Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270199014419/br1268sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270199014419/br1268Isup2.hkl |
CCDC reference: 142736
An aqueous solution containing Na2WO4·2H2O (12.0 g) and glycine (1.0 g) was stirred for 10 min at pH 10. H3PO4 (85%, 0.28 ml) was added and the solution stirred for another 15 min at pH 9. A slow dropwise addition of HCl (12 M, 3.5 ml) to the solution with stirring gradually led to the formation of a white precipitate. The solution was filtered after stirring for 4 h. Colourless single crystals of (I) were obtained from the filtrate (at pH 7.1) after a few days.
Since the large positive (3.86 e Å−3) and negative (−4.63 e Å−3) difference Fourier peaks are located at short distances from W2 (1.04 Å) and W6 (0.90 Å), respectively, these peaks can be attributed to ghosts of the heavy W atoms.
Data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN (Molecular Structure Corporation, 1989); program(s) used to solve structure: SHELXS86 (Sheldrick, 1985); program(s) used to refine structure: TEXSAN; molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: TEXSAN.
Na10(H2W12O42)·2C2H5NO2·28H2O | Z = 1 |
Mr = 3764.65 | Dx = 3.664 Mg m−3 |
Triclinic, P1 | Mo Kα radiation, λ = 0.7107 Å |
a = 11.86 (1) Å | Cell parameters from 25 reflections |
b = 12.60 (1) Å | θ = 10.0–12.5° |
c = 13.02 (2) Å | µ = 20.36 mm−1 |
α = 74.3 (1)° | T = 298 K |
β = 79.6 (1)° | Plate, colourless |
γ = 66.0 (1)° | 0.12 × 0.12 × 0.05 mm |
V = 1706 (8) Å3 |
Rigaku AFC-5S diffractometer | Rint = 0.055 |
ω–2θ scans | θmax = 27.5° |
Absorption correction: ψ scan (North, Phillips & Mathews, 1968) | h = 0→15 |
Tmin = 0.108, Tmax = 0.369 | k = −14→16 |
8194 measured reflections | l = −16→16 |
7818 independent reflections | 3 standard reflections every 100 reflections |
7188 reflections with F2 > σ(F2) | intensity decay: 5.9% |
Refinement on F | H-atom parameters not defined |
R[F2 > 2σ(F2)] = 0.051 | w = 1/[σ2(Fo) + 0.00036|Fo|2] |
wR(F2) = 0.063 | (Δ/σ)max = 0.001 |
S = 1.98 | Δρmax = 3.86 e Å−3 |
7188 reflections | Δρmin = −4.63 e Å−3 |
260 parameters |
Na10(H2W12O42)·2C2H5NO2·28H2O | γ = 66.0 (1)° |
Mr = 3764.65 | V = 1706 (8) Å3 |
Triclinic, P1 | Z = 1 |
a = 11.86 (1) Å | Mo Kα radiation |
b = 12.60 (1) Å | µ = 20.36 mm−1 |
c = 13.02 (2) Å | T = 298 K |
α = 74.3 (1)° | 0.12 × 0.12 × 0.05 mm |
β = 79.6 (1)° |
Rigaku AFC-5S diffractometer | 7188 reflections with F2 > σ(F2) |
Absorption correction: ψ scan (North, Phillips & Mathews, 1968) | Rint = 0.055 |
Tmin = 0.108, Tmax = 0.369 | 3 standard reflections every 100 reflections |
8194 measured reflections | intensity decay: 5.9% |
7818 independent reflections |
R[F2 > 2σ(F2)] = 0.051 | 260 parameters |
wR(F2) = 0.063 | H-atom parameters not defined |
S = 1.98 | Δρmax = 3.86 e Å−3 |
7188 reflections | Δρmin = −4.63 e Å−3 |
x | y | z | Uiso*/Ueq | ||
W1 | 0.75539 (5) | 0.50445 (5) | 0.61159 (4) | 0.0096 (1) | |
W2 | 0.51645 (5) | 0.42682 (5) | 0.72593 (4) | 0.0085 (1) | |
W3 | 0.79446 (5) | 0.20305 (5) | 0.59269 (4) | 0.0097 (1) | |
W4 | 0.46896 (5) | 0.70252 (5) | 0.57356 (4) | 0.0080 (1) | |
W5 | 0.43760 (5) | 0.87885 (5) | 0.28950 (4) | 0.0114 (1) | |
W6 | 0.71520 (5) | 0.67256 (5) | 0.33326 (4) | 0.0102 (1) | |
Na1 | 1.0332 (6) | 0.5538 (6) | 0.1716 (5) | 0.025 (2) | |
Na2 | 1.0067 (7) | 0.8522 (6) | 0.0351 (5) | 0.032 (2) | |
Na3 | 0.1387 (6) | 1.1040 (7) | 0.4424 (6) | 0.034 (2) | |
Na4 | 0.3179 (6) | 1.0175 (6) | 0.6566 (5) | 0.026 (2) | |
Na5 | 0.3968 (6) | 0.3278 (6) | 1.0399 (5) | 0.026 (2) | |
O1 | 0.6451 (8) | 0.6586 (8) | 0.6177 (7) | 0.010 (2)* | |
O2 | 0.5428 (8) | 0.7436 (8) | 0.4330 (8) | 0.012 (2)* | |
O3 | 0.4095 (9) | 0.8353 (9) | 0.6135 (8) | 0.019 (2)* | |
O4 | 0.4537 (8) | 0.6003 (8) | 0.7131 (8) | 0.012 (2)* | |
O5 | 0.5797 (7) | 0.5115 (7) | 0.5625 (7) | 0.007 (2)* | |
O6 | 0.7795 (8) | 0.5602 (8) | 0.4585 (8) | 0.012 (2)* | |
O7 | 0.8254 (9) | 0.5991 (8) | 0.2388 (8) | 0.015 (2)* | |
O8 | 0.7696 (9) | 0.7800 (9) | 0.3374 (9) | 0.020 (2)* | |
O9 | 0.5911 (8) | 0.7796 (8) | 0.2328 (8) | 0.015 (2)* | |
O10 | 0.8853 (9) | 0.5023 (9) | 0.6543 (8) | 0.017 (2)* | |
O11 | 0.6819 (8) | 0.4391 (8) | 0.7391 (8) | 0.014 (2)* | |
O12 | 0.8168 (8) | 0.3471 (8) | 0.5774 (7) | 0.011 (2)* | |
O13 | 0.9020 (9) | 0.1467 (9) | 0.4912 (8) | 0.018 (2)* | |
O14 | 0.8802 (9) | 0.1231 (9) | 0.7047 (9) | 0.019 (2)* | |
O15 | 0.7066 (8) | 0.0964 (8) | 0.6104 (8) | 0.012 (2)* | |
O16 | 0.6626 (8) | 0.3064 (8) | 0.4679 (8) | 0.012 (2)* | |
O17 | 0.6209 (8) | 0.2770 (8) | 0.6912 (8) | 0.012 (2)* | |
O18 | 0.3832 (8) | 0.4408 (8) | 0.6673 (8) | 0.014 (2)* | |
O19 | 0.4814 (9) | 0.3865 (9) | 0.8601 (9) | 0.021 (2)* | |
O20 | 0.4803 (9) | 0.9861 (9) | 0.3164 (8) | 0.016 (2)* | |
O21 | 0.3675 (10) | 0.9501 (10) | 0.1700 (9) | 0.024 (2)* | |
O22 | 0.498 (1) | 0.121 (1) | 1.025 (1) | 0.048 (4)* | |
O23 | 0.577 (1) | 0.328 (1) | 1.097 (1) | 0.037 (3)* | |
O24 | 0.219 (1) | 0.328 (1) | 0.979 (1) | 0.036 (3)* | |
O25 | 0.296 (1) | 0.530 (1) | 1.066 (1) | 0.054 (4)* | |
O26 | 0.117 (1) | 1.146 (1) | 0.260 (1) | 0.053 (4)* | |
O27 | 0.037 (1) | 1.310 (1) | 0.432 (1) | 0.040 (3)* | |
O28 | 0.3309 (10) | 1.1058 (10) | 0.4723 (9) | 0.025 (2)* | |
O29 | 0.1296 (10) | 0.9999 (10) | 0.6248 (9) | 0.025 (2)* | |
O30 | 0.295 (1) | 0.932 (1) | 0.840 (1) | 0.049 (4)* | |
O31 | 0.792 (1) | 0.898 (1) | 0.007 (1) | 0.054 (4)* | |
O32 | 1.044 (1) | 0.977 (1) | −0.121 (1) | 0.036 (3)* | |
O33 | 0.936 (1) | 0.341 (1) | 0.0094 (10) | 0.029 (3)* | |
O34 | 0.995 (1) | 0.748 (1) | 0.2117 (9) | 0.027 (3)* | |
O35 | 1.008 (1) | 0.398 (1) | 0.1215 (10) | 0.028 (3)* | |
O36 | 1.220 (1) | 0.811 (1) | 0.080 (1) | 0.048 (4)* | |
O37 | 0.338 (1) | 0.238 (1) | 1.219 (1) | 0.045 (3)* | |
N1 | 0.847 (1) | 0.358 (1) | 0.287 (1) | 0.019 (3)* | |
C1 | 0.940 (1) | 0.361 (1) | 0.099 (1) | 0.020 (3)* | |
C2 | 0.841 (2) | 0.333 (2) | 0.187 (2) | 0.031 (4)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
W1 | 0.0097 (2) | 0.0112 (3) | 0.0097 (3) | −0.0062 (2) | −0.0003 (2) | −0.0019 (2) |
W2 | 0.0115 (2) | 0.0103 (3) | 0.0051 (2) | −0.0064 (2) | 0.0020 (2) | −0.0017 (2) |
W3 | 0.0089 (2) | 0.0100 (3) | 0.0102 (3) | −0.0041 (2) | 0.0006 (2) | −0.0023 (2) |
W4 | 0.0093 (2) | 0.0088 (2) | 0.0063 (3) | −0.0045 (2) | 0.0015 (2) | −0.0019 (2) |
W5 | 0.0133 (3) | 0.0107 (3) | 0.0097 (3) | −0.0062 (2) | 0.0010 (2) | −0.0001 (2) |
W6 | 0.0117 (2) | 0.0117 (3) | 0.0082 (3) | −0.0072 (2) | 0.0034 (2) | −0.0021 (2) |
Na1 | 0.026 (3) | 0.034 (4) | 0.019 (3) | −0.017 (3) | 0.001 (3) | −0.006 (3) |
Na2 | 0.046 (4) | 0.031 (4) | 0.019 (4) | −0.019 (3) | 0.003 (3) | −0.005 (3) |
Na3 | 0.035 (4) | 0.039 (4) | 0.024 (4) | −0.013 (3) | −0.003 (3) | 0.000 (3) |
Na4 | 0.028 (3) | 0.022 (3) | 0.029 (4) | −0.009 (3) | −0.006 (3) | −0.006 (3) |
Na5 | 0.028 (3) | 0.035 (4) | 0.019 (3) | −0.018 (3) | −0.001 (3) | −0.002 (3) |
W1—O10 | 1.718 (9) | W6—O2 | 2.203 (9) |
W1—O1 | 1.864 (9) | O33—C1 | 1.26 (2) |
W1—O11 | 1.875 (10) | O35—C1 | 1.20 (2) |
W1—O6 | 1.936 (10) | N1—C2 | 1.43 (2) |
W1—O12 | 1.962 (9) | C1—C2 | 1.56 (2) |
W1—O5 | 2.249 (8) | Na1—O7 | 2.35 (1) |
W2—O19 | 1.71 (1) | Na1—O35 | 2.37 (1) |
W2—O18 | 1.802 (9) | Na1—O33ii | 2.41 (1) |
W2—O17 | 1.914 (9) | Na1—O10iii | 2.44 (1) |
W2—O4 | 1.972 (9) | Na1—O34 | 2.49 (1) |
W2—O11 | 2.070 (9) | Na1—O25iv | 3.10 (2) |
W2—O5 | 2.253 (9) | Na2—O32 | 2.30 (1) |
W3—O13 | 1.74 (1) | Na2—O34 | 2.33 (1) |
W3—O14 | 1.76 (1) | Na2—O31 | 2.44 (2) |
W3—O12 | 1.892 (9) | Na2—O33ii | 2.46 (1) |
W3—O15 | 1.957 (9) | Na2—O32v | 2.50 (1) |
W3—O17 | 2.210 (9) | Na2—O36 | 2.52 (2) |
W3—O16 | 2.213 (9) | Na3—O26 | 2.32 (2) |
W4—O3 | 1.72 (1) | Na3—O27 | 2.35 (2) |
W4—O16i | 1.794 (9) | Na3—O29 | 2.39 (1) |
W4—O2 | 1.913 (10) | Na3—O28 | 2.39 (1) |
W4—O4 | 1.949 (10) | Na3—O13vi | 2.62 (1) |
W4—O1 | 2.079 (9) | Na3—O15i | 2.63 (1) |
W4—O5 | 2.257 (8) | Na4—O3 | 2.28 (1) |
W5—O21 | 1.74 (1) | Na4—O8vii | 2.35 (1) |
W5—O20 | 1.755 (9) | Na4—O30 | 2.35 (2) |
W5—O9 | 1.894 (10) | Na4—O28 | 2.36 (1) |
W5—O15i | 1.924 (9) | Na4—O29 | 2.45 (1) |
W5—O17i | 2.276 (9) | Na4—O20vii | 2.46 (1) |
W5—O2 | 2.311 (9) | Na5—O24 | 2.38 (1) |
W6—O8 | 1.736 (10) | Na5—O23 | 2.38 (1) |
W6—O7 | 1.768 (10) | Na5—O37 | 2.41 (2) |
W6—O6 | 1.888 (9) | Na5—O19 | 2.42 (1) |
W6—O9 | 1.956 (10) | Na5—O25 | 2.42 (2) |
W6—O18i | 2.183 (9) | Na5—O22 | 2.43 (2) |
N1···O7 | 2.85 (2) | O25···O33i | 2.77 (2) |
N1···O18i | 2.98 (2) | O26···O35vi | 3.07 (2) |
N1···O27viii | 2.98 (2) | O26···O37xii | 3.19 (2) |
N1···O16 | 3.04 (2) | O26···O27 | 3.21 (2) |
N1···O13 | 3.16 (2) | O28···O37xii | 3.27 (2) |
N1···O26viii | 3.26 (2) | O28···O29 | 3.30 (2) |
O22···O30ix | 3.02 (2) | O29···O32xi | 3.26 (2) |
O22···O37 | 3.18 (2) | O30···O32xi | 2.77 (2) |
O22···O22x | 3.28 (3) | O30···O31vii | 3.07 (2) |
O23···O30ix | 2.94 (2) | O30···O36xi | 3.23 (2) |
O23···O25ix | 3.00 (2) | O32···O34v | 3.21 (2) |
O23···O25 | 3.28 (2) | O32···O32v | 3.26 (3) |
O23···O36iii | 3.30 (2) | O32···O36v | 3.26 (2) |
O24···O35xi | 2.81 (2) | O33···O35 | 2.21 (2) |
O24···O31i | 2.86 (2) | O33···O34ii | 3.22 (2) |
O24···O33xi | 3.26 (2) | O34···O36 | 3.17 (2) |
O10—W1—O1 | 101.0 (4) | O3—W4—O4 | 97.7 (4) |
O10—W1—O11 | 102.0 (4) | O3—W4—O1 | 93.5 (4) |
O10—W1—O6 | 101.4 (4) | O3—W4—O5 | 163.3 (4) |
O10—W1—O12 | 101.4 (4) | O16i—W4—O2 | 96.6 (4) |
O10—W1—O5 | 177.2 (4) | O16i—W4—O4 | 91.5 (4) |
O1—W1—O11 | 92.1 (4) | O16i—W4—O1 | 162.4 (4) |
O1—W1—O6 | 88.0 (4) | O16i—W4—O5 | 89.5 (4) |
O1—W1—O12 | 157.3 (4) | O2—W4—O4 | 156.0 (4) |
O1—W1—O5 | 77.0 (3) | O2—W4—O1 | 82.9 (4) |
O11—W1—O6 | 156.2 (4) | O2—W4—O5 | 86.0 (4) |
O11—W1—O12 | 86.6 (4) | O4—W4—O1 | 82.6 (4) |
O11—W1—O5 | 76.2 (4) | O4—W4—O5 | 71.5 (3) |
O6—W1—O12 | 84.3 (4) | O1—W4—O5 | 72.8 (3) |
O6—W1—O5 | 80.7 (3) | O21—W5—O20 | 103.3 (5) |
O12—W1—O5 | 80.7 (3) | O21—W5—O9 | 98.0 (5) |
O19—W2—O18 | 103.5 (5) | O21—W5—O15i | 100.1 (5) |
O19—W2—O17 | 102.1 (5) | O21—W5—O17i | 91.8 (4) |
O19—W2—O4 | 98.1 (4) | O21—W5—O2 | 166.2 (4) |
O19—W2—O11 | 96.1 (4) | O20—W5—O9 | 100.8 (4) |
O19—W2—O5 | 165.0 (4) | O20—W5—O15i | 95.9 (4) |
O18—W2—O17 | 95.3 (4) | O20—W5—O17i | 162.9 (4) |
O18—W2—O4 | 91.2 (4) | O20—W5—O2 | 88.8 (4) |
O18—W2—O11 | 160.0 (4) | O9—W5—O15i | 151.8 (4) |
O18—W2—O5 | 87.5 (4) | O9—W5—O17i | 84.8 (4) |
O17—W2—O4 | 156.6 (4) | O9—W5—O2 | 72.9 (4) |
O17—W2—O11 | 84.1 (4) | O15i—W5—O17i | 73.2 (3) |
O17—W2—O5 | 86.6 (4) | O15i—W5—O2 | 85.0 (4) |
O4—W2—O11 | 82.2 (4) | O17i—W5—O2 | 77.3 (3) |
O4—W2—O5 | 71.2 (3) | O8—W6—O7 | 101.2 (5) |
O11—W2—O5 | 72.5 (3) | O8—W6—O6 | 99.1 (4) |
O13—W3—O14 | 100.4 (5) | O8—W6—O9 | 94.6 (4) |
O13—W3—O12 | 99.5 (4) | O8—W6—O18i | 170.6 (4) |
O13—W3—O15 | 95.7 (4) | O8—W6—O2 | 94.6 (4) |
O13—W3—O17 | 163.7 (4) | O7—W6—O6 | 97.9 (4) |
O13—W3—O16 | 87.1 (4) | O7—W6—O9 | 96.6 (4) |
O14—W3—O12 | 97.0 (4) | O7—W6—O18i | 86.7 (4) |
O14—W3—O15 | 95.4 (4) | O7—W6—O2 | 162.5 (4) |
O14—W3—O17 | 93.3 (4) | O6—W6—O9 | 157.7 (4) |
O14—W3—O16 | 171.8 (4) | O6—W6—O18i | 84.7 (4) |
O12—W3—O15 | 158.3 (4) | O6—W6—O2 | 87.0 (4) |
O12—W3—O17 | 87.4 (4) | O9—W6—O18i | 79.3 (4) |
O12—W3—O16 | 84.9 (4) | O9—W6—O2 | 74.4 (4) |
O15—W3—O17 | 74.1 (4) | O18i—W6—O2 | 77.0 (3) |
O15—W3—O16 | 80.5 (4) | O35—C1—O33 | 127 (1) |
O17—W3—O16 | 78.8 (3) | O35—C1—C2 | 118 (1) |
O3—W4—O16i | 103.8 (4) | O33—C1—C2 | 114 (1) |
O3—W4—O2 | 102.2 (4) | N1—C2—C1 | 112 (1) |
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) −x+2, −y+1, −z; (iii) −x+2, −y+1, −z+1; (iv) x+1, y, z−1; (v) −x+2, −y+2, −z; (vi) x−1, y+1, z; (vii) −x+1, −y+2, −z+1; (viii) x+1, y−1, z; (ix) −x+1, −y+1, −z+2; (x) −x+1, −y, −z+2; (xi) x−1, y, z+1; (xii) x, y+1, z−1. |
Experimental details
Crystal data | |
Chemical formula | Na10(H2W12O42)·2C2H5NO2·28H2O |
Mr | 3764.65 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 298 |
a, b, c (Å) | 11.86 (1), 12.60 (1), 13.02 (2) |
α, β, γ (°) | 74.3 (1), 79.6 (1), 66.0 (1) |
V (Å3) | 1706 (8) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 20.36 |
Crystal size (mm) | 0.12 × 0.12 × 0.05 |
Data collection | |
Diffractometer | Rigaku AFC-5S diffractometer |
Absorption correction | ψ scan (North, Phillips & Mathews, 1968) |
Tmin, Tmax | 0.108, 0.369 |
No. of measured, independent and observed [F2 > σ(F2)] reflections | 8194, 7818, 7188 |
Rint | 0.055 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.051, 0.063, 1.98 |
No. of reflections | 7188 |
No. of parameters | 260 |
No. of restraints | ? |
H-atom treatment | H-atom parameters not defined |
Δρmax, Δρmin (e Å−3) | 3.86, −4.63 |
Computer programs: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1988), MSC/AFC Diffractometer Control Software, TEXSAN (Molecular Structure Corporation, 1989), SHELXS86 (Sheldrick, 1985), TEXSAN, ORTEPII (Johnson, 1976).
Na1—O7 | 2.35 (1) | Na3—O28 | 2.39 (1) |
Na1—O35 | 2.37 (1) | Na3—O13v | 2.62 (1) |
Na1—O33i | 2.41 (1) | Na3—O15vi | 2.63 (1) |
Na1—O10ii | 2.44 (1) | Na4—O3 | 2.28 (1) |
Na1—O34 | 2.49 (1) | Na4—O8vii | 2.35 (1) |
Na1—O25iii | 3.10 (2) | Na4—O30 | 2.35 (2) |
Na2—O32 | 2.30 (1) | Na4—O28 | 2.36 (1) |
Na2—O34 | 2.33 (1) | Na4—O29 | 2.45 (1) |
Na2—O31 | 2.44 (2) | Na4—O20vii | 2.46 (1) |
Na2—O33i | 2.46 (1) | Na5—O24 | 2.38 (1) |
Na2—O32iv | 2.50 (1) | Na5—O23 | 2.38 (1) |
Na2—O36 | 2.52 (2) | Na5—O37 | 2.41 (2) |
Na3—O26 | 2.32 (2) | Na5—O19 | 2.42 (1) |
Na3—O27 | 2.35 (2) | Na5—O25 | 2.42 (2) |
Na3—O29 | 2.39 (1) | Na5—O22 | 2.43 (2) |
N1···O7 | 2.85 (2) | N1···O16 | 3.04 (2) |
N1···O18vi | 2.98 (2) | N1···O13 | 3.16 (2) |
N1···O27viii | 2.98 (2) | N1···O26viii | 3.26 (2) |
Symmetry codes: (i) −x+2, −y+1, −z; (ii) −x+2, −y+1, −z+1; (iii) x+1, y, z−1; (iv) −x+2, −y+2, −z; (v) x−1, y+1, z; (vi) −x+1, −y+1, −z+1; (vii) −x+1, −y+2, −z+1; (viii) x+1, y−1, z. |
The recent discovery of biological activities of polyoxometallates (Yamase, Fujita & Fukushima, 1988; Yamase, 1994) led us to focus on the interaction behaviour of polyoxometallates with biomolecules. With regard to the complexation of polyoxomolybdates with amino acids or peptides, Na2[Mo8O26(lysineH2)2]·8H2O (Inoue & Yamase, 1995) and [Mo4O12(glycylglycylglycine)2]·9H2O (Yamase, Inoue, Naruke & Fukaya, 1999) have been obtained from aqueous molybdate solutions (pH 3) containing lysine and glycylglycylglycine, respectively. The former consists of a γ-type octamolybdate coordinated by two lysine ligands through their carboxylate O atoms. The latter consists of a polymeric [Mo4O12]\infinity chain attached by glycylglycylglycine ligands through both carboxylate O atoms. For the extension of our investigation on the polyoxomolybdate-based complexes to polyoxotungstate-based ones, we recently prepared the title compound, (I), from aqueous tungstate solution in the presence of glycine at pH 7.1.
Fig. 1 shows an ORTEPII (Johnson, 1976) drawing of the [H2W12O42]10− anion, which is isostructural with those of known paratungstate salts, for instance, Na10[H2W12O42].20H2O (Evans & Rollins, 1976) and Na10[H2W12O42].26H2O (Cruywagen et al., 1986). The two protons in the centrosymmetric [H2W12O42]10− anion are attached to triply bridging O5 and O5i atoms, as shown by their low bond valence sum (1.09) (Brown, 1980). W—O distances and O—W—O angles are essentially similar to those of other paratungstate compounds.
Since the negative charge of the [H2W12O42]10− anion is completely compensated by Na+ cations, the glycine molecule seems to be zwitterionic. Fig. 2 (top) is a packing diagram of (I). Each of all the Na+ cations is octahedrally coordinated by six O atoms belonging to the [H2W12O42]10− anions, crystallization water molecules, or carboxylate O atoms (Table 1). As shown in Fig. 2 (bottom), four NaO6 octahedra, including Na1, Na2 and their symmetry-related Na atoms, are linearly connected by edge-sharing and linked by the glycine molecules through carboxylate O33 and O35 atoms [with distances of Na1···O33 2.41 (1), Na1···O35 2.37 (1) and Na2···O33 2.46 (1) Å] to form a polymeric [(glycine)2Na4O14]\infinity chain running along the b axis. Furthermore, as shown in Fig. 2 (top), the amino N1 of the glycine is hydrogen bonded to a neighbouring [H2W12O42]10− anion at its terminal [O7, O13] and bridging [O16, O18] atoms, with N···O distances of 2.85 (2), 3.16 (2), 3.04 (2) and 2.98 (2) Å, respectively (Table 2).
In conclusion, unlike the polyoxomolybdate-amino acid complexes, in the title compound the glycine molecule interacts with the paratungstate anion by N···O hydrogen bonding without any direct coordination of the carboxylate O atoms to the W centre.