Na2MoO2As2O7.

Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na(+) cations are located. In this framework, the As(V) atoms are tetra-hedrally coordinated and form an As2O7 group. The Mo(VI) atom is displaced from the center of an octa-hedron of O atoms. Two Na(+) cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb), AMOP2O7 (A = Na, K, Rb; M = Mo, Nb) and MoP2O7 are discussed.

Related literature

For background to the physico-chemical properties of related compounds, see: Daidouh et al. (1997 ▶); Troup & Clearfield (1977 ▶); Guesdon et al. (1990 ▶). For details of structurally related compounds, see: Averbuch-Pouchot (1988 ▶, 1989 ▶); Zid et al. (1998 ▶, 2003 ▶); Ledain et al. (1996 ▶); Gueho et al. (1992 ▶); Fakhfakh et al. (1994 ▶); Linde et al. (1980 ▶); Leclaire et al. (1988 ▶). For the preparation, see: Zid & Jouini (1996 ▶); Zid et al. (1997 ▶, 1998 ▶); Hajji et al. (2004 ▶); Hajji & Zid (2006 ▶); Jouini et al. (2012 ▶); Ben Hlila et al. (2009 ▶). For bond-valence sums, see: Brown & Altermatt (1985 ▶).

Experimental

Crystal data

Na2MoO2As2O7

M = 435.76

Monoclinic,

a = 7.1130 (7) Å

b = 12.056 (2) Å

c = 9.8030 (9) Å

β = 100.48 (2)°

V = 826.63 (18) Å3

Z = 4

Mo Kα radiation

μ = 9.66 mm−1

T = 298 K

0.56 × 0.32 × 0.21 mm

Data collection

Enraf–Nonius CAD-4 diffractometer

Absorption correction: ψ scan (North et al., 1968 ▶) T min = 0.037, T max = 0.134

2280 measured reflections

1790 independent reflections

1711 reflections with I > 2σ(I)

R int = 0.019

2 standard reflections every 120 min intensity decay: 1.2%

Refinement

R[F 2 > 2σ(F 2)] = 0.022

wR(F 2) = 0.058

S = 1.25

1790 reflections

137 parameters

Δρmax = 0.83 e Å−3

Δρmin = −0.75 e Å−3

Data collection: CAD-4 EXPRESS (Duisenberg, 1992 ▶; Macíček & Yordanov, 1992 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 1998 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶).

Click here for additional data file.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812048167/br2214sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812048167/br2214Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Na2MoO2As2O7	F(000) = 808
Mr = 435.76	Dx = 3.501 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 7.1130 (7) Å	θ = 10–15°
b = 12.056 (2) Å	µ = 9.66 mm−1
c = 9.8030 (9) Å	T = 298 K
β = 100.48 (2)°	Prism, yellow
V = 826.63 (18) Å3	0.56 × 0.32 × 0.21 mm
Z = 4

Enraf–Nonius CAD-4 diffractometer	1711 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.019
Graphite monochromator	θmax = 27.0°, θmin = 2.7°
ω/2θ scans	h = −9→9
Absorption correction: ψ scan (North et al., 1968)	k = −1→15
Tmin = 0.037, Tmax = 0.134	l = −12→1
2280 measured reflections	2 standard reflections every 120 min
1790 independent reflections	intensity decay: 1.2%

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.022	w = 1/[σ2(Fo2) + (0.0229P)2 + 2.4476P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.058	(Δ/σ)max = 0.001
S = 1.25	Δρmax = 0.83 e Å−3
1790 reflections	Δρmin = −0.75 e Å−3
137 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.0083 (4)

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
Mo1	0.14180 (4)	0.82040 (3)	0.04354 (3)	0.01031 (11)
As1	0.42263 (5)	0.83066 (3)	0.78808 (4)	0.01048 (12)
As2	0.81207 (5)	0.92725 (3)	0.79392 (4)	0.00972 (12)
Na1	0.3687 (3)	0.09290 (17)	0.8660 (2)	0.0314 (4)
Na2	0.504 (10)	0.986 (5)	0.494 (7)	0.047 (7)	0.50
Na3	0.9657 (8)	0.9978 (6)	0.4736 (5)	0.0263 (13)	0.50
O1	0.4007 (4)	0.8279 (2)	0.9549 (3)	0.0166 (6)
O2	0.3637 (4)	0.9467 (2)	0.7019 (3)	0.0165 (6)
O3	0.3405 (4)	0.7092 (2)	0.7129 (3)	0.0151 (5)
O4	0.0359 (4)	0.8798 (2)	0.8550 (3)	0.0142 (5)
O5	0.7368 (4)	0.0110 (2)	0.9099 (3)	0.0136 (5)
O6	0.9545 (4)	0.8561 (3)	0.1218 (3)	0.0212 (6)
O7	0.6693 (4)	0.8070 (2)	0.7961 (3)	0.0158 (6)
O8	0.7899 (4)	0.9695 (3)	0.6338 (3)	0.0198 (6)
O9	0.0977 (5)	0.6856 (2)	0.0018 (3)	0.0237 (7)

	U11	U22	U33	U12	U13	U23
Mo1	0.00956 (17)	0.00924 (17)	0.01180 (17)	0.00032 (11)	0.00105 (12)	0.00149 (11)
As1	0.0103 (2)	0.01014 (19)	0.01110 (19)	−0.00184 (13)	0.00220 (14)	−0.00231 (13)
As2	0.00852 (18)	0.01071 (19)	0.00969 (18)	−0.00010 (13)	0.00098 (13)	0.00109 (13)
Na1	0.0221 (9)	0.0364 (10)	0.0343 (10)	0.0016 (8)	0.0013 (8)	−0.0166 (9)
Na2	0.023 (4)	0.09 (2)	0.026 (9)	0.028 (13)	0.005 (5)	0.027 (13)
Na3	0.032 (4)	0.0183 (15)	0.035 (4)	0.002 (3)	0.022 (3)	0.004 (3)
O1	0.0135 (13)	0.0258 (15)	0.0105 (12)	0.0011 (11)	0.0024 (10)	−0.0042 (11)
O2	0.0182 (14)	0.0141 (13)	0.0169 (13)	0.0001 (11)	0.0023 (11)	0.0011 (11)
O3	0.0167 (13)	0.0130 (13)	0.0144 (12)	−0.0048 (11)	−0.0001 (10)	−0.0022 (11)
O4	0.0113 (12)	0.0185 (14)	0.0116 (12)	0.0022 (10)	−0.0010 (10)	0.0018 (10)
O5	0.0139 (12)	0.0115 (12)	0.0153 (12)	0.0018 (10)	0.0023 (10)	−0.0009 (10)
O6	0.0173 (14)	0.0267 (15)	0.0211 (14)	0.0035 (12)	0.0073 (11)	0.0058 (12)
O7	0.0122 (13)	0.0116 (12)	0.0243 (14)	−0.0022 (10)	0.0056 (11)	−0.0031 (11)
O8	0.0152 (13)	0.0312 (16)	0.0129 (13)	0.0042 (12)	0.0024 (10)	0.0085 (12)
O9	0.0277 (16)	0.0133 (14)	0.0277 (16)	−0.0043 (12)	−0.0014 (13)	0.0008 (12)

Mo1—O9	1.692 (3)	Na1—O2viii	2.382 (3)
Mo1—O6i	1.709 (3)	Na1—O6iv	2.403 (3)
Mo1—O4ii	1.997 (3)	Na1—O3ix	2.725 (3)
Mo1—O3iii	2.006 (3)	Na1—O5x	2.749 (3)
Mo1—O1ii	2.177 (3)	Na1—O5	2.759 (3)
Mo1—O5iv	2.223 (3)	Na1—O7ix	3.017 (3)
As1—O2	1.649 (3)	Na2—O8	2.25 (7)
As1—O1	1.671 (3)	Na2—O8xi	2.29 (7)
As1—O3	1.695 (3)	Na2—O2xi	2.43 (7)
As1—O7	1.765 (3)	Na2—O2	2.47 (7)
As2—O8	1.630 (3)	Na3—O8	2.204 (8)
As2—O5v	1.679 (3)	Na3—O8xii	2.226 (7)
As2—O4vi	1.695 (3)	Na3—O9xiii	2.329 (8)
As2—O7	1.772 (3)	Na3—O9xiv	2.398 (8)
Na1—O1vii	2.374 (3)	Na3—O2xi	2.726 (5)
O9—Mo1—O6i	103.00 (16)	O6iv—Na1—O3ix	131.68 (13)
O9—Mo1—O4ii	95.67 (13)	O1vii—Na1—O5x	81.05 (10)
O6i—Mo1—O4ii	97.55 (13)	O2viii—Na1—O5x	103.30 (12)
O9—Mo1—O3iii	95.80 (14)	O6iv—Na1—O5x	70.98 (10)
O6i—Mo1—O3iii	99.37 (13)	O3ix—Na1—O5x	142.44 (11)
O4ii—Mo1—O3iii	156.85 (11)	O1vii—Na1—O5	61.30 (10)
O9—Mo1—O1ii	94.41 (14)	O2viii—Na1—O5	74.79 (10)
O6i—Mo1—O1ii	162.57 (13)	O6iv—Na1—O5	166.71 (13)
O4ii—Mo1—O1ii	79.62 (11)	O3ix—Na1—O5	58.68 (9)
O3iii—Mo1—O1ii	79.51 (11)	O5x—Na1—O5	95.82 (10)
O9—Mo1—O5iv	167.51 (13)	O1vii—Na1—O7ix	91.68 (11)
O6i—Mo1—O5iv	89.03 (13)	O2viii—Na1—O7ix	106.75 (11)
O4ii—Mo1—O5iv	85.92 (10)	O6iv—Na1—O7ix	79.20 (11)
O3iii—Mo1—O5iv	78.69 (11)	O3ix—Na1—O7ix	53.88 (8)
O1ii—Mo1—O5iv	73.65 (10)	O5x—Na1—O7ix	143.06 (10)
O2—As1—O1	117.26 (14)	O5—Na1—O7ix	112.34 (10)
O2—As1—O3	118.35 (14)	O8—Na2—O8xi	171 (3)
O1—As1—O3	108.81 (14)	O8—Na2—O2xi	94 (3)
O2—As1—O7	108.54 (13)	O8xi—Na2—O2xi	86 (2)
O1—As1—O7	102.82 (14)	O8—Na2—O2	86 (2)
O3—As1—O7	98.11 (13)	O8xi—Na2—O2	92 (2)
O8—As2—O5v	118.50 (14)	O2xi—Na2—O2	171 (2)
O8—As2—O4vi	111.47 (13)	O8—Na3—O8xii	163.26 (19)
O5v—As2—O4vi	110.97 (13)	O8—Na3—O9xiii	86.1 (3)
O8—As2—O7	108.19 (15)	O8xii—Na3—O9xiii	93.4 (3)
O5v—As2—O7	103.27 (13)	O8—Na3—O9xiv	92.1 (3)
O4vi—As2—O7	102.88 (13)	O8xii—Na3—O9xiv	83.9 (3)
O1vii—Na1—O2viii	136.07 (13)	O9xiii—Na3—O9xiv	164.40 (18)
O1vii—Na1—O6iv	113.49 (12)	O8—Na3—O2xi	87.3 (2)
O2viii—Na1—O6iv	109.05 (13)	O8xii—Na3—O2xi	108.3 (2)
O1vii—Na1—O3ix	62.93 (10)	O9xiii—Na3—O2xi	70.52 (19)
O2viii—Na1—O3ix	96.18 (11)	O9xiv—Na3—O2xi	124.9 (2)