The title compounds, bis(pyridine-2,6-dicarboxylato-
N,
O,O′)copper(II) monohydrate, [Cu(C
7H
4NO
4)
2]·H
2O, andbis(pyridine-2,6-dicarboxylato-
N,
O,
O′)zinc(II) trihydrate, [Zn(C
7H
4NO
4)
2]·3H
2O, have distorted octahedral geometries about the metal centres. Both metal ions are bonded to four O atoms and two pyridyl-N atoms from the two terdentate ligand molecules, which are nearly perpendicular to each other. The copper(II) complex has twofold crystallographic symmetry and contains two different ligand molecules, one of which is neutral and another doubly ionized. In contrast, the zinc(II) complex contains two identical singly ionized ligand molecules. Both crystal structures are stabilized by O—H
O intermolecular hydrogen bonds between the complex and the water molecules.
Supporting information
CCDC references: 143228; 143229
Compound (I): the blue crystal used for analysis was obtained by slow
evaporation from a solution in ethanol:water (1:1) of a mixture containing
pyridine-2,6-dicarboxylic acid and copper(II) chloride dihydrate in a 4:1
molar ratio at room temperature.
Compound(II): the colourless crystal used for analysis was obtained by the slow
evaporation from a solution in ethanol:water (1:1) of a mixture containing
pyridine-2,6-dicarboxylic acid and zinc(II) sulfate heptahydrate in a 4:1
molar ratio at room temperature.
The H atoms of the carboxyl groups in (I) and (II) were located from difference
Fourier maps. Other H atoms were initially located from difference Fourier
maps, removed and then placed in calculated positions.
The two H atoms bonded to O5 of the water molecule in (I) are not found in the
Fourier maps, but are accounted for in the formula sum and formula weight
calculations.
For both compounds, data collection: MSC/AFC Diffractometer Control Software (Molecular Structure Corporation, 1992a); cell refinement: MSC/AFC Diffractometer Control Software; data reduction: TEXSAN PROCESS (Molecular Structure Corporation, 1992b); program(s) used to solve structure: SIR88 (Burla et al., 1989); program(s) used to refine structure: TEXSAN/LS (Molecular Structure Corporation, 1992); molecular graphics: ORTEPII (Johnson, 1976).
Crystal data top
[Cu(C7H4NO4)2]·H2O | Dx = 1.843 Mg m−3 |
Mr = 413.80 | Mo Kα radiation, λ = 0.71069 Å |
Orthorhombic, Pnna | Cell parameters from 25 reflections |
a = 7.903 (4) Å | θ = 14.1–15.0° |
b = 11.068 (4) Å | µ = 1.52 mm−1 |
c = 17.053 (3) Å | T = 296 K |
V = 1491 (1) Å3 | Pillar, blue |
Z = 4 | 0.40 × 0.10 × 0.10 mm |
Data collection top
Rigaku AFC5R diffractometer | Rint = 0 |
ω–2θ scans | θmax = 27.5° |
Absorption correction: ψ scan (North et al., 1968) | h = 0→9 |
Tmin = 0.784, Tmax = 0.859 | k = 0→14 |
1727 measured reflections | l = 0→21 |
1727 independent reflections | 3 standard reflections every 150 reflections |
1724 reflections with I > 0.00σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | H-atom parameters not refined |
R[F2 > 2σ(F2)] = 0.081 | w = 1/σ2(Fo) |
wR(F2) = 0.129 | (Δ/σ)max < 0.001 |
S = 1.03 | Δρmax = 1.06 e Å−3 |
1724 reflections | Δρmin = −0.75 e Å−3 |
121 parameters | |
Crystal data top
[Cu(C7H4NO4)2]·H2O | V = 1491 (1) Å3 |
Mr = 413.80 | Z = 4 |
Orthorhombic, Pnna | Mo Kα radiation |
a = 7.903 (4) Å | µ = 1.52 mm−1 |
b = 11.068 (4) Å | T = 296 K |
c = 17.053 (3) Å | 0.40 × 0.10 × 0.10 mm |
Data collection top
Rigaku AFC5R diffractometer | 1724 reflections with I > 0.00σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0 |
Tmin = 0.784, Tmax = 0.859 | 3 standard reflections every 150 reflections |
1727 measured reflections | intensity decay: none |
1727 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.081 | 121 parameters |
wR(F2) = 0.129 | H-atom parameters not refined |
S = 1.03 | Δρmax = 1.06 e Å−3 |
1724 reflections | Δρmin = −0.75 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Cu1 | 0.7500 | 0.0000 | 0.31655 (3) | 0.0263 | |
O1 | 0.5177 (4) | 0.2672 (3) | 0.4344 (2) | 0.0451 | |
O2 | 0.6131 (4) | 0.1509 (3) | 0.3369 (2) | 0.0360 | |
O3 | 1.0058 (4) | 0.1062 (3) | 0.2785 (2) | 0.0394 | |
O4 | 1.1465 (4) | 0.1373 (3) | 0.1657 (2) | 0.0389 | |
O5 | 0.3744 (4) | 0.2500 | 0.2500 | 0.0326 | |
N1 | 0.7500 | 0.0000 | 0.4288 (2) | 0.0246 | |
N2 | 0.7500 | 0.0000 | 0.1987 (2) | 0.0237 | |
C1 | 0.6753 (5) | 0.0911 (4) | 0.4656 (2) | 0.0266 | |
C2 | 0.6743 (5) | 0.0945 (4) | 0.5470 (2) | 0.0341 | |
C3 | 0.7500 | 0.0000 | 0.5871 (3) | 0.0398 | |
C4 | 0.5947 (5) | 0.1798 (4) | 0.4105 (2) | 0.0322 | |
C5 | 0.8759 (5) | 0.0510 (4) | 0.1579 (2) | 0.0272 | |
C6 | 0.8771 (5) | 0.0562 (4) | 0.0765 (2) | 0.0319 | |
C7 | 0.7500 | 0.0000 | 0.0362 (3) | 0.0340 | |
C8 | 1.0157 (5) | 0.1019 (4) | 0.2074 (2) | 0.0302 | |
H1 | 0.6239 | 0.1670 | 0.5786 | 0.0439 | |
H2 | 0.7500 | 0.0000 | 0.6432 | 0.0439 | |
H3 | 0.9602 | 0.1082 | 0.0485 | 0.0439 | |
H4 | 0.7500 | 0.0000 | −0.0204 | 0.0439 | |
H5 | 1.2395 | 0.1705 | 0.2018 | 0.0439 | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0290 (3) | 0.0307 (4) | 0.0192 (3) | 0.0035 (4) | 0.0000 | 0.0000 |
O1 | 0.052 (2) | 0.036 (2) | 0.047 (2) | 0.016 (2) | −0.001 (2) | −0.009 (2) |
O2 | 0.044 (2) | 0.035 (2) | 0.029 (1) | 0.012 (1) | −0.003 (1) | 0.000 (1) |
O3 | 0.037 (2) | 0.052 (2) | 0.029 (1) | −0.016 (2) | −0.005 (1) | 0.006 (1) |
O4 | 0.031 (1) | 0.051 (2) | 0.035 (2) | −0.011 (1) | 0.001 (1) | 0.002 (1) |
O5 | 0.021 (2) | 0.043 (2) | 0.034 (2) | 0.0000 | 0.0000 | 0.006 (2) |
N1 | 0.026 (2) | 0.030 (2) | 0.018 (2) | −0.001 (2) | 0.0000 | 0.0000 |
N2 | 0.022 (2) | 0.026 (2) | 0.024 (2) | 0.002 (2) | 0.0000 | 0.0000 |
C1 | 0.024 (2) | 0.028 (2) | 0.028 (2) | −0.002 (2) | 0.000 (2) | −0.004 (2) |
C2 | 0.031 (2) | 0.045 (3) | 0.026 (2) | −0.003 (2) | 0.000 (2) | −0.006 (2) |
C3 | 0.034 (3) | 0.063 (4) | 0.023 (2) | −0.007 (4) | 0.0000 | 0.0000 |
C4 | 0.027 (2) | 0.036 (2) | 0.034 (2) | −0.001 (2) | −0.001 (2) | −0.007 (2) |
C5 | 0.026 (2) | 0.028 (2) | 0.028 (2) | 0.002 (2) | 0.000 (2) | −0.001 (2) |
C6 | 0.029 (2) | 0.041 (2) | 0.026 (2) | 0.005 (2) | 0.006 (2) | 0.005 (2) |
C7 | 0.034 (3) | 0.048 (3) | 0.020 (2) | 0.005 (3) | 0.0000 | 0.0000 |
C8 | 0.024 (2) | 0.032 (2) | 0.035 (2) | −0.004 (2) | −0.004 (2) | 0.005 (2) |
Geometric parameters (Å, º) top
Cu1—O2 | 2.019 (3) | N1—C1 | 1.327 (4) |
Cu1—O3 | 2.427 (3) | N1—C1i | 1.327 (4) |
Cu1—N1 | 1.914 (4) | N2—C5 | 1.339 (4) |
Cu1—N2 | 2.009 (4) | N2—C5i | 1.339 (4) |
Cu1—O2i | 2.019 (3) | C1—C2 | 1.388 (5) |
Cu1—O3i | 2.427 (3) | C1—C4 | 1.501 (6) |
O1—C4 | 1.213 (5) | C2—C3 | 1.385 (5) |
O2—C4 | 1.303 (4) | C5—C6 | 1.390 (5) |
O3—C8 | 1.216 (5) | C5—C8 | 1.500 (5) |
O4—C8 | 1.314 (5) | C6—C7 | 1.366 (5) |
| | | |
O2—Cu1—O2i | 160.2 (2) | Cu1—N2—C5 | 121.3 (2) |
O2—Cu1—O3 | 95.3 (1) | Cu1—N2—C5i | 121.3 (2) |
O2i—Cu1—N1 | 80.10 (8) | C5—N2—C5i | 117.3 (4) |
O3—Cu1—N2 | 74.50 (7) | N1—C1—C2 | 119.8 (4) |
O3i—Cu1—N1 | 105.50 (7) | N1—C1—C4 | 112.9 (3) |
O2—Cu1—O3i | 90.0 (1) | C2—C1—C4 | 127.3 (4) |
O2—Cu1—N1 | 80.10 (8) | C1—C2—C3 | 118.0 (4) |
O2—Cu1—N2 | 99.90 (8) | C2—C3—C2i | 120.9 (5) |
O2i—Cu1—O3 | 90.0 (1) | O1—C4—O2 | 125.2 (4) |
O2i—Cu1—O3i | 95.3 (1) | O1—C4—C1 | 121.6 (4) |
O2i—Cu1—N2 | 99.90 (8) | O2—C4—C1 | 113.2 (3) |
O3—Cu1—O3i | 149.0 (1) | N2—C5—C6 | 122.8 (4) |
O3—Cu1—N1 | 105.50 (7) | N2—C5—C8 | 114.4 (3) |
O3i—Cu1—N2 | 74.50 (7) | C6—C5—C8 | 122.8 (4) |
N1—Cu1—N2 | 180.0000 | C5—C6—C7 | 118.6 (4) |
Cu1—O2—C4 | 115.4 (3) | C6—C7—C6i | 119.7 (5) |
Cu1—O3—C8 | 107.5 (3) | O3—C8—O4 | 125.3 (4) |
Cu1—N1—C1 | 118.3 (2) | O3—C8—C5 | 121.9 (4) |
Cu1—N1—C1i | 118.3 (2) | O4—C8—C5 | 112.8 (3) |
C1—N1—C1i | 123.5 (4) | | |
| | | |
Cu1—O2—C4—O1 | 179.7 (3) | O3—Cu1—O2—C4 | −102.3 (3) |
Cu1—O2—C4—C1 | −2.0 (4) | O3i—Cu1—O3—C8 | −4.0 (3) |
Cu1—O3—C8—O4 | −171.8 (3) | O3—Cu1—N1—C1 | 90.2 (2) |
Cu1—O3—C8—C5 | 6.7 (5) | O3—Cu1—N2—C5 | 0.6 (2) |
Cu1—N1—C1—C2 | −179.4 (3) | O3—C8—C5—N2 | −6.7 (6) |
Cu1—N1—C1—C4 | 2.2 (3) | O3—C8—C5—C6 | 173.4 (4) |
Cu1—N2—C5—C6 | −177.8 (3) | O4—C8—C5—N2 | 171.9 (3) |
Cu1—N2—C5—C8 | 2.3 (4) | O4—C8—C5—C6 | −8.0 (6) |
O1—C4—C1—N1 | 178.4 (4) | N1—Cu1—O2—C4 | 2.5 (3) |
O1—C4—C1—C2 | 0.2 (7) | N1—Cu1—O3—C8 | 176.0 (3) |
O2i—Cu1—O2—C4 | 2.5 (3) | N1—C1—C2—C3 | −1.1 (5) |
O2—Cu1—O3—C8 | −102.8 (3) | N2—Cu1—O2—C4 | −177.5 (3) |
O2—Cu1—N1—C1 | −2.6 (2) | N2—Cu1—O3—C8 | −4.0 (3) |
O2—Cu1—N2—C5 | 93.4 (2) | N2—C5—C6—C7 | −4.3 (6) |
O2—C4—C1—N1 | 0.0 (5) | C1i—N1—C1—C2 | 0.6 (3) |
O2—C4—C1—C2 | −178.2 (4) | C1i—N1—C1—C4 | −177.8 (3) |
Symmetry code: (i) −x+3/2, −y, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H5···O5ii | 1.03 | 1.61 | 2.621 (4) | 168 |
O5···O2 | | | 2.638 (4) | |
Symmetry code: (ii) x+1, y, z. |
Crystal data top
[Zn(C7H4NO4)2]·3H2O | Dx = 1.724 Mg m−3 |
Mr = 451.65 | Mo Kα radiation, λ = 0.71069 Å |
Monoclinic, P21/a | Cell parameters from 25 reflections |
a = 13.765 (2) Å | θ = 14.8–15.0° |
b = 10.052 (2) Å | µ = 1.48 mm−1 |
c = 14.060 (2) Å | T = 296 K |
β = 116.554 (8)° | Pillar, colourless |
V = 1740.3 (4) Å3 | 0.50 × 0.15 × 0.15 mm |
Z = 4 | |
Data collection top
Rigaku AFC5R diffractometer | Rint = 0.017 |
ω–2θ scans | θmax = 27.5° |
Absorption correction: ψ scan (North et al., 1968) | h = 0→17 |
Tmin = 0.755, Tmax = 0.801 | k = 0→13 |
4392 measured reflections | l = −18→16 |
3991 independent reflections | 3 standard reflections every 150 reflections |
3991 reflections with I > 0.00σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | H-atom parameters not refined |
R[F2 > 2σ(F2)] = 0.058 | w = 1/σ2(Fo) |
wR(F2) = 0.114 | (Δ/σ)max < 0.001 |
S = 1.36 | Δρmax = 0.81 e Å−3 |
3991 reflections | Δρmin = −0.63 e Å−3 |
253 parameters | |
Crystal data top
[Zn(C7H4NO4)2]·3H2O | V = 1740.3 (4) Å3 |
Mr = 451.65 | Z = 4 |
Monoclinic, P21/a | Mo Kα radiation |
a = 13.765 (2) Å | µ = 1.48 mm−1 |
b = 10.052 (2) Å | T = 296 K |
c = 14.060 (2) Å | 0.50 × 0.15 × 0.15 mm |
β = 116.554 (8)° | |
Data collection top
Rigaku AFC5R diffractometer | 3991 reflections with I > 0.00σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.017 |
Tmin = 0.755, Tmax = 0.801 | 3 standard reflections every 150 reflections |
4392 measured reflections | intensity decay: none |
3991 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.058 | 253 parameters |
wR(F2) = 0.114 | H-atom parameters not refined |
S = 1.36 | Δρmax = 0.81 e Å−3 |
3991 reflections | Δρmin = −0.63 e Å−3 |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
Zn1 | 0.73609 (3) | 0.00684 (3) | 0.74961 (2) | 0.0439 | |
O1 | 0.9084 (2) | 0.0566 (2) | 0.7625 (2) | 0.0497 | |
O2 | 1.0634 (2) | 0.1557 (2) | 0.8743 (2) | 0.0551 | |
O3 | 0.6093 (2) | 0.0335 (2) | 0.9603 (2) | 0.0524 | |
O4 | 0.6263 (2) | −0.0066 (2) | 0.8126 (2) | 0.0492 | |
O5 | 0.7837 (2) | −0.2164 (2) | 0.7769 (1) | 0.0492 | |
O6 | 0.7773 (2) | −0.3978 (2) | 0.6819 (2) | 0.0574 | |
O7 | 0.5726 (2) | 0.2270 (3) | 0.4784 (2) | 0.0831 | |
O8 | 0.6661 (2) | 0.1733 (2) | 0.6505 (2) | 0.0548 | |
O9 | 0.8895 (2) | 0.4764 (2) | 0.8470 (2) | 0.0590 | |
O10 | 1.1359 (2) | 0.1109 (2) | 0.7460 (2) | 0.0691 | |
O11 | 1.0102 (6) | 0.0471 (7) | 0.3932 (7) | 0.2842 | |
N1 | 0.8236 (2) | 0.0860 (2) | 0.8946 (2) | 0.0346 | |
N2 | 0.6831 (2) | −0.0739 (2) | 0.6044 (2) | 0.0370 | |
C1 | 0.9233 (2) | 0.1353 (3) | 0.9266 (2) | 0.0370 | |
C2 | 0.9770 (2) | 0.1990 (3) | 1.0228 (2) | 0.0445 | |
C3 | 0.9255 (2) | 0.2104 (3) | 1.0870 (2) | 0.0508 | |
C4 | 0.8218 (2) | 0.1592 (3) | 1.0535 (2) | 0.0454 | |
C5 | 0.7732 (2) | 0.0971 (3) | 0.9556 (2) | 0.0357 | |
C6 | 0.9662 (2) | 0.1132 (3) | 0.8465 (2) | 0.0401 | |
C7 | 0.6597 (2) | 0.0363 (3) | 0.9065 (2) | 0.0407 | |
C8 | 0.6973 (2) | −0.2019 (3) | 0.5898 (2) | 0.0402 | |
C9 | 0.6608 (2) | −0.2552 (4) | 0.4888 (2) | 0.0543 | |
C10 | 0.6073 (3) | −0.1725 (4) | 0.4029 (2) | 0.0614 | |
C11 | 0.5923 (2) | −0.0415 (4) | 0.4180 (2) | 0.0565 | |
C12 | 0.6316 (2) | 0.0071 (3) | 0.5217 (2) | 0.0434 | |
C13 | 0.7580 (2) | −0.2749 (3) | 0.6927 (2) | 0.0413 | |
C14 | 0.6220 (2) | 0.1490 (3) | 0.5509 (3) | 0.0524 | |
H1 | 1.0478 | 0.2345 | 1.0445 | 0.0534 | |
H2 | 0.9612 | 0.2529 | 1.1542 | 0.0605 | |
H3 | 0.7852 | 0.1668 | 1.0967 | 0.0541 | |
H4 | 1.0849 | 0.1276 | 0.8118 | 0.0748 | |
H5 | 0.6725 | −0.3463 | 0.4790 | 0.0644 | |
H6 | 0.5806 | −0.2069 | 0.3328 | 0.0733 | |
H7 | 0.5559 | 0.0160 | 0.3589 | 0.0678 | |
H8 | 0.8210 | −0.4484 | 0.7525 | 0.0748 | |
H9 | 0.8730 | 0.4925 | 0.8990 | 0.0748 | |
H10 | 0.9642 | 0.4709 | 0.8818 | 0.0748 | |
H11 | 1.1573 | 0.1971 | 0.7223 | 0.0748 | |
H12 | 1.1108 | 0.0370 | 0.7069 | 0.0748 | |
H13 | 0.9851 | 0.0204 | 0.4419 | 0.0748 | |
H14 | 0.9683 | 0.1086 | 0.3174 | 0.0748 | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Zn1 | 0.0425 (2) | 0.0522 (2) | 0.0322 (2) | −0.0028 (1) | 0.0124 (1) | −0.0055 (1) |
O1 | 0.043 (1) | 0.063 (1) | 0.046 (1) | −0.0064 (10) | 0.0229 (9) | −0.007 (1) |
O2 | 0.041 (1) | 0.060 (1) | 0.070 (1) | −0.0106 (10) | 0.029 (1) | −0.010 (1) |
O3 | 0.047 (1) | 0.069 (1) | 0.049 (1) | −0.0063 (10) | 0.0288 (10) | −0.003 (1) |
O4 | 0.0386 (10) | 0.067 (1) | 0.040 (1) | −0.0126 (10) | 0.0160 (8) | −0.0096 (9) |
O5 | 0.054 (1) | 0.050 (1) | 0.034 (1) | 0.0037 (9) | 0.0109 (9) | 0.0001 (9) |
O6 | 0.070 (1) | 0.049 (1) | 0.052 (1) | 0.012 (1) | 0.027 (1) | −0.001 (1) |
O7 | 0.085 (2) | 0.084 (2) | 0.078 (2) | 0.031 (2) | 0.034 (2) | 0.043 (2) |
O8 | 0.055 (1) | 0.048 (1) | 0.060 (1) | 0.0057 (10) | 0.025 (1) | 0.005 (1) |
O9 | 0.046 (1) | 0.074 (2) | 0.054 (1) | 0.014 (1) | 0.020 (1) | 0.010 (1) |
O10 | 0.077 (2) | 0.059 (1) | 0.097 (2) | −0.005 (1) | 0.061 (1) | −0.005 (1) |
O11 | 0.197 (6) | 0.190 (5) | 0.46 (1) | −0.077 (5) | 0.141 (7) | −0.205 (7) |
N1 | 0.034 (1) | 0.034 (1) | 0.033 (1) | −0.0006 (9) | 0.0123 (8) | −0.0012 (9) |
N2 | 0.029 (1) | 0.051 (1) | 0.028 (1) | 0.0000 (10) | 0.0110 (8) | 0.0031 (10) |
C1 | 0.033 (1) | 0.032 (1) | 0.040 (1) | 0.000 (1) | 0.011 (1) | 0.001 (1) |
C2 | 0.036 (1) | 0.039 (2) | 0.048 (2) | −0.004 (1) | 0.010 (1) | −0.003 (1) |
C3 | 0.054 (2) | 0.051 (2) | 0.039 (1) | −0.006 (1) | 0.013 (1) | −0.015 (1) |
C4 | 0.049 (2) | 0.045 (2) | 0.041 (1) | −0.001 (1) | 0.019 (1) | −0.005 (1) |
C5 | 0.035 (1) | 0.035 (1) | 0.036 (1) | 0.001 (1) | 0.015 (1) | 0.001 (1) |
C6 | 0.035 (1) | 0.037 (1) | 0.046 (2) | 0.002 (1) | 0.017 (1) | 0.001 (1) |
C7 | 0.036 (1) | 0.043 (1) | 0.041 (1) | 0.000 (1) | 0.016 (1) | 0.001 (1) |
C8 | 0.032 (1) | 0.053 (2) | 0.035 (1) | −0.003 (1) | 0.015 (1) | −0.005 (1) |
C9 | 0.048 (2) | 0.071 (2) | 0.042 (2) | −0.003 (2) | 0.020 (1) | −0.012 (1) |
C10 | 0.055 (2) | 0.094 (3) | 0.034 (2) | −0.006 (2) | 0.018 (1) | −0.014 (2) |
C11 | 0.036 (1) | 0.098 (3) | 0.031 (1) | 0.000 (2) | 0.011 (1) | 0.014 (2) |
C12 | 0.029 (1) | 0.065 (2) | 0.035 (1) | 0.003 (1) | 0.014 (1) | 0.012 (1) |
C13 | 0.034 (1) | 0.049 (2) | 0.041 (1) | 0.002 (1) | 0.016 (1) | 0.001 (1) |
C14 | 0.038 (2) | 0.066 (2) | 0.054 (2) | 0.010 (1) | 0.022 (1) | 0.021 (2) |
Geometric parameters (Å, º) top
Zn1—O1 | 2.350 (2) | N1—C5 | 1.327 (3) |
Zn1—O4 | 2.070 (2) | N2—C8 | 1.331 (4) |
Zn1—O5 | 2.321 (2) | N2—C12 | 1.334 (3) |
Zn1—O8 | 2.115 (2) | C1—C2 | 1.376 (4) |
Zn1—N1 | 2.011 (2) | C1—C6 | 1.504 (4) |
Zn1—N2 | 2.007 (2) | C2—C3 | 1.379 (4) |
O1—C6 | 1.230 (3) | C3—C4 | 1.387 (4) |
O2—C6 | 1.287 (3) | C4—C5 | 1.381 (4) |
O3—C7 | 1.235 (3) | C5—C7 | 1.525 (4) |
O4—C7 | 1.264 (3) | C8—C9 | 1.385 (4) |
O5—C13 | 1.224 (3) | C8—C13 | 1.499 (4) |
O6—C13 | 1.286 (3) | C9—C10 | 1.378 (5) |
O7—C14 | 1.223 (4) | C10—C11 | 1.365 (5) |
O8—C14 | 1.277 (4) | C11—C12 | 1.397 (4) |
N1—C1 | 1.334 (3) | C12—C14 | 1.506 (4) |
| | | |
O1—Zn1—O4 | 152.33 (8) | C1—C2—C3 | 118.3 (2) |
O1—Zn1—O5 | 89.54 (8) | C2—C3—C4 | 120.0 (3) |
O1—Zn1—O8 | 91.69 (8) | C3—C4—C5 | 118.2 (3) |
O1—Zn1—N1 | 73.21 (8) | N1—C5—C4 | 121.4 (2) |
O1—Zn1—N2 | 93.44 (8) | N1—C5—C7 | 113.5 (2) |
O4—Zn1—O5 | 94.18 (8) | C4—C5—C7 | 125.0 (2) |
O4—Zn1—O8 | 97.39 (8) | O1—C6—O2 | 125.7 (3) |
O4—Zn1—N1 | 79.22 (8) | O1—C6—C1 | 119.0 (2) |
O4—Zn1—N2 | 113.95 (8) | O2—C6—C1 | 115.3 (2) |
O5—Zn1—O8 | 152.37 (8) | O3—C7—O4 | 126.1 (3) |
O5—Zn1—N1 | 102.60 (8) | O3—C7—C5 | 118.3 (2) |
O5—Zn1—N2 | 74.01 (8) | O4—C7—C5 | 115.5 (2) |
O8—Zn1—N1 | 104.18 (8) | N2—C8—C9 | 121.4 (3) |
O8—Zn1—N2 | 78.36 (9) | N2—C8—C13 | 112.5 (2) |
N1—Zn1—N2 | 166.39 (8) | C9—C8—C13 | 126.1 (3) |
Zn1—O1—C6 | 111.8 (2) | C8—C9—C10 | 118.2 (3) |
Zn1—O4—C7 | 115.5 (2) | C9—C10—C11 | 120.3 (3) |
Zn1—O5—C13 | 111.5 (2) | C10—C11—C12 | 119.0 (3) |
Zn1—O8—C14 | 115.1 (2) | N2—C12—C11 | 120.2 (3) |
Zn1—N1—C1 | 123.2 (2) | N2—C12—C14 | 114.7 (2) |
Zn1—N1—C5 | 116.0 (2) | C11—C12—C14 | 125.1 (3) |
C1—N1—C5 | 120.5 (2) | O5—C13—O6 | 126.1 (3) |
Zn1—N2—C8 | 122.4 (2) | O5—C13—C8 | 119.5 (3) |
Zn1—N2—C12 | 116.7 (2) | O6—C13—C8 | 114.3 (2) |
C8—N2—C12 | 120.9 (2) | O7—C14—O8 | 127.3 (3) |
N1—C1—C2 | 121.6 (2) | O7—C14—C12 | 117.6 (3) |
N1—C1—C6 | 112.5 (2) | O8—C14—C12 | 115.1 (2) |
C2—C1—C6 | 125.9 (2) | | |
| | | |
Zn1—O1—C6—O2 | −177.9 (2) | O1—C6—C1—N1 | 1.1 (3) |
O2—C6—C1—C2 | 2.0 (4) | O7—C14—C12—N2 | −177.8 (3) |
Zn1—O1—C6—C1 | 2.8 (3) | O1—C6—C1—C2 | −178.7 (3) |
O3—C7—C5—N1 | 175.1 (2) | O7—C14—C12—C11 | 2.8 (4) |
Zn1—O4—C7—O3 | −177.3 (2) | O2—C6—C1—N1 | −178.3 (2) |
O3—C7—C5—C4 | −5.2 (4) | O8—Zn1—O1—C6 | 100.2 (2) |
Zn1—O4—C7—C5 | 2.9 (3) | O8—Zn1—O4—C7 | −103.5 (2) |
O4—Zn1—O1—C6 | −9.3 (3) | C1—C2—C3—C4 | −0.5 (4) |
Zn1—O5—C13—O6 | 177.2 (2) | O8—Zn1—O5—C13 | 1.2 (3) |
O4—Zn1—O5—C13 | 115.9 (2) | C2—C1—N1—C5 | −0.1 (4) |
Zn1—O5—C13—C8 | −3.5 (3) | O8—Zn1—N1—C1 | −82.3 (2) |
O4—Zn1—O8—C14 | −111.0 (2) | C2—C3—C4—C5 | 0.3 (5) |
Zn1—O8—C14—O7 | 176.7 (3) | O8—Zn1—N1—C5 | 92.3 (2) |
O4—Zn1—N1—C1 | −177.2 (2) | C3—C2—C1—C6 | −179.9 (3) |
Zn1—O8—C14—C12 | −2.3 (3) | O8—Zn1—N2—C8 | 179.2 (2) |
O4—Zn1—N1—C5 | −2.7 (2) | C3—C4—C5—C7 | −179.6 (3) |
Zn1—N1—C1—C2 | 174.3 (2) | O8—Zn1—N2—C12 | −1.2 (2) |
O4—Zn1—N2—C8 | −87.8 (2) | C5—N1—C1—C6 | −179.8 (2) |
Zn1—N1—C1—C6 | −5.5 (3) | O8—C14—C12—N2 | 1.3 (4) |
O4—Zn1—N2—C12 | 91.7 (2) | C8—N2—C12—C11 | −0.5 (4) |
Zn1—N1—C5—C4 | −174.9 (2) | O8—C14—C12—C11 | −178.1 (3) |
O4—C7—C5—N1 | −5.1 (3) | C8—N2—C12—C14 | −179.9 (2) |
Zn1—N1—C5—C7 | 4.8 (3) | N1—Zn1—O1—C6 | −4.1 (2) |
O4—C7—C5—C4 | 174.5 (3) | C8—C9—C10—C11 | 0.8 (5) |
Zn1—N2—C8—C9 | −179.4 (2) | N1—Zn1—O4—C7 | −0.4 (2) |
O5—Zn1—O1—C6 | −107.4 (2) | C9—C8—N2—C12 | 1.0 (4) |
Zn1—N2—C8—C13 | −1.1 (3) | N1—Zn1—O5—C13 | −164.2 (2) |
O5—Zn1—O4—C7 | 101.7 (2) | C9—C10—C11—C12 | −0.3 (5) |
Zn1—N2—C12—C11 | 179.9 (2) | N1—Zn1—O8—C14 | 168.3 (2) |
O5—Zn1—O8—C14 | 2.9 (3) | C10—C9—C8—C13 | −179.2 (3) |
Zn1—N2—C12—C14 | 0.5 (3) | N1—Zn1—N2—C8 | 76.9 (4) |
O5—Zn1—N1—C1 | 90.8 (2) | C10—C11—C12—C14 | 179.5 (3) |
O1—Zn1—O4—C7 | 4.7 (3) | N1—Zn1—N2—C12 | −103.5 (4) |
O5—Zn1—N1—C5 | −94.6 (2) | C12—N2—C8—C13 | 179.3 (2) |
O1—Zn1—O5—C13 | −91.6 (2) | N1—C1—C2—C3 | 0.4 (4) |
O5—Zn1—N2—C8 | −0.4 (2) | N1—C5—C4—C3 | 0.1 (4) |
O1—Zn1—O8—C14 | 95.2 (2) | N2—Zn1—O1—C6 | 178.6 (2) |
O5—Zn1—N2—C12 | 179.2 (2) | N2—Zn1—O4—C7 | 176.0 (2) |
O1—Zn1—N1—C1 | 5.2 (2) | N2—Zn1—O5—C13 | 2.2 (2) |
O5—C13—C8—N2 | 3.3 (4) | N2—Zn1—O8—C14 | 2.0 (2) |
O1—Zn1—N1—C5 | 179.8 (2) | N2—Zn1—N1—C1 | 16.9 (5) |
O5—C13—C8—C9 | −178.5 (3) | N2—Zn1—N1—C5 | −168.5 (3) |
O1—Zn1—N2—C8 | 88.1 (2) | N2—C8—C9—C10 | −1.1 (4) |
O6—C13—C8—N2 | −177.3 (2) | N2—C12—C11—C10 | 0.2 (4) |
O1—Zn1—N2—C12 | −92.3 (2) | C1—N1—C5—C4 | −0.2 (4) |
O6—C13—C8—C9 | 0.9 (4) | C1—N1—C5—C7 | 179.5 (2) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H4···O10 | 1.08 | 1.40 | 2.462 (4) | 166 |
O6—H8···O9i | 1.03 | 1.45 | 2.483 (2) | 174 |
O9—H9···O3ii | 0.87 | 1.93 | 2.762 (3) | 160 |
O9—H10···O3iii | 0.92 | 1.80 | 2.719 (3) | 175 |
O10—H11···O8iii | 1.02 | 1.69 | 2.679 (3) | 164 |
O10—H12···O11iv | 0.90 | 1.84 | 2.623 (6) | 145 |
O11—H13···O11iv | 0.93 | 2.39 | 3.28 (2) | 159 |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y+1/2, −z+2; (iii) x+1/2, −y+1/2, z; (iv) −x+2, −y, −z+1. |
Experimental details
| (I) | (II) |
Crystal data |
Chemical formula | [Cu(C7H4NO4)2]·H2O | [Zn(C7H4NO4)2]·3H2O |
Mr | 413.80 | 451.65 |
Crystal system, space group | Orthorhombic, Pnna | Monoclinic, P21/a |
Temperature (K) | 296 | 296 |
a, b, c (Å) | 7.903 (4), 11.068 (4), 17.053 (3) | 13.765 (2), 10.052 (2), 14.060 (2) |
α, β, γ (°) | 90, 90, 90 | 90, 116.554 (8), 90 |
V (Å3) | 1491 (1) | 1740.3 (4) |
Z | 4 | 4 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 1.52 | 1.48 |
Crystal size (mm) | 0.40 × 0.10 × 0.10 | 0.50 × 0.15 × 0.15 |
|
Data collection |
Diffractometer | Rigaku AFC5R diffractometer | Rigaku AFC5R diffractometer |
Absorption correction | ψ scan (North et al., 1968) | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.784, 0.859 | 0.755, 0.801 |
No. of measured, independent and observed [I > 0.00σ(I)] reflections | 1727, 1727, 1724 | 4392, 3991, 3991 |
Rint | 0 | 0.017 |
(sin θ/λ)max (Å−1) | 0.650 | 0.650 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.081, 0.129, 1.03 | 0.058, 0.114, 1.36 |
No. of reflections | 1724 | 3991 |
No. of parameters | 121 | 253 |
No. of restraints | ? | ? |
H-atom treatment | H-atom parameters not refined | H-atom parameters not refined |
Δρmax, Δρmin (e Å−3) | 1.06, −0.75 | 0.81, −0.63 |
Selected geometric parameters (Å, º) for (I) topCu1—O2 | 2.019 (3) | Cu1—N1 | 1.914 (4) |
Cu1—O3 | 2.427 (3) | Cu1—N2 | 2.009 (4) |
| | | |
O2—Cu1—O3 | 95.3 (1) | O3i—Cu1—N1 | 105.50 (7) |
O2i—Cu1—N1 | 80.10 (8) | C5—C6—C7 | 118.6 (4) |
O3—Cu1—N2 | 74.50 (7) | | |
Symmetry code: (i) −x+3/2, −y, z. |
Hydrogen-bond geometry (Å, º) for (I) top
D—H···A | D—H | H···A | D···A | D—H···A |
O4—H5···O5ii | 1.03 | 1.61 | 2.621 (4) | 168 |
O5···O2 | . | . | 2.638 (4) | . |
Symmetry code: (ii) x+1, y, z. |
Selected geometric parameters (Å, º) for (II) topZn1—O1 | 2.350 (2) | Zn1—O8 | 2.115 (2) |
Zn1—O4 | 2.070 (2) | Zn1—N1 | 2.011 (2) |
Zn1—O5 | 2.321 (2) | Zn1—N2 | 2.007 (2) |
| | | |
O1—Zn1—O4 | 152.33 (8) | O4—Zn1—N2 | 113.95 (8) |
O1—Zn1—O5 | 89.54 (8) | O5—Zn1—O8 | 152.37 (8) |
O1—Zn1—O8 | 91.69 (8) | O5—Zn1—N1 | 102.60 (8) |
O1—Zn1—N1 | 73.21 (8) | O5—Zn1—N2 | 74.01 (8) |
O1—Zn1—N2 | 93.44 (8) | O8—Zn1—N1 | 104.18 (8) |
O4—Zn1—O5 | 94.18 (8) | O8—Zn1—N2 | 78.36 (9) |
O4—Zn1—O8 | 97.39 (8) | N1—Zn1—N2 | 166.39 (8) |
O4—Zn1—N1 | 79.22 (8) | | |
Hydrogen-bond geometry (Å, º) for (II) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H4···O10 | 1.08 | 1.399 | 2.462 (4) | 166 |
O6—H8···O9i | 1.03 | 1.451 | 2.483 (2) | 174 |
O9—H9···O3ii | 0.87 | 1.927 | 2.762 (3) | 160 |
O9—H10···O3iii | 0.92 | 1.799 | 2.719 (3) | 175 |
O10—H11···O8iii | 1.02 | 1.685 | 2.679 (3) | 164 |
O10—H12···O11iv | 0.90 | 1.836 | 2.623 (6) | 145 |
O11—H13···O11iv | 0.93 | 2.387 | 3.28 (2) | 159 |
Symmetry codes: (i) x, y−1, z; (ii) −x+3/2, y+1/2, −z+2; (iii) x+1/2, −y+1/2, z; (iv) −x+2, −y, −z+1. |
Pyridine-2,6-dicarboxylic acid (dipicolinic acid), (I), is a compound produced by bacterial spores (Powell, 1953) which contain 5–15% of it on a dry weight basis (Church & Halvorson, 1959). It has been considered as the central component for the high heat resistance of bacterial spores, based on the hypothesis that the metal chelates of pyridine-2,6-dicarboxylic acid with divalent metal ions within the spores construct a stabilizing structure analogous to bone substance in higher animals (Chung et al., 1971). Many crystal structures of the chelate compounds of pyridine-2,6-dicarboxylic acid with divalent ions such as CaII (Strahs & Dickerson, 1968), AgII (Drew et al., 1969, 1970), TiII (Schwarzenbach, 1970), SrII (Palmer et al., 1972), NiII (Quaglieri et al., 1972), FeII (Laié et al., 1995a,b,c; Laié, Gourdon, Launay & Tuchagues, 1995) and CuII (Quaglieri et al., 1972) have been determined. In order to clarify the coordination modes of chelate compounds of pyridine-2,6-dicarboxylic acid with biologically important transition metal ions, we have analyzed 1:2 complexes of transition metal ions, CuII and ZnII with pyridine-2,6-dicarboxylic acid (compounds (I) and (II), respectively). \sch
In (I), the complex is located on a twofold axis of symmetry which passes through C3, N1, Cu1, N2 and C7 (Fig. 1) and contains two ligands with different degrees of deprotonation, one being neutral and the other dianionic. The CuII ion is bonded to the nitrogen [Cu1—N1 1.914 (4) Å] and two crystallographically equivalent, negatively charged O atoms [Cu1—O2 2.019 (3) Å] of the dianionic ligand. It is also bonded, although less strongly, to the N atom [Cu1—N2 2.009 (4) Å] and two crystallographically equivalent ketonic O atoms [Cu1—O3 2.427 (3) Å] of the neutral ligand. In the (1:1) complex of CuII and pyridine-2,6-dicarboxylic acid (Chastain, 1965), the Cu—N distance of is 1.91 Å and that of CuII—O is 2.03 Å, which are comparable to the values for the doubly ionized ligand observed in this study. The bond angle of C1—C4—O2 113.2 (3)° around the carboxylato C atom of the dianionic ligand is significantly narrower than the corresponding angle C5—C8—O3 of 121.9 (4)° in the neutral ligand. These differences may depend on the electrostatic attractive force between the positively charged CuII ion and negatively charged O atoms of the dianionic ligand. The carboxylato groups of the dianionic ligand and the carboxyl groups of the neutral ligand lie almost in the plane of the corresponding pyridine ring as indicated by the torsion angles O2—C4—C1—N1 [0.0 (5)°] and O3—C8—C5—N2 [-6.7 (6)°].
In contrast to (I), (II) contains two identical, monoanionic ligands. The ZnII ion is bonded to the pyridyl N atoms [Zn1—N1 2.011 (2), Zn1—N2 2.007 (2) Å], the two carboxylato O atoms [Zn1—O4 2.070 (2), Zn1—O8 2.115 (2) Å] and the two ketonic O atoms of the carboxyl groups [Zn1—O1 2.350 (2), Zn1—O5 2.321 (2) Å]. The bond angles C5—C7—O4 [115.5 (2)°] and C12—C14—O8 [115.1 (2)°] around the carboxylato C atoms are somewhat narrower than the corresponding angles around the carboxyl C atoms C1—C6—O1 [119.0 (2)°] and C8—C13—O5 [119.5 (3)°]. These differences may also depend on the electrostatic attractive force between the positively charged ZnII ion and negatively charged O atoms of the anionic carboxylato groups as observed in the CuII complex. The carboxyl and carboxylato groups of the ligand molecules lie almost in the plane of the corresponding plane, as indicated by torsion angles N1—C5—C7—O3 175.1 (2), N1—C1—C6—O1 1.1 (3), N2—C8—C13—O5 3.3 (4) and N2—C12—C14—O7 - 177.8 (3)°.
The overall coordination modes about the CuII and ZnII ions are similar with a distorted octahedral (trans meridional) geometry. Both metal ions are six-coordinate, and are bonded similarly to the two N and four O atoms from the two terdentate ligand molecules, which are oriented nearly perpendicular to each other. However, the copper(II) complex contains two different ligands, one neutral and one dianionic, whereas the zinc(II) complex contains two identical monoanionic ligands. This different behaviour of the ligands may be a manifestation of the Jahn-Teller effect, which is exhibited by copper(II) with its d9 electron configuration, but not by zinc(II) with d10.
In all of the crystal structures of 1:2 chelate complexes with transition metal ions, the ligand adopts an almost planar planar conformation, and acts as the terdentate ligand molecule in which the central metal ion is bonded to two N and four O atoms from two ligand molecules. The results of this study indicate that pyridine-2,6-dicarboxylic acid is a potential captor for transition metals in bacterial spores and its likely coordination mode in such a role. This planar conformation is also observed in the free ligand. (Takusagawa et al., 1973) is also manifested in the chelate compounds.
In the crystal structures of both (I) and (II), molecules of the metal complex are connected by O—H···O type hydrogen bonds to the uncoordinated water molecules (Tables 2 and 4). Stacking interactions between pyridine rings of the dianionic ligands are observed in the copper(II) complex, but not in the zinc(II) complex.