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Volume 67 
Part 9 
Page i49  
September 2011  

Received 12 July 2011
Accepted 4 August 2011
Online 17 August 2011

Key indicators
Single-crystal X-ray study
T = 290 K
Mean [sigma](P-O) = 0.004 Å
R = 0.046
wR = 0.112
Data-to-parameter ratio = 11.5
Details
Open access

The mixed-valent titanium phosphate, Li2Ti2(PO4)3, dilithium dititanium(III/IV) tris(orthophosphate)

aDivision of Energy Systems Research and Department of Chemistry, Ajou University, Suwon 443-749, Republic of Korea
Correspondence e-mail: hsyun@ajou.ac.kr

The mixed-valent titanium phosphate, Li2Ti2(PO4)3, has been prepared by the reactive halide flux method. The title compound is isostructural with Li2TiM(PO4)3 (M = Fe, Cr) and Li2FeZr(PO4)3 and has the same 3[infinity][Ti2(PO4)3]2- framework as the previously reported Li3-xM2(PO4)3 phases. The framework is built up from corner-sharing TiO6 octahedra and PO4 tetrahedra, one of which has 2 symmetry. The Li+ ions are located on one crystallographic position and reside in the vacancies of the framework. They are surrounded by four O atoms in a distorted tetrahedral coordination. The classical charge-balance of the title compound can be represented as Li+2(Ti3+/Ti4+)(PO43-)3.

Related literature

The synthesis and structural characterization of stoichiometric Li2TiM(PO4)3 (M = Fe and Cr) and Li2FeZr(PO4)3 have been reported by Patoux et al. (2004[Patoux, S., Rousse, G., Leriche, J.-B. & Masquelier, C. (2004). Solid State Sci. 6, 1113-1120.]) and Catti (2001[Catti, M. (2001). J. Solid State Chem. 156, 305-312.]), respectively. For related phosphates with general formula Li3-xM2(PO4)3 (0 [less-than or equal to] x [less-than or equal to] 1), see: Wang & Hwu (1991[Wang, S. & Hwu, S.-J. (1991). J. Solid State Chem. 90, 377-381.]) for Li2.72Ti2(PO4)3. For Li batteries based on Li3-xM2(PO4)3 phases, see: Yin et al. (2003[Yin, S.-C., Grondey, H., Strobel, P., Anne, M. & Nazar, L. F. (2003). J. Am. Chem. Soc. 125, 10402-10411.]). For ionic conductivities of these phases, see: Sato et al. (2000[Sato, M., Ohkawa, H., Yoshida, K., Saito, M., Uematsu, K. & Toda, K. (2000). Solid State Ionics, 135, 137-142.]). For ionic radii, see: Shannon (1976[Shannon, R. D. (1976). Acta Cryst. A32, 751-767.]). For structure validation, see: Spek (2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Experimental

Crystal data
  • Li2Ti2(PO4)3

  • Mr = 394.59

  • Orthorhombic, P b c n

  • a = 12.0344 (5) Å

  • b = 8.5795 (5) Å

  • c = 8.6794 (4) Å

  • V = 896.14 (7) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 2.39 mm-1

  • T = 290 K

  • 0.22 × 0.16 × 0.14 mm

Data collection
  • Rigaku R-AXIS RAPID diffractometer

  • Absorption correction: multi-scan (ABSCOR; Higashi, 1995[Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.]) Tmin = 0.802, Tmax = 1.000

  • 6671 measured reflections

  • 1004 independent reflections

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

  • Rint = 0.035

Refinement
  • R[F2 > 2[sigma](F2)] = 0.046

  • wR(F2) = 0.112

  • S = 1.37

  • 1004 reflections

  • 87 parameters

  • [Delta][rho]max = 0.49 e Å-3

  • [Delta][rho]min = -0.74 e Å-3

Data collection: RAPID-AUTO (Rigaku, 2006[Rigaku (2006). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan.]); cell refinement: RAPID-AUTO; data reduction: RAPID-AUTO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: locally modified version of ORTEP (Johnson, 1965[Johnson, C. K. (1965). ORTEP. Report ORNL-3794. Oak Ridge National Laboratory, Tennessee, USA.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2513 ).


Acknowledgements

This work was supported by the Priority Research Centers Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2010-0029617). Use was made of the X-ray facilities supported by Ajou University.

References

Catti, M. (2001). J. Solid State Chem. 156, 305-312.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.  [CrossRef] [ChemPort] [details]
Higashi, T. (1995). ABSCOR. Rigaku Corporation, Tokyo, Japan.
Johnson, C. K. (1965). ORTEP. Report ORNL-3794. Oak Ridge National Laboratory, Tennessee, USA.
Patoux, S., Rousse, G., Leriche, J.-B. & Masquelier, C. (2004). Solid State Sci. 6, 1113-1120.
Rigaku (2006). RAPID-AUTO. Rigaku Corporation, Tokyo, Japan.
Sato, M., Ohkawa, H., Yoshida, K., Saito, M., Uematsu, K. & Toda, K. (2000). Solid State Ionics, 135, 137-142.
Shannon, R. D. (1976). Acta Cryst. A32, 751-767.  [CrossRef] [details]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]
Spek, A. L. (2009). Acta Cryst. D65, 148-155.  [ISI] [CrossRef] [details]
Wang, S. & Hwu, S.-J. (1991). J. Solid State Chem. 90, 377-381.
Yin, S.-C., Grondey, H., Strobel, P., Anne, M. & Nazar, L. F. (2003). J. Am. Chem. Soc. 125, 10402-10411.


Acta Cryst (2011). E67, i49  [ doi:10.1107/S1600536811031606 ]

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