[en] This patent describes a composition of matter. It has the formula [A_w(R₄X _n - H₃O)_s]{(Mo₂O₄)_p(O)_q[PO_4-x]r} mH₂O where A is Li, Na, K, Rb, Cs, Tl, Mg, Ca, Sr, Ba, NH₄ or combinations thereof R = C₆H₅, or C_αH_2α+1; X is N, P, As, or combinations thereof; Mo has oxidation state ≤ + 5; n > o; s ≥ o; p,r > 0; q,w,m ≥o; and o ≤ x < 4

[en] The molybdenum (IV) diphosphate crystallizes in the Pa3 space group with a = 7.944(1) A. The refinement of the atomic parameters with 55 reflections leads to R = 0.048 and R ω = 0.056. The tridimensional framework is built up from Mo0₆ octahedra sharing their corners with P₂0₇ groups. These polyhedra are in mixed layers which exhibit pentagonal windows. 20 refs

[en] An automatic spectrophotometric method for the determination of europium in the presence of yttrium and other lanthanides is described. The method is based on a modification of a recently devised manual procedure consisting of the reduction, on a Jones reductor, of europium(III) to europium(II) which is used to reduce molybdophosphate to a molybdenum blue. The method is capable of analysing solutions containing 10-400 μg of europium per ml at a rate of 20 samples per hour. There is no interference from yttrium or other lanthanides and the method is suitable for application to europium determining after a group separation. When applied to mineral samples coefficients of variation between 2.5 and 3.8% were obtained. (orig.)

No abstract available

[en] A Mo(V) oligophosphate, built up of di and triphosphate groups, Cs(MoO)₄(P₂O₇)₂(P₃O₁₀) has been synthesized for the first time. This compound crystallizes in the triclinic P-1 space group with a=9.411(1)A, b=10.754(1)A, c=12.517(1)A, α=94.534(6)^o, β=102.520(6)^o, γ=103.663(4)^o. This original structure can be described by the association of MoO₆ octahedra, MoP₂O₁₁ units built up of one P₂O₇ group sharing two apices with the same MoO₆ octahedron, and triphosphates groups P₃O₁₀. The resulting tridimensional framework forms large S-shaped tunnels running along c where the Cs⁺ cations are located

[en] By using amines with different lengths, two layered cobalt-molybdenum phosphates with different interlayer distances, (C₂N₂H₁₀) [HCo(H₂O)₂P₂MoO₁₀] (1), and (C₃N₂H₁₂)₄{Co₃ [P₄Mo₆O₂₆(OH)₅]₂}. 5H₂O (2), have been hydrothermally synthesized and characterized. In compound 1, the H₂en direct the [CoMoP₂] clusters to form a layered framework. By changing the lengths of protonated organic amines (H₂en to 1, 3-H₂pn), compound 2 is obtained, in which the sandwich-shaped [Co (Mo₆P₄)₂] clusters are linked by tetrahedrally coordinated cobalt into a layered framework. With the lengths of protonated organic amines increasing, the interlayer distances in compound 2 become larger. This work successfully demonstrates that tuning the lengths and conformation of the protonated organic amines can provide a facile route for the formation of organically templated inorganic open-framework materials. Additionally, susceptibility measurement shows that the two compounds both exhibit antiferromagnetic interactions. -- Graphical abstract: By using amines with different lengths, two layered cobalt-molybdenum phosphates with different interlayer distances have been hydrothermally synthesized. Display Omitted Research highlights: → Two layered compounds have been synthesized by utilizing amines with different lengths. → The chain lengths of amines can influence the overall supramolecular framework of the PMo-TMCs. → The conformation of amines may influence the stacking mode of the inorganic building blocks. → Susceptibility measurement shows that the two compounds both exhibit antiferromagnetic interactions.

[en] Highlights: • NASICON-type NaMo₂(PO₄)₃ electrode material was prepared by freeze-drying technique. • NaMo₂(PO₄)₃ shows partially reversible Na-deintercalation above 3.6 V vs. Na/Na⁺. • Reversible insertion of 1.8 Na occurs at 2.45 V vs. Na/Na⁺ via two-phase mechanism. • Na-rich Na_1+xMo₂(PO₄)₃ phase maintains the NASICON-type framework. Vital need to reduce battery cost inspired intensive research in the field of sodium-storage systems, which required extending the range of perspective electrode materials. Herein, we present a new member of the electrochemically active NASICON material family, rhombohedral NaMo₂(PO₄)₃, which demonstrates both Mo⁺⁴/Mo⁺⁵ and Mo⁺⁴/Mo⁺³ redox activities towards sodium (de)intercalation. Desodiation of the initial NaMo₂(PO₄)₃ material with subsequent discharge within the 1.2–4.0 V range leads to a multi-electron redox transition with reversible capacity of 130 mAh g⁻¹. However, the single Mo⁺⁴/Mo⁺³ redox transition at 2.45 V (vs. Na/Na⁺) with capacity of 95 mAh g⁻¹ was found to be more stable during cycling, and operando X-ray diffraction confirmed its two-phase mechanism. Sodiation of the initial phase results in Na_2.5Mo₂(PO₄)₃, which maintains the parent NASICON structure (R-3c, a = 8.90532(7) Å, c = 22.2379(3) Å, V = 1527.30(3) ų), with two Na-positions being almost equal in occupancy and energy.

No abstract available

[en] Two new Mo(V) and Mo(V)/Mo(VI) phosphates, β-Ba(MoO)₂(P₂O₇)₂ and Ba(MoO)₂O(P₂O₇)PO₄, with original tunnel structures have been synthesized. The first one crystallizes in the space group P2₁/n with a=8.004A, b=7.899A, c=9.539A, β=91.67^o, and the second one in the space group Cc with a=13.020A, b=9.686A, c=8.636A, β=99.50^o. β-Ba(MoO)₂(P₂O₇)₂ shows close relationships with the α-form, i.e., it consists of similar MoP₂O₁₁ units sharing their apices and forming [MoP₂O₁₀]_∞ chains. It differs from the latter by the configuration of the chains, so that one chain is linked to four other identical chains, instead of six chains in the α-form. Like the α-form, the β-form exhibits intersecting tunnels running along [010] and [011] direction where the Ba²⁺ cations sit. The 3D-framework of the second phosphate Ba(MoO)₂O(P₂O₇)PO₄, is built up of MoO₆ octahedra, P₂O₇ groups, and PO₄ tetrahedra, can be described by the assemblage of zig-zag [Mo₂P₂O₁₄]_∞ chains through PO₄ tetrahedra, forming large tunnels running along c-vector, occupied by Ba²⁺ cations. In this framework one observes that adjacent tunnels communicate through large six-sided windows, showing the opened character of this structure. The magnetic behaviour of these phosphates is discussed with respect to the results previously obtained by Canadell et al. [Chem. Mater. 9 (1997) 68]

[en] A simplified method for synthesis of the white form of molybdenyl phosphate of the empirical composition 2MoO₃xP₂O₅x5H₂O was proposed and its some properties were studied. The synthesis was performed by dissolving H₂MoO₄ in H₃PO₄ at room temperature. The solution obtained was heated up to 50-60 deg C and molybdenyl phosphate was crystallized during 6-8 hours on stirring. Thermographic, X-ray diffraction and infra-red studies were made of the compound synthesized and its formula Mo(OH)₃xPO₄xH₂O was established. On the basis of thermal analysis one may conclude that at 100-150 deg C crystal water is removed and at higher temperatures constitution water evolves as a result of destruction of hydroxonium ions and hydroxyl groups