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Volume 68 
Part 12 
Page i92  
December 2012  

Received 19 October 2012
Accepted 31 October 2012
Online 10 November 2012

Key indicators
Single-crystal X-ray study
T = 293 K
Mean [sigma](Pr-O) = 0.001 Å
Disorder in main residue
R = 0.018
wR = 0.047
Data-to-parameter ratio = 25.1
Details
Open access

The pyrochlore-type molybdate Pr2Mo1.73Sc0.27O7

aUnité Sciences Chimiques de Rennes, UMR CNRS No. 6226, Université de Rennes I - INSA Rennes, Campus de Beaulieu, 35042 Rennes CEDEX, France
Correspondence e-mail: Patrick.Gougeon@univ-rennes1.fr

Dipraseodymium molybdenum scandium heptaoxide, Pr2Mo1.73Sc0.27O7, crystallizes in the cubic pyrochlore-type structure. In the crystal, (Mo,Sc)O6 octahedra are linked together by common corners, forming a three-dimensional [(Mo,Sc)2O6] framework. The Pr atom and another O atom atom are located in the voids of this framework. The Mo and the Sc atom are distributed statistically over the same 16d crystallographic position, with site-occupancy factors of 0.867 (3) and 0.133 (3), respectively. The Pr3+ ions are surrounded by six O atoms from the MoO6 octahedra and by two other O atoms, forming a ditrigonal scalenohedron. All atoms lie on special positions. The Pr and the statistically distributed (Mo,Sc) sites are in the 16c and 16d positions with .-3m symmetry, and two O atoms are in 48f and 8a positions with 2.mm and -43m site symmetry, respectively.

Related literature

For pyrochlore-type molybdates, see, for example: Hubert (1974[Hubert, Ph. H. (1974). Bull. Soc. Chim. Fr. 11, 2385-2386.]); Subramanian et al. (1983[Subramanian, M. A., Aravamudan, G. & Subba Rao, G. V. (1983). Prog. Solid State Chem. 15, 55-143.]); Gall & Gougeon (2008[Gall, P. & Gougeon, P. (2008). Acta Cryst. E64, i42.]). For the physical properties of some rare-earth molybdate pyrochlores, see: Hill et al. (1989[Hill, P., Labroo, S., Zhang, X. & Ali, N. (1989). J. Less Common Met. 149, 327-330.]); Ali et al. (1989[Ali, N., Hill, M., Labroo, S. & Greedan, J. (1989). J. Solid State Chem. 83, 178-187.]); Miyoshi et al. (2001[Miyoshi, K., Honda, K., Yamashita, T., Fujiwara, K. & Takeuchi, J. (2001). J. Magn. Magn. Mater. 226, 898-899.], 2003[Miyoshi, K., Honda, K., Hiraoka, T., Fujiwara, K., Takeuchi, J. & Hamasaki, T. (2003). Physica B, 329, 1059-1060.]). An attempt to synthesize ScPr9Mo16O35, a compound with the LiNd9Mo16O35 type structure (Gougeon et al., 2011[Gougeon, P., Gall, P., Cuny, J., Gautier, R., Le Polles, L., Delevoye, L. & Trebosc, J. (2011). Chem. Eur. J. 17, 13806-130813.]), was unsuccessful, resulting in a multiphase product with Pr2Mo1.73Sc0.27O7 and Pr16Mo21O56 (Gougeon & Gall, 2011[Gougeon, P. & Gall, P. (2011). Acta Cryst. E67, i34-i35.]) as predominant phases.

Experimental

Crystal data
  • Pr2Mo1.73Sc0.27O7

  • Mr = 571.69

  • Cubic, [F d \overline 3m ]

  • a = 10.5271 (3) Å

  • V = 1166.61 (6) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 20.33 mm-1

  • T = 293 K

  • 0.10 × 0.06 × 0.05 mm

Data collection
  • Nonius KappaCCD diffractometer

  • Absorption correction: analytical (de Meulenaar & Tompa, 1965[Meulenaer, J. de & Tompa, H. (1965). Acta Cryst. A19, 1014-1018.]) Tmin = 0.302, Tmax = 0.461

  • 9208 measured reflections

  • 326 independent reflections

  • 269 reflections with I > 2[sigma](I)

  • Rint = 0.044

Refinement
  • R[F2 > 2[sigma](F2)] = 0.018

  • wR(F2) = 0.047

  • S = 1.33

  • 326 reflections

  • 13 parameters

  • [Delta][rho]max = 0.79 e Å-3

  • [Delta][rho]min = -0.81 e Å-3

Table 1
Selected bond lengths (Å)

Pr1-O2 2.2792
Pr1-O1i 2.5795 (13)
Mo1-O1ii 2.0440 (8)
Symmetry codes: (i) [z-{\script{1\over 4}}, x-{\script{1\over 4}}, -y]; (ii) [x, y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: COLLECT (Nonius, 1998[Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands]); cell refinement: COLLECT; data reduction: EVALCCD (Duisenberg et al., 2003[Duisenberg, A. J. M., Kroon-Batenburg, L. M. J. & Schreurs, A. M. M. (2003). J. Appl. Cryst. 36, 220-229.]); program(s) used to solve structure: SIR97 (Altomare et al., 1999[Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2001[Brandenburg, K. (2001). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: RU2045 ).


Acknowledgements

Intensity data were collected at the Centre de diffractométrie de l'Université de Rennes I (www.cdifx.univ-rennes1.fr).

References

Ali, N., Hill, M., Labroo, S. & Greedan, J. (1989). J. Solid State Chem. 83, 178-187.  [CrossRef] [ChemPort] [ISI]
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115-119.  [ISI] [CrossRef] [ChemPort] [details]
Brandenburg, K. (2001). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Duisenberg, A. J. M., Kroon-Batenburg, L. M. J. & Schreurs, A. M. M. (2003). J. Appl. Cryst. 36, 220-229.  [ISI] [CrossRef] [ChemPort] [details]
Gall, P. & Gougeon, P. (2008). Acta Cryst. E64, i42.  [CrossRef] [details]
Gougeon, P. & Gall, P. (2011). Acta Cryst. E67, i34-i35.  [CrossRef] [details]
Gougeon, P., Gall, P., Cuny, J., Gautier, R., Le Polles, L., Delevoye, L. & Trebosc, J. (2011). Chem. Eur. J. 17, 13806-130813.  [CrossRef] [ChemPort] [PubMed]
Hill, P., Labroo, S., Zhang, X. & Ali, N. (1989). J. Less Common Met. 149, 327-330.  [CrossRef]
Hubert, Ph. H. (1974). Bull. Soc. Chim. Fr. 11, 2385-2386.
Meulenaer, J. de & Tompa, H. (1965). Acta Cryst. A19, 1014-1018.
Miyoshi, K., Honda, K., Hiraoka, T., Fujiwara, K., Takeuchi, J. & Hamasaki, T. (2003). Physica B, 329, 1059-1060.  [CrossRef]
Miyoshi, K., Honda, K., Yamashita, T., Fujiwara, K. & Takeuchi, J. (2001). J. Magn. Magn. Mater. 226, 898-899.  [ISI] [CrossRef]
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Subramanian, M. A., Aravamudan, G. & Subba Rao, G. V. (1983). Prog. Solid State Chem. 15, 55-143.  [CrossRef] [ChemPort] [ISI]


Acta Cryst (2012). E68, i92  [ doi:10.1107/S1600536812045138 ]

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