Acta Cryst. (2008). E64, i73 [ doi:10.1107/S1600536808030328 ]
![[kappa]](/logos/entities/kappa_rmgif.gif)
O)molybdate(VI)]-![[mu]](/logos/entities/mu_rmgif.gif)
-sulfato-2O:O']]Single crystals of the title compound, {Na4[MoVIO2(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[MoVIO2(SO4)3], with its monomeric anion, this sodium analogue contains a polymeric anion of the type {[MoVIO2(SO4)2--(SO4)]4-}n. The MoVI 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.
Crystals were grown from a melt of equimolar amounts of MoO3, Na2SO4, and Na2S2O7, using a method described previously (Nørbygaard et al., 1998).
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.
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).
![[Figure 1]](./wm2186fig1thm.gif)
| Fig. 1. Plot of the asymmetric unit of Na4[MoVI(SO4)3O2], showing atoms as ellipsoids at the 50% probability level. [Symmetry code A) x+0.5, -y+0.5, -z+1.] |
![[Figure 2]](./wm2186fig2thm.gif)
| Fig. 2. The crystal packing of Na4[MoVI(SO4)3O2], viewed along the b axis, showing the chains (thick black lines). Ellipsoids are displayed at the 50% probability level. |
| 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) Å3 | Tabular, colorless |
| Z = 4 | 0.24 × 0.18 × 0.02 mm |
| Bruker SMART APEX CCD diffractometer | 2861 independent reflections |
| Radiation source: normal-focus sealed tube | 2817 reflections with I > 2σ(I) |
| graphite | 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 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)] = 0.017 | w = 1/[σ2(Fo2) + (0.0214P)2 + 0.3747P] where P = (Fo2 + 2Fc2)/3 |
| wR(F2) = 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 | Flack parameter: 0.01 (2) |
| Na4[Mo(SO4)3O2] | V = 1188.97 (15) Å3 |
| Mr = 508.08 | Z = 4 |
| Orthorhombic, P212121 | Mo Kα radiation |
| a = 8.4739 (6) Å | µ = 1.86 mm−1 |
| b = 9.2892 (7) Å | T = 120 K |
| c = 15.1046 (11) Å | 0.24 × 0.18 × 0.02 mm |
| Bruker SMART APEX CCD diffractometer | 2861 independent reflections |
| Absorption correction: gaussian (SHELXTL; Sheldrick, 2008) | 2817 reflections with I > 2σ(I) |
| Tmin = 0.665, Tmax = 0.964 | Rint = 0.031 |
| 14125 measured reflections | θmax = 28.0° |
| R[F2 > 2σ(F2)] = 0.017 | 0 restraints |
| wR(F2) = 0.042 | Δρmax = 0.51 e Å−3 |
| S = 1.10 | Δρmin = −0.26 e Å−3 |
| 2861 reflections | Absolute structure: Flack (1983), 1205 Friedel pairs |
| 199 parameters | Flack parameter: 0.01 (2) |
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. |
| 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) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| 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) |
| Mo1—O2 | 1.6905 (16) | Na1—O9iv | 2.4972 (19) |
| Mo1—O1 | 1.7108 (16) | Na1—O1ii | 2.7652 (18) |
| Mo1—O5 | 1.9925 (16) | Na2—O13 | 2.3333 (18) |
| Mo1—O4 | 2.0102 (16) | Na2—O14v | 2.3350 (19) |
| Mo1—O6i | 2.1661 (15) | Na2—O10vi | 2.3415 (19) |
| Mo1—O3 | 2.1907 (15) | Na2—O9i | 2.3932 (19) |
| S1—O7 | 1.4564 (16) | Na2—O7ii | 2.5262 (18) |
| S1—O8 | 1.4681 (17) | Na2—O1vi | 2.7006 (19) |
| S1—O3 | 1.4941 (16) | Na2—S3v | 3.3837 (11) |
| S1—O6 | 1.4953 (16) | Na3—O11i | 2.3524 (19) |
| S2—O9 | 1.4516 (17) | Na3—O2iv | 2.3649 (19) |
| S2—O11 | 1.4575 (17) | Na3—O13 | 2.4115 (18) |
| S2—O10 | 1.4581 (17) | Na3—O10vi | 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—O7ii | 2.3065 (19) |
| S3—O13 | 1.4627 (16) | Na4—O12 | 2.407 (2) |
| S3—O5 | 1.5346 (16) | Na4—O11ii | 2.4078 (19) |
| Na1—O12ii | 2.2713 (18) | Na4—O8 | 2.4629 (19) |
| Na1—O8 | 2.3273 (19) | Na4—O1ii | 2.5003 (19) |
| Na1—O14iii | 2.3649 (19) | Na4—O13 | 2.5297 (19) |
| Na1—O4iv | 2.4394 (18) | ||
| O2—Mo1—O1 | 102.72 (8) | O11i—Na3—O3 | 129.03 (7) |
| O2—Mo1—O5 | 91.81 (7) | O2iv—Na3—O3 | 75.84 (6) |
| O1—Mo1—O5 | 101.77 (7) | O13—Na3—O3 | 83.71 (6) |
| O2—Mo1—O4 | 95.58 (7) | O10vi—Na3—O3 | 134.87 (6) |
| O1—Mo1—O4 | 93.46 (7) | O11i—Na3—O8 | 175.92 (7) |
| O5—Mo1—O4 | 161.18 (7) | O2iv—Na3—O8 | 73.41 (6) |
| O2—Mo1—O6i | 92.71 (7) | O13—Na3—O8 | 74.78 (6) |
| O1—Mo1—O6i | 163.68 (7) | O10vi—Na3—O8 | 81.61 (6) |
| O5—Mo1—O6i | 82.77 (6) | O3—Na3—O8 | 53.34 (5) |
| O4—Mo1—O6i | 79.62 (6) | O7ii—Na4—O12 | 121.20 (7) |
| O2—Mo1—O3 | 167.36 (7) | O7ii—Na4—O11ii | 90.91 (6) |
| O1—Mo1—O3 | 89.16 (7) | O12—Na4—O11ii | 83.88 (6) |
| O5—Mo1—O3 | 81.39 (6) | O7ii—Na4—O8 | 102.80 (7) |
| O4—Mo1—O3 | 87.91 (6) | O12—Na4—O8 | 104.28 (6) |
| O6i—Mo1—O3 | 75.92 (6) | O11ii—Na4—O8 | 156.62 (7) |
| O7—S1—O8 | 111.01 (10) | O7ii—Na4—O1ii | 81.21 (6) |
| O7—S1—O3 | 111.95 (9) | O12—Na4—O1ii | 154.90 (7) |
| O8—S1—O3 | 107.53 (10) | O11ii—Na4—O1ii | 84.66 (6) |
| O7—S1—O6 | 109.52 (9) | O8—Na4—O1ii | 78.95 (6) |
| O8—S1—O6 | 109.65 (10) | O7ii—Na4—O13 | 78.73 (6) |
| O3—S1—O6 | 107.08 (9) | O12—Na4—O13 | 58.10 (6) |
| O9—S2—O11 | 113.77 (10) | O11ii—Na4—O13 | 124.20 (7) |
| O9—S2—O10 | 112.83 (10) | O8—Na4—O13 | 77.59 (6) |
| O11—S2—O10 | 111.33 (10) | O1ii—Na4—O13 | 144.70 (7) |
| O9—S2—O4 | 103.55 (9) | Mo1—O1—Na4vii | 131.27 (9) |
| O11—S2—O4 | 107.18 (10) | Mo1—O1—Na2viii | 110.49 (7) |
| O10—S2—O4 | 107.52 (10) | Na4vii—O1—Na2viii | 91.78 (6) |
| O14—S3—O12 | 112.83 (10) | Mo1—O1—Na1vii | 128.10 (8) |
| O14—S3—O13 | 112.19 (10) | Na4vii—O1—Na1vii | 93.53 (5) |
| O12—S3—O13 | 110.37 (10) | Na2viii—O1—Na1vii | 89.08 (5) |
| O14—S3—O5 | 106.14 (9) | Mo1—O2—Na3i | 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) |
| O12ii—Na1—O8 | 119.12 (7) | Mo1—O3—Na3 | 108.85 (6) |
| O12ii—Na1—O14iii | 115.36 (7) | S2—O4—Mo1 | 131.46 (9) |
| O8—Na1—O14iii | 99.58 (7) | S2—O4—Na1i | 98.63 (8) |
| O12ii—Na1—O4iv | 131.24 (7) | Mo1—O4—Na1i | 127.05 (8) |
| O8—Na1—O4iv | 86.40 (6) | S3—O5—Mo1 | 136.93 (10) |
| O14iii—Na1—O4iv | 98.10 (6) | S1—O6—Mo1iv | 125.67 (9) |
| O12ii—Na1—O9iv | 82.33 (6) | S1—O7—Na4vii | 129.39 (10) |
| O8—Na1—O9iv | 141.19 (7) | S1—O7—Na2vii | 125.94 (10) |
| O14iii—Na1—O9iv | 98.72 (7) | Na4vii—O7—Na2vii | 101.54 (7) |
| O4iv—Na1—O9iv | 57.26 (6) | S1—O8—Na1 | 119.62 (10) |
| O12ii—Na1—O1ii | 72.64 (6) | S1—O8—Na4 | 107.73 (9) |
| O8—Na1—O1ii | 76.04 (6) | Na1—O8—Na4 | 106.56 (7) |
| O14iii—Na1—O1ii | 69.21 (5) | S1—O8—Na3 | 95.05 (8) |
| O4iv—Na1—O1ii | 155.81 (6) | Na1—O8—Na3 | 125.35 (7) |
| O9iv—Na1—O1ii | 142.71 (6) | Na4—O8—Na3 | 100.15 (7) |
| O13—Na2—O14v | 130.56 (7) | S2—O9—Na2iv | 147.79 (11) |
| O13—Na2—O10vi | 85.66 (6) | S2—O9—Na1i | 99.36 (8) |
| O14v—Na2—O10vi | 143.70 (7) | Na2iv—O9—Na1i | 99.58 (7) |
| O13—Na2—O9i | 79.43 (6) | S2—O10—Na2viii | 139.66 (10) |
| O14v—Na2—O9i | 98.75 (7) | S2—O10—Na3viii | 121.13 (10) |
| O10vi—Na2—O9i | 89.40 (7) | Na2viii—O10—Na3viii | 91.56 (6) |
| O13—Na2—O7ii | 78.32 (6) | S2—O11—Na3iv | 119.33 (9) |
| O14v—Na2—O7ii | 93.97 (6) | S2—O11—Na4vii | 111.58 (9) |
| O10vi—Na2—O7ii | 91.17 (7) | Na3iv—O11—Na4vii | 128.97 (8) |
| O9i—Na2—O7ii | 157.64 (7) | S3—O12—Na1vii | 138.53 (11) |
| O13—Na2—O1vi | 156.46 (7) | S3—O12—Na4 | 98.37 (8) |
| O14v—Na2—O1vi | 70.79 (6) | Na1vii—O12—Na4 | 122.67 (8) |
| O10vi—Na2—O1vi | 73.15 (6) | S3—O13—Na2 | 141.74 (10) |
| O9i—Na2—O1vi | 109.81 (6) | S3—O13—Na3 | 117.23 (9) |
| O7ii—Na2—O1vi | 91.70 (6) | Na2—O13—Na3 | 92.48 (6) |
| O11i—Na3—O2iv | 110.07 (7) | S3—O13—Na4 | 93.14 (8) |
| O11i—Na3—O13 | 101.80 (6) | Na2—O13—Na4 | 100.69 (7) |
| O2iv—Na3—O13 | 148.13 (7) | Na3—O13—Na4 | 107.34 (7) |
| O11i—Na3—O10vi | 95.79 (7) | S3—O14—Na2ix | 124.60 (10) |
| O2iv—Na3—O10vi | 95.42 (7) | S3—O14—Na1x | 124.66 (10) |
| O13—Na3—O10vi | 81.85 (6) | Na2ix—O14—Na1x | 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. |
| Mo1—O2 | 1.6905 (16) | Mo1—O4 | 2.0102 (16) |
| Mo1—O1 | 1.7108 (16) | Mo1—O6i | 2.1661 (15) |
| Mo1—O5 | 1.9925 (16) | Mo1—O3 | 2.1907 (15) |
| Symmetry codes: (i) x+1/2, −y+1/2, −z+1. |
Berg, R. W., Ferré, I. M. & Schäffer, S. J. C. (2006). Vib. Spectrosc., 42, 346–352.
Berg, R. W. & Thorup, N. (2005). Inorg. Chem. 44, 3485–3493.
Borup, F., Berg, R. W. & Nielsen, K. (1990). Acta Chem. Scand. 44, 328–331.
Bruker (2002). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Flack, H. D. (1983). Acta Cryst. A39, 876–881.
Nielsen, K., Fehrmann, R. & Eriksen, K. M. (1993). Inorg. Chem. 32, 4825–4828.
Nørbygaard, T., Berg, R. W. & Nielsen, K. (1998). Molten Salts XI. Proceedings of the Electrochemical Society 98–11, pp. 553–565. Pennington, NJ: Electrochemical Society
Rasmussen, S. B., Rasmussen, R. M., Fehrmann, R. & Nielsen, K. (2003). Inorg. Chem. 42, 7123–7128.
Salles, L., Robert, F., Semmer, V., Jeannin, Y. & Bregeault, J. (1996). Bull. Soc. Chim. Fr. 133, 319–328.
Schäffer, S. J. C. & Berg, R. W. (2005). Acta Cryst. E61, i49–i51.
Schäffer, S. J. C. & Berg, R. W. (2008). Acta Cryst. E64, i20.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.
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 SO42- 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 MoVI 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.