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The asymmetric unit of the title coordination polymer, {[Co2(C10H2O8)(H2O)4]·2H2O}n, contains two crystallographically distinct CoII cations, located on inversion centers. Each CoII cation exists in an octa­hedral coordination environment formed by two water mol­ecules and four carboxyl­ate groups. The deprotonated benzene-1,2,4,5-tetra­carboxylic acid ligand, with the center of the benzene ring located on an inversion center, bridges CoII cations to form a (3,4)-connected three-dimensional network that is topologically related to Pt3O4 (waserite). O—H...O hydrogen bonding between coordinated water mol­ecules and carboxylate groups helps to stabilize the crystal structure. One water molecules is disordered over two positions, with almost equal occupancies.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807025901/xu2263sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807025901/xu2263Isup2.hkl
Contains datablock I

CCDC reference: 654717

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](C-C) = 0.004 Å
  • H-atom completeness 72%
  • Disorder in main residue
  • R factor = 0.038
  • wR factor = 0.103
  • Data-to-parameter ratio = 14.4

checkCIF/PLATON results

No syntax errors found



Alert level C PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low ....... 0.97 PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ? PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)... ? PLAT301_ALERT_3_C Main Residue Disorder ......................... 1.00 Perc. PLAT311_ALERT_2_C Isolated Disordered Oxygen Atom (No H's ?) ..... >O31A PLAT311_ALERT_2_C Isolated Disordered Oxygen Atom (No H's ?) ..... <O31B
Alert level G FORMU01_ALERT_2_G There is a discrepancy between the atom counts in the _chemical_formula_sum and the formula from the _atom_site* data. Atom count from _chemical_formula_sum:C5 H7 Co1 O7 Atom count from the _atom_site data: C5 H5 Co1 O7 CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected. CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional? From the CIF: _cell_formula_units_Z 2 From the CIF: _chemical_formula_sum C5 H7 Co O7 TEST: Compare cell contents of formula and atom_site data atom Z*formula cif sites diff C 10.00 10.00 0.00 H 14.00 10.00 4.00 Co 2.00 2.00 0.00 O 14.00 14.00 0.00
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 7 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 3 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check

Comment top

As shown in figure 1, a half of the Benzene-1,2,4,5-tetracarboxylic acid (H4btec) is observed in the crystallographic asymmetric unit with center of the benzene ring located on a crystallographic 1 position. The observation of symmetrical C?O bond lengths ranges from 1.250 (2) to 1.265 (3) Å indicates that all of the carboxyl groups of the H4btec are deprotonated to become the btec4- anion. The asymmetric unit of the title compound contains two crystallographic distinct CoII cations, located on crystallographic inversion centers with site occupation factor of 0.5. Each Co ion exists in an octahedral coordination environment (Table 1) formed by two water molecules and four carboxylate groups. The btec4- ligands bridges Co ions to form a three-dimensional metal-organic framework with one-dimensional channels in the [010] direction that are occupied by disordered guest water molecules and coordinated water molecules (Fig. 2). The formula of the compound is assigned to be [Co2(C10H2O8)(H2O)4.2H2O]n. A NiII analogue, and a CoII-btec coordination polymer with different contents of unit-cell packing were previously reported (Yang et al., 2003; Kumagai et al., 2002).

The network topology of the title compound is analyzed. The carbon atom of the carboxylate group serves as a simple three-connected node linking benzene ring and two Co ions. The benzene ring of the Benzene-1,2,4,5-tetracarboxylate ligand serves as a planar four-connected node. If coordinated water molecules are neglected, each Co ion also serves as a planar four-connected secondary building unit on the basis of four coordinated carboxylate groups. As a result, the title compound represents a new example of a (3,4)-connected net that is topologically related to Pt3O4 (waserite) (O'Keeffe et al., 2000; Wells, 1977).

The O—H···O hydroge bonding between coordinated water molecules and carboxyl groups helps to stabilize the crystal structure (Table 2).

Related literature top

For related structures, see: Kumagai et al. (2002); O'Keeffe et al. (2000); Wells (1977); Yang et al. (2003).

Experimental top

All reagents and solvents were used as obtained without further purification. CoCl2.6H2O (0.6 mmol), H4btec (0.5 mmol) and NaOH (1.0 mmol) were dissolved in 8 ml of distilled water. The mixture was sealed in a Teflon-lined stainless steel vessel and held at 383 K for 72 h. The vessel was gradually cooled to room temperature, and red crystals suitable for crystallographic analysis were obtained after 4 d.

Refinement top

The C-bound H atoms were placed in calculated positions (C—H = 0.93 Å) and refined in the riding-model approximation with Uiso(H) = 1.2Ueq(C). The H atoms of the coordinated water molecules were located in a difference Fourier map, and refined as riding model with O—H distances range from 0.82 to 0.85 Å, and with Uiso(H) = 1.5Ueq(O). The PLATON SQUEEZE procedure was used to treat regions of disordered guest molecules that could not be judiciously modeled in terms of atomic sites (Spek, 2003). The number of electrons thus located, 17 per unit cell, is assigned to two molecules of water solvent and is included in the formula, formula weight, calculated density, µ and F(000). There is difference between the reported and calculated values. Two largest residual densities located from the difference Fourier map separated by 1.93 Å are assigned to two disordered guest water molecules O31A and O31B. The refinement of relative site occupation factor leads to 0.53 and 0.47 for O31A and O31B, respectively. No attempt was made to locate hydrogen atoms of the disordered guest water molecules.

Structure description top

As shown in figure 1, a half of the Benzene-1,2,4,5-tetracarboxylic acid (H4btec) is observed in the crystallographic asymmetric unit with center of the benzene ring located on a crystallographic 1 position. The observation of symmetrical C?O bond lengths ranges from 1.250 (2) to 1.265 (3) Å indicates that all of the carboxyl groups of the H4btec are deprotonated to become the btec4- anion. The asymmetric unit of the title compound contains two crystallographic distinct CoII cations, located on crystallographic inversion centers with site occupation factor of 0.5. Each Co ion exists in an octahedral coordination environment (Table 1) formed by two water molecules and four carboxylate groups. The btec4- ligands bridges Co ions to form a three-dimensional metal-organic framework with one-dimensional channels in the [010] direction that are occupied by disordered guest water molecules and coordinated water molecules (Fig. 2). The formula of the compound is assigned to be [Co2(C10H2O8)(H2O)4.2H2O]n. A NiII analogue, and a CoII-btec coordination polymer with different contents of unit-cell packing were previously reported (Yang et al., 2003; Kumagai et al., 2002).

The network topology of the title compound is analyzed. The carbon atom of the carboxylate group serves as a simple three-connected node linking benzene ring and two Co ions. The benzene ring of the Benzene-1,2,4,5-tetracarboxylate ligand serves as a planar four-connected node. If coordinated water molecules are neglected, each Co ion also serves as a planar four-connected secondary building unit on the basis of four coordinated carboxylate groups. As a result, the title compound represents a new example of a (3,4)-connected net that is topologically related to Pt3O4 (waserite) (O'Keeffe et al., 2000; Wells, 1977).

The O—H···O hydroge bonding between coordinated water molecules and carboxyl groups helps to stabilize the crystal structure (Table 2).

For related structures, see: Kumagai et al. (2002); O'Keeffe et al. (2000); Wells (1977); Yang et al. (2003).

Computing details top

Data collection: XSCANS (Bruker, 1991); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997) and PLATON (Spek, 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The asymmetric unit, expanded to show the complete coordination of the Co ions, with displacement ellipsoids drawn at the 50% probability level. Guest water molecules are omitted for clarity. (Symmetry codes are the same as geometric tables.)
[Figure 2] Fig. 2. Solid-state packing diagram of the three-dimensional framework.
[Figure 3] Fig. 3. Topological view of the Pt3O4 related (3,4)-connected net of the titel compound. (black sphere: C atom of carboxylate group; white sphere: center of btec4- ligand; grey sphere: Co ion.)
Poly[[tetraaqua(µ6-benzene-1,2,4,5-tetracarboxylato)dicobalt(II)] dihydrate] top
Crystal data top
[Co2(C10H2O8)(H2O)4]·2H2OZ = 2
Mr = 238.04F(000) = 240
Triclinic, P1Dx = 1.966 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 6.9362 (7) ÅCell parameters from 34 reflections
b = 7.4559 (6) Åθ = 5.6–12.8°
c = 8.2797 (7) ŵ = 2.14 mm1
α = 90.342 (8)°T = 298 K
β = 109.848 (7)°Column, red
γ = 93.161 (7)°0.3 × 0.1 × 0.1 mm
V = 402.00 (6) Å3
Data collection top
Bruker P4
diffractometer
1570 reflections with I > 2σ(I)
Radiation source: sealed tubeRint = 0.028
Graphite monochromatorθmax = 28.0°, θmin = 2.6°
2θ/ω scansh = 91
Absorption correction: ψ scan
(North et al., 1968)
k = 99
Tmin = 0.685, Tmax = 0.811l = 1010
2314 measured reflections3 standard reflections every 24 reflections
1883 independent reflections intensity decay: 1.0%
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.038 w = 1/[σ2(Fo2) + (0.0533P)2 + 0.4406P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.103(Δ/σ)max < 0.001
S = 1.05Δρmax = 0.59 e Å3
1883 reflectionsΔρmin = 0.77 e Å3
131 parameters
Crystal data top
[Co2(C10H2O8)(H2O)4]·2H2Oγ = 93.161 (7)°
Mr = 238.04V = 402.00 (6) Å3
Triclinic, P1Z = 2
a = 6.9362 (7) ÅMo Kα radiation
b = 7.4559 (6) ŵ = 2.14 mm1
c = 8.2797 (7) ÅT = 298 K
α = 90.342 (8)°0.3 × 0.1 × 0.1 mm
β = 109.848 (7)°
Data collection top
Bruker P4
diffractometer
1570 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.028
Tmin = 0.685, Tmax = 0.8113 standard reflections every 24 reflections
2314 measured reflections intensity decay: 1.0%
1883 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0380 restraints
wR(F2) = 0.103H-atom parameters constrained
S = 1.05Δρmax = 0.59 e Å3
1883 reflectionsΔρmin = 0.77 e Å3
131 parameters
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Co1000.50.01624 (16)
Co20.50.50.50.01426 (16)
O10.1694 (3)0.2325 (3)0.6119 (3)0.0223 (4)
O20.4875 (3)0.3576 (3)0.7123 (3)0.0227 (4)
O30.2645 (3)0.1283 (3)0.5378 (3)0.0268 (5)
O40.5570 (3)0.2620 (3)0.6499 (2)0.0175 (4)
O210.0391 (4)0.0928 (4)0.2669 (3)0.0342 (6)
H21A0.1510.15380.28260.051*
H21B0.03370.08860.16560.051*
O220.1793 (3)0.5155 (3)0.3953 (3)0.0265 (5)
H22A0.12240.60920.4040.04*
H22B0.14210.43970.45590.04*
O31A0.0980 (8)0.2254 (8)0.0766 (7)0.0469 (18)0.527 (8)
O31B0.1415 (13)0.4510 (14)0.0178 (11)0.089 (4)0.473 (8)
C10.3523 (4)0.2411 (4)0.7155 (3)0.0155 (5)
C20.4193 (4)0.1081 (4)0.8574 (3)0.0150 (5)
C30.4640 (4)0.0677 (4)0.8333 (3)0.0136 (5)
C40.4246 (4)0.1563 (4)0.6596 (3)0.0145 (5)
C50.4549 (4)0.1741 (4)1.0238 (3)0.0163 (5)
H5A0.42410.29121.03990.02*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co10.0143 (3)0.0151 (3)0.0165 (3)0.00031 (19)0.0018 (2)0.00175 (19)
Co20.0178 (3)0.0117 (3)0.0122 (2)0.00056 (19)0.00392 (19)0.00044 (18)
O10.0210 (10)0.0161 (10)0.0224 (10)0.0007 (8)0.0018 (8)0.0031 (8)
O20.0236 (11)0.0234 (11)0.0181 (9)0.0065 (8)0.0042 (8)0.0048 (8)
O30.0238 (11)0.0343 (13)0.0170 (10)0.0117 (9)0.0015 (8)0.0091 (9)
O40.0177 (9)0.0163 (9)0.0170 (9)0.0033 (7)0.0035 (8)0.0042 (7)
O210.0222 (11)0.0541 (16)0.0214 (11)0.0087 (11)0.0028 (9)0.0053 (10)
O220.0219 (10)0.0225 (11)0.0346 (12)0.0025 (9)0.0088 (9)0.0006 (9)
O31A0.038 (3)0.059 (4)0.040 (3)0.001 (3)0.009 (2)0.004 (3)
O31B0.068 (6)0.092 (7)0.067 (5)0.026 (5)0.023 (4)0.007 (5)
C10.0210 (13)0.0127 (12)0.0120 (11)0.0002 (10)0.0048 (10)0.0032 (9)
C20.0143 (12)0.0158 (12)0.0127 (11)0.0026 (10)0.0025 (10)0.0019 (9)
C30.0140 (12)0.0147 (12)0.0107 (11)0.0023 (9)0.0032 (9)0.0035 (9)
C40.0174 (12)0.0129 (12)0.0130 (11)0.0008 (10)0.0052 (10)0.0026 (9)
C50.0201 (13)0.0131 (12)0.0158 (12)0.0007 (10)0.0062 (10)0.0018 (9)
Geometric parameters (Å, º) top
Co1—O12.065 (2)O3—C41.250 (3)
Co1—O1i2.065 (2)O4—C41.264 (3)
Co1—O3i2.046 (2)O4—Co2v2.0996 (19)
Co1—O32.046 (2)O21—H21A0.8472
Co1—O212.151 (2)O21—H21B0.8188
Co1—O21i2.151 (2)O22—H22A0.8359
Co2—O2ii2.083 (2)O22—H22B0.8447
Co2—O22.083 (2)C1—C21.508 (4)
Co2—O4iii2.0996 (19)C2—C31.392 (4)
Co2—O4iv2.0996 (19)C2—C51.395 (3)
Co2—O222.105 (2)C3—C5vi1.398 (4)
Co2—O22ii2.105 (2)C3—C41.511 (3)
O1—C11.265 (3)C5—C3vi1.398 (4)
O2—C11.250 (3)C5—H5A0.93
O3i—Co1—O3180.00 (12)O4iv—Co2—O22ii96.15 (8)
O3i—Co1—O189.65 (9)O22—Co2—O22ii180.0000 (10)
O3—Co1—O190.35 (9)C1—O1—Co1125.58 (19)
O3i—Co1—O1i90.35 (9)C1—O2—Co2126.83 (18)
O3—Co1—O1i89.65 (9)C4—O3—Co1137.74 (18)
O1—Co1—O1i180C4—O4—Co2v126.45 (17)
O3i—Co1—O2194.40 (10)Co1—O21—H21A113.9
O3—Co1—O2185.60 (10)Co1—O21—H21B134.3
O1—Co1—O2185.35 (9)H21A—O21—H21B111.6
O1i—Co1—O2194.65 (9)Co2—O22—H22A121.8
O3i—Co1—O21i85.60 (10)Co2—O22—H22B99.9
O3—Co1—O21i94.40 (10)H22A—O22—H22B105.4
O1—Co1—O21i94.65 (9)O2—C1—O1124.3 (3)
O1i—Co1—O21i85.35 (9)O2—C1—C2115.2 (2)
O21—Co1—O21i180.0000 (10)O1—C1—C2120.4 (2)
O2ii—Co2—O2180.0000 (10)C3—C2—C5119.3 (2)
O2ii—Co2—O4iii91.12 (8)C3—C2—C1124.0 (2)
O2—Co2—O4iii88.88 (8)C5—C2—C1116.4 (2)
O2ii—Co2—O4iv88.88 (8)C2—C3—C5vi119.4 (2)
O2—Co2—O4iv91.12 (8)C2—C3—C4124.2 (2)
O4iii—Co2—O4iv180C5vi—C3—C4116.4 (2)
O2ii—Co2—O2286.24 (9)O3—C4—O4123.9 (2)
O2—Co2—O2293.76 (9)O3—C4—C3119.9 (2)
O4iii—Co2—O2296.15 (8)O4—C4—C3116.1 (2)
O4iv—Co2—O2283.85 (8)C2—C5—C3vi121.4 (2)
O2ii—Co2—O22ii93.76 (9)C2—C5—H5A119.3
O2—Co2—O22ii86.24 (9)C3vi—C5—H5A119.3
O4iii—Co2—O22ii83.85 (8)
Symmetry codes: (i) x, y, z+1; (ii) x+1, y+1, z+1; (iii) x, y+1, z; (iv) x+1, y, z+1; (v) x, y1, z; (vi) x+1, y, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O21—H21A···O4iv0.852.032.864 (3)169
O21—H21B···O31A0.822.172.876 (6)144
O22—H22A···O3iii0.842.252.848 (3)129
O22—H22B···O10.841.992.790 (3)157
Symmetry codes: (iii) x, y+1, z; (iv) x+1, y, z+1.

Experimental details

Crystal data
Chemical formula[Co2(C10H2O8)(H2O)4]·2H2O
Mr238.04
Crystal system, space groupTriclinic, P1
Temperature (K)298
a, b, c (Å)6.9362 (7), 7.4559 (6), 8.2797 (7)
α, β, γ (°)90.342 (8), 109.848 (7), 93.161 (7)
V3)402.00 (6)
Z2
Radiation typeMo Kα
µ (mm1)2.14
Crystal size (mm)0.3 × 0.1 × 0.1
Data collection
DiffractometerBruker P4
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.685, 0.811
No. of measured, independent and
observed [I > 2σ(I)] reflections
2314, 1883, 1570
Rint0.028
(sin θ/λ)max1)0.661
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.038, 0.103, 1.05
No. of reflections1883
No. of parameters131
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.59, 0.77

Computer programs: XSCANS (Bruker, 1991), XSCANS, SHELXS97 (Sheldrick, 1997) and PLATON (Spek, 2003), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Selected bond lengths (Å) top
Co1—O12.065 (2)Co2—O22.083 (2)
Co1—O32.046 (2)Co2—O4i2.0996 (19)
Co1—O212.151 (2)Co2—O222.105 (2)
Symmetry code: (i) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O21—H21A···O4ii0.852.032.864 (3)169
O21—H21B···O31A0.822.172.876 (6)144
O22—H22A···O3i0.842.252.848 (3)129
O22—H22B···O10.841.992.790 (3)157
Symmetry codes: (i) x, y+1, z; (ii) x+1, y, z+1.
 

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