Cs10Ta29.27O78

Zeuner, M.; Hofer, A.; Schnick, W.

doi:10.1107/S1600536809002967

inorganic compounds

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ISSN: 2056-9890

Volume 65| Part 2| February 2009| Page i12

doi:10.1107/S1600536809002967

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Cs₁₀Ta_29.27O₇₈

Martin Zeuner,^a Alexander Hofer ^a and Wolfgang Schnick ^a ^*

^aDepartment Chemie und Biochemie, Ludwig-Maximilians-Universität München, Lehrstuhl für Anorganische Festkörperchemie, Butenandtstrasse 5–13, D-81377 München, Germany
^*Correspondence e-mail: wolfgang.schnick@uni-muenchen.de

(Received 13 January 2009; accepted 23 January 2009; online 28 January 2009)

Single crystals of caesium tantalate(V), Cs₁₀Ta_29.27O₇₈, were obtained as a serendipitous product in a welded tantalum ampoule by a blank reaction of CsBr and bismuth subnitrate [Bi₅O(OH)₉(NO₃)₄] with the container material. The crystal structure of the title compound is made up of a three-dimensional framework constituted by two types of layers, viz. (Ta₆O₁₅)_n and (Ta₃O₉)_n, parallel to (001), which are linked together by TaO₆ octahedra (3m. symmetry) along [001]. This framework has cavities where three independent Cs⁺ ions (3m. and $[\overline{6}]$ m2 symmetry, respectively) are located. The compound reveals a Ta deficiency at one trigonal prismatic coordinated site ( $[\overline{6}]$ m2 symmetry). The composition of the title compound was verified by energy-dispersive X-ray analysis of single crystals.

Related literature

For a previous powder diffraction study of Cs₁₀Ta_29.27O₇₈, see: Michel et al. (1978 ). For an isotypic compound, see: Haddad & Jouini (1997 ). For general background and related structures, see: du Boulay et al. (2003 ); Magnéli (1953 ); Marini et al. (1979 ); Serafin & Hoppe (1982 ).

Experimental

Crystal data

Cs₁₀Ta_29.27O₇₈
M_r = 7873.51
Hexagonal, P 6₃ /m m c
a = 7.5170 (11) Å
c = 36.340 (7) Å
V = 1778.3 (5) Å³
Z = 1
Mo Kα radiation
μ = 49.96 mm⁻¹
T = 294 (2) K
0.03 × 0.02 × 0.01 mm

Data collection

Stoe IPDS-I diffractometer
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999 ) T_min = 0.218, T_max = 0.607
14043 measured reflections
855 independent reflections
587 reflections with I > 2σ(I)
R_int = 0.119

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.083
S = 0.89
855 reflections
67 parameters
Δρ_max = 1.54 e Å⁻³
Δρ_min = −3.28 e Å⁻³

Data collection: X-AREA (Stoe & Cie, 2002 ); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809002967/wm2217sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809002967/wm2217Isup2.hkl

checkCIF report

Comment top

The title compound has a three-dimensional framework, constituted by two types of layers, (Ta₆O₁₅)_n (Fig. 1, green) and (Ta₃O₉)_n (Fig. 2, blue), parallel to (001). These layers are linked together along [001], according to the sequence (Ta₆O₁₅)_n-TaO₆-(Ta₃O₉)_n-(Ta₃O₉)_n-TaO₆, by sharing corners of TaO₆ octahedra (red, Fig. 3). The tantalum atom with deficient occupation is located in a site with trigonal-prismatic coordinated sites (yellow), between two Ta₃O₉ units belonging to two neighboring (Ta₃O₉)_n layers. This framework has cavities which communicate with interconnected channels, parallel to [100]. Cs⁺ ions (black) are located in these cavities. Geometric parameters of the title compound are in the usual ranges. Based on a previous powder diffraction study of Cs₁₀Ta_29.27O₇₈ reported by Michel et al. (1978), an additional Ta site was found, but was not observed in the current re-investigation. The closely related structure of Tl₁₀Nb_29.2O₇₈ was also reported (Marini et al., 1979) with an additional Nb site with too short interatomic distances between the Nb atoms.

The title compound crystallizes isotypically with Rb₅VONb₁₄O₃₈ (Haddad & Jouini, 1997), in which the vanadium atom occupies the trigonal-prismatic Ta deficiency site of the title compound. The related compound Cs₃Ta₅O₁₄ was first investigated by powder diffraction studies by Serafin & Hoppe (1982) and was later re-investigated on the basis of single-crystal X-ray diffraction by du Boulay et al. (2003). An overview on the related hexagonal tungsten bronzes of potassium, rubidium and caesium was presented by Magnéli (1953).

Related literature top

For a previous powder diffraction study of Cs₁₀Ta_29.27O₇₈, see: Michel et al. (1978). For an isotypic compound, see: Haddad & Jouini (1997). For general background and related structures, see: du Boulay et al. (2003); Magnéli (1953); Marini et al. (1979); Serafin & Hoppe (1982).

Experimental top

The title compound was obtained as a serendipitious product by the reaction of CsBr and bismuth subnitrate (Bi₅O(OH)₉(NO₃)₄, 98%, Sigma-Aldrich) with the tantalum container material. It was synthesized under argon at temperatures of 1523 K in a welded tantalum ampoule. The air stable title compound crystallizes in brown rods. The chemical composition of the single-crystal was confirmed by energy-dispersive X-ray (EDX) analysis which revealed no impurity elements.

Computing details top

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-AREA (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. View along [001] on the (Ta₆O₁₅)_n layer.
	Fig. 2. View along [001] on the (Ta₃O₉)_n layer.
	Fig. 3. View along [010] on the layers of the title compound connected via TaO₆ octahedra. Displacement ellipsoids are drawn at the 50% probability level.

caesium tantalate(V) top

Crystal data top

Cs₁₀Ta_29.27O₇₈	D_x = 7.352 Mg m⁻³
M_r = 7873.51	Mo Kα radiation, λ = 0.71073 Å
Hexagonal, P6₃/mmc	Cell parameters from 1275 reflections
Hall symbol: -P 6c 2c	θ = 2.6–31.6°
a = 7.5170 (11) Å	µ = 49.96 mm⁻¹
c = 36.340 (7) Å	T = 294 K
V = 1778.3 (5) Å³	Rod, brown
Z = 1	0.03 × 0.02 × 0.01 mm
F(000) = 3310.4

Data collection top

Stoe IPDS-I diffractometer	855 independent reflections
Radiation source: fine-focus sealed tube	587 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.119
ω scans	θ_max = 27.5°, θ_min = 3.1°
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	h = −9→9
T_min = 0.218, T_max = 0.607	k = −9→9
14043 measured reflections	l = −46→46

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F² > 2σ(F²)] = 0.033	Secondary atom site location: difference Fourier map
wR(F²) = 0.083	w = 1/[σ²(F_o²) + (0.0516P)²] where P = (F_o² + 2F_c²)/3
S = 0.89	(Δ/σ)_max < 0.001
855 reflections	Δρ_max = 1.54 e Å⁻³
67 parameters	Δρ_min = −3.28 e Å⁻³

Crystal data top

Cs₁₀Ta_29.27O₇₈	Z = 1
M_r = 7873.51	Mo Kα radiation
Hexagonal, P6₃/mmc	µ = 49.96 mm⁻¹
a = 7.5170 (11) Å	T = 294 K
c = 36.340 (7) Å	0.03 × 0.02 × 0.01 mm
V = 1778.3 (5) Å³

Data collection top

Stoe IPDS-I diffractometer	855 independent reflections
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	587 reflections with I > 2σ(I)
T_min = 0.218, T_max = 0.607	R_int = 0.119
14043 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	67 parameters
wR(F²) = 0.083	0 restraints
S = 0.89	Δρ_max = 1.54 e Å⁻³
855 reflections	Δρ_min = −3.28 e Å⁻³

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Ta1	0.0000	0.0000	0.11749 (3)	0.0166 (2)
Ta2	0.33551 (10)	0.16775 (5)	0.034126 (15)	0.01525 (19)
Ta3	0.17146 (6)	0.34292 (11)	0.196383 (17)	0.0204 (2)
Ta4	0.0000	0.0000	0.2500	0.0163 (8)	0.633 (10)
O1	0.0814 (19)	0.5407 (9)	0.1881 (4)	0.021 (2)
O2	0.5486 (9)	0.4514 (9)	0.0368 (3)	0.019 (2)
O3	0.1256 (9)	0.2511 (18)	0.1456 (3)	0.022 (2)
O4	0.2470 (17)	0.1235 (8)	0.0825 (3)	0.017 (2)
O5	0.1410 (8)	−0.1410 (8)	0.0233 (3)	0.012 (2)
O6	0.2379 (18)	0.1190 (9)	0.2082 (3)	0.019 (2)
O7	0.1878 (15)	0.376 (3)	0.2500	0.023 (4)
Cs1	0.6667	0.3333	0.2500	0.0337 (6)
Cs2	0.3333	0.6667	0.08755 (7)	0.0459 (6)
Cs3	0.6667	0.3333	0.13681 (8)	0.0564 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ta1	0.0158 (3)	0.0158 (3)	0.0180 (5)	0.00791 (16)	0.000	0.000
Ta2	0.0141 (3)	0.0144 (3)	0.0173 (3)	0.00703 (15)	−0.0001 (2)	−0.00005 (11)
Ta3	0.0181 (3)	0.0217 (4)	0.0226 (4)	0.01083 (19)	−0.00299 (13)	−0.0060 (3)
Ta4	0.0151 (10)	0.0151 (10)	0.0188 (13)	0.0075 (5)	0.000	0.000
O1	0.019 (5)	0.014 (4)	0.031 (6)	0.010 (3)	−0.001 (5)	0.000 (2)
O2	0.020 (4)	0.020 (4)	0.022 (5)	0.013 (5)	0.002 (2)	−0.002 (2)
O3	0.025 (5)	0.019 (6)	0.020 (5)	0.010 (3)	0.000 (2)	0.000 (4)
O4	0.016 (5)	0.016 (4)	0.019 (5)	0.008 (3)	0.007 (4)	0.004 (2)
O5	0.015 (4)	0.015 (4)	0.002 (4)	0.005 (4)	−0.0019 (19)	0.0019 (19)
O6	0.016 (5)	0.013 (4)	0.028 (6)	0.008 (3)	0.000 (4)	0.000 (2)
O7	0.021 (6)	0.038 (11)	0.015 (7)	0.019 (5)	0.000	0.000
Cs1	0.0317 (9)	0.0317 (9)	0.0377 (15)	0.0159 (5)	0.000	0.000
Cs2	0.0443 (8)	0.0443 (8)	0.0493 (15)	0.0221 (4)	0.000	0.000
Cs3	0.0626 (11)	0.0626 (11)	0.0441 (14)	0.0313 (6)	0.000	0.000

Geometric parameters (Å, º) top

Ta1—O3	1.928 (12)	Ta3—O7	1.960 (2)
Ta1—O3ⁱ	1.928 (12)	Ta3—O6ⁱⁱ	2.028 (12)
Ta1—O3ⁱⁱ	1.928 (12)	Ta3—O6	2.027 (10)
Ta1—O4ⁱ	2.050 (11)	Ta3—Ta4	2.9631 (8)
Ta1—O4ⁱⁱ	2.050 (11)	Ta4—O6ⁱ	2.170 (12)
Ta1—O4	2.050 (11)	Ta4—O6ⁱⁱ	2.170 (12)
Ta2—O4	1.850 (11)	Ta4—O6^vii	2.170 (12)
Ta2—O2	1.925 (7)	Ta4—O6	2.170 (12)
Ta2—O2ⁱⁱⁱ	1.925 (8)	Ta4—O6^viii	2.170 (12)
Ta2—O5ⁱⁱ	2.070 (4)	Ta4—O6^ix	2.170 (12)
Ta2—O5	2.070 (4)	Ta4—O7ⁱⁱ	2.45 (2)
Ta2—O5^iv	2.114 (10)	Ta4—O7	2.45 (2)
Ta2—Ta2^v	3.3049 (10)	Ta4—O7^ix	2.446 (19)
Ta2—Ta2^iv	3.3049 (10)	Ta4—Ta3ⁱⁱ	2.9631 (8)
Ta3—O3	1.940 (12)	Ta4—Ta3ⁱ	2.9631 (8)
Ta3—O1	1.941 (12)	Ta4—Ta3^vii	2.9631 (8)
Ta3—O1^vi	1.941 (12)

O3—Ta1—O3ⁱ	94.5 (5)	O3—Ta3—Ta4	113.2 (4)
O3—Ta1—O3ⁱⁱ	94.5 (5)	O1—Ta3—Ta4	127.0 (4)
O3ⁱ—Ta1—O3ⁱⁱ	94.5 (5)	O1^vi—Ta3—Ta4	127.0 (4)
O3—Ta1—O4ⁱ	173.7 (5)	O7—Ta3—Ta4	55.1 (6)
O3ⁱ—Ta1—O4ⁱ	89.8 (3)	O6ⁱⁱ—Ta3—Ta4	47.1 (3)
O3ⁱⁱ—Ta1—O4ⁱ	89.8 (3)	O6—Ta3—Ta4	47.1 (3)
O3—Ta1—O4ⁱⁱ	89.8 (3)	O6ⁱ—Ta4—O6ⁱⁱ	76.4 (5)
O3ⁱ—Ta1—O4ⁱⁱ	173.7 (5)	O6ⁱ—Ta4—O6^vii	138.2 (2)
O3ⁱⁱ—Ta1—O4ⁱⁱ	89.8 (3)	O6ⁱⁱ—Ta4—O6^vii	138.2 (2)
O4ⁱ—Ta1—O4ⁱⁱ	85.6 (5)	O6ⁱ—Ta4—O6	76.4 (5)
O3—Ta1—O4	89.8 (3)	O6ⁱⁱ—Ta4—O6	76.4 (5)
O3ⁱ—Ta1—O4	89.8 (3)	O6^vii—Ta4—O6	88.9 (6)
O3ⁱⁱ—Ta1—O4	173.7 (5)	O6ⁱ—Ta4—O6^viii	138.2 (2)
O4ⁱ—Ta1—O4	85.6 (5)	O6ⁱⁱ—Ta4—O6^viii	88.9 (6)
O4ⁱⁱ—Ta1—O4	85.6 (5)	O6^vii—Ta4—O6^viii	76.4 (5)
O4—Ta2—O2	100.2 (4)	O6—Ta4—O6^viii	138.2 (2)
O4—Ta2—O2ⁱⁱⁱ	100.2 (4)	O6ⁱ—Ta4—O6^ix	88.9 (6)
O2—Ta2—O2ⁱⁱⁱ	87.5 (7)	O6ⁱⁱ—Ta4—O6^ix	138.2 (2)
O4—Ta2—O5ⁱⁱ	89.5 (4)	O6^vii—Ta4—O6^ix	76.4 (5)
O2—Ta2—O5ⁱⁱ	85.4 (4)	O6—Ta4—O6^ix	138.2 (2)
O2ⁱⁱⁱ—Ta2—O5ⁱⁱ	168.9 (4)	O6^viii—Ta4—O6^ix	76.4 (5)
O4—Ta2—O5	89.5 (4)	O6ⁱ—Ta4—O7ⁱⁱ	69.09 (12)
O2—Ta2—O5	168.9 (4)	O6ⁱⁱ—Ta4—O7ⁱⁱ	69.09 (12)
O2ⁱⁱⁱ—Ta2—O5	85.4 (4)	O6^vii—Ta4—O7ⁱⁱ	135.5 (3)
O5ⁱⁱ—Ta2—O5	100.3 (6)	O6—Ta4—O7ⁱⁱ	135.5 (3)
O4—Ta2—O5^iv	152.4 (5)	O6^viii—Ta4—O7ⁱⁱ	69.09 (12)
O2—Ta2—O5^iv	99.7 (4)	O6^ix—Ta4—O7ⁱⁱ	69.09 (12)
O2ⁱⁱⁱ—Ta2—O5^iv	99.7 (4)	O6ⁱ—Ta4—O7	135.5 (3)
O5ⁱⁱ—Ta2—O5^iv	73.2 (4)	O6ⁱⁱ—Ta4—O7	69.09 (12)
O5—Ta2—O5^iv	73.2 (4)	O6^vii—Ta4—O7	69.09 (12)
O4—Ta2—Ta2^v	127.6 (2)	O6—Ta4—O7	69.09 (12)
O2—Ta2—Ta2^v	132.2 (3)	O6^viii—Ta4—O7	69.09 (12)
O2ⁱⁱⁱ—Ta2—Ta2^v	83.1 (3)	O6^ix—Ta4—O7	135.5 (3)
O5ⁱⁱ—Ta2—Ta2^v	95.4 (3)	O7ⁱⁱ—Ta4—O7	120.000 (1)
O5—Ta2—Ta2^v	38.3 (3)	O6ⁱ—Ta4—O7^ix	69.09 (12)
O5^iv—Ta2—Ta2^v	37.37 (10)	O6ⁱⁱ—Ta4—O7^ix	135.5 (3)
O4—Ta2—Ta2^iv	127.6 (2)	O6^vii—Ta4—O7^ix	69.09 (12)
O2—Ta2—Ta2^iv	83.1 (3)	O6—Ta4—O7^ix	69.09 (12)
O2ⁱⁱⁱ—Ta2—Ta2^iv	132.2 (3)	O6^viii—Ta4—O7^ix	135.5 (3)
O5ⁱⁱ—Ta2—Ta2^iv	38.3 (3)	O6^ix—Ta4—O7^ix	69.09 (12)
O5—Ta2—Ta2^iv	95.4 (3)	O7ⁱⁱ—Ta4—O7^ix	120.000 (1)
O5^iv—Ta2—Ta2^iv	37.37 (10)	O7—Ta4—O7^ix	120.000 (2)
Ta2^v—Ta2—Ta2^iv	69.83 (3)	Ta3ⁱⁱ—Ta4—Ta3^vii	135.741 (10)
O3—Ta3—O1	93.3 (4)	Ta3ⁱ—Ta4—Ta3^vii	135.741 (10)
O3—Ta3—O1^vi	93.3 (5)	Ta3—O1—Ta3^x	140.3 (7)
O1—Ta3—O1^vi	94.1 (7)	Ta2—O2—Ta2^xi	151.8 (7)
O3—Ta3—O7	168.3 (7)	Ta1—O3—Ta3	139.9 (7)
O1—Ta3—O7	94.7 (5)	Ta2—O4—Ta1	146.5 (7)
O1^vi—Ta3—O7	94.7 (5)	Ta2ⁱ—O5—Ta2	132.0 (6)
O3—Ta3—O6ⁱⁱ	88.8 (4)	Ta2ⁱ—O5—Ta2^v	104.3 (3)
O1—Ta3—O6ⁱⁱ	91.5 (5)	Ta2—O5—Ta2^v	104.3 (3)
O1^vi—Ta3—O6ⁱⁱ	173.9 (5)	Ta3ⁱ—O6—Ta3	145.0 (6)
O7—Ta3—O6ⁱⁱ	82.4 (6)	Ta3ⁱ—O6—Ta4	89.8 (3)
O3—Ta3—O6	88.8 (4)	Ta3—O6—Ta4	89.8 (3)
O1—Ta3—O6	173.9 (5)	Ta3—O7—Ta3^vii	167.5 (11)
O1^vi—Ta3—O6	91.5 (5)	Ta3—O7—Ta4	83.8 (6)
O7—Ta3—O6	82.4 (5)	Ta3^vii—O7—Ta4	83.8 (6)
O6ⁱⁱ—Ta3—O6	82.9 (6)

Symmetry codes: (i) −x+y, −x, z; (ii) −y, x−y, z; (iii) −y+1, x−y, z; (iv) x−y, x, −z; (v) y, −x+y, −z; (vi) −y+1, x−y+1, z; (vii) x, y, −z+1/2; (viii) −y, x−y, −z+1/2; (ix) −x+y, −x, −z+1/2; (x) −x+y, −x+1, z; (xi) −x+y+1, −x+1, z.

Experimental details

Crystal data
Chemical formula	Cs₁₀Ta_29.27O₇₈
M_r	7873.51
Crystal system, space group	Hexagonal, P6₃/mmc
Temperature (K)	294
a, c (Å)	7.5170 (11), 36.340 (7)
V (Å³)	1778.3 (5)
Z	1
Radiation type	Mo Kα
µ (mm⁻¹)	49.96
Crystal size (mm)	0.03 × 0.02 × 0.01

Data collection
Diffractometer	Stoe IPDS-I diffractometer
Absorption correction	Numerical (X-SHAPE; Stoe & Cie, 1999)
T_min, T_max	0.218, 0.607
No. of measured, independent and observed [I > 2σ(I)] reflections	14043, 855, 587
R_int	0.119
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.083, 0.89
No. of reflections	855
No. of parameters	67
Δρ_max, Δρ_min (e Å⁻³)	1.54, −3.28

Computer programs: X-AREA (Stoe & Cie, 2002), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999).

Acknowledgements

The authors are indebted to Thomas Miller for performing the single-crystal X-ray diffractometry. Financial support by the Fonds der Chemischen Industrie is gratefully acknowledged.

References

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