catena-Poly[tetra­sodium [[cis-dioxido-trans-bis­(sulfato-κO)molybdate(VI)]-μ-sulfato-κ²O:O′]]

Single crystals of the title compound, {Na₄[Mo^VIO₂(SO₄)₃]}_n, were grown from a melt of MoO₃ and Na₂SO₄ in Na₂S₂O₇. In contrast to the structure of the isoformular K compound, K₄[Mo^VIO₂(SO₄)₃], with its monomeric anion, this sodium analogue contains a polymeric anion of the type {[Mo^VIO₂(SO₄)₂-μ-(SO₄)]⁴⁻}_n. The Mo^VI cations, surrounded by two tightly bonded O atoms and four O atoms of one bridging and two terminal sulfato ligands, form zigzag chains parallel to [100]. All four Na⁺ cations are situated between the anionic chains and have distorted octa­hedral coordination spheres.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](S-O) = 0.002 Å
• R factor = 0.017
• wR factor = 0.043
• Data-to-parameter ratio = 14.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.98
           From the CIF: _reflns_number_total               2861
           Count of symmetry unique reflns         1662
           Completeness (_total/calc)            172.14%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1199
           Fraction of Friedel pairs measured     0.721
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Considerable amounts of molybdenum(VI) oxide, a solid well known for its insolubility in many acids, can be dissolved in sulfate melts at high temperatures, as was previously found for the chemically related tungsten(VI) oxide (Schäffer & Berg, 2005, Berg et al., 2006). When varying molar amounts of MoO₃, Na₂SO₄, and hygroscopic Na₂S₂O₇ are placed in ampoules in a dry box, sealed, and heated to equilibration in a rocking furnace at 773 K for ca. 1 h, the resulting clear melts contain [MoO₂]²⁺ moieties that are bonded to SO₄^2- units. The compositions of the reaction products have been determined to be in the stoichiometric ratio 1:1:1, or MoO₃ + M₂SO₄ + M₂S₂O₇ → M₄[Mo(SO₄)₃O₂]. In the case where M = K, a monomeric anion is formed (Schäffer & Berg, 2008), while for M = Na the anion is in a polymeric form.

The distorted octahedral coordination sphere of the Mo^VI cation contains two oxido ligands (cis), two terminally bound sulfato ligands (trans), and two O atoms of symmetry-related (x + 1/2, -y + 1/2, -z + 1) bridging sulfato ligands (cis), with O–Mo–O angles between any two cis oxygen atoms deviating as much as 15° from ideal values. The Mo–O bond distances to the tightly- bonded oxido ligands are similar (1.6905 (16) Å, 1.7108 (16) Å), which is expected as both bonds are trans to oxygen atoms in the bridging sulfato ligands. The Mo–O distances to the terminal sulfato ligands (Mo1–O4 and Mo1–O5) are slightly shorter than those to the brigding sulfato ligands, Mo1–03 and Mo1–O6A. The Mo–O distances compare well with previously reported values for related structures (Salles et al., 1996; Nørbygaard et al., 1998; Schäffer & Berg, 2008).

The coordination geometry of the sulfato ligands can be described as slightly distorted from tetrahedral, with angles ranging from 103.55 (9) to 113.77 (10)°. From the shortest to the longest, the S–O bond distances vary by type: S to terminal O atoms, 1.4516 (17)–1.4681 (17) Å; S to briding O atoms, 1.4941 (16) Å and 1.4953 (16) Å; S in the terminal sulfato ligands to the coordinating O atoms, 1.5589 (17) Å and 1.5346 (16) Å. This variation is typical for sulfato complexes of many different transition metal centers (Borup et al., 1990; Nielsen et al., 1993; Rasmussen et al., 2003, and Berg & Thorup, 2005).

All four sodium cations are situated between the anionic chains and are six-coordinate with Na–O bond distances ranging from 2.2713 (18) to 2.7652 (18) Å.

Related literature

The structure of the title isoformular potassium compound, K₄[Mo^VI(SO₄)₃O₂], was determined by Schäffer & Berg (2008). For related Mo-containing compounds, see: Salles et al. (1996) and Nørbygaard et al. (1998). Related compounds with Mo replaced by W were discussed by Schäffer & Berg (2005) and Berg et al. (2006). Other sulfato complexes coordinated to late transition metal centers were reported by Berg & Thorup (2005), Borup et al. (1990), Nielsen et al. (1993) and Rasmussen et al. (2003).

S2. Experimental

Crystals were grown from a melt of equimolar amounts of MoO₃, Na₂SO₄, and Na₂S₂O₇, using a method described previously (Nørbygaard et al., 1998).

S3. Refinement

On the basis of 1205 unmerged Friedel opposites, the fractional contribrution of the racemic twin was negligible (Flack, 1983). The two highest peaks in the final difference Fourier map were, respectively, 0.78 Å and 0.79 Å from Mo1, and the deepest hole was 1.31 Å from S2.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT (Bruker, 2002); data reduction: SAINT (Bruker, 2002); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. Plot of the asymmetric unit of Na4[Mo^VI(SO4)3O2], showing atoms as ellipsoids at the 50% probability level. [Symmetry code A) x+0.5, -y+0.5, -z+1.]
	Fig. 2. The crystal packing of Na4[Mo^VI(SO4)3O2], viewed along the b axis, showing the chains (thick black lines). Ellipsoids are displayed at the 50% probability level.

catena-Poly[tetrasodium [[cis-dioxido-trans- bis(sulfato-κO)molybdate(VI)]-µ-sulfato-κ²O:O']]

Crystal data

Na4[Mo(SO4)3O2]	F(000) = 984
Mr = 508.08	Dx = 2.838 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 5457 reflections
a = 8.4739 (6) Å	θ = 2.6–27.9°
b = 9.2892 (7) Å	µ = 1.86 mm^−1
c = 15.1046 (11) Å	T = 120 K
V = 1188.97 (15) Å^3	Tabular, colorless
Z = 4	0.24 × 0.18 × 0.02 mm

Data collection

Bruker SMART APEX CCD diffractometer	2861 independent reflections
Radiation source: normal-focus sealed tube	2817 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ω scans	θmax = 28.0°, θmin = 2.6°
Absorption correction: gaussian (SHELXTL; Sheldrick, 2008)	h = −11→11
Tmin = 0.665, Tmax = 0.964	k = −12→12
14125 measured reflections	l = −19→19

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.017	w = 1/[σ^2(Fo^2) + (0.0214P)^2 + 0.3747P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.042	(Δ/σ)max = 0.001
S = 1.10	Δρmax = 0.51 e Å^−3
2861 reflections	Δρmin = −0.26 e Å^−3
199 parameters	Absolute structure: Flack (1983), 1205 Friedel pairs
0 restraints	Absolute structure parameter: 0.01 (2)

Special details

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. Five frame series were filtered for statistical outliers then corrected for absorption by integration using SHELXTL/XPREP (Bruker, 2001) before using SAINT/SADABS (Bruker, 2002) to sort, merge, and scale the combined data. A series of identical frames was collected twice during the experiment to monitor decay. No decay correction was applied. The systematic conditions suggested the uambiguous space group. The structure was solved by direct methods (Sheldrick, 2001). The final space group choice was confirmed by successful convergence of the full-matrix least-squares refinement on F². An extinction correction was not applied. The two highest peaks in the final difference Fourier map were, repectively, 0.78Å and 0.79Å from Mo1; the deepest hole was 1.31Å from S2. The final map had no other significant features. A final analysis of variance between observed and calculated structure factors showed no dependence on amplitude or resolution.

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

	x	y	z	Uiso*/Ueq
Mo1	0.77389 (2)	0.108886 (19)	0.426923 (11)	0.00683 (5)
S1	0.42167 (6)	0.29669 (6)	0.38157 (3)	0.00770 (11)
S2	0.52730 (7)	−0.14389 (6)	0.48393 (3)	0.00870 (11)
S3	0.87553 (6)	0.37753 (6)	0.29746 (3)	0.00819 (10)
Na1	0.20072 (11)	0.58268 (10)	0.34042 (6)	0.01293 (19)
Na2	0.80653 (11)	0.75841 (10)	0.31656 (6)	0.01239 (19)
Na3	0.67303 (11)	0.51270 (10)	0.46834 (6)	0.0144 (2)
Na4	0.57005 (11)	0.46216 (10)	0.21305 (6)	0.01274 (19)
O1	0.70335 (19)	0.03236 (17)	0.33180 (10)	0.0107 (3)
O2	0.94651 (19)	0.02131 (17)	0.44263 (11)	0.0119 (3)
O3	0.57359 (18)	0.25797 (17)	0.42577 (11)	0.0107 (3)
O4	0.6456 (2)	−0.02040 (17)	0.50576 (10)	0.0116 (3)
O5	0.88450 (19)	0.28237 (18)	0.38036 (10)	0.0120 (3)
O6	0.29354 (19)	0.27689 (17)	0.44854 (9)	0.0096 (3)
O7	0.3902 (2)	0.20606 (18)	0.30489 (10)	0.0123 (3)
O8	0.4313 (2)	0.44896 (18)	0.35609 (11)	0.0124 (3)
O9	0.49519 (19)	−0.20813 (17)	0.56967 (11)	0.0130 (3)
O10	0.60611 (19)	−0.24259 (18)	0.42327 (12)	0.0147 (3)
O11	0.38958 (19)	−0.07781 (18)	0.44282 (11)	0.0139 (3)
O12	0.7888 (2)	0.29908 (17)	0.22934 (10)	0.0124 (3)
O13	0.7899 (2)	0.50790 (17)	0.32281 (10)	0.0126 (3)
O14	1.03833 (19)	0.40786 (18)	0.27218 (10)	0.0133 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Mo1	0.00576 (8)	0.00737 (9)	0.00738 (8)	0.00034 (7)	−0.00028 (6)	−0.00021 (7)
S1	0.0056 (2)	0.0096 (3)	0.0078 (2)	0.0014 (2)	−0.00017 (19)	−0.0001 (2)
S2	0.0073 (2)	0.0093 (2)	0.0095 (2)	−0.0009 (2)	0.0006 (2)	−0.00087 (19)
S3	0.0073 (2)	0.0087 (2)	0.0086 (2)	−0.0001 (2)	0.00067 (18)	0.0004 (2)
Na1	0.0125 (5)	0.0130 (5)	0.0133 (4)	0.0022 (4)	0.0012 (3)	0.0019 (3)
Na2	0.0111 (5)	0.0126 (4)	0.0135 (4)	0.0012 (4)	0.0018 (4)	0.0017 (3)
Na3	0.0123 (4)	0.0166 (5)	0.0145 (5)	−0.0034 (4)	0.0023 (4)	−0.0024 (4)
Na4	0.0107 (4)	0.0156 (5)	0.0120 (4)	0.0010 (4)	−0.0008 (4)	0.0020 (4)
O1	0.0097 (8)	0.0119 (8)	0.0104 (7)	0.0002 (6)	−0.0002 (6)	−0.0008 (6)
O2	0.0113 (8)	0.0112 (8)	0.0130 (8)	0.0020 (6)	−0.0021 (6)	−0.0007 (6)
O3	0.0086 (7)	0.0128 (7)	0.0107 (7)	0.0044 (6)	−0.0029 (7)	−0.0008 (7)
O4	0.0138 (8)	0.0116 (8)	0.0095 (7)	−0.0053 (7)	−0.0018 (6)	0.0001 (6)
O5	0.0116 (8)	0.0121 (8)	0.0122 (8)	−0.0036 (6)	−0.0020 (6)	0.0042 (6)
O6	0.0080 (7)	0.0110 (7)	0.0098 (7)	−0.0010 (6)	0.0006 (6)	−0.0012 (6)
O7	0.0116 (8)	0.0162 (9)	0.0092 (7)	0.0016 (7)	−0.0016 (6)	−0.0028 (6)
O8	0.0121 (8)	0.0111 (8)	0.0140 (8)	0.0018 (7)	0.0023 (7)	0.0023 (6)
O9	0.0141 (8)	0.0131 (8)	0.0119 (7)	−0.0042 (6)	−0.0001 (7)	0.0028 (7)
O10	0.0151 (8)	0.0119 (8)	0.0171 (8)	−0.0010 (7)	0.0051 (7)	−0.0045 (7)
O11	0.0093 (8)	0.0190 (9)	0.0133 (8)	0.0021 (7)	−0.0016 (6)	0.0017 (6)
O12	0.0141 (8)	0.0120 (8)	0.0109 (7)	−0.0002 (7)	−0.0015 (6)	−0.0011 (6)
O13	0.0106 (8)	0.0108 (8)	0.0163 (8)	0.0025 (7)	−0.0008 (7)	−0.0015 (6)
O14	0.0095 (8)	0.0167 (9)	0.0136 (7)	−0.0012 (7)	0.0042 (6)	0.0008 (7)

Geometric parameters (Å, º)

Mo1—O2	1.6905 (16)	Na1—O9^iv	2.4972 (19)
Mo1—O1	1.7108 (16)	Na1—O1^ii	2.7652 (18)
Mo1—O5	1.9925 (16)	Na2—O13	2.3333 (18)
Mo1—O4	2.0102 (16)	Na2—O14^v	2.3350 (19)
Mo1—O6^i	2.1661 (15)	Na2—O10^vi	2.3415 (19)
Mo1—O3	2.1907 (15)	Na2—O9^i	2.3932 (19)
S1—O7	1.4564 (16)	Na2—O7^ii	2.5262 (18)
S1—O8	1.4681 (17)	Na2—O1^vi	2.7006 (19)
S1—O3	1.4941 (16)	Na2—S3^v	3.3837 (11)
S1—O6	1.4953 (16)	Na3—O11^i	2.3524 (19)
S2—O9	1.4516 (17)	Na3—O2^iv	2.3649 (19)
S2—O11	1.4575 (17)	Na3—O13	2.4115 (18)
S2—O10	1.4581 (17)	Na3—O10^vi	2.4398 (19)
S2—O4	1.5589 (17)	Na3—O3	2.5928 (19)
S3—O14	1.4590 (17)	Na3—O8	2.724 (2)
S3—O12	1.4595 (16)	Na4—O7^ii	2.3065 (19)
S3—O13	1.4627 (16)	Na4—O12	2.407 (2)
S3—O5	1.5346 (16)	Na4—O11^ii	2.4078 (19)
Na1—O12^ii	2.2713 (18)	Na4—O8	2.4629 (19)
Na1—O8	2.3273 (19)	Na4—O1^ii	2.5003 (19)
Na1—O14^iii	2.3649 (19)	Na4—O13	2.5297 (19)
Na1—O4^iv	2.4394 (18)
O2—Mo1—O1	102.72 (8)	O11^i—Na3—O3	129.03 (7)
O2—Mo1—O5	91.81 (7)	O2^iv—Na3—O3	75.84 (6)
O1—Mo1—O5	101.77 (7)	O13—Na3—O3	83.71 (6)
O2—Mo1—O4	95.58 (7)	O10^vi—Na3—O3	134.87 (6)
O1—Mo1—O4	93.46 (7)	O11^i—Na3—O8	175.92 (7)
O5—Mo1—O4	161.18 (7)	O2^iv—Na3—O8	73.41 (6)
O2—Mo1—O6^i	92.71 (7)	O13—Na3—O8	74.78 (6)
O1—Mo1—O6^i	163.68 (7)	O10^vi—Na3—O8	81.61 (6)
O5—Mo1—O6^i	82.77 (6)	O3—Na3—O8	53.34 (5)
O4—Mo1—O6^i	79.62 (6)	O7^ii—Na4—O12	121.20 (7)
O2—Mo1—O3	167.36 (7)	O7^ii—Na4—O11^ii	90.91 (6)
O1—Mo1—O3	89.16 (7)	O12—Na4—O11^ii	83.88 (6)
O5—Mo1—O3	81.39 (6)	O7^ii—Na4—O8	102.80 (7)
O4—Mo1—O3	87.91 (6)	O12—Na4—O8	104.28 (6)
O6^i—Mo1—O3	75.92 (6)	O11^ii—Na4—O8	156.62 (7)
O7—S1—O8	111.01 (10)	O7^ii—Na4—O1^ii	81.21 (6)
O7—S1—O3	111.95 (9)	O12—Na4—O1^ii	154.90 (7)
O8—S1—O3	107.53 (10)	O11^ii—Na4—O1^ii	84.66 (6)
O7—S1—O6	109.52 (9)	O8—Na4—O1^ii	78.95 (6)
O8—S1—O6	109.65 (10)	O7^ii—Na4—O13	78.73 (6)
O3—S1—O6	107.08 (9)	O12—Na4—O13	58.10 (6)
O9—S2—O11	113.77 (10)	O11^ii—Na4—O13	124.20 (7)
O9—S2—O10	112.83 (10)	O8—Na4—O13	77.59 (6)
O11—S2—O10	111.33 (10)	O1^ii—Na4—O13	144.70 (7)
O9—S2—O4	103.55 (9)	Mo1—O1—Na4^vii	131.27 (9)
O11—S2—O4	107.18 (10)	Mo1—O1—Na2^viii	110.49 (7)
O10—S2—O4	107.52 (10)	Na4^vii—O1—Na2^viii	91.78 (6)
O14—S3—O12	112.83 (10)	Mo1—O1—Na1^vii	128.10 (8)
O14—S3—O13	112.19 (10)	Na4^vii—O1—Na1^vii	93.53 (5)
O12—S3—O13	110.37 (10)	Na2^viii—O1—Na1^vii	89.08 (5)
O14—S3—O5	106.14 (9)	Mo1—O2—Na3^i	147.82 (9)
O12—S3—O5	108.22 (9)	S1—O3—Mo1	145.42 (10)
O13—S3—O5	106.73 (10)	S1—O3—Na3	99.86 (8)
O12^ii—Na1—O8	119.12 (7)	Mo1—O3—Na3	108.85 (6)
O12^ii—Na1—O14^iii	115.36 (7)	S2—O4—Mo1	131.46 (9)
O8—Na1—O14^iii	99.58 (7)	S2—O4—Na1^i	98.63 (8)
O12^ii—Na1—O4^iv	131.24 (7)	Mo1—O4—Na1^i	127.05 (8)
O8—Na1—O4^iv	86.40 (6)	S3—O5—Mo1	136.93 (10)
O14^iii—Na1—O4^iv	98.10 (6)	S1—O6—Mo1^iv	125.67 (9)
O12^ii—Na1—O9^iv	82.33 (6)	S1—O7—Na4^vii	129.39 (10)
O8—Na1—O9^iv	141.19 (7)	S1—O7—Na2^vii	125.94 (10)
O14^iii—Na1—O9^iv	98.72 (7)	Na4^vii—O7—Na2^vii	101.54 (7)
O4^iv—Na1—O9^iv	57.26 (6)	S1—O8—Na1	119.62 (10)
O12^ii—Na1—O1^ii	72.64 (6)	S1—O8—Na4	107.73 (9)
O8—Na1—O1^ii	76.04 (6)	Na1—O8—Na4	106.56 (7)
O14^iii—Na1—O1^ii	69.21 (5)	S1—O8—Na3	95.05 (8)
O4^iv—Na1—O1^ii	155.81 (6)	Na1—O8—Na3	125.35 (7)
O9^iv—Na1—O1^ii	142.71 (6)	Na4—O8—Na3	100.15 (7)
O13—Na2—O14^v	130.56 (7)	S2—O9—Na2^iv	147.79 (11)
O13—Na2—O10^vi	85.66 (6)	S2—O9—Na1^i	99.36 (8)
O14^v—Na2—O10^vi	143.70 (7)	Na2^iv—O9—Na1^i	99.58 (7)
O13—Na2—O9^i	79.43 (6)	S2—O10—Na2^viii	139.66 (10)
O14^v—Na2—O9^i	98.75 (7)	S2—O10—Na3^viii	121.13 (10)
O10^vi—Na2—O9^i	89.40 (7)	Na2^viii—O10—Na3^viii	91.56 (6)
O13—Na2—O7^ii	78.32 (6)	S2—O11—Na3^iv	119.33 (9)
O14^v—Na2—O7^ii	93.97 (6)	S2—O11—Na4^vii	111.58 (9)
O10^vi—Na2—O7^ii	91.17 (7)	Na3^iv—O11—Na4^vii	128.97 (8)
O9^i—Na2—O7^ii	157.64 (7)	S3—O12—Na1^vii	138.53 (11)
O13—Na2—O1^vi	156.46 (7)	S3—O12—Na4	98.37 (8)
O14^v—Na2—O1^vi	70.79 (6)	Na1^vii—O12—Na4	122.67 (8)
O10^vi—Na2—O1^vi	73.15 (6)	S3—O13—Na2	141.74 (10)
O9^i—Na2—O1^vi	109.81 (6)	S3—O13—Na3	117.23 (9)
O7^ii—Na2—O1^vi	91.70 (6)	Na2—O13—Na3	92.48 (6)
O11^i—Na3—O2^iv	110.07 (7)	S3—O13—Na4	93.14 (8)
O11^i—Na3—O13	101.80 (6)	Na2—O13—Na4	100.69 (7)
O2^iv—Na3—O13	148.13 (7)	Na3—O13—Na4	107.34 (7)
O11^i—Na3—O10^vi	95.79 (7)	S3—O14—Na2^ix	124.60 (10)
O2^iv—Na3—O10^vi	95.42 (7)	S3—O14—Na1^x	124.66 (10)
O13—Na3—O10^vi	81.85 (6)	Na2^ix—O14—Na1^x	109.32 (7)

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