Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807027961/bi2194sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807027961/bi2194Isup2.hkl |
CCDC reference: 1225689
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (C-C) = 0.004 Å
- R factor = 0.024
- wR factor = 0.055
- Data-to-parameter ratio = 11.6
checkCIF/PLATON results
No syntax errors found
Alert level C STRVA01_ALERT_4_C Flack test results are ambiguous. From the CIF: _refine_ls_abs_structure_Flack 0.452 From the CIF: _refine_ls_abs_structure_Flack_su 0.015 PLAT033_ALERT_2_C Flack Parameter Value Deviates 2 * su from zero. 0.45 PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density .... 3.59 PLAT369_ALERT_2_C Long C(sp2)-C(sp2) Bond C1 - C2 ... 1.55 Ang. PLAT369_ALERT_2_C Long C(sp2)-C(sp2) Bond C8 - C9 ... 1.55 Ang. PLAT731_ALERT_1_C Bond Calc 0.82(3), Rep 0.820(10) ...... 3.00 su-Ra O5 -H52 1.555 1.555 PLAT735_ALERT_1_C D-H Calc 0.82(3), Rep 0.820(10) ...... 3.00 su-Ra O5 -H52 1.555 1.555 PLAT736_ALERT_1_C H...A Calc 1.89(3), Rep 1.880(10) ...... 3.00 su-Ra H52 -O2 1.555 4.456
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 26.02 From the CIF: _reflns_number_total 2198 Count of symmetry unique reflns 1318 Completeness (_total/calc) 166.77% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 880 Fraction of Friedel pairs measured 0.668 Are heavy atom types Z>Si present yes PLAT794_ALERT_5_G Check Predicted Bond Valency for Co1 (2) 2.06 PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 3
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 8 ALERT level C = Check and explain 3 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 4 ALERT type 2 Indicator that the structure model may be wrong or deficient 1 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 1 ALERT type 5 Informative message, check
For the isostructural FeII and NiII analogues, see: Hao & Liu (2007); Hao et al. (2007).
All chemicals were used as purchased from Jinan Henghua Sci & Tec Co. Ltd. A mixture of NiCl2.6H2O (0.5 mmol), KOH (0.5 mmol), 2-pyrazine carboxylic acid (0.5 mmol), EtOH (8 ml) and H2O (8 ml) in a 25 ml Teflon-lined stainless steel autoclave was heated to 413 K for 2 d. On cooling to room temperature, red crystals were obtained in a yield of 36%. Elemental analysis calculated: C 37.15, H 3.10, N 17.34, Co 18.27%; found: C 37.12, H 3.12, N 17.38, Co 18.19%.
H atoms on C atoms were placed geometrically and refined as riding with C—H = 0.93 Å and Uiso(H)= 1.2Ueq(C). The H atoms of the water molecule were located from difference Fourier maps and were refined with distance restraints of O—H = 0.82 (1) Å and H···H = 1.35 (1) Å. The refined Flack parameter (Flack, 1983) from 907 Friedel pairs is 0.452 (15), indicating inversion twinning.
The title compound, [Co(C5H3N2O2)2(H2O)]n, is isostructural with its FeII and NiII analogues (Hao & Liu, 2007; Hao, Mu & Liu, 2007).
The CoII atom is coordinated in a bidentate fashion by two O and two N atoms from two independent pyrazine-2-carboxylate anions. The distorted octahedral coordination is completed by another N atom from a third pyrazine-2-carboxylate ligand, and by the O atom of a water molecule (Fig. 1). The Co—N and Co—O bond lengths are in the range 2.057 (2)–2.104 (2) and 2.0384 (17)–2.0723 (18) Å, respectively.
One pyrazine-2-carboxylate ligand coordinates to a neighboring CoII atom via its second N atom, leading to a polymeric structure with zigzag chains extending parallel to the b axis (Fig. 2). Hydrogen bonding between the water molecules stabilizes the structure.
For the isostructural FeII and NiII analogues, see: Hao & Liu (2007); Hao et al. (2007).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2001); software used to prepare material for publication: SHELXTL.
[Co(C5H3N2O2)2(H2O)] | F(000) = 652 |
Mr = 323.13 | Dx = 1.871 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 2198 reflections |
a = 8.0121 (10) Å | θ = 2.5–26.0° |
b = 9.5327 (10) Å | µ = 1.52 mm−1 |
c = 15.023 (2) Å | T = 298 K |
V = 1147.4 (2) Å3 | Block, red |
Z = 4 | 0.10 × 0.10 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 2064 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.026 |
Graphite monochromator | θmax = 26.0°, θmin = 2.5° |
ω scans | h = −8→9 |
5916 measured reflections | k = −11→10 |
2198 independent reflections | l = −18→9 |
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)] = 0.024 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.055 | w = 1/[σ2(Fo2) + (0.0323P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max < 0.001 |
2198 reflections | Δρmax = 0.80 e Å−3 |
190 parameters | Δρmin = −0.22 e Å−3 |
3 restraints | Absolute structure: Flack (1983), with 907 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.452 (15) |
[Co(C5H3N2O2)2(H2O)] | V = 1147.4 (2) Å3 |
Mr = 323.13 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 8.0121 (10) Å | µ = 1.52 mm−1 |
b = 9.5327 (10) Å | T = 298 K |
c = 15.023 (2) Å | 0.10 × 0.10 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 2064 reflections with I > 2σ(I) |
5916 measured reflections | Rint = 0.026 |
2198 independent reflections |
R[F2 > 2σ(F2)] = 0.024 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.055 | Δρmax = 0.80 e Å−3 |
S = 1.04 | Δρmin = −0.22 e Å−3 |
2198 reflections | Absolute structure: Flack (1983), with 907 Friedel pairs |
190 parameters | Absolute structure parameter: 0.452 (15) |
3 restraints |
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 | ||
Co1 | 0.42683 (4) | 0.36583 (3) | 0.409285 (19) | 0.01727 (9) | |
C1 | 0.6433 (3) | 0.5285 (3) | 0.51916 (18) | 0.0279 (6) | |
C2 | 0.4620 (3) | 0.5736 (3) | 0.54104 (17) | 0.0279 (6) | |
C3 | 0.4253 (4) | 0.6652 (3) | 0.60858 (18) | 0.0388 (7) | |
H3A | 0.5122 | 0.7030 | 0.6419 | 0.047* | |
C4 | 0.1419 (3) | 0.6488 (3) | 0.57852 (19) | 0.0363 (6) | |
H4A | 0.0320 | 0.6742 | 0.5902 | 0.044* | |
C5 | 0.1760 (3) | 0.5570 (3) | 0.51064 (18) | 0.0311 (6) | |
H5A | 0.0890 | 0.5208 | 0.4767 | 0.037* | |
C6 | 0.6842 (3) | 0.0674 (3) | 0.23679 (18) | 0.0291 (6) | |
H6A | 0.7913 | 0.0407 | 0.2200 | 0.035* | |
C7 | 0.3951 (3) | 0.0422 (3) | 0.22755 (17) | 0.0251 (6) | |
H7A | 0.3024 | −0.0040 | 0.2046 | 0.030* | |
C8 | 0.1943 (3) | 0.1916 (3) | 0.31693 (16) | 0.0229 (5) | |
C9 | 0.3723 (3) | 0.1454 (3) | 0.28905 (15) | 0.0226 (5) | |
C10 | 0.6630 (3) | 0.1690 (3) | 0.29927 (18) | 0.0274 (6) | |
H10A | 0.7555 | 0.2117 | 0.3249 | 0.033* | |
N1 | 0.3349 (3) | 0.5187 (2) | 0.49264 (13) | 0.0254 (5) | |
N2 | 0.2661 (3) | 0.7025 (3) | 0.62837 (17) | 0.0447 (7) | |
N3 | 0.5503 (3) | 0.0048 (2) | 0.19881 (13) | 0.0253 (5) | |
N4 | 0.5061 (3) | 0.2085 (2) | 0.32447 (14) | 0.0239 (5) | |
O1 | 0.7625 (2) | 0.5798 (3) | 0.55879 (15) | 0.0487 (6) | |
O2 | 0.6535 (2) | 0.43497 (18) | 0.45923 (11) | 0.0270 (4) | |
O3 | 0.1939 (2) | 0.29727 (18) | 0.36884 (11) | 0.0268 (4) | |
O4 | 0.0688 (2) | 0.13059 (19) | 0.29097 (11) | 0.0356 (4) | |
O5 | 0.4188 (3) | 0.23496 (19) | 0.51651 (12) | 0.0333 (4) | |
H51 | 0.501 (2) | 0.219 (3) | 0.5471 (17) | 0.041 (10)* | |
H52 | 0.344 (3) | 0.179 (3) | 0.527 (2) | 0.067 (13)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Co1 | 0.01816 (14) | 0.01545 (14) | 0.01821 (14) | 0.00010 (13) | 0.00071 (13) | −0.00059 (13) |
C1 | 0.0271 (13) | 0.0267 (14) | 0.0297 (14) | 0.0013 (11) | −0.0016 (11) | 0.0032 (11) |
C2 | 0.0294 (16) | 0.0273 (13) | 0.0271 (13) | −0.0015 (11) | −0.0007 (11) | 0.0022 (11) |
C3 | 0.0341 (15) | 0.0380 (16) | 0.0443 (18) | −0.0030 (14) | −0.0049 (14) | −0.0150 (12) |
C4 | 0.0303 (13) | 0.0336 (15) | 0.0449 (16) | 0.0038 (12) | 0.0041 (12) | −0.0077 (14) |
C5 | 0.0264 (14) | 0.0285 (14) | 0.0384 (16) | −0.0029 (11) | −0.0033 (12) | 0.0001 (11) |
C6 | 0.0240 (14) | 0.0298 (14) | 0.0333 (15) | 0.0011 (11) | −0.0001 (11) | −0.0042 (12) |
C7 | 0.0265 (15) | 0.0234 (12) | 0.0253 (12) | 0.0009 (10) | −0.0018 (11) | −0.0023 (10) |
C8 | 0.0221 (13) | 0.0243 (12) | 0.0222 (13) | 0.0001 (10) | 0.0014 (10) | 0.0025 (10) |
C9 | 0.0263 (12) | 0.0220 (12) | 0.0196 (11) | −0.0010 (11) | −0.0008 (9) | 0.0026 (10) |
C10 | 0.0229 (13) | 0.0283 (15) | 0.0309 (14) | 0.0003 (11) | −0.0014 (11) | −0.0033 (11) |
N1 | 0.0261 (11) | 0.0218 (11) | 0.0281 (11) | −0.0007 (9) | −0.0004 (9) | −0.0001 (9) |
N2 | 0.0410 (15) | 0.0440 (15) | 0.0492 (15) | 0.0038 (12) | 0.0048 (12) | −0.0184 (12) |
N3 | 0.0282 (12) | 0.0228 (10) | 0.0248 (10) | −0.0014 (10) | −0.0011 (9) | −0.0007 (8) |
N4 | 0.0246 (11) | 0.0221 (11) | 0.0251 (12) | 0.0006 (9) | 0.0011 (9) | 0.0032 (9) |
O1 | 0.0305 (11) | 0.0535 (13) | 0.0620 (14) | −0.0047 (10) | −0.0088 (10) | −0.0188 (11) |
O2 | 0.0270 (9) | 0.0237 (9) | 0.0303 (10) | 0.0020 (8) | −0.0022 (8) | −0.0017 (8) |
O3 | 0.0246 (9) | 0.0272 (10) | 0.0285 (9) | 0.0015 (8) | 0.0031 (7) | −0.0033 (8) |
O4 | 0.0255 (9) | 0.0383 (10) | 0.0432 (10) | −0.0059 (11) | 0.0014 (9) | −0.0096 (9) |
O5 | 0.0331 (10) | 0.0326 (10) | 0.0341 (10) | −0.0102 (10) | −0.0081 (10) | 0.0126 (8) |
Co1—O5 | 2.0384 (17) | C5—H5A | 0.930 |
Co1—N1 | 2.057 (2) | C6—N3 | 1.354 (3) |
Co1—N4 | 2.068 (2) | C6—C10 | 1.359 (4) |
Co1—O3 | 2.0687 (17) | C6—H6A | 0.930 |
Co1—O2 | 2.0723 (18) | C7—C9 | 1.362 (4) |
Co1—N3i | 2.104 (2) | C7—N3 | 1.364 (3) |
C1—O1 | 1.227 (3) | C7—H7A | 0.930 |
C1—O2 | 1.270 (3) | C8—O4 | 1.226 (3) |
C1—C2 | 1.550 (4) | C8—O3 | 1.274 (3) |
C2—N1 | 1.357 (3) | C8—C9 | 1.550 (3) |
C2—C3 | 1.371 (4) | C9—N4 | 1.339 (3) |
C3—N2 | 1.357 (4) | C10—N4 | 1.366 (3) |
C3—H3A | 0.930 | C10—H10A | 0.930 |
C4—N2 | 1.346 (4) | N3—Co1ii | 2.104 (2) |
C4—C5 | 1.371 (4) | O5—H51 | 0.82 (1) |
C4—H4A | 0.930 | O5—H52 | 0.82 (1) |
C5—N1 | 1.352 (3) | ||
O5—Co1—N1 | 86.63 (8) | N3—C6—C10 | 120.4 (2) |
O5—Co1—N4 | 93.02 (8) | N3—C6—H6A | 119.8 |
N1—Co1—N4 | 176.88 (9) | C10—C6—H6A | 119.8 |
O5—Co1—O3 | 90.59 (8) | C9—C7—N3 | 121.7 (2) |
N1—Co1—O3 | 94.56 (8) | C9—C7—H7A | 119.1 |
N4—Co1—O3 | 82.34 (7) | N3—C7—H7A | 119.1 |
O5—Co1—O2 | 86.35 (8) | O4—C8—O3 | 124.6 (2) |
N1—Co1—O2 | 82.42 (8) | O4—C8—C9 | 122.3 (2) |
N4—Co1—O2 | 100.65 (8) | O3—C8—C9 | 113.1 (2) |
O3—Co1—O2 | 175.81 (7) | N4—C9—C7 | 119.1 (2) |
O5—Co1—N3i | 176.49 (9) | N4—C9—C8 | 120.1 (2) |
N1—Co1—N3i | 93.15 (8) | C7—C9—C8 | 120.8 (2) |
N4—Co1—N3i | 87.39 (8) | C6—C10—N4 | 120.2 (2) |
O3—Co1—N3i | 92.92 (8) | C6—C10—H10A | 119.9 |
O2—Co1—N3i | 90.15 (8) | N4—C10—H10A | 119.9 |
O1—C1—O2 | 125.0 (3) | C5—N1—C2 | 119.7 (2) |
O1—C1—C2 | 121.0 (2) | C5—N1—Co1 | 130.57 (18) |
O2—C1—C2 | 113.9 (2) | C2—N1—Co1 | 109.32 (17) |
N1—C2—C3 | 118.8 (2) | C4—N2—C3 | 118.3 (2) |
N1—C2—C1 | 118.9 (2) | C6—N3—C7 | 118.3 (2) |
C3—C2—C1 | 122.3 (2) | C6—N3—Co1ii | 122.25 (17) |
N2—C3—C2 | 122.0 (3) | C7—N3—Co1ii | 119.24 (16) |
N2—C3—H3A | 119.0 | C9—N4—C10 | 120.2 (2) |
C2—C3—H3A | 119.0 | C9—N4—Co1 | 108.97 (16) |
N2—C4—C5 | 120.6 (3) | C10—N4—Co1 | 130.79 (17) |
N2—C4—H4A | 119.7 | C1—O2—Co1 | 115.09 (16) |
C5—C4—H4A | 119.7 | C8—O3—Co1 | 115.28 (15) |
N1—C5—C4 | 120.6 (3) | Co1—O5—H51 | 122.1 (19) |
N1—C5—H5A | 119.7 | Co1—O5—H52 | 125 (2) |
C4—C5—H5A | 119.7 | H51—O5—H52 | 111.4 (17) |
O1—C1—C2—N1 | 177.0 (2) | C10—C6—N3—C7 | −2.7 (4) |
O2—C1—C2—N1 | −4.0 (3) | C10—C6—N3—Co1ii | 172.10 (19) |
O1—C1—C2—C3 | −4.1 (4) | C9—C7—N3—C6 | 3.8 (4) |
O2—C1—C2—C3 | 174.8 (2) | C9—C7—N3—Co1ii | −171.17 (18) |
N1—C2—C3—N2 | 0.0 (4) | C7—C9—N4—C10 | −0.3 (4) |
C1—C2—C3—N2 | −178.9 (3) | C8—C9—N4—C10 | −179.3 (2) |
N2—C4—C5—N1 | 0.1 (4) | C7—C9—N4—Co1 | 176.90 (18) |
N3—C7—C9—N4 | −2.3 (4) | C8—C9—N4—Co1 | −2.1 (3) |
N3—C7—C9—C8 | 176.6 (2) | C6—C10—N4—C9 | 1.3 (4) |
O4—C8—C9—N4 | −174.9 (2) | C6—C10—N4—Co1 | −175.16 (18) |
O3—C8—C9—N4 | 4.9 (3) | O5—Co1—N4—C9 | 89.80 (17) |
O4—C8—C9—C7 | 6.2 (4) | O3—Co1—N4—C9 | −0.39 (16) |
O3—C8—C9—C7 | −174.1 (2) | O2—Co1—N4—C9 | 176.64 (16) |
N3—C6—C10—N4 | 0.2 (4) | N3i—Co1—N4—C9 | −93.69 (16) |
C4—C5—N1—C2 | −1.3 (4) | O5—Co1—N4—C10 | −93.4 (2) |
C4—C5—N1—Co1 | 170.45 (19) | O3—Co1—N4—C10 | 176.4 (2) |
C3—C2—N1—C5 | 1.3 (4) | O2—Co1—N4—C10 | −6.6 (2) |
C1—C2—N1—C5 | −179.9 (2) | N3i—Co1—N4—C10 | 83.1 (2) |
C3—C2—N1—Co1 | −172.1 (2) | O1—C1—O2—Co1 | 177.7 (2) |
C1—C2—N1—Co1 | 6.8 (3) | C2—C1—O2—Co1 | −1.2 (3) |
O5—Co1—N1—C5 | −91.2 (2) | O5—Co1—O2—C1 | −83.30 (18) |
O3—Co1—N1—C5 | −0.9 (2) | N1—Co1—O2—C1 | 3.78 (18) |
O2—Co1—N1—C5 | −178.0 (2) | N4—Co1—O2—C1 | −175.68 (18) |
N3i—Co1—N1—C5 | 92.3 (2) | N3i—Co1—O2—C1 | 96.94 (18) |
O5—Co1—N1—C2 | 81.21 (17) | O4—C8—O3—Co1 | 174.82 (19) |
O3—Co1—N1—C2 | 171.53 (16) | C9—C8—O3—Co1 | −4.9 (3) |
O2—Co1—N1—C2 | −5.55 (16) | O5—Co1—O3—C8 | −89.72 (18) |
N3i—Co1—N1—C2 | −95.29 (16) | N1—Co1—O3—C8 | −176.38 (17) |
C5—C4—N2—C3 | 1.1 (5) | N4—Co1—O3—C8 | 3.24 (17) |
C2—C3—N2—C4 | −1.2 (4) | N3i—Co1—O3—C8 | 90.22 (18) |
Symmetry codes: (i) −x+1, y+1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H52···O2iii | 0.82 (1) | 1.88 (1) | 2.697 (3) | 172 (3) |
O5—H51···O3iv | 0.82 (1) | 2.00 (1) | 2.814 (3) | 172 (3) |
Symmetry codes: (iii) x−1/2, −y+1/2, −z+1; (iv) x+1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | [Co(C5H3N2O2)2(H2O)] |
Mr | 323.13 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 8.0121 (10), 9.5327 (10), 15.023 (2) |
V (Å3) | 1147.4 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.52 |
Crystal size (mm) | 0.10 × 0.10 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5916, 2198, 2064 |
Rint | 0.026 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.024, 0.055, 1.04 |
No. of reflections | 2198 |
No. of parameters | 190 |
No. of restraints | 3 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.80, −0.22 |
Absolute structure | Flack (1983), with 907 Friedel pairs |
Absolute structure parameter | 0.452 (15) |
Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SAINT-Plus, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2001), SHELXTL.
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H52···O2i | 0.82 (1) | 1.88 (1) | 2.697 (3) | 172 (3) |
O5—H51···O3ii | 0.82 (1) | 2.00 (1) | 2.814 (3) | 172 (3) |
Symmetry codes: (i) x−1/2, −y+1/2, −z+1; (ii) x+1/2, −y+1/2, −z+1. |
Subscribe to Acta Crystallographica Section E: Crystallographic Communications
The full text of this article is available to subscribers to the journal.
- Information on subscribing
- Sample issue
- If you have already subscribed, you may need to register
The title compound, [Co(C5H3N2O2)2(H2O)]n, is isostructural with its FeII and NiII analogues (Hao & Liu, 2007; Hao, Mu & Liu, 2007).
The CoII atom is coordinated in a bidentate fashion by two O and two N atoms from two independent pyrazine-2-carboxylate anions. The distorted octahedral coordination is completed by another N atom from a third pyrazine-2-carboxylate ligand, and by the O atom of a water molecule (Fig. 1). The Co—N and Co—O bond lengths are in the range 2.057 (2)–2.104 (2) and 2.0384 (17)–2.0723 (18) Å, respectively.
One pyrazine-2-carboxylate ligand coordinates to a neighboring CoII atom via its second N atom, leading to a polymeric structure with zigzag chains extending parallel to the b axis (Fig. 2). Hydrogen bonding between the water molecules stabilizes the structure.