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The title compound, [Co(C5H3N2O2)2(H2O)]n, prepared by hydro­thermal synthesis, is isostructural with its FeII and NiII analogues. The asymmetric unit contains two bidendate pyrazine-2-carboxyl­ate anions bonded to CoII in the equatorial plane through one N and one O atom. The CoII atoms are linked into chains by the second N atom of one of the pyrazine-2-carboxyl­ate anions bonding to an axial site of a neighbouring CoII atom. The slightly distorted octa­hedral coordination around CoII is completed by a water mol­ecule, which forms hydrogen bonds to link the chains into a three-dimensional structure. The refined Flack parameter of 0.452 (15) indicates inversion twinning.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807027961/bi2194sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536807027961/bi2194Isup2.hkl
Contains datablock I

CCDC reference: 1225689

Key indicators

  • Single-crystal X-ray study
  • T = 298 K
  • Mean [sigma](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

Comment top

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.

Related literature top

For the isostructural FeII and NiII analogues, see: Hao & Liu (2007); Hao et al. (2007).

Experimental top

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%.

Refinement top

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.

Structure description top

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).

Computing details top

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.

Figures top
[Figure 1] Fig. 1. The asymmetric unit of the title compound expanded to show the complete coordination sphere of CoII. Displacement ellipsoids are shown at 30% probability for non-H atoms. Symmetry code (i): 1 - x, y + 1/2, -z + 1/2.
[Figure 2] Fig. 2. View of the [Co(C5H3N2O2)2(H2O)]n coordination polymer.
catena-Poly[[aqua(pyrazine-2-carboxylato)cobalt(II)]-µ-pyrazine-2-carboxylato] top
Crystal data top
[Co(C5H3N2O2)2(H2O)]F(000) = 652
Mr = 323.13Dx = 1.871 Mg m3
Orthorhombic, P212121Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2abCell parameters from 2198 reflections
a = 8.0121 (10) Åθ = 2.5–26.0°
b = 9.5327 (10) ŵ = 1.52 mm1
c = 15.023 (2) ÅT = 298 K
V = 1147.4 (2) Å3Block, red
Z = 40.10 × 0.10 × 0.10 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
2064 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.026
Graphite monochromatorθmax = 26.0°, θmin = 2.5°
ω scansh = 89
5916 measured reflectionsk = 1110
2198 independent reflectionsl = 189
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.024H 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 reflectionsΔρmax = 0.80 e Å3
190 parametersΔρmin = 0.22 e Å3
3 restraintsAbsolute structure: Flack (1983), with 907 Friedel pairs
Primary atom site location: structure-invariant direct methodsAbsolute structure parameter: 0.452 (15)
Crystal data top
[Co(C5H3N2O2)2(H2O)]V = 1147.4 (2) Å3
Mr = 323.13Z = 4
Orthorhombic, P212121Mo Kα radiation
a = 8.0121 (10) ŵ = 1.52 mm1
b = 9.5327 (10) ÅT = 298 K
c = 15.023 (2) Å0.10 × 0.10 × 0.10 mm
Data collection top
Bruker SMART CCD area-detector
diffractometer
2064 reflections with I > 2σ(I)
5916 measured reflectionsRint = 0.026
2198 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.024H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.055Δρmax = 0.80 e Å3
S = 1.04Δρmin = 0.22 e Å3
2198 reflectionsAbsolute structure: Flack (1983), with 907 Friedel pairs
190 parametersAbsolute structure parameter: 0.452 (15)
3 restraints
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.

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Co10.42683 (4)0.36583 (3)0.409285 (19)0.01727 (9)
C10.6433 (3)0.5285 (3)0.51916 (18)0.0279 (6)
C20.4620 (3)0.5736 (3)0.54104 (17)0.0279 (6)
C30.4253 (4)0.6652 (3)0.60858 (18)0.0388 (7)
H3A0.51220.70300.64190.047*
C40.1419 (3)0.6488 (3)0.57852 (19)0.0363 (6)
H4A0.03200.67420.59020.044*
C50.1760 (3)0.5570 (3)0.51064 (18)0.0311 (6)
H5A0.08900.52080.47670.037*
C60.6842 (3)0.0674 (3)0.23679 (18)0.0291 (6)
H6A0.79130.04070.22000.035*
C70.3951 (3)0.0422 (3)0.22755 (17)0.0251 (6)
H7A0.30240.00400.20460.030*
C80.1943 (3)0.1916 (3)0.31693 (16)0.0229 (5)
C90.3723 (3)0.1454 (3)0.28905 (15)0.0226 (5)
C100.6630 (3)0.1690 (3)0.29927 (18)0.0274 (6)
H10A0.75550.21170.32490.033*
N10.3349 (3)0.5187 (2)0.49264 (13)0.0254 (5)
N20.2661 (3)0.7025 (3)0.62837 (17)0.0447 (7)
N30.5503 (3)0.0048 (2)0.19881 (13)0.0253 (5)
N40.5061 (3)0.2085 (2)0.32447 (14)0.0239 (5)
O10.7625 (2)0.5798 (3)0.55879 (15)0.0487 (6)
O20.6535 (2)0.43497 (18)0.45923 (11)0.0270 (4)
O30.1939 (2)0.29727 (18)0.36884 (11)0.0268 (4)
O40.0688 (2)0.13059 (19)0.29097 (11)0.0356 (4)
O50.4188 (3)0.23496 (19)0.51651 (12)0.0333 (4)
H510.501 (2)0.219 (3)0.5471 (17)0.041 (10)*
H520.344 (3)0.179 (3)0.527 (2)0.067 (13)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Co10.01816 (14)0.01545 (14)0.01821 (14)0.00010 (13)0.00071 (13)0.00059 (13)
C10.0271 (13)0.0267 (14)0.0297 (14)0.0013 (11)0.0016 (11)0.0032 (11)
C20.0294 (16)0.0273 (13)0.0271 (13)0.0015 (11)0.0007 (11)0.0022 (11)
C30.0341 (15)0.0380 (16)0.0443 (18)0.0030 (14)0.0049 (14)0.0150 (12)
C40.0303 (13)0.0336 (15)0.0449 (16)0.0038 (12)0.0041 (12)0.0077 (14)
C50.0264 (14)0.0285 (14)0.0384 (16)0.0029 (11)0.0033 (12)0.0001 (11)
C60.0240 (14)0.0298 (14)0.0333 (15)0.0011 (11)0.0001 (11)0.0042 (12)
C70.0265 (15)0.0234 (12)0.0253 (12)0.0009 (10)0.0018 (11)0.0023 (10)
C80.0221 (13)0.0243 (12)0.0222 (13)0.0001 (10)0.0014 (10)0.0025 (10)
C90.0263 (12)0.0220 (12)0.0196 (11)0.0010 (11)0.0008 (9)0.0026 (10)
C100.0229 (13)0.0283 (15)0.0309 (14)0.0003 (11)0.0014 (11)0.0033 (11)
N10.0261 (11)0.0218 (11)0.0281 (11)0.0007 (9)0.0004 (9)0.0001 (9)
N20.0410 (15)0.0440 (15)0.0492 (15)0.0038 (12)0.0048 (12)0.0184 (12)
N30.0282 (12)0.0228 (10)0.0248 (10)0.0014 (10)0.0011 (9)0.0007 (8)
N40.0246 (11)0.0221 (11)0.0251 (12)0.0006 (9)0.0011 (9)0.0032 (9)
O10.0305 (11)0.0535 (13)0.0620 (14)0.0047 (10)0.0088 (10)0.0188 (11)
O20.0270 (9)0.0237 (9)0.0303 (10)0.0020 (8)0.0022 (8)0.0017 (8)
O30.0246 (9)0.0272 (10)0.0285 (9)0.0015 (8)0.0031 (7)0.0033 (8)
O40.0255 (9)0.0383 (10)0.0432 (10)0.0059 (11)0.0014 (9)0.0096 (9)
O50.0331 (10)0.0326 (10)0.0341 (10)0.0102 (10)0.0081 (10)0.0126 (8)
Geometric parameters (Å, º) top
Co1—O52.0384 (17)C5—H5A0.930
Co1—N12.057 (2)C6—N31.354 (3)
Co1—N42.068 (2)C6—C101.359 (4)
Co1—O32.0687 (17)C6—H6A0.930
Co1—O22.0723 (18)C7—C91.362 (4)
Co1—N3i2.104 (2)C7—N31.364 (3)
C1—O11.227 (3)C7—H7A0.930
C1—O21.270 (3)C8—O41.226 (3)
C1—C21.550 (4)C8—O31.274 (3)
C2—N11.357 (3)C8—C91.550 (3)
C2—C31.371 (4)C9—N41.339 (3)
C3—N21.357 (4)C10—N41.366 (3)
C3—H3A0.930C10—H10A0.930
C4—N21.346 (4)N3—Co1ii2.104 (2)
C4—C51.371 (4)O5—H510.82 (1)
C4—H4A0.930O5—H520.82 (1)
C5—N11.352 (3)
O5—Co1—N186.63 (8)N3—C6—C10120.4 (2)
O5—Co1—N493.02 (8)N3—C6—H6A119.8
N1—Co1—N4176.88 (9)C10—C6—H6A119.8
O5—Co1—O390.59 (8)C9—C7—N3121.7 (2)
N1—Co1—O394.56 (8)C9—C7—H7A119.1
N4—Co1—O382.34 (7)N3—C7—H7A119.1
O5—Co1—O286.35 (8)O4—C8—O3124.6 (2)
N1—Co1—O282.42 (8)O4—C8—C9122.3 (2)
N4—Co1—O2100.65 (8)O3—C8—C9113.1 (2)
O3—Co1—O2175.81 (7)N4—C9—C7119.1 (2)
O5—Co1—N3i176.49 (9)N4—C9—C8120.1 (2)
N1—Co1—N3i93.15 (8)C7—C9—C8120.8 (2)
N4—Co1—N3i87.39 (8)C6—C10—N4120.2 (2)
O3—Co1—N3i92.92 (8)C6—C10—H10A119.9
O2—Co1—N3i90.15 (8)N4—C10—H10A119.9
O1—C1—O2125.0 (3)C5—N1—C2119.7 (2)
O1—C1—C2121.0 (2)C5—N1—Co1130.57 (18)
O2—C1—C2113.9 (2)C2—N1—Co1109.32 (17)
N1—C2—C3118.8 (2)C4—N2—C3118.3 (2)
N1—C2—C1118.9 (2)C6—N3—C7118.3 (2)
C3—C2—C1122.3 (2)C6—N3—Co1ii122.25 (17)
N2—C3—C2122.0 (3)C7—N3—Co1ii119.24 (16)
N2—C3—H3A119.0C9—N4—C10120.2 (2)
C2—C3—H3A119.0C9—N4—Co1108.97 (16)
N2—C4—C5120.6 (3)C10—N4—Co1130.79 (17)
N2—C4—H4A119.7C1—O2—Co1115.09 (16)
C5—C4—H4A119.7C8—O3—Co1115.28 (15)
N1—C5—C4120.6 (3)Co1—O5—H51122.1 (19)
N1—C5—H5A119.7Co1—O5—H52125 (2)
C4—C5—H5A119.7H51—O5—H52111.4 (17)
O1—C1—C2—N1177.0 (2)C10—C6—N3—C72.7 (4)
O2—C1—C2—N14.0 (3)C10—C6—N3—Co1ii172.10 (19)
O1—C1—C2—C34.1 (4)C9—C7—N3—C63.8 (4)
O2—C1—C2—C3174.8 (2)C9—C7—N3—Co1ii171.17 (18)
N1—C2—C3—N20.0 (4)C7—C9—N4—C100.3 (4)
C1—C2—C3—N2178.9 (3)C8—C9—N4—C10179.3 (2)
N2—C4—C5—N10.1 (4)C7—C9—N4—Co1176.90 (18)
N3—C7—C9—N42.3 (4)C8—C9—N4—Co12.1 (3)
N3—C7—C9—C8176.6 (2)C6—C10—N4—C91.3 (4)
O4—C8—C9—N4174.9 (2)C6—C10—N4—Co1175.16 (18)
O3—C8—C9—N44.9 (3)O5—Co1—N4—C989.80 (17)
O4—C8—C9—C76.2 (4)O3—Co1—N4—C90.39 (16)
O3—C8—C9—C7174.1 (2)O2—Co1—N4—C9176.64 (16)
N3—C6—C10—N40.2 (4)N3i—Co1—N4—C993.69 (16)
C4—C5—N1—C21.3 (4)O5—Co1—N4—C1093.4 (2)
C4—C5—N1—Co1170.45 (19)O3—Co1—N4—C10176.4 (2)
C3—C2—N1—C51.3 (4)O2—Co1—N4—C106.6 (2)
C1—C2—N1—C5179.9 (2)N3i—Co1—N4—C1083.1 (2)
C3—C2—N1—Co1172.1 (2)O1—C1—O2—Co1177.7 (2)
C1—C2—N1—Co16.8 (3)C2—C1—O2—Co11.2 (3)
O5—Co1—N1—C591.2 (2)O5—Co1—O2—C183.30 (18)
O3—Co1—N1—C50.9 (2)N1—Co1—O2—C13.78 (18)
O2—Co1—N1—C5178.0 (2)N4—Co1—O2—C1175.68 (18)
N3i—Co1—N1—C592.3 (2)N3i—Co1—O2—C196.94 (18)
O5—Co1—N1—C281.21 (17)O4—C8—O3—Co1174.82 (19)
O3—Co1—N1—C2171.53 (16)C9—C8—O3—Co14.9 (3)
O2—Co1—N1—C25.55 (16)O5—Co1—O3—C889.72 (18)
N3i—Co1—N1—C295.29 (16)N1—Co1—O3—C8176.38 (17)
C5—C4—N2—C31.1 (5)N4—Co1—O3—C83.24 (17)
C2—C3—N2—C41.2 (4)N3i—Co1—O3—C890.22 (18)
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H52···O2iii0.82 (1)1.88 (1)2.697 (3)172 (3)
O5—H51···O3iv0.82 (1)2.00 (1)2.814 (3)172 (3)
Symmetry codes: (iii) x1/2, y+1/2, z+1; (iv) x+1/2, y+1/2, z+1.

Experimental details

Crystal data
Chemical formula[Co(C5H3N2O2)2(H2O)]
Mr323.13
Crystal system, space groupOrthorhombic, P212121
Temperature (K)298
a, b, c (Å)8.0121 (10), 9.5327 (10), 15.023 (2)
V3)1147.4 (2)
Z4
Radiation typeMo Kα
µ (mm1)1.52
Crystal size (mm)0.10 × 0.10 × 0.10
Data collection
DiffractometerBruker SMART CCD area-detector
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
5916, 2198, 2064
Rint0.026
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.055, 1.04
No. of reflections2198
No. of parameters190
No. of restraints3
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.80, 0.22
Absolute structureFlack (1983), with 907 Friedel pairs
Absolute structure parameter0.452 (15)

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SAINT-Plus, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 2001), SHELXTL.

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O5—H52···O2i0.82 (1)1.88 (1)2.697 (3)172 (3)
O5—H51···O3ii0.82 (1)2.00 (1)2.814 (3)172 (3)
Symmetry codes: (i) x1/2, y+1/2, z+1; (ii) x+1/2, y+1/2, z+1.
 

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