Molybdenum (IV) pyrophosphate isostructural with ZrP2O7

Kinomura, Nobukazu; Hirose, Mitsuaki; Kumada, Nobuhiro; Muto, Fumio

doi:10.1016/0025-5408(85)90004-2

Cited by 18 publications

(2 citation statements)

References 9 publications

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“…A cubic structure is found for phosphates of the type A 4+ P 2 O 7 , where A 4+ may be Si, Ge, Sn, Pb, Ti, Zr, Hf, Mo, W, Re, Ce, Th, U, or Pu. − Double substitution on the A site leads to a series of the type A 3+ 0.5 A 5+ 5.5 P 2 O 7 , where A 3+ may be Bi, Sb, or a rare earth and A 5+ may be Nb, Ta, or Sb . One form of Sb 3+ Sb 5+ (P 2 O 7 ) 2 also has a closely related structure …”

Section: Introductionmentioning

confidence: 99%

Unusual 180° P−O−P Bond Angles in ZrP₂O₇

et al. 1996

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The structure of cubic ZrP(2)O(7) at room temperature has been solved and refined using a combination of modeling and high-resolution neutron powder diffraction data. The cell edge is 24.74 Å, the space group is Pa&thremacr;, and Z is 108. For those P(2)O(7) units not on a 3-fold axis, the P-O-P angles range from 134 degrees to 162 degrees. Two crystallographically distinct P(2)O(7) groups are on three fold axes with P-O-P angles thus constrained to be 180 degrees on average. The structure of cubic ZrP(2)O(7) was also refined from data taken at 227, 290, 371, 435, and 610 degrees C. The 3 x 3 x 3 superstructure present at room temperature disappears at about 290 degrees C, and all P-O-P angles of P(2)O(7) are then constrained by symmetry to be 180 degrees on average. The exceptionally low thermal expansion shown by ZrP(2)O(7) above 290 degrees C is likely related to the unusual P-O-P angle.

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Section: Introductionmentioning

confidence: 99%

Unusual 180° P−O−P Bond Angles in ZrP₂O₇

et al. 1996

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“…The possibility of deviation from stoichiometry for sodium has been effectively Brought to you by | New York University Bobst Library Technical Service Authenticated Download Date | 6/24/15 3:14 AM observed; a pure phase has indeed been isolated for 0.25 < .v < 0.50, whereas the X-ray diffraction patterns show up a mixture of this phase and of MOP 2 0 7 (Kinomura et al, 1985) for 0 < χ < 0.25, and the formation of another unidentified oxide for χ > 0.5. Thus Na 0 .3oMoP 2 0 7 corresponds to an intermediate composition in which the Na + ions and cationic vacancies are statistically distributed over the two types of sites.…”

Section: Leading To the Structural Formulation [μο(2)ρ4θ!] [Mo(l)03]mentioning

confidence: 99%

Na_xMoP₂O₇, a mixed valence molybdenum diphosphate with a tunnel structure

Leclaire¹,

Borel²,

Grandin³

et al. 1988

Zeitschrift Für Kristallographie - Crystalline Materials

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Na x MoP 2 0 7 crystal structure / Mixed valence molybdenum / Tunnel structure / Sodium molybdenum diphosphateAbstract. The crystal structure of Na 0 .3MoP 2 O 7 has been solved by threedimensional single crystal X-ray analysis. The refinement in the cell of symmetry PI with a = 4.8813(6) A, b = 7.0110(5) A, c = 8.2563(4) A, α = 91.400(5) Α, β = 92.466(8)°, y = 106.551(9)°, Ζ = 2 has led to R = 0.030 and R w = 0.031 for 3327 reflections with I > 3σ(/). The framework of the structure, built up from corner-sharing Mo0 6 octahedra and diphosphate groups, delimits large octogonal tunnels where the Na + ions are located. This structure is closely related to that of NaMoP 2 0 7 which differs only by the stacking of similar layers.

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