystal structure.

High-resolution molybdenum K-edge X-ray emission spectroscopy (XES) was used to characterize the K beta(4) and K beta' ' valence-to-core transition bands in the oxo-Mo compounds K(2)MoO(4), MoO(S(2)CNEt(2))(2), and MoO(2)(S(2)CNEt(2))(2). The K beta(4) and K beta' ' emission bands are attributed to transitions to the Mo 1s core hole from molecular orbitals possessing primarily molybdenum 4d and oxygen 2s character, respectively. This communication describes the first assignment of the K beta' ' interatomic band in the emission spectra of molybdenum complexes. Additionally, the K beta(4) and K beta' 'transitions are shown to be sensitive to the chemical and electronic environment of the metal, suggesting that high-resolution XES might be an effective method for elucidating the nature of the molybdenum centers in biological systems.