Each of the two acid H atoms in the centrosymmetric [C6H2(CO2H)2(CO2)2]2- dianion of disodium dihydrogen 1,2,4,5-benzenetetracarboxylate dihydrate, 2Na+·C10H4O82-·2H2O, holds together a pair of adjacent carboxyl groups so that all four groups are coplanar with the aromatic ring. The Na+ cation has a distorted octahedral coordination made up of two cis-coordinated water molecules and the O atoms of four carboxyl groups belonging to four different dianions; the water molecule acts as a bridge between two Na+ ions related by an inversion center.
Supporting information
CCDC reference: 200719
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (C-C) = 0.003 Å
- R factor = 0.041
- wR factor = 0.107
- Data-to-parameter ratio = 11.2
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Alert Level C:
REFLT_03
From the CIF: _diffrn_reflns_theta_max 28.10
From the CIF: _reflns_number_total 1311
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 1429
Completeness (_total/calc) 91.74%
Alert C: < 95% complete
PLAT_369 Alert C Long C(sp2)-C(sp2) Bond C1 - C2 = 1.53 Ang.
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
2 Alert Level C = Please check
Data collection: SMART (Bruker, 1997); cell refinement: SAINT (Bruker, 1997); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.
Disodium dihydrogen 1,2,4,5-benzenetetracarboxylate dihydrate
top
Crystal data top
2Na+·C10H4O82−·2H2O | Z = 1 |
Mr = 334.14 | F(000) = 170 |
Triclinic, P1 | Dx = 1.888 Mg m−3 |
a = 5.490 (1) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 6.799 (2) Å | Cell parameters from 722 reflections |
c = 8.716 (2) Å | θ = 2.4–28.1° |
α = 79.742 (4)° | µ = 0.23 mm−1 |
β = 75.852 (3)° | T = 298 K |
γ = 69.517 (3)° | Plate, colorless |
V = 294.0 (1) Å3 | 0.31 × 0.15 × 0.11 mm |
Data collection top
Bruker AXS SMART diffractometer | 962 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.018 |
Graphite monochromator | θmax = 28.1°, θmin = 2.4° |
ω scans | h = −6→7 |
1893 measured reflections | k = −8→8 |
1311 independent reflections | l = −6→11 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.041 | All H-atom parameters refined |
wR(F2) = 0.107 | w = 1/[σ2(Fo2) + (0.0621P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.94 | (Δ/σ)max = 0.001 |
1311 reflections | Δρmax = 0.24 e Å−3 |
117 parameters | Δρmin = −0.32 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.28 (3) |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Na1 | 0.6607 (2) | 0.5560 (1) | 0.6215 (1) | 0.0301 (3) | |
O1 | 0.7707 (3) | 0.8477 (2) | 0.6957 (2) | 0.0299 (4) | |
O2 | 0.6462 (3) | 0.6567 (3) | 0.9097 (2) | 0.0337 (4) | |
O3 | 0.6600 (3) | 0.5898 (3) | 1.1867 (2) | 0.0337 (4) | |
O4 | 0.8852 (3) | 0.6371 (2) | 1.3456 (2) | 0.0294 (4) | |
O1w | 0.7035 (3) | 0.2410 (3) | 0.4935 (2) | 0.0326 (4) | |
C1 | 0.7563 (4) | 0.7935 (3) | 0.8403 (2) | 0.0237 (5) | |
C2 | 0.8759 (4) | 0.8928 (3) | 0.9346 (2) | 0.0212 (5) | |
C3 | 0.9026 (4) | 0.8397 (3) | 1.0946 (2) | 0.0208 (5) | |
C4 | 0.8134 (4) | 0.6783 (3) | 1.2180 (2) | 0.0227 (5) | |
C5 | 0.9742 (4) | 1.0492 (3) | 0.8468 (3) | 0.0234 (5) | |
H1o | 0.639 (6) | 0.612 (5) | 1.056 (4) | 0.07 (1)* | |
H1w1 | 0.850 (7) | 0.209 (5) | 0.438 (4) | 0.06 (1)* | |
H1w2 | 0.697 (5) | 0.121 (5) | 0.553 (4) | 0.05 (1)* | |
H5 | 0.956 (4) | 1.087 (4) | 0.740 (3) | 0.02 (1)* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Na1 | 0.0320 (5) | 0.0339 (5) | 0.0292 (5) | −0.0151 (4) | −0.0102 (4) | −0.0002 (4) |
O1 | 0.043 (1) | 0.036 (1) | 0.019 (1) | −0.021 (1) | −0.010 (1) | 0.000 (1) |
O2 | 0.048 (1) | 0.043 (1) | 0.024 (1) | −0.032 (1) | −0.010 (1) | 0.002 (1) |
O3 | 0.048 (1) | 0.044 (1) | 0.023 (1) | −0.034 (1) | −0.009 (1) | 0.004 (1) |
O4 | 0.037 (1) | 0.034 (1) | 0.022 (1) | −0.019 (1) | −0.010 (1) | 0.007 (1) |
O1w | 0.031 (1) | 0.033 (1) | 0.031 (1) | −0.011 (1) | −0.005 (1) | 0.004 (1) |
C1 | 0.026 (1) | 0.026 (1) | 0.022 (1) | −0.011 (1) | −0.006 (1) | −0.004 (1) |
C2 | 0.022 (1) | 0.024 (1) | 0.020 (1) | −0.009 (1) | −0.005 (1) | −0.003 (1) |
C3 | 0.022 (1) | 0.023 (1) | 0.018 (1) | −0.009 (1) | −0.003 (1) | −0.002 (1) |
C4 | 0.025 (1) | 0.024 (1) | 0.019 (1) | −0.010 (1) | −0.003 (1) | −0.001 (1) |
C5 | 0.029 (1) | 0.025 (1) | 0.018 (1) | −0.010 (1) | −0.008 (1) | 0.000 (1) |
Geometric parameters (Å, º) top
Na1—O1 | 2.491 (2) | C1—C2 | 1.527 (3) |
Na1—O2 | 2.695 (2) | C2—C5 | 1.385 (3) |
Na1—O3i | 2.463 (2) | C2—C3 | 1.407 (3) |
Na1—O4ii | 2.482 (2) | C3—C5v | 1.397 (3) |
Na1—O4iii | 2.439 (2) | C3—C4 | 1.516 (3) |
Na1—O1w | 2.501 (2) | C5—C3v | 1.397 (3) |
Na1—O1wiv | 2.337 (2) | O2—H1o | 1.25 (3) |
O1—C1 | 1.240 (3) | O3—H1o | 1.15 (3) |
O2—C1 | 1.269 (3) | O1w—H1w1 | 0.81 (3) |
O3—C4 | 1.293 (2) | O1w—H1w2 | 0.89 (3) |
O4—C4 | 1.223 (2) | C5—H5 | 0.94 (2) |
| | | |
O1—Na1—O2 | 49.6 (1) | Na1iii—O4—Na1vi | 97.4 (1) |
O1—Na1—O3i | 118.6 (1) | Na1iv—O1w—Na1 | 89.0 (1) |
O1—Na1—O4ii | 87.2 (1) | O1—C1—O2 | 121.0 (2) |
O1—Na1—O4iii | 81.2 (1) | O1—C1—C2 | 118.9 (2) |
O1—Na1—O1w | 160.8 (1) | O2—C1—C2 | 120.1 (2) |
O1—Na1—O1wiv | 98.6 (1) | C5—C2—C3 | 118.0 (2) |
O2—Na1—O3i | 73.2 (1) | C5—C2—C1 | 114.2 (2) |
O2—Na1—O4ii | 135.0 (1) | C3—C2—C1 | 127.8 (2) |
O2—Na1—O4iii | 79.2 (1) | C5v—C3—C2 | 117.1 (2) |
O2—Na1—O1w | 139.2 (1) | C5v—C3—C4 | 113.3 (2) |
O2—Na1—O1wiv | 114.8 (1) | C2—C3—C4 | 129.6 (2) |
O3i—Na1—O4ii | 151.6 (1) | O4—C4—O3 | 121.6 (2) |
O3i—Na1—O4iii | 111.6 (1) | O4—C4—C3 | 119.3 (2) |
O3i—Na1—O1w | 78.6 (1) | O3—C4—C3 | 119.1 (2) |
O3i—Na1—O1wiv | 84.8 (1) | C2—C5—C3v | 124.9 (2) |
O4ii—Na1—O4iii | 82.6 (1) | C1—O2—H1o | 117 (1) |
O4ii—Na1—O1w | 78.4 (1) | Na1—O2—H1o | 152 (1) |
O4ii—Na1—O1wiv | 79.1 (1) | C4—O3—H1o | 116 (2) |
O4iii—Na1—O1w | 84.5 (1) | Na1i—O3—H1o | 116 (2) |
O4iii—Na1—O1wiv | 161.6 (1) | Na1iv—O1w—H1w1 | 119 (2) |
O1w—Na1—O1wiv | 91.0 (1) | Na1—O1w—H1w1 | 106 (2) |
C1—O1—Na1 | 99.0 (1) | Na1iv—O1w—H1w2 | 118 (2) |
C1—O2—Na1 | 88.5 (1) | Na1—O1w—H1w2 | 120 (2) |
C4—O3—Na1i | 127.2 (1) | H1w1—O1w—H1w2 | 104 (3) |
C4—O4—Na1iii | 124.2 (1) | C2—C5—H5 | 119 (1) |
C4—O4—Na1vi | 132.6 (1) | C3v—C5—H5 | 116 (1) |
| | | |
O1wiv—Na1—O1—C1 | 123.2 (1) | Na1—O2—C1—C2 | −166.0 (2) |
O4iii—Na1—O1—C1 | −75.5 (1) | O1—C1—C2—C5 | 4.5 (3) |
O3i—Na1—O1—C1 | 34.4 (2) | O2—C1—C2—C5 | −176.0 (2) |
O4ii—Na1—O1—C1 | −158.4 (1) | O1—C1—C2—C3 | −173.6 (2) |
O1w—Na1—O1—C1 | −117.5 (2) | O2—C1—C2—C3 | 6.0 (3) |
O2—Na1—O1—C1 | 7.8 (1) | C5—C2—C3—C5v | 0.4 (3) |
O1wiv—Na1—O2—C1 | −87.4 (1) | C1—C2—C3—C5v | 178.4 (2) |
O4iii—Na1—O2—C1 | 80.1 (1) | C5—C2—C3—C4 | 179.5 (2) |
O3i—Na1—O2—C1 | −163.3 (1) | C1—C2—C3—C4 | −2.5 (4) |
O4ii—Na1—O2—C1 | 12.2 (2) | Na1iii—O4—C4—O3 | 110.9 (2) |
O1—Na1—O2—C1 | −7.5 (1) | Na1vi—O4—C4—O3 | −36.0 (3) |
O1w—Na1—O2—C1 | 148.3 (1) | Na1iii—O4—C4—C3 | −70.1 (2) |
O1wiv—Na1—O1w—Na1iv | 0.0 | Na1vi—O4—C4—C3 | 143.0 (2) |
O4iii—Na1—O1w—Na1iv | −162.1 (1) | Na1i—O3—C4—O4 | 26.0 (3) |
O3i—Na1—O1w—Na1iv | 84.5 (1) | Na1i—O3—C4—C3 | −153.0 (1) |
O4ii—Na1—O1w—Na1iv | −78.6 (1) | C5v—C3—C4—O4 | −10.1 (3) |
O1—Na1—O1w—Na1iv | −120.4 (2) | C2—C3—C4—O4 | 170.8 (2) |
O2—Na1—O1w—Na1iv | 131.4 (1) | C5v—C3—C4—O3 | 168.9 (2) |
Na1—O1—C1—O2 | −14.8 (2) | C2—C3—C4—O3 | −10.2 (3) |
Na1—O1—C1—C2 | 164.7 (2) | C3—C2—C5—C3v | −0.4 (4) |
Na1—O2—C1—O1 | 13.5 (2) | C1—C2—C5—C3v | −178.7 (2) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) x, y, z−1; (iii) −x+2, −y+1, −z+2; (iv) −x+1, −y+1, −z+1; (v) −x+2, −y+2, −z+2; (vi) x, y, z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1w—H1w1···O1vii | 0.81 (3) | 2.06 (3) | 2.868 (2) | 174 (3) |
O1w—H1w2···O1viii | 0.89 (3) | 2.02 (3) | 2.888 (2) | 166 (3) |
O3—H1o···O2 | 1.15 (3) | 1.25 (3) | 2.390 (2) | 169 (3) |
Symmetry codes: (vii) −x+2, −y+1, −z+1; (viii) x, y−1, z. |