The Ni atom in the title compound, {[Ni2(C10H2O8)(C4H4N2)(H2O)4]·2H2O}n, exists in an octahedral NO5Ni coordination environment that is defined by the two O atoms of a chelating carboxyl group, the O atom of a monodentate carboxyl group belonging to another carboxylato tetraanion, two water molecules and the N atom of the N-heterocycle. The tetracarboxylato anion and the pyrazine molecule are each located on a center of inversion. The bonding pattern leads to the formation of a layer structure; the layers are linked into a three-dimensional network by extensive hydrogen bonds involving the water molecules and the O atoms of the anionic unit.
Supporting information
CCDC reference: 222802
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (C-C) = 0.007 Å
- R factor = 0.065
- wR factor = 0.142
- Data-to-parameter ratio = 13.2
checkCIF/PLATON results
No syntax errors found
Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ..... 0.93
Alert level B
PLAT731_ALERT_1_B Bond Calc 0.84(5), Rep 0.840(10) .... 5.00 su-Ratio
O1W -H1W1 1.555 1.555
PLAT731_ALERT_1_B Bond Calc 0.84(6), Rep 0.850(10) .... 6.00 su-Ratio
O2W -H2W1 1.555 1.555
PLAT731_ALERT_1_B Bond Calc 0.85(5), Rep 0.850(10) .... 5.00 su-Ratio
O2W -H2W2 1.555 1.555
PLAT731_ALERT_1_B Bond Calc 0.85(6), Rep 0.850(10) .... 6.00 su-Ratio
O3W -H3W1 1.555 1.555
PLAT735_ALERT_1_B D-H Calc 0.84(5), Rep 0.840(10) .... 5.00 su-Ratio
O1W -H1W1 1.555 1.555
PLAT735_ALERT_1_B D-H Calc 0.85(5), Rep 0.850(10) .... 5.00 su-Ratio
O2W -H2W2 1.555 1.555
PLAT735_ALERT_1_B D-H Calc 0.84(6), Rep 0.850(10) .... 6.00 su-Ratio
O2W -H2W1 1.555 1.555
PLAT735_ALERT_1_B D-H Calc 0.85(6), Rep 0.850(10) .... 6.00 su-Ratio
O3W -H3W1 1.555 1.555
PLAT736_ALERT_1_B H...A Calc 1.96(5), Rep 1.960(10) .... 5.00 su-Ratio
H2W2 -O1W 1.555 2.676
PLAT736_ALERT_1_B H...A Calc 1.90(6), Rep 1.900(10) .... 6.00 su-Ratio
H2W1 -O3W 1.555 1.455
Alert level C
ABSTM02_ALERT_3_C The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
Tmin and Tmax reported: 0.616 0.919
Tmin' and Tmax expected: 0.738 0.919
RR' = 0.835
Please check that your absorption correction is appropriate.
REFLT03_ALERT_3_C Reflection count < 95% complete
From the CIF: _diffrn_reflns_theta_max 28.30
From the CIF: _diffrn_reflns_theta_full 0.00
From the CIF: _reflns_number_total 2152
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 2304
Completeness (_total/calc) 93.40%
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .. ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .. ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by .......... 2.00 Ratio
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large ........... 0.82
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ..... ?
PLAT213_ALERT_2_C Atom C3 has ADP max/min Ratio ........... 3.10 oblate
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang.. 7
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 (CIF) Linear Torsion Angle # 11
O3 -NI1 -N1 -C6 -64.00 2.00 2.667 1.555 1.555 1.555
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 (CIF) Linear Torsion Angle # 16
O3 -NI1 -N1 -C7 107.00 1.00 2.667 1.555 1.555 1.555
PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ...... 6
PLAT731_ALERT_1_C Bond Calc 0.85(4), Rep 0.850(10) .... 4.00 su-Ratio
O1W -H1W2 1.555 1.555
PLAT731_ALERT_1_C Bond Calc 0.85(4), Rep 0.850(10) .... 4.00 su-Ratio
O3W -H3W2 1.555 1.555
PLAT735_ALERT_1_C D-H Calc 0.85(4), Rep 0.850(10) .... 4.00 su-Ratio
O1W -H1W2 1.555 1.555
PLAT735_ALERT_1_C D-H Calc 0.85(4), Rep 0.850(10) .... 4.00 su-Ratio
O3W -H3W2 1.555 1.555
PLAT736_ALERT_1_C H...A Calc 1.82(5), Rep 1.82(2) .... 2.50 su-Ratio
H1W1 -O4 1.555 2.667
PLAT736_ALERT_1_C H...A Calc 2.02(3), Rep 2.020(10) .... 3.00 su-Ratio
H3W2 -O3 1.555 1.665
PLAT764_ALERT_4_C Overcomplete CIF Bond list Detected (Rep/Expd) 1.11 Ratio
1 ALERT level A = In general: serious problem
10 ALERT level B = Potentially serious problem
19 ALERT level C = Check and explain
0 ALERT level G = General alerts; check
19 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
5 ALERT type 3 Indicator that the structure quality may be low
5 ALERT type 4 Improvement, methodology, query or suggestion
1,2,4,5-Benzenetetracarboxylic acid anhydride (pyromellitic anhydride, 0.22 g, 1 mmol) dissolved in water (15 ml) containing sodium hydroxide (0.16 g, 4 mmol). Nickel dinitrate hexahydrate (0.58 g, 2 mmol) and pyrazine (0.16 g, 2 mmol) dissolved in water (3 ml) were added. The mixture was placed in a 20 ml Teflon-lined stainless-steel bomb. The bomb was heated at 453 K for 100 h. Crystals separated from the solution when the bomb was cooled down at a rate of 5 K h−1.
The use of too small a value for the ω-dependent absorption correction in SADABS (Sheldrick, 1996) lead to non-positive definites for several atoms, and a compromise value of 0.5 was used for which only one atom (C3) was non-positive definite. The displacement parameter of this atom was made nearly isotropic by an ISOR 0.01 command in SHELXL97 (Sheldrick, 1997). The aromatic H atoms were generated geometrically and were included in the refinement in the riding-model approximation, with Uiso(H) = 1.2Ueq(C). The water H atoms were located and refined with restraints of O—H = 0.85±0.01 Å and H···H = 1.39±0.01 Å, and Uiso(H) = 1.2Ueq(O).
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); 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.
tetraaqua(1,2,4,5-benzenetetracarboxylato)(pyrazine)dinickel(II) dihydrate
top
Crystal data top
[Ni2(C10H2O8)(C4H4N2)(H2O)4]·2H2O | Z = 1 |
Mr = 555.72 | F(000) = 284 |
Triclinic, P1 | Dx = 1.991 Mg m−3 |
a = 7.2005 (5) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.0322 (5) Å | Cell parameters from 2804 reflections |
c = 9.3735 (6) Å | θ = 2.3–28.3° |
α = 96.175 (1)° | µ = 2.12 mm−1 |
β = 101.872 (1)° | T = 298 K |
γ = 116.245 (1)° | Irregular block, green |
V = 463.50 (5) Å3 | 0.14 × 0.13 × 0.04 mm |
Data collection top
Bruker APEX area-detector diffractometer | 2152 independent reflections |
Radiation source: fine-focus sealed tube | 2055 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
ϕ and ω scans | θmax = 28.3°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −9→9 |
Tmin = 0.616, Tmax = 0.919 | k = −10→10 |
5415 measured reflections | l = −12→12 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.065 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.25 | w = 1/[σ2(Fo2) + (0.0629P)2 + 0.259P] where P = (Fo2 + 2Fc2)/3 |
2152 reflections | (Δ/σ)max = 0.001 |
163 parameters | Δρmax = 0.95 e Å−3 |
12 restraints | Δρmin = −0.65 e Å−3 |
Crystal data top
[Ni2(C10H2O8)(C4H4N2)(H2O)4]·2H2O | γ = 116.245 (1)° |
Mr = 555.72 | V = 463.50 (5) Å3 |
Triclinic, P1 | Z = 1 |
a = 7.2005 (5) Å | Mo Kα radiation |
b = 8.0322 (5) Å | µ = 2.12 mm−1 |
c = 9.3735 (6) Å | T = 298 K |
α = 96.175 (1)° | 0.14 × 0.13 × 0.04 mm |
β = 101.872 (1)° | |
Data collection top
Bruker APEX area-detector diffractometer | 2152 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2055 reflections with I > 2σ(I) |
Tmin = 0.616, Tmax = 0.919 | Rint = 0.041 |
5415 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.065 | 12 restraints |
wR(F2) = 0.142 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.25 | Δρmax = 0.95 e Å−3 |
2152 reflections | Δρmin = −0.65 e Å−3 |
163 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Ni1 | 0.60108 (8) | 0.81218 (8) | 0.67559 (6) | 0.0110 (2) | |
O1 | 0.6582 (5) | 0.5750 (5) | 0.6851 (4) | 0.017 (1) | |
O2 | 0.8599 (5) | 0.8424 (4) | 0.8517 (4) | 0.018 (1) | |
O3 | 0.5956 (5) | 0.2995 (5) | 1.1964 (4) | 0.021 (1) | |
O4 | 0.9037 (5) | 0.3347 (6) | 1.3403 (4) | 0.028 (1) | |
N1 | 0.8301 (6) | 0.9266 (6) | 0.5624 (4) | 0.018 (1) | |
O1w | 0.3494 (5) | 0.7163 (5) | 0.4853 (4) | 0.018 (1) | |
O2w | 0.6017 (6) | 1.0632 (5) | 0.7309 (4) | 0.023 (1) | |
O3w | 1.3406 (7) | 1.0949 (7) | 0.8959 (5) | 0.040 (1) | |
C1 | 0.8069 (7) | 0.6716 (6) | 0.8048 (5) | 0.015 (1) | |
C2 | 0.9098 (7) | 0.5810 (6) | 0.9020 (5) | 0.015 (1) | |
C3 | 0.8153 (7) | 0.5061 (6) | 1.0095 (5) | 0.015 (1) | |
C4 | 0.9005 (7) | 0.4241 (7) | 1.1087 (5) | 0.017 (1) | |
C5 | 0.7944 (7) | 0.3455 (7) | 1.2247 (5) | 0.017 (1) | |
C6 | 1.0016 (8) | 1.0989 (7) | 0.6229 (6) | 0.022 (1) | |
C7 | 0.8302 (8) | 0.8267 (7) | 0.4382 (5) | 0.021 (1) | |
H1w1 | 0.242 (6) | 0.689 (7) | 0.519 (6) | 0.021* | |
H1w2 | 0.309 (8) | 0.607 (4) | 0.433 (5) | 0.021* | |
H2w1 | 0.520 (8) | 1.076 (8) | 0.779 (6) | 0.028* | |
H2w2 | 0.620 (9) | 1.135 (7) | 0.669 (5) | 0.028* | |
H3w1 | 1.222 (6) | 1.021 (8) | 0.911 (8) | 0.047* | |
H3w2 | 1.418 (9) | 1.163 (8) | 0.983 (3) | 0.047* | |
H3 | 0.6903 | 0.5105 | 1.0160 | 0.018* | |
H6 | 1.0065 | 1.1707 | 0.7097 | 0.026* | |
H7 | 0.7149 | 0.7059 | 0.3932 | 0.025* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Ni1 | 0.0108 (3) | 0.0142 (3) | 0.0113 (3) | 0.0073 (2) | 0.0052 (2) | 0.0062 (2) |
O1 | 0.015 (2) | 0.022 (2) | 0.016 (2) | 0.010 (1) | 0.001 (1) | 0.004 (1) |
O2 | 0.020 (2) | 0.018 (2) | 0.018 (2) | 0.011 (1) | 0.004 (1) | 0.005 (1) |
O3 | 0.016 (2) | 0.035 (2) | 0.021 (2) | 0.014 (2) | 0.011 (1) | 0.016 (2) |
O4 | 0.020 (2) | 0.053 (2) | 0.021 (2) | 0.021 (2) | 0.010 (2) | 0.021 (2) |
N1 | 0.015 (2) | 0.022 (2) | 0.019 (2) | 0.008 (2) | 0.007 (2) | 0.008 (2) |
O1w | 0.017 (2) | 0.022 (2) | 0.016 (2) | 0.010 (1) | 0.005 (1) | 0.004 (1) |
O2w | 0.032 (2) | 0.023 (2) | 0.025 (2) | 0.018 (2) | 0.015 (2) | 0.011 (2) |
O3w | 0.030 (2) | 0.057 (3) | 0.023 (2) | 0.017 (2) | 0.007 (2) | −0.005 (2) |
C1 | 0.011 (2) | 0.021 (2) | 0.014 (2) | 0.008 (2) | 0.006 (2) | 0.009 (2) |
C2 | 0.013 (2) | 0.019 (2) | 0.017 (2) | 0.011 (2) | 0.004 (2) | 0.005 (2) |
C3 | 0.019 (2) | 0.013 (2) | 0.023 (2) | 0.011 (2) | 0.009 (2) | 0.014 (2) |
C4 | 0.014 (2) | 0.021 (2) | 0.018 (2) | 0.008 (2) | 0.009 (2) | 0.008 (2) |
C5 | 0.018 (2) | 0.022 (2) | 0.017 (2) | 0.012 (2) | 0.009 (2) | 0.008 (2) |
C6 | 0.022 (2) | 0.024 (2) | 0.018 (2) | 0.010 (2) | 0.008 (2) | 0.004 (2) |
C7 | 0.017 (2) | 0.022 (2) | 0.019 (2) | 0.006 (2) | 0.006 (2) | 0.002 (2) |
Geometric parameters (Å, º) top
Ni1—O1 | 2.126 (3) | C3—C4 | 1.389 (6) |
Ni1—O2 | 2.123 (3) | C4—C2ii | 1.408 (6) |
Ni1—O3i | 2.014 (3) | C4—C5 | 1.493 (6) |
Ni1—O1w | 2.049 (3) | C6—C7iii | 1.367 (7) |
Ni1—O2w | 2.025 (4) | C7—C6iii | 1.367 (7) |
Ni1—N1 | 2.068 (4) | O1w—H1w1 | 0.84 (1) |
O1—C1 | 1.262 (6) | O1w—H1w2 | 0.85 (1) |
O2—C1 | 1.248 (6) | O2w—H2w1 | 0.85 (1) |
O3—C5 | 1.269 (5) | O2w—H2w2 | 0.85 (1) |
O4—C5 | 1.237 (6) | O3w—H3w1 | 0.85 (1) |
N1—C6 | 1.339 (6) | O3w—H3w2 | 0.85 (1) |
N1—C7 | 1.341 (6) | C3—H3 | 0.93 |
C1—C2 | 1.500 (6) | C6—H6 | 0.93 |
C2—C3 | 1.375 (6) | C7—H7 | 0.93 |
C2—C4ii | 1.408 (6) | | |
| | | |
O1—Ni1—O2 | 61.7 (1) | C3—C2—C1 | 117.2 (4) |
O1—Ni1—O3i | 84.9 (1) | C4ii—C2—C1 | 123.3 (4) |
O1—Ni1—O1w | 103.2 (1) | C2—C3—C4 | 122.1 (4) |
O1—Ni1—O2w | 162.8 (1) | C3—C4—C2ii | 118.4 (4) |
O1—Ni1—N1 | 91.5 (1) | C3—C4—C5 | 120.6 (4) |
O2—Ni1—O3i | 87.8 (1) | C2ii—C4—C5 | 121.0 (4) |
O2—Ni1—O1w | 164.8 (1) | O4—C5—O3 | 125.2 (4) |
O2—Ni1—O2w | 101.8 (1) | O4—C5—C4 | 119.2 (4) |
O2—Ni1—N1 | 85.8 (1) | O3—C5—C4 | 115.6 (4) |
O3i—Ni1—O1w | 93.2 (1) | N1—C6—C7iii | 122.5 (5) |
O3i—Ni1—O2w | 89.8 (1) | N1—C7—C6iii | 120.6 (4) |
O3i—Ni1—N1 | 173.6 (1) | Ni1—O1w—H1w1 | 103 (4) |
O1w—Ni1—O2w | 93.4 (1) | Ni1—O1w—H1w2 | 117 (4) |
O1w—Ni1—N1 | 92.8 (1) | H1w1—O1w—H1w2 | 98 (5) |
O2w—Ni1—N1 | 92.2 (2) | Ni1—O2w—H2w1 | 123 (4) |
C1—O1—Ni1 | 88.5 (3) | Ni1—O2w—H2w2 | 119 (4) |
C1—O2—Ni1 | 89.0 (3) | H2w1—O2w—H2w2 | 109 (5) |
C5—O3—Ni1i | 127.0 (3) | H3w1—O3w—H3w2 | 103 (7) |
C6—N1—C7 | 116.9 (4) | C2—C3—H3 | 119.0 |
C6—N1—Ni1 | 119.8 (3) | C4—C3—H3 | 119.0 |
C7—N1—Ni1 | 122.8 (3) | N1—C6—H6 | 118.7 |
O2—C1—O1 | 120.5 (4) | C7iii—C6—H6 | 118.7 |
O2—C1—C2 | 118.0 (4) | N1—C7—H7 | 119.7 |
O1—C1—C2 | 121.2 (4) | C6iii—C7—H7 | 119.7 |
C3—C2—C4ii | 119.5 (4) | | |
| | | |
O3i—Ni1—O1—C1 | −87.2 (3) | Ni1—O2—C1—C2 | −169.0 (3) |
O2w—Ni1—O1—C1 | −14.7 (6) | Ni1—O1—C1—O2 | −5.2 (4) |
O1w—Ni1—O1—C1 | −179.3 (2) | Ni1—O1—C1—C2 | 168.8 (4) |
N1—Ni1—O1—C1 | 87.5 (3) | O2—C1—C2—C3 | 85.6 (5) |
O2—Ni1—O1—C1 | 3.0 (2) | O1—C1—C2—C3 | −88.5 (5) |
O3i—Ni1—O2—C1 | 82.3 (3) | O2—C1—C2—C4ii | −92.0 (6) |
O2w—Ni1—O2—C1 | 171.7 (3) | O1—C1—C2—C4ii | 93.8 (6) |
O1w—Ni1—O2—C1 | −11.8 (6) | C4ii—C2—C3—C4 | −0.2 (8) |
N1—Ni1—O2—C1 | −97.0 (3) | C1—C2—C3—C4 | −178.0 (4) |
O1—Ni1—O2—C1 | −3.0 (2) | C2—C3—C4—C2ii | 0.2 (8) |
O3i—Ni1—N1—C6 | −64 (2) | C2—C3—C4—C5 | 179.5 (4) |
O2w—Ni1—N1—C6 | 43.6 (4) | Ni1i—O3—C5—O4 | −2.5 (7) |
O1w—Ni1—N1—C6 | 137.1 (4) | Ni1i—O3—C5—C4 | 179.5 (3) |
O2—Ni1—N1—C6 | −58.1 (4) | C3—C4—C5—O4 | −155.1 (5) |
O1—Ni1—N1—C6 | −119.6 (4) | C2ii—C4—C5—O4 | 24.2 (7) |
O3i—Ni1—N1—C7 | 107 (1) | C3—C4—C5—O3 | 22.9 (7) |
O2w—Ni1—N1—C7 | −144.9 (4) | C2ii—C4—C5—O3 | −157.8 (4) |
O1w—Ni1—N1—C7 | −51.4 (4) | C7—N1—C6—C7iii | 0.7 (8) |
O2—Ni1—N1—C7 | 113.4 (4) | Ni1—N1—C6—C7iii | 172.7 (4) |
O1—Ni1—N1—C7 | 51.9 (4) | C6—N1—C7—C6iii | −0.7 (8) |
Ni1—O2—C1—O1 | 5.3 (4) | Ni1—N1—C7—C6iii | −172.4 (4) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+2, −y+1, −z+2; (iii) −x+2, −y+2, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1w—H1w2···O1iv | 0.85 (1) | 1.87 (3) | 2.660 (5) | 155 (5) |
O1w—H1w1···O4i | 0.84 (1) | 1.82 (2) | 2.621 (5) | 157 (5) |
O2w—H2w2···O1wv | 0.85 (1) | 1.96 (1) | 2.807 (5) | 176 (6) |
O2w—H2w1···O3wvi | 0.85 (1) | 1.90 (1) | 2.744 (5) | 176 (6) |
O3w—H3w1···O2 | 0.85 (1) | 2.26 (3) | 3.047 (5) | 155 (6) |
O3w—H3w2···O3vii | 0.85 (1) | 2.02 (1) | 2.866 (5) | 174 (7) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (iv) −x+1, −y+1, −z+1; (v) −x+1, −y+2, −z+1; (vi) x−1, y, z; (vii) x+1, y+1, z. |
Experimental details
Crystal data |
Chemical formula | [Ni2(C10H2O8)(C4H4N2)(H2O)4]·2H2O |
Mr | 555.72 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 298 |
a, b, c (Å) | 7.2005 (5), 8.0322 (5), 9.3735 (6) |
α, β, γ (°) | 96.175 (1), 101.872 (1), 116.245 (1) |
V (Å3) | 463.50 (5) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 2.12 |
Crystal size (mm) | 0.14 × 0.13 × 0.04 |
|
Data collection |
Diffractometer | Bruker APEX area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.616, 0.919 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5415, 2152, 2055 |
Rint | 0.041 |
(sin θ/λ)max (Å−1) | 0.667 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.065, 0.142, 1.25 |
No. of reflections | 2152 |
No. of parameters | 163 |
No. of restraints | 12 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.95, −0.65 |
Selected geometric parameters (Å, º) topNi1—O1 | 2.126 (3) | Ni1—O1w | 2.049 (3) |
Ni1—O2 | 2.123 (3) | Ni1—O2w | 2.025 (4) |
Ni1—O3i | 2.014 (3) | Ni1—N1 | 2.068 (4) |
| | | |
O1—Ni1—O2 | 61.7 (1) | O2—Ni1—N1 | 85.8 (1) |
O1—Ni1—O3i | 84.9 (1) | O3i—Ni1—O1w | 93.2 (1) |
O1—Ni1—O1w | 103.2 (1) | O3i—Ni1—O2w | 89.8 (1) |
O1—Ni1—O2w | 162.8 (1) | O3i—Ni1—N1 | 173.6 (1) |
O1—Ni1—N1 | 91.5 (1) | O1w—Ni1—O2w | 93.4 (1) |
O2—Ni1—O3i | 87.8 (1) | O1w—Ni1—N1 | 92.8 (1) |
O2—Ni1—O1w | 164.8 (1) | O2w—Ni1—N1 | 92.2 (2) |
O2—Ni1—O2w | 101.8 (1) | | |
Symmetry code: (i) −x+1, −y+1, −z+2. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O1w—H1w2···O1ii | 0.85 (1) | 1.87 (3) | 2.660 (5) | 155 (5) |
O1w—H1w1···O4i | 0.84 (1) | 1.82 (2) | 2.621 (5) | 157 (5) |
O2w—H2w2···O1wiii | 0.85 (1) | 1.96 (1) | 2.807 (5) | 176 (6) |
O2w—H2w1···O3wiv | 0.85 (1) | 1.90 (1) | 2.744 (5) | 176 (6) |
O3w—H3w1···O2 | 0.85 (1) | 2.26 (3) | 3.047 (5) | 155 (6) |
O3w—H3w2···O3v | 0.85 (1) | 2.02 (1) | 2.866 (5) | 174 (7) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, −y+1, −z+1; (iii) −x+1, −y+2, −z+1; (iv) x−1, y, z; (v) x+1, y+1, z. |
A number of the adducts of nickel benzenepolycarboxylates with N-heterocycles have been reported (Li et al., 2003; Yuan et al., 2001). To this number has been added the 4,4'-bipyridine adduct of nickel terephthalate (Yang et al., 2003a) and of nickel phthalate (Yang et al., 2003b). The present pyrazine adduct, (I), of dinickel 1,2,4,5-benzenetetracarboxylate exists as a dihydrate (Fig. 1).
The Ni atom in (I) exists in an octahedral NO5Ni environment that is defined by the two O atoms of a chelating –CO2 group, the O atom of a monodentate CO2 group of another tetraanion, two water molecules and the N atom of pyrazine (Table 1). The tetracarboxylate anion and the pyrazine molecule are located on a center of inversion. The bonding pattern leads to the formation of layers (Fig. 2); the layers are linked into a three-dimensional network by hydrogen bonds involving the water molecules (Table 2).