(NH₄)₂(SO₄)_0.71(SeO₄)_0.29Te(OH)₆

The main feature of the title structure, ammonium sulfate selenate tellurate, is the presence of three different chalcogenate species in the same compound. The crystal structure contains planes of SO₄/SeO₄ tetra­hedra alternating with planes of Te(OH)₆ octa­hedra. Disordered NH₄⁺ cations are inter­calated between these planes. Both octa­hedra and SO₄/SeO₄ tetra­hedra are linked by O—H...O hydrogen bonds.

S1. Comment

In pursuing our study of sulfate selenate tellurate salts, amongst which we have solved Cs₂(SO₄)_0.57(SeO₄)_0.43^.Te(OH)₆ (Abdelhedi, Dammak, Cousson, Nierlich & Abdelwaheb, 2005) and Rb₂(SO₄)_0.5(SeO₄)_0.5^.Te(OH)₆ (Abdelhedi, Dammak, Cousson & Kolsi, 2005), we have grown the title compound, (NH₄)₂(SO₄)_0.71(SeO₄)_0.29^.Te(OH)₆ (NSSeTe). The structure (Fig. 1) is built up of planes of Te(OH)₆ octahedra (at x = 0 and 1/2) alternating with planes of SO₄/SeO₄ tetrahedra (at x = 1/4 and 3/4), with disordered NH₄ cations intercalated between these planes. The S and Se atoms occupy the same site. In the SO₄/SeO₄ tetrahedra, the S/Se—O distances range from 1.5165 (12) Å to 1.5246 (12) Å, intermediate between those in (NH₄)₂SO₄^.Te(OH)₆ (1.373 (11)–1.565 (8) Å) (Zilber et al., 1981) and (NH₄)₂SeO₄^.Te(OH)₆ (1.622 (4)–1.639 (4) Å) (Litaiem et al., 2005). In the octahedral groups, the Te—O distances vary from 1.9021 (13) to 1.9133 (11) Å with O—Te—O angles that range between 87.15 (5) and 92.85 (5)°. Each NH₄ cation is coordinated to three oxygen atoms belonging to S/SeO₄ tetrahedra and six oxygen atoms from Te(OH)₆ octahedra. The structure is stabilized by O—H···O hydrogen bonds. The O···H distances in this compound vary from 1.7558 (12)Å to 1.897 (11)Å with O—H···O angles ranging from 155.47 (8)° to 172.90 (11)°. Figure 2 shows the packing arrangement of the NSSeTe material.

Related literature

For related literature, see: Abdelhedi, Dammak, Cousson, Nierlich & Abdelwaheb et al. (2005); Abdelhedi, Dammak, Cousson & Kolsi (2005); Litaiem et al. (2005). _publ_section_exptl_refinement and _refine_ls_hydrogen_treatment entries say that H atoms were refined but no s.u. values are given for these parameters in the CIF; please clarify.

For related literature, see: Zilber et al. (1981).

S2. Experimental

Transparent, colorless single crystals of the title composition were grown from aqueous solution of a mixture of telluric acid, H₆TeO₆ (Aldrich, 99%), ammonium carbonate (NH₄)₂CO₃, (Aldrich 99.9%), selenic acid, H₂SeO₄ (Aldrich 94%) and ammonium sulfate (NH₄)₂SO₄, (Aldrich 99.999%) at room temperature. (The stoichiometric ratio 1:0.5:0.5:0.5).

S3. Refinement

Hydrogen atoms on Te(OH)₆ groups were located in an electron density difference map and were refined isotropically. As a result of disorder, ammonium hydrogen atoms could not be found and therefore could not be included in the model.

Computing details

Data collection: COLLECT (Nonius, 2001); cell refinement: DENZO/SCALEPACK; data reduction: DENZO/SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS86 (Sheldrick, 1986); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: DIAMOND (Brandenburg & Berndt, 1999); software used to prepare material for publication: CRYSTALS.

Figures

	Fig. 1. A part of the structure of (NH4)2(SO4)0.71(SeO4)0.29Te(OH)6, showing the asymmetric unit (expanded by symmetry to give complete tellurate octahedra). Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes:(a) -x + 1,-y, -z; b) -x, -y + 1, -z]
	Fig. 2. Crystal structure of (NH4)2(SO4)0.71(SeO4)0.29Te(OH)6 showing the hydrogen bonds.

Diammonium sulfate-selenate tellurate

Crystal data

2(NH4)^+·O4S0.71Se0.29^2^−·H6O6Te	F(000) = 724.66
Mr = 385.23	Dx = 2.552 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 7138 reflections
a = 13.7340 (2) Å	θ = 2.7–30.1°
b = 6.6583 (1) Å	µ = 4.20 mm^−1
c = 11.4582 (2) Å	T = 298 K
β = 106.827 (1)°	Parallelepiped, colourless
V = 1002.93 (3) Å^3	0.30 × 0.26 × 0.20 mm
Z = 4

Data collection

Nonius KappaCCD diffractometer	2213 reflections with I > 3σ(I)
Graphite monochromator	Rint = 0.030
φ rotation scans with 2°steps	θmax = 30.1°, θmin = 3.1°
Absorption correction: multi-scan (MULABS in PLATON; Spek, 1998)	h = −19→19
Tmin = 0.32, Tmax = 0.43	k = −8→9
14354 measured reflections	l = −16→16
2940 independent reflections

Refinement

Refinement on F	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.016	Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) [weight] = 1.0/[A0*T0(x) + A1*T1(x) ··· + An-1]*Tn-1(x)] where Ai are the Chebychev coefficients listed below and x = F /Fmax Method = Robust Weighting (Prince, 1982) W = [weight] * [1-(deltaF/6*sigmaF)^2]^2 Ai are: 0.466 0.314 0.278 Prince, E. (1982). Mathematical Techniques in Crystallography and Materials Science. Springer-Verlag: New York. Watkin, D. (1994). Acta Cryst. A50, 411–437.
wR(F^2) = 0.021	(Δ/σ)max = 0.001
S = 1.01	Δρmax = 0.64 e Å^−3
2213 reflections	Δρmin = −0.42 e Å^−3
114 parameters	Extinction correction: Larson 1970 Crystallographic Computing eq 22
1 restraint	Extinction coefficient: 22.5 (17)
Primary atom site location: structure-invariant direct methods

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Te1	0.5000	0.0000	0.0000	0.0154
Te2	0.0000	0.5000	0.0000	0.0147
Se1	0.248690 (13)	−0.010650 (13)	0.233850 (13)	0.0152	0.2869 (11)
S1	0.248690 (13)	−0.010650 (13)	0.233850 (13)	0.0152	0.7131 (11)
N1	0.14479 (12)	0.4841 (2)	0.34630 (14)	0.0278
N2	0.35360 (14)	0.4953 (2)	0.09225 (17)	0.0352
O1	0.46433 (12)	−0.0932 (2)	0.13912 (13)	0.0452
O2	0.63403 (8)	−0.10532 (19)	0.06867 (11)	0.0283
O3	0.53678 (11)	0.25802 (19)	0.07172 (13)	0.0401
O4	0.01747 (9)	0.73221 (17)	0.10219 (11)	0.0261
O5	−0.05209 (9)	0.35904 (17)	0.11395 (11)	0.0268
O6	0.13448 (8)	0.41154 (18)	0.08537 (11)	0.0246
O7	0.20637 (10)	0.0546 (2)	0.33679 (12)	0.0331
O8	0.33787 (9)	0.12668 (18)	0.23575 (11)	0.0285
O9	0.28331 (10)	−0.22762 (18)	0.25249 (11)	0.0318
O10	0.16707 (10)	0.00918 (17)	0.11171 (11)	0.0311
H1	0.4196	−0.0021	0.1629	0.0380*
H2	0.6289	−0.2126	0.1214	0.0450*
H3	0.6021	0.2640	0.1280	0.0470*
H4	0.0737	0.7940	0.0949	0.0470*
H5	−0.0969	0.4446	0.1410	0.0440*
H6	0.1315	0.2718	0.1009	0.0550*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Te1	0.013986 (18)	0.015896 (18)	0.016686 (18)	0.001266 (18)	0.004796 (18)	0.000916 (18)
Te2	0.015036 (18)	0.015496 (18)	0.014246 (18)	−0.000284 (18)	0.005266 (18)	0.000376 (18)
Se1	0.014780 (13)	0.015480 (13)	0.015440 (13)	−0.001180 (13)	0.004510 (13)	−0.000510 (13)
S1	0.014780 (13)	0.015480 (13)	0.015440 (13)	−0.001180 (13)	0.004510 (13)	−0.000510 (13)
N1	0.0320 (7)	0.0270 (7)	0.0255 (6)	0.0011 (5)	0.0100 (6)	−0.0006 (5)
N2	0.0403 (9)	0.0311 (8)	0.0371 (8)	−0.0007 (6)	0.0158 (7)	−0.0002 (6)
O1	0.0571 (9)	0.0488 (8)	0.0440 (8)	0.0286 (7)	0.0374 (7)	0.0248 (7)
O2	0.0180 (5)	0.0303 (6)	0.0351 (6)	0.0045 (5)	0.0053 (4)	0.0070 (5)
O3	0.0372 (7)	0.0227 (6)	0.0469 (8)	0.0033 (5)	−0.0092 (6)	−0.0090 (5)
O4	0.0263 (5)	0.0244 (5)	0.0293 (5)	−0.0038 (4)	0.0109 (4)	−0.0098 (4)
O5	0.0324 (6)	0.0246 (5)	0.0295 (6)	0.0026 (5)	0.0187 (5)	0.0077 (4)
O6	0.0184 (5)	0.0256 (5)	0.0272 (5)	0.0021 (4)	0.0025 (4)	0.0013 (4)
O7	0.0347 (6)	0.0374 (6)	0.0337 (6)	−0.0065 (5)	0.0199 (5)	−0.0074 (5)
O8	0.0280 (6)	0.0287 (6)	0.0320 (6)	−0.0055 (5)	0.0135 (5)	−0.0047 (4)
O9	0.0306 (6)	0.0244 (6)	0.0360 (6)	0.0017 (5)	0.0028 (5)	0.0016 (5)
O10	0.0319 (6)	0.0267 (6)	0.0288 (6)	−0.0039 (5)	−0.0005 (4)	0.0018 (4)

Geometric parameters (Å, º)

Te1—O2^i	1.9133 (11)	Se1—O8	1.5236 (12)
Te1—O3^i	1.9083 (12)	Se1—O9	1.5165 (12)
Te1—O1^i	1.9021 (13)	Se1—O10	1.5246 (12)
Te1—O1	1.9021 (13)	S1—O7	1.5213 (12)
Te1—O2	1.9133 (11)	S1—O8	1.5236 (12)
Te1—O3	1.9083 (12)	S1—O9	1.5165 (12)
Te2—O6^ii	1.9154 (10)	S1—O10	1.5246 (12)
Te2—O4^ii	1.9122 (11)	O1—H1	0.957
Te2—O5^ii	1.9075 (11)	O2—H2	0.951
Te2—O4	1.9122 (11)	O3—H3	0.942
Te2—O5	1.9075 (11)	O4—H4	0.900
Te2—O6	1.9154 (10)	O5—H5	0.954
Se1—O7	1.5213 (12)	O6—H6	0.950
O2^i—Te1—O3^i	92.85 (5)	O4—Te2—O5	89.09 (5)
O2^i—Te1—O1^i	89.22 (6)	O6^ii—Te2—O6	179.994
O3^i—Te1—O1^i	91.89 (7)	O4^ii—Te2—O6	89.75 (5)
O2^i—Te1—O1	90.78 (6)	O5^ii—Te2—O6	90.21 (5)
O3^i—Te1—O1	88.11 (7)	O4—Te2—O6	90.25 (5)
O1^i—Te1—O1	179.994	O5—Te2—O6	89.79 (5)
O2^i—Te1—O2	179.994	O7—Se1—O8	107.68 (7)
O3^i—Te1—O2	87.15 (5)	O7—Se1—O9	109.71 (8)
O1^i—Te1—O2	90.78 (6)	O8—Se1—O9	110.59 (7)
O1—Te1—O2	89.22 (6)	O7—Se1—O10	110.04 (8)
O2^i—Te1—O3	87.15 (5)	O8—Se1—O10	109.60 (7)
O3^i—Te1—O3	179.994	O9—Se1—O10	109.21 (6)
O1^i—Te1—O3	88.11 (7)	O7—S1—O8	107.68 (7)
O1—Te1—O3	91.89 (7)	O7—S1—O9	109.71 (8)
O2—Te1—O3	92.85 (5)	O8—S1—O9	110.59 (7)
O6^ii—Te2—O4^ii	90.25 (5)	O7—S1—O10	110.04 (8)
O6^ii—Te2—O5^ii	89.79 (5)	O8—S1—O10	109.60 (7)
O4^ii—Te2—O5^ii	89.09 (5)	O9—S1—O10	109.21 (6)
O6^ii—Te2—O4	89.75 (5)	Te1—O1—H1	111.974
O4^ii—Te2—O4	179.994	Te1—O2—H2	107.281
O5^ii—Te2—O4	90.91 (5)	Te1—O3—H3	114.442
O6^ii—Te2—O5	90.21 (5)	Te2—O4—H4	105.768
O4^ii—Te2—O5	90.91 (5)	Te2—O5—H5	109.488
O5^ii—Te2—O5	179.994	Te2—O6—H6	108.017

Symmetry codes: (i) −x+1, −y, −z; (ii) −x, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D—H···A
O1—H1···O8	0.9572 (13)	1.7984 (12)	166.50 (9)
O2—H2···O8^iii	0.9512 (12)	1.8974 (11)	158.11 (8)
O3—H3···O9^iv	0.9420 (13)	1.7628 (12)	172.90 (11)
O4—H4···O10^v	0.9000 (11)	1.8951 (12)	155.47 (8)
O5—H5···O7^vi	0.9538 (12)	1.7558 (12)	162.99 (9)
O6—H6···O10	0.9504 (12)	1.8101 (12)	158.93 (8)

Symmetry codes: (iii) −x+1, y−1/2, −z+1/2; (iv) −x+1, y+1/2, −z+1/2; (v) x, y+1, z; (vi) −x, y+1/2, −z+1/2.