Cs3Sm7Se12

Schneck, C.; Elbe, A.; Schurz, C.M.; Schleid, T.

doi:10.1107/S1600536811051919

Volume 68
Part 1
Page i2
January 2012

Received 14 November 2011
Accepted 1 December 2011
Online 7 December 2011

Key indicators
Single-crystal X-ray study
T = 293 K
Mean (Sm-Se) = 0.001 Å
Disorder in main residue
R = 0.035
wR = 0.072
Data-to-parameter ratio = 29.7
Details

Cs₃Sm₇Se₁₂

Christof Schneck,^a Andreas Elbe,^a Christian M. Schurz ^a and Thomas Schleid ^a ^*

^aInstitut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
Correspondence e-mail: schleid@iac.uni-stuttgart.de

The title compound, tricaesium heptasamarium(III) dodecaselenide, is setting a new starting point for realization of the channel structure of the Cs₃M₇Se₁₂ series, now with M = Sm, Gd-Er. This Cs₃Y₇Se₁₂-type arrangement is structurally based on the Z-type sesquiselenides M₂Se₃ adopting the Sc₂S₃ structure. Thus, the structural set-up of Cs₃Sm₇Se₁₂ consists of edge- and vertex-connected [SmSe₆]^9- octahedra [d_Ø(Sm³⁺ - Se^2-) = 2.931 Å], forming a rock-salt-related network [Sm₇Se₁₂]^3- with channels along [001] that are apt to take up monovalent cations (here Cs⁺) with coordination numbers of 7 + 1 for one and of 6 for the second cation. The latter cation has a trigonal-prismatic coordination and shows half-occupancy, resulting in an impossible short distance [2.394 (4) Å] between symmetrically coupled Cs⁺ cations of the same kind. While one Sm atom occupies Wyckoff position 2b with site symmetry ..2/m, all other 11 crystallographically different atoms (namely 2 × Cs, 3 × Sm and 6 × Se) are located at Wyckoff positions 4g with site symmetry ..m.

Related literature

For prototypic Cs₃Y₇Se₁₂ or Rb₃Yb₇Se₁₂, see: Folchnandt & Schleid (1996); Kim et al. (1996). For other representatives of the A₃M₇Ch₁₂ series, see: Folchnandt & Schleid (1997, 1998, 2000); Tougaît et al. (2001); Lissner et al. (2002). A detailed description of the relation between the crystal structures of the Cs₃M₇Se₁₂ series and Z-type Sc₂Ch₃ (Dismukes & White, 1964) is provided by Folchnandt & Schleid (1998).

Experimental

Crystal data

Cs₃Sm₇Se₁₂
M_r = 2398.70
Orthorhombic, P n n m
a = 13.0387 (9) Å
b = 26.6742 (19) Å
c = 4.2351 (3) Å
V = 1472.95 (18) Å³
Z = 2
Mo K radiation
= 32.19 mm^-1
T = 293 K
0.10 × 0.07 × 0.05 mm

Data collection

Stoe IPDS-I diffractometer
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999) T_min = 0.115, T_max = 0.216
15080 measured reflections
2135 independent reflections
1587 reflections with I > 2(I)
R_int = 0.065

Refinement

R[F² > 2(F²)] = 0.035
wR(F²) = 0.072
S = 0.97
2135 reflections
72 parameters
_max = 2.09 e Å^-3
_min = -1.78 e Å^-3

Table 1
Selected bond lengths (Å)

Cs1-Se4ⁱ	3.6071 (12)
Cs1-Se4ⁱⁱ	3.6071 (12)
Cs1-Se6ⁱⁱ	3.7129 (12)
Cs1-Se6ⁱ	3.7129 (12)
Cs1-Se3ⁱⁱⁱ	3.7639 (14)
Cs1-Se5ⁱ	3.8053 (12)
Cs1-Se5ⁱⁱ	3.8053 (12)
Cs1-Se1	4.5421 (14)
Cs2-Se2ⁱⁱ	3.5286 (16)
Cs2-Se2ⁱ	3.5286 (16)
Cs2-Se2^v	3.6917 (17)
Cs2-Se2^vi	3.6917 (17)
Cs2-Se5ⁱⁱⁱ	3.719 (2)
Cs2-Se6ⁱⁱⁱ	3.924 (2)
Symmetry codes: (i) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, z-{\script{1\over 2}}]$ ; (iii) -x+1, -y+1, -z; (iv) -x+1, -y, -z; (v) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z-{\script{1\over 2}}]$ ; (vi) $[x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2561 ).

Acknowledgements

This work was supported by the State of Baden-Württemberg (Stuttgart) and the German Research Foundation (DFG; Bonn) within the funding programme Open Access Publishing. We thank Dr Falk Lissner for the data collection.

References

Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Dismukes, J. P. & White, J. G. (1964). Inorg. Chem. 3, 1220-1228.
Folchnandt, M. & Schleid, Th. (1996). Z. Kristallogr. Suppl. 12, 125.
Folchnandt, M. & Schleid, Th. (1997). Z. Anorg. Allg. Chem. 623, 1501-1502.
Folchnandt, M. & Schleid, Th. (1998). Z. Anorg. Allg. Chem. 624, 1595-1600.
Folchnandt, M. & Schleid, Th. (2000). Z. Kristallogr. New Cryst. Struct. 215, 9-10.
Kim, S.-J., Park, S.-J., Yun, H. & Do, J. (1996). Inorg. Chem. 35, 5283-5289.
Lissner, F., Hartenbach, I. & Schleid, Th. (2002). Z. Anorg. Allg. Chem. 628, 1552-1555.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Stoe & Cie (1992). DIF4 and REDU4. Stoe & Cie, Darmstadt, Germany.
Stoe & Cie (1999). X-SHAPE. Stoe & Cie, Darmstadt, Germany.
Tougaît, O., Noël, H. & Ibers, J. A. (2001). Solid State Sci. 3, 513-518.

inorganic compounds