Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270102014658/jz1517sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270102014658/jz1517Isup2.hkl |
CCDC reference: 195610
[Cd(CH3COO)2]·2H2O (1.33 g, 5 mmol) was dissolved in deionized water (10 ml). A solution (10 ml) of acetylenedicarboxylic acid (0.57 g, 5 mmol) in deionized water was added; the resulting solution had a pH of 2. Immediately, a colourless precipitate formed, which was filtered after 2 h at 278 K. The resulting colourless crystals of (I) decomposed slowly in air by forming a brown solid, but in a sealed capillary during the X-ray analysis no decomposition of the single-crystal was observed. In vacuum, a yellow solid is obtained, which is amorphous to X-rays.
The absorption correction (X-RED; Stoe & Cie, 2001) was performed after optimizing the crystal shape using X-SHAPE (Stoe & Cie, 1999). The H atoms were identified in difference Fourier syntheses and refined freely.
During our studies of coordination polymers of the acetylenedicarboxylate dianion, C2(COO)22- (Pantenburg & Ruschewitz, 2002; Hohn et al., 2002), colourless crystals of the title compound, (I), were obtained, and its crystal structure is presented here. \sch
The structure of (I) is composed of sevenfold coordination polyhedra at the CdII ions, which are linked by the bifunctional acetylenedicarboxylate ligands to form zigzag chains. The coordination polyhedron around the CdII ion is formed by two chelating bidentate carboxylate groups and three water molecules (Fig. 1). The Cd—O distances range between 2.259 (2) and 2.664 (2) Å (Table 1). As the latter Cd—O distance (Cd1—O221) is longer than the next longest [Cd1—O122 2.487 (2) Å] by about 0.2 Å, the description of the Cd coordination as a 6 + 1 polyhedron may be an appropriate alternative. The Cd—O distances are similar to those found in other cadmium(II) carboxylates, e.g. rhombohedral cadmium malonate dihydrate [2.280 (3)–2.543 (3) Å, coordination number 7; Naumov et al., 2001].
The weakly coordinating nature of atom O221 is associated with the shortest C—O distance in the carboxylate groups [C22—O221 1.237 (3) Å], indicative of more double-bonding character for this C—O bond and consistent with its slightly higher Ueq. The other C—O distances range from 1.247 (3) to 1.269 (3) Å.
The C—C distances in the two crystallographically distinct acetylenedicarboxylate dianions are as expected; C11—C11i 1.197 (5) Å and C21—C21ii 1.189 (5) Å for a C≡C triple bond, and C11—C12 1.461 (3) Å and C21—C22 1.468 (4) Å for a C—C single bond [symmetry codes: (i); (ii)]. The dianions are almost linear [C11i—C11—C12 177.7 (3)° and C21ii—C21—C22 177.6 (3)°] and the carboxylate groups of one anion are almost coplanar. The torsion angles in the two anions range between 0.0 (2) and 1.6 (3)°, and 0.0 (2) and 1.1 (3)°, respectively.
The Cd polyhedra are linked by the bifunctional carboxylates to form zigzag chains running parallel to [120] (Fig. 2). The deviation from linearity is defined by the C12—Cd1—C22 angle, which is 131.09 (7)°. In [Co{C2(COO)2}(H2O)4]·2H2O (Pantenburg & Ruschewitz, 2002), the only other known example of a coordination polymer of acetylenedicarboxylate crystallizing in a chain structure, the CoII ion is coordinated octahedrally by two unidentate carboxylate groups in trans positions and four water molecules. Thus a linear polymeric chain structure is formed.
In both [Co{C2(COO)2}(H2O)4]·2H2O and (I), these chains are connected by hydrogen bonds, which involve additional water molecules [atom O6 in (I)]. In (I), the O—H···O hydrogen bonds vary between 2.671 (4) Å (O121···O5) and 2.770 (4) Å (O3···O6), connecting the zigzag chains to form a three-dimensional network.
Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXL97.
[Cd(C4O4)(H2O)3]·H2O | F(000) = 576 |
Mr = 296.50 | Dx = 2.249 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 19461 reflections |
a = 6.8195 (7) Å | θ = 1.5–32.4° |
b = 7.953 (1) Å | µ = 2.51 mm−1 |
c = 16.387 (2) Å | T = 170 K |
β = 99.811 (8)° | Column, colourless |
V = 875.74 (17) Å3 | 0.54 × 0.14 × 0.13 mm |
Z = 4 |
Stoe IPDS II diffractometer | 1912 independent reflections |
Radiation source: fine-focus sealed tube | 1545 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.046 |
Detector resolution: not measured pixels mm-1 | θmax = 27.0°, θmin = 2.5° |
oscillation scans | h = −8→8 |
Absorption correction: numerical (X-RED; Stoe & Cie, 2001) | k = −10→10 |
Tmin = 0.242, Tmax = 0.785 | l = −20→20 |
16485 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.020 | All H-atom parameters refined |
wR(F2) = 0.048 | w = 1/[σ2(Fo2) + (0.0225P)2 + 0.4864P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max = 0.001 |
1912 reflections | Δρmax = 0.40 e Å−3 |
151 parameters | Δρmin = −0.40 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0049 (4) |
[Cd(C4O4)(H2O)3]·H2O | V = 875.74 (17) Å3 |
Mr = 296.50 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 6.8195 (7) Å | µ = 2.51 mm−1 |
b = 7.953 (1) Å | T = 170 K |
c = 16.387 (2) Å | 0.54 × 0.14 × 0.13 mm |
β = 99.811 (8)° |
Stoe IPDS II diffractometer | 1912 independent reflections |
Absorption correction: numerical (X-RED; Stoe & Cie, 2001) | 1545 reflections with I > 2σ(I) |
Tmin = 0.242, Tmax = 0.785 | Rint = 0.046 |
16485 measured reflections |
R[F2 > 2σ(F2)] = 0.020 | 0 restraints |
wR(F2) = 0.048 | All H-atom parameters refined |
S = 1.08 | Δρmax = 0.40 e Å−3 |
1912 reflections | Δρmin = −0.40 e Å−3 |
151 parameters |
Experimental. A suitable single-crystal was carefully selected under a polarizing microscope and mounted in a glass capillary. The scattering intensities were collected on an imaging plate diffractometer (IPDS II, Stoe & Cie) equipped with a fine focus sealed tube X-ray source (Mo Kα, λ = 0.71073 Å) operating at 50 kV and 40 mA. Intensity data for [Cd(C2(COO)2)(H2O)3]·H2O were collected at 170 K by ω scans in 225 frames (0 < ω < 180°, ψ = 0°; 0 < ω < 180°, ψ = 135°; 0 < ω < 90°, ψ = 180°; Δω = 2°, exposure time 3 min) in the 2θ range 2.9–64.8°. Structure solution and refinement were carried out using the programs SIR92 (Altomare et al., 1993) and SHELXL97 (Sheldrick, 1997). The H-atom positions for [Cd(C2(COO)2)(H2O)3]·(H2O) were taken from difference Fourier maps at the end of the refinement and refined isotropically without constraints. A numerical absorption correction (X-RED; Stoe & Cie, 2001) was applied after optimization of the crystal shape (X-SHAPE; Stoe & Cie, 1999)). The last cycles of refinement included atomic positions for all atoms, anisotropic parameters for all non-H atoms and isotropic displacement parameters for all H atoms. The refinement was based on F2 for ALL reflections. |
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. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
Cd1 | 0.69040 (2) | 0.00390 (2) | 0.36793 (1) | 0.01726 (9) | |
C11 | 0.9654 (4) | 0.4366 (3) | 0.4840 (2) | 0.0183 (5) | |
C12 | 0.8755 (4) | 0.2815 (3) | 0.4472 (2) | 0.0192 (5) | |
O121 | 0.8372 (3) | 0.2717 (2) | 0.36923 (11) | 0.0245 (4) | |
O122 | 0.8368 (3) | 0.1659 (2) | 0.49343 (11) | 0.0230 (4) | |
C21 | 0.5167 (4) | −0.4423 (3) | 0.4791 (2) | 0.0205 (6) | |
C22 | 0.5639 (4) | −0.2972 (3) | 0.4307 (2) | 0.0210 (5) | |
O221 | 0.5180 (3) | −0.2977 (3) | 0.35428 (12) | 0.0298 (5) | |
O222 | 0.6546 (3) | −0.1760 (2) | 0.47104 (11) | 0.0229 (4) | |
O3 | 0.3880 (3) | 0.1224 (3) | 0.3695 (2) | 0.0240 (4) | |
H31 | 0.371 (5) | 0.199 (5) | 0.343 (2) | 0.026 (9)* | |
H32 | 0.371 (6) | 0.143 (5) | 0.411 (3) | 0.043 (12)* | |
O4 | 0.9636 (3) | −0.1499 (3) | 0.34812 (14) | 0.0224 (4) | |
H41 | 1.038 (5) | −0.159 (4) | 0.390 (2) | 0.031 (9)* | |
H42 | 1.029 (7) | −0.121 (6) | 0.316 (3) | 0.07 (2)* | |
O5 | 0.5837 (3) | 0.0220 (3) | 0.22886 (12) | 0.0234 (4) | |
H51 | 0.585 (5) | 0.108 (6) | 0.206 (2) | 0.046 (12)* | |
H52 | 0.625 (5) | −0.053 (5) | 0.198 (2) | 0.040 (11)* | |
O6 | 1.1559 (4) | −0.0807 (3) | 0.22012 (13) | 0.0255 (5) | |
H61 | 1.092 (6) | 0.012 (5) | 0.196 (3) | 0.047 (11)* | |
H62 | 1.256 (7) | −0.052 (6) | 0.236 (3) | 0.06 (2)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cd1 | 0.02422 (13) | 0.01310 (11) | 0.01410 (11) | −0.00283 (8) | 0.00228 (7) | −0.00024 (7) |
C11 | 0.0200 (14) | 0.0171 (11) | 0.0170 (13) | −0.0003 (9) | 0.0013 (10) | 0.0014 (9) |
C12 | 0.0199 (13) | 0.0157 (12) | 0.0212 (13) | −0.0008 (10) | 0.0016 (10) | −0.0020 (10) |
O121 | 0.0379 (11) | 0.0186 (9) | 0.0166 (10) | −0.0096 (8) | 0.0037 (8) | −0.0022 (7) |
O122 | 0.0310 (11) | 0.0163 (9) | 0.0200 (9) | −0.0064 (8) | −0.0007 (8) | 0.0026 (7) |
C21 | 0.0232 (14) | 0.0174 (12) | 0.0220 (14) | −0.0007 (10) | 0.0073 (11) | 0.0000 (9) |
C22 | 0.0240 (13) | 0.0153 (12) | 0.0257 (14) | 0.0015 (10) | 0.0100 (11) | 0.0025 (10) |
O221 | 0.0450 (12) | 0.0249 (10) | 0.0192 (10) | −0.0085 (9) | 0.0045 (9) | 0.0039 (8) |
O222 | 0.0338 (11) | 0.0146 (8) | 0.0221 (10) | −0.0061 (8) | 0.0096 (8) | −0.0006 (7) |
O3 | 0.0320 (12) | 0.0218 (11) | 0.0185 (11) | 0.0039 (8) | 0.0053 (9) | −0.0001 (9) |
O4 | 0.0261 (11) | 0.0231 (10) | 0.0175 (10) | 0.0017 (8) | 0.0022 (9) | 0.0024 (8) |
O5 | 0.0378 (12) | 0.0182 (10) | 0.0146 (9) | 0.0020 (9) | 0.0057 (8) | 0.0002 (8) |
O6 | 0.0255 (12) | 0.0265 (11) | 0.0231 (11) | −0.0020 (9) | 0.0001 (9) | 0.0006 (9) |
Cd1—O222 | 2.259 (2) | C21—C22 | 1.468 (4) |
Cd1—O3 | 2.272 (2) | C22—O221 | 1.237 (3) |
Cd1—O5 | 2.276 (2) | C22—O222 | 1.269 (3) |
Cd1—O4 | 2.298 (2) | O3—H31 | 0.75 (4) |
Cd1—O121 | 2.352 (2) | O3—H32 | 0.72 (4) |
Cd1—O122 | 2.487 (2) | O4—H41 | 0.78 (4) |
Cd1—O221 | 2.664 (2) | O4—H42 | 0.77 (5) |
C11—C11i | 1.197 (5) | O5—H51 | 0.78 (4) |
C11—C12 | 1.461 (3) | O5—H52 | 0.86 (4) |
C12—O122 | 1.247 (3) | O6—H61 | 0.91 (4) |
C12—O121 | 1.262 (3) | O6—H62 | 0.73 (5) |
C21—C21ii | 1.189 (5) | ||
O121—Cd1—O122 | 54.07 (6) | O4—Cd1—O122 | 99.89 (7) |
O221—Cd1—O222 | 52.42 (6) | O5—Cd1—O4 | 91.19 (8) |
O221—Cd1—O4 | 82.28 (7) | O5—Cd1—O121 | 90.85 (7) |
O221—Cd1—O122 | 130.17 (6) | O5—Cd1—O122 | 144.11 (7) |
O221—Cd1—O121 | 175.75 (6) | C11i—C11—C12 | 177.7 (4) |
O221—Cd1—O3 | 89.19 (7) | O122—C12—O121 | 122.7 (2) |
O221—Cd1—O5 | 84.92 (7) | O122—C12—C11 | 119.3 (2) |
O222—Cd1—O3 | 92.29 (8) | O121—C12—C11 | 118.0 (2) |
O222—Cd1—O5 | 137.07 (7) | C21ii—C21—C22 | 177.6 (4) |
O222—Cd1—O4 | 87.83 (8) | O221—C22—O222 | 123.1 (2) |
O222—Cd1—O121 | 131.83 (6) | O221—C22—C21 | 120.3 (2) |
O222—Cd1—O122 | 77.81 (6) | O222—C22—C21 | 116.6 (2) |
O3—Cd1—O5 | 81.34 (8) | H31—O3—H32 | 109 (4) |
O3—Cd1—O4 | 169.15 (7) | H41—O4—H42 | 105 (4) |
O3—Cd1—O121 | 90.57 (8) | H51—O5—H52 | 107 (4) |
O3—Cd1—O122 | 90.73 (7) | H61—O6—H62 | 105 (4) |
O4—Cd1—O121 | 97.43 (7) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+1, −y−1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···O6iii | 0.75 (4) | 2.03 (4) | 2.770 (3) | 175 (4) |
O3—H32···O222iv | 0.72 (4) | 1.99 (4) | 2.711 (3) | 173 (4) |
O4—H41···O122v | 0.78 (4) | 1.96 (4) | 2.722 (3) | 165 (3) |
O4—H42···O6 | 0.77 (5) | 1.95 (5) | 2.713 (3) | 167 (5) |
O5—H51···O4iii | 0.78 (4) | 2.12 (5) | 2.892 (3) | 169 (4) |
O5—H52···O121vi | 0.86 (4) | 1.82 (4) | 2.670 (3) | 169 (3) |
O6—H61···O221iii | 0.91 (4) | 1.83 (4) | 2.732 (3) | 175 (4) |
O6—H62···O5vii | 0.73 (5) | 2.33 (5) | 3.009 (3) | 156 (5) |
O6—H62···O3vii | 0.73 (5) | 2.62 (5) | 3.129 (3) | 129 (4) |
Symmetry codes: (iii) −x+3/2, y+1/2, −z+1/2; (iv) −x+1, −y, −z+1; (v) −x+2, −y, −z+1; (vi) −x+3/2, y−1/2, −z+1/2; (vii) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | [Cd(C4O4)(H2O)3]·H2O |
Mr | 296.50 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 170 |
a, b, c (Å) | 6.8195 (7), 7.953 (1), 16.387 (2) |
β (°) | 99.811 (8) |
V (Å3) | 875.74 (17) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.51 |
Crystal size (mm) | 0.54 × 0.14 × 0.13 |
Data collection | |
Diffractometer | Stoe IPDS II |
Absorption correction | Numerical (X-RED; Stoe & Cie, 2001) |
Tmin, Tmax | 0.242, 0.785 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 16485, 1912, 1545 |
Rint | 0.046 |
(sin θ/λ)max (Å−1) | 0.639 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.020, 0.048, 1.08 |
No. of reflections | 1912 |
No. of parameters | 151 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.40, −0.40 |
Computer programs: X-AREA (Stoe & Cie, 2001), X-AREA, SIR92 (Altomare et al., 1993), SHELXL97 (Sheldrick, 1997), DIAMOND (Brandenburg, 2001), SHELXL97.
Cd1—O222 | 2.259 (2) | C11—C12 | 1.461 (3) |
Cd1—O3 | 2.272 (2) | C12—O122 | 1.247 (3) |
Cd1—O5 | 2.276 (2) | C12—O121 | 1.262 (3) |
Cd1—O4 | 2.298 (2) | C21—C21ii | 1.189 (5) |
Cd1—O121 | 2.352 (2) | C21—C22 | 1.468 (4) |
Cd1—O122 | 2.487 (2) | C22—O221 | 1.237 (3) |
Cd1—O221 | 2.664 (2) | C22—O222 | 1.269 (3) |
C11—C11i | 1.197 (5) | ||
O121—Cd1—O122 | 54.07 (6) | O3—Cd1—O4 | 169.15 (7) |
O221—Cd1—O222 | 52.42 (6) | O3—Cd1—O121 | 90.57 (8) |
O221—Cd1—O4 | 82.28 (7) | O3—Cd1—O122 | 90.73 (7) |
O221—Cd1—O122 | 130.17 (6) | O4—Cd1—O121 | 97.43 (7) |
O221—Cd1—O121 | 175.75 (6) | O4—Cd1—O122 | 99.89 (7) |
O221—Cd1—O3 | 89.19 (7) | O5—Cd1—O4 | 91.19 (8) |
O221—Cd1—O5 | 84.92 (7) | O5—Cd1—O121 | 90.85 (7) |
O222—Cd1—O3 | 92.29 (8) | O5—Cd1—O122 | 144.11 (7) |
O222—Cd1—O5 | 137.07 (7) | C11i—C11—C12 | 177.7 (4) |
O222—Cd1—O4 | 87.83 (8) | O122—C12—O121 | 122.7 (2) |
O222—Cd1—O121 | 131.83 (6) | C21ii—C21—C22 | 177.6 (4) |
O222—Cd1—O122 | 77.81 (6) | O221—C22—O222 | 123.1 (2) |
O3—Cd1—O5 | 81.34 (8) |
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) −x+1, −y−1, −z+1. |
D—H···A | D—H | H···A | D···A | D—H···A |
O3—H31···O6iii | 0.75 (4) | 2.03 (4) | 2.770 (3) | 175 (4) |
O3—H32···O222iv | 0.72 (4) | 1.99 (4) | 2.711 (3) | 173 (4) |
O4—H41···O122v | 0.78 (4) | 1.96 (4) | 2.722 (3) | 165 (3) |
O4—H42···O6 | 0.77 (5) | 1.95 (5) | 2.713 (3) | 167 (5) |
O5—H51···O4iii | 0.78 (4) | 2.12 (5) | 2.892 (3) | 169 (4) |
O5—H52···O121vi | 0.86 (4) | 1.82 (4) | 2.670 (3) | 169 (3) |
O6—H61···O221iii | 0.91 (4) | 1.83 (4) | 2.732 (3) | 175 (4) |
O6—H62···O5vii | 0.73 (5) | 2.33 (5) | 3.009 (3) | 156 (5) |
O6—H62···O3vii | 0.73 (5) | 2.62 (5) | 3.129 (3) | 129 (4) |
Symmetry codes: (iii) −x+3/2, y+1/2, −z+1/2; (iv) −x+1, −y, −z+1; (v) −x+2, −y, −z+1; (vi) −x+3/2, y−1/2, −z+1/2; (vii) x+1, y, z. |
During our studies of coordination polymers of the acetylenedicarboxylate dianion, C2(COO)22- (Pantenburg & Ruschewitz, 2002; Hohn et al., 2002), colourless crystals of the title compound, (I), were obtained, and its crystal structure is presented here. \sch
The structure of (I) is composed of sevenfold coordination polyhedra at the CdII ions, which are linked by the bifunctional acetylenedicarboxylate ligands to form zigzag chains. The coordination polyhedron around the CdII ion is formed by two chelating bidentate carboxylate groups and three water molecules (Fig. 1). The Cd—O distances range between 2.259 (2) and 2.664 (2) Å (Table 1). As the latter Cd—O distance (Cd1—O221) is longer than the next longest [Cd1—O122 2.487 (2) Å] by about 0.2 Å, the description of the Cd coordination as a 6 + 1 polyhedron may be an appropriate alternative. The Cd—O distances are similar to those found in other cadmium(II) carboxylates, e.g. rhombohedral cadmium malonate dihydrate [2.280 (3)–2.543 (3) Å, coordination number 7; Naumov et al., 2001].
The weakly coordinating nature of atom O221 is associated with the shortest C—O distance in the carboxylate groups [C22—O221 1.237 (3) Å], indicative of more double-bonding character for this C—O bond and consistent with its slightly higher Ueq. The other C—O distances range from 1.247 (3) to 1.269 (3) Å.
The C—C distances in the two crystallographically distinct acetylenedicarboxylate dianions are as expected; C11—C11i 1.197 (5) Å and C21—C21ii 1.189 (5) Å for a C≡C triple bond, and C11—C12 1.461 (3) Å and C21—C22 1.468 (4) Å for a C—C single bond [symmetry codes: (i); (ii)]. The dianions are almost linear [C11i—C11—C12 177.7 (3)° and C21ii—C21—C22 177.6 (3)°] and the carboxylate groups of one anion are almost coplanar. The torsion angles in the two anions range between 0.0 (2) and 1.6 (3)°, and 0.0 (2) and 1.1 (3)°, respectively.
The Cd polyhedra are linked by the bifunctional carboxylates to form zigzag chains running parallel to [120] (Fig. 2). The deviation from linearity is defined by the C12—Cd1—C22 angle, which is 131.09 (7)°. In [Co{C2(COO)2}(H2O)4]·2H2O (Pantenburg & Ruschewitz, 2002), the only other known example of a coordination polymer of acetylenedicarboxylate crystallizing in a chain structure, the CoII ion is coordinated octahedrally by two unidentate carboxylate groups in trans positions and four water molecules. Thus a linear polymeric chain structure is formed.
In both [Co{C2(COO)2}(H2O)4]·2H2O and (I), these chains are connected by hydrogen bonds, which involve additional water molecules [atom O6 in (I)]. In (I), the O—H···O hydrogen bonds vary between 2.671 (4) Å (O121···O5) and 2.770 (4) Å (O3···O6), connecting the zigzag chains to form a three-dimensional network.