(IUCr) Redetermination of tricalcium trilanthanum pentakis(orthoborate) from single-crystal data

Volume 64
Part 6
Page i37
June 2008

Received 30 April 2008
Accepted 15 May 2008
Online 21 May 2008

Key indicators
Single-crystal X-ray study
T = 293 K
Mean (La-B) = 0.004 Å
R = 0.012
wR = 0.031
Data-to-parameter ratio = 10.1
Details

Redetermination of tricalcium trilanthanum pentakis(orthoborate) from single-crystal data

Tianyong Zhou ^a and Ning Ye ^a ^*

^aFujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
Correspondence e-mail: nye@fjirsm.ac.cn

Single crystals of the title compound, Ca₃La₃(BO₃)₅, were obtained by spontaneous nucleation from a high-temperature melt. The crystal structure of Ca₃La₃(BO₃)₅ has been determined previously from X-ray powder data [Zhang, Liang, Chen, He & Xu (2001). J. Alloys Compd, 327, 96-99]. The present refinement shows a significant improvement in terms of the precision of the geometric parameters and the correct determination of the absolute configuration in space group P6₃mc with all atoms refined with anisotropic displacement parameters. The structure consists of isolated BO₃ triangles and distorted [CaO₈] and [LaO₁₀] polyhedra. Except for one O atom, all other atoms are situated on special positions: La, all O and one B atom on mirror planes, and two B atoms with site symmetry 3m.

Related literature

For phase equilibria in the system La₂O₃-CaO-B₂O₃, see: Zhang et al. (2001a). For a previous structure analysis of Ca₃La₃(BO₃)₅ based on X-ray powder diffraction data, see: Zhang et al. (2001b). For non-linear optical (NLO) applications of borate crystals containing triangular BO₃ anions, see: Chen et al. (1999). For a review of the geometry of the BO₃ group, see: Zobetz (1982). For the potential applications of Ca₃La₃(BO₃)₅ for photoluminescence, see: Zhang et al. (2005); Han et al. (2007).

Experimental

Crystal data

Ca₃La₃(BO₃)₅
M_r = 831.02
Hexagonal, P 6₃ m c
a = 10.530 (3) Å
c = 6.398 (2) Å
V = 614.4 (3) Å³
Z = 2
Mo K radiation
= 11.59 mm^-1
T = 293 (2) K
0.22 × 0.12 × 0.10 mm

Data collection

Rigaku Mercury CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2000) T_min = 0.206, T_max = 0.304
4065 measured reflections
534 independent reflections
534 reflections with I > 2(I)
R_int = 0.035

Refinement

R[F² > 2(F²)] = 0.012
wR(F²) = 0.030
S = 0.89
534 reflections
53 parameters
1 restraint
_max = 0.41 e Å^-3
_min = -0.59 e Å^-3
Absolute structure: Flack (1983), 236 Friedel pairs
Flack parameter: -0.03 (3)

Table 1
Selected geometric parameters (Å, °)

Ca1-O4ⁱ	2.3139 (13)
Ca1-O1ⁱⁱ	2.376 (3)
Ca1-O3	2.382 (4)
Ca1-O1ⁱⁱⁱ	2.662 (3)
La1-O1^iv	2.501 (2)
La1-O4^v	2.516 (4)
La1-O2^vi	2.6639 (15)
La1-O3^vii	2.8112 (8)
B1-O4	1.358 (6)
B1-O1ⁱ	1.384 (3)
B2-O2^viii	1.374 (3)
B3-O3	1.389 (3)

O4-B1-O1ⁱ	119.7 (2)
O1ⁱ-B1-O1^x	120.6 (4)
O2^viii-B2-O2^xi	120
O3^ix-B3-O3	120
Symmetry codes: (i) -y+1, x-y+1, z; (ii) $[x-y+1, x, z+{\script{1\over 2}}]$ ; (iii) -x+y, -x+1, z; (iv) $[y-1, x, z-{\script{1\over 2}}]$ ; (v) x, y, z-1; (vi) $[x-y+1, x+1, z-{\script{1\over 2}}]$ ; (vii) $[x-y, x, z-{\script{1\over 2}}]$ ; (viii) $[y-1, -x+y-1, z-{\script{1\over 2}}]$ ; (ix) -x+y+1, -x+1, z; (x) -x+y, y, z; (xi) $[x-y+1, x, z-{\script{1\over 2}}]$ .

Data collection: CrystalClear (Rigaku, 2000); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2004); software used to prepare material for publication: enCIFer (Allen et al., 2004).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2179 ).

Acknowledgements

This project was supported by the National Science Foundation of China (grant No. 60608018).

References

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335-338.
Brandenburg, K. (2004). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Chen, C. T., Ye, N., Lin, J., Jiang, J., Zeng, W. R. & Wu, B. C. (1999). Adv. Mater. 11, 1071-1078.
Flack, H. D. (1983). Acta Cryst. A39, 876-881.
Han, B., Liang, H. B. & Lin, H. H. (2007). Appl. Phys. A Matter. Sci. Process. 88, 705-709.
Rigaku (2000). CrystalClear. Rigaku Corporation, Tokyo, Japan.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Zhang, Y., Chen, X. L., Liang, J. K., Gao, Y. G. & Xu, T. (2001a). J. Alloys Compd, 315, 198-202.
Zhang, Y., Li, Y. D. & Yin, Y. S. (2005). J. Alloys Compd, 400, 222-226.
Zhang, Y., Liang, J. K., Chen, X. L., He, M. & Xu, T. (2001b). J. Alloys Compd, 327, 96-99.
Zobetz, E. (1982). Z. Kristallogr. 160, 81-92.

inorganic compounds