Molybdates structural

A substantial number of Mo peroxo complexes has been structurally characterized. These complexes all have nearly symmetrically side-on-bound peroxide. Among them are mononuclear, dinuclear, tetranuclear and heptanuclear compounds. The tetranuclear and hep-tanuclear complexes are related to the isopoly molybdates. Structural studies have identified... 

The plutonium-bearing precipitate obtained from nitric acid solutions (containing molybdenum, zirconium and plutonium) gives an X-ray powder diffraction pattern not distinguishable from that of ZrMo207(0H)2(H20)2 precipitated without plutonium. However, since the Pu content is low, the Pu could be present either in the Pu molybdate structure or replacing Zr in the Zr molybdate structure and not be detected in the X-ray patterns. 

Present data on the Zr and Pu molybdates have not provided evidence for the existence of heteropoly molybdate structures for those precipitates obtained from 1-5M HN03. 

Zachariasen1s empirical rules relating bond strengths and bond lengths in 4f and 5f oxides is demonstrated to be useful when applied to the simple and complex molybdate structures (12). 

Characterization data evidenced that the prepared NiMo04 is stoichiometric and that Cs is deposited only on the catalyst surface (atomic ratio Cs/Mo = 0.03) not affecting the molybdate structure. However, Cs doping causes a decrease of the catalyst surface area Sbet (NiMo04) = 44.1 m /g and Sbet (3% Cs-NiMo04) = 28.7 mVg. Moreover, the promoted sample exhibits a higher surface basicity, electrical conductivity and also a larger resistance to reduction [4,5,12]. 

The ferric molybdate, Fe2(Mo04)3, has a structure related to the garnet type but without cations in the 8-coordinated sites. The quadrupole splitting of 0-25 mm s at room temperature is only half that found in conventional garnets, implying that the octahedral Fe " site has a lower distortion in the molybdate structure [175]. 

Eug(W07)3.5H20. The presence of five water molecules in the tungstate structure, that is, an extra molecule in relation to the molybdate, can be pointed out as the main factor leading to such quenching phenomena. Furthermore, the presence of a larger number of oxygen atoms in the molybdate structure can promote efficient energy absorption and transfer to the europium cation. 

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