Acta Cryst. (2009). E65, m637 [ doi:10.1107/S1600536809016791 ]
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2N3,O4)copper(II)In the title compound, [Cu(C6H5N2O4)2], the copper(II) atom lies on an inversion centre and is in an N2O2 four-coordinate environment with a nearly regular square-planar geometry. An extended network of intramolecular O-H
O and intermolecular N-HO and C-HO hydrogen bonds stabilizes the crystal structure.
Blue single crystals of title compound were obtained by hydrothermal treatment of CuCl2 (1 mmol), 2-methyl-1H-imidazole-4,5-dicarboxylic acid (1 mmol) and water (5 ml) over 2 days at 388 K. Yield: 61% (based on CuCl2).
The hydroxyl H atom was located from a difference Fourier map but not refined [Uiso(H)=1.5Ueq(O)]. All other H atoms were placed at calculated positions and refined as riding, with C—H = 0.96 Å, N—H = 0.86 Å, and with Uiso(H)=1.5Ueq(C) and Uiso(H)=1.2Ueq(N)
Data collection: CrystalClear (Rigaku, 2005); cell refinement: CrystalClear (Rigaku, 2005); data reduction: CrystalClear (Rigaku, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL/PC (Sheldrick, 2008); software used to prepare material for publication: SHELXTL/PC (Sheldrick, 2008).
![[Figure 1]](./rz2318fig1thm.gif)
| Fig. 1. The molecular structure of the title compound, showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Atoms labelled with suffix A are generated by the symmetry operation (-x,1 - y,-z). |
![[Figure 2]](./rz2318fig2thm.gif)
| Fig. 2. Packing diagram of the title compound viewed along the a axis. Intermolecular hydrogen bonds are shown as dashed lines. |
| [Cu(C6H5N2O4)2] | F000 = 406 |
| Mr = 401.78 | Dx = 1.893 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 2111 reflections |
| a = 7.3780 (17) Å | θ = 3.1–27.5º |
| b = 7.575 (2) Å | µ = 1.61 mm−1 |
| c = 12.863 (3) Å | T = 292 K |
| β = 101.287 (13)º | Prism, blue |
| V = 705.0 (3) Å3 | 0.30 × 0.25 × 0.20 mm |
| Z = 2 |
| Rigaku SCXmini diffractometer | 1609 independent reflections |
| Radiation source: fine-focus sealed tube | 1472 reflections with I > 2σ(I) |
| Monochromator: graphite | Rint = 0.019 |
| Detector resolution: 13.6612 pixels mm-1 | θmax = 27.5º |
| T = 292 K | θmin = 3.1º |
| ω scans | h = −9→9 |
| Absorption correction: multi-scan (CrystalClear; Rigaku, 2005) | k = −9→8 |
| Tmin = 0.638, Tmax = 0.727 | l = −16→16 |
| 5198 measured reflections |
| 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)] = 0.030 | H-atom parameters constrained |
| wR(F2) = 0.084 | w = 1/[σ2(Fo2) + (0.0506P)2 + 0.3299P] where P = (Fo2 + 2Fc2)/3 |
| S = 1.07 | (Δ/σ)max < 0.001 |
| 1609 reflections | Δρmax = 0.28 e Å−3 |
| 116 parameters | Δρmin = −0.66 e Å−3 |
| Primary atom site location: structure-invariant direct methods | Extinction correction: none |
| [Cu(C6H5N2O4)2] | V = 705.0 (3) Å3 |
| Mr = 401.78 | Z = 2 |
| Monoclinic, P21/n | Mo Kα |
| a = 7.3780 (17) Å | µ = 1.61 mm−1 |
| b = 7.575 (2) Å | T = 292 K |
| c = 12.863 (3) Å | 0.30 × 0.25 × 0.20 mm |
| β = 101.287 (13)º |
| Rigaku SCXmini diffractometer | 1609 independent reflections |
| Absorption correction: multi-scan (CrystalClear; Rigaku, 2005) | 1472 reflections with I > 2σ(I) |
| Tmin = 0.638, Tmax = 0.727 | Rint = 0.019 |
| 5198 measured reflections |
| R[F2 > 2σ(F2)] = 0.030 | 116 parameters |
| wR(F2) = 0.084 | H-atom parameters constrained |
| S = 1.07 | Δρmax = 0.28 e Å−3 |
| 1609 reflections | Δρmin = −0.66 e Å−3 |
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 | ||
| Cu1 | 0.0000 | 0.5000 | 0.0000 | 0.02591 (14) | |
| C1 | 0.3363 (3) | 0.5580 (3) | 0.26068 (15) | 0.0322 (4) | |
| H1A | 0.4201 | 0.6562 | 0.2725 | 0.048* | |
| H1B | 0.3575 | 0.4828 | 0.3219 | 0.048* | |
| H1C | 0.2114 | 0.6005 | 0.2482 | 0.048* | |
| C2 | 0.3672 (2) | 0.4571 (3) | 0.16737 (14) | 0.0222 (4) | |
| C3 | 0.3316 (2) | 0.3269 (2) | 0.01393 (13) | 0.0211 (3) | |
| C4 | 0.5089 (2) | 0.2949 (2) | 0.06414 (13) | 0.0221 (4) | |
| C5 | 0.6677 (3) | 0.2144 (3) | 0.02784 (15) | 0.0267 (4) | |
| C6 | 0.2221 (2) | 0.2795 (3) | −0.09127 (14) | 0.0241 (4) | |
| N1 | 0.24525 (19) | 0.4288 (2) | 0.07763 (11) | 0.0216 (3) | |
| N2 | 0.5278 (2) | 0.3781 (2) | 0.16036 (11) | 0.0226 (3) | |
| H2A | 0.6266 | 0.3796 | 0.2086 | 0.027* | |
| O1 | 0.06229 (18) | 0.3460 (2) | −0.11265 (10) | 0.0328 (3) | |
| O2 | 0.29058 (19) | 0.1816 (2) | −0.15194 (10) | 0.0325 (3) | |
| O3 | 0.6306 (2) | 0.1289 (2) | −0.06309 (11) | 0.0362 (4) | |
| H3A | 0.5102 | 0.1358 | −0.0972 | 0.054* | |
| O4 | 0.8232 (2) | 0.2331 (2) | 0.07777 (12) | 0.0396 (4) |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| Cu1 | 0.01512 (18) | 0.0374 (2) | 0.02196 (19) | 0.00490 (12) | −0.00433 (12) | −0.00595 (12) |
| C1 | 0.0263 (10) | 0.0449 (12) | 0.0231 (9) | 0.0015 (9) | −0.0008 (7) | −0.0072 (8) |
| C2 | 0.0190 (8) | 0.0268 (9) | 0.0190 (8) | −0.0015 (7) | −0.0004 (6) | 0.0029 (7) |
| C3 | 0.0172 (8) | 0.0242 (9) | 0.0205 (8) | −0.0010 (6) | 0.0000 (6) | 0.0001 (6) |
| C4 | 0.0189 (8) | 0.0240 (9) | 0.0217 (8) | 0.0008 (7) | −0.0001 (6) | 0.0029 (7) |
| C5 | 0.0210 (8) | 0.0291 (10) | 0.0294 (9) | 0.0036 (7) | 0.0034 (7) | 0.0054 (7) |
| C6 | 0.0201 (8) | 0.0304 (10) | 0.0196 (8) | −0.0010 (7) | −0.0013 (6) | −0.0023 (7) |
| N1 | 0.0165 (7) | 0.0275 (8) | 0.0190 (7) | 0.0003 (6) | −0.0013 (5) | −0.0017 (6) |
| N2 | 0.0172 (7) | 0.0294 (8) | 0.0184 (7) | 0.0003 (6) | −0.0038 (5) | 0.0025 (6) |
| O1 | 0.0206 (7) | 0.0470 (9) | 0.0263 (7) | 0.0062 (6) | −0.0065 (5) | −0.0103 (6) |
| O2 | 0.0252 (7) | 0.0441 (8) | 0.0256 (7) | 0.0036 (6) | −0.0010 (5) | −0.0113 (6) |
| O3 | 0.0273 (7) | 0.0465 (9) | 0.0342 (8) | 0.0079 (6) | 0.0047 (6) | −0.0077 (6) |
| O4 | 0.0196 (7) | 0.0569 (10) | 0.0390 (8) | 0.0073 (7) | −0.0025 (6) | 0.0007 (7) |
| Cu1—N1 | 1.9633 (15) | C3—N1 | 1.370 (2) |
| Cu1—N1i | 1.9633 (15) | C3—C6 | 1.478 (2) |
| Cu1—O1 | 1.9830 (14) | C4—N2 | 1.372 (2) |
| Cu1—O1i | 1.9830 (14) | C4—C5 | 1.475 (3) |
| C1—C2 | 1.478 (3) | C5—O4 | 1.208 (2) |
| C1—H1A | 0.9600 | C5—O3 | 1.318 (2) |
| C1—H1B | 0.9600 | C6—O2 | 1.252 (2) |
| C1—H1C | 0.9600 | C6—O1 | 1.262 (2) |
| C2—N1 | 1.335 (2) | N2—H2A | 0.8600 |
| C2—N2 | 1.346 (2) | O3—H3A | 0.9117 |
| C3—C4 | 1.363 (2) | ||
| N1—Cu1—N1i | 180.0 | C3—C4—N2 | 105.31 (15) |
| N1—Cu1—O1 | 83.56 (6) | C3—C4—C5 | 132.21 (17) |
| N1i—Cu1—O1 | 96.44 (6) | N2—C4—C5 | 121.95 (16) |
| N1—Cu1—O1i | 96.44 (6) | O4—C5—O3 | 122.69 (18) |
| N1i—Cu1—O1i | 83.56 (6) | O4—C5—C4 | 120.88 (18) |
| O1—Cu1—O1i | 180.00 (5) | O3—C5—C4 | 116.37 (16) |
| C2—C1—H1A | 109.5 | O2—C6—O1 | 125.06 (16) |
| C2—C1—H1B | 109.5 | O2—C6—C3 | 119.96 (16) |
| H1A—C1—H1B | 109.5 | O1—C6—C3 | 114.98 (16) |
| C2—C1—H1C | 109.5 | C2—N1—C3 | 107.11 (14) |
| H1A—C1—H1C | 109.5 | C2—N1—Cu1 | 142.56 (13) |
| H1B—C1—H1C | 109.5 | C3—N1—Cu1 | 109.91 (11) |
| N1—C2—N2 | 108.89 (16) | C2—N2—C4 | 109.26 (14) |
| N1—C2—C1 | 126.93 (17) | C2—N2—H2A | 125.4 |
| N2—C2—C1 | 124.18 (16) | C4—N2—H2A | 125.4 |
| C4—C3—N1 | 109.42 (15) | C6—O1—Cu1 | 114.58 (11) |
| C4—C3—C6 | 133.84 (17) | C5—O3—H3A | 114.3 |
| N1—C3—C6 | 116.72 (15) | ||
| N1—C3—C4—N2 | 0.6 (2) | C4—C3—N1—C2 | −1.1 (2) |
| C6—C3—C4—N2 | 178.80 (19) | C6—C3—N1—C2 | −179.58 (16) |
| N1—C3—C4—C5 | −170.85 (19) | C4—C3—N1—Cu1 | 173.21 (12) |
| C6—C3—C4—C5 | 7.3 (4) | C6—C3—N1—Cu1 | −5.3 (2) |
| C3—C4—C5—O4 | 163.5 (2) | O1—Cu1—N1—C2 | 175.3 (2) |
| N2—C4—C5—O4 | −6.8 (3) | O1i—Cu1—N1—C2 | −4.7 (2) |
| C3—C4—C5—O3 | −13.6 (3) | O1—Cu1—N1—C3 | 4.36 (12) |
| N2—C4—C5—O3 | 176.04 (17) | O1i—Cu1—N1—C3 | −175.64 (12) |
| C4—C3—C6—O2 | 4.4 (3) | N1—C2—N2—C4 | −0.7 (2) |
| N1—C3—C6—O2 | −177.58 (17) | C1—C2—N2—C4 | 179.41 (18) |
| C4—C3—C6—O1 | −174.8 (2) | C3—C4—N2—C2 | 0.0 (2) |
| N1—C3—C6—O1 | 3.2 (3) | C5—C4—N2—C2 | 172.59 (17) |
| N2—C2—N1—C3 | 1.1 (2) | O2—C6—O1—Cu1 | −178.45 (16) |
| C1—C2—N1—C3 | −179.04 (19) | C3—C6—O1—Cu1 | 0.7 (2) |
| N2—C2—N1—Cu1 | −170.06 (15) | N1—Cu1—O1—C6 | −2.89 (14) |
| C1—C2—N1—Cu1 | 9.8 (4) | N1i—Cu1—O1—C6 | 177.11 (14) |
| Symmetry codes: (i) −x, −y+1, −z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N2—H2A···O2ii | 0.86 | 2.01 | 2.822 (2) | 157 |
| C1—H1A···O4iii | 0.96 | 2.49 | 3.217 (2) | 132 |
| C1—H1B···O3iv | 0.96 | 2.58 | 3.285 (3) | 130 |
| C1—H1C···O1i | 0.96 | 2.43 | 3.258 (3) | 144 |
| O3—H3A···O2 | 0.91 | 1.67 | 2.576 (2) | 171 |
| Symmetry codes: (ii) x+1/2, −y+1/2, z+1/2; (iii) −x+3/2, y+1/2, −z+1/2; (iv) x−1/2, −y+1/2, z+1/2; (i) −x, −y+1, −z. |
| D—H···A | D—H | H···A | D···A | D—H···A |
| N2—H2A···O2i | 0.86 | 2.01 | 2.822 (2) | 157 |
| C1—H1A···O4ii | 0.96 | 2.49 | 3.217 (2) | 132 |
| C1—H1B···O3iii | 0.96 | 2.58 | 3.285 (3) | 130 |
| C1—H1C···O1iv | 0.96 | 2.43 | 3.258 (3) | 144 |
| O3—H3A···O2 | 0.91 | 1.67 | 2.576 (2) | 171 |
| Symmetry codes: (i) x+1/2, −y+1/2, z+1/2; (ii) −x+3/2, y+1/2, −z+1/2; (iii) x−1/2, −y+1/2, z+1/2; (iv) −x, −y+1, −z. |
The work was supported by National Basic Public Welfare Research Program of China (IMBF-20060403).
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The study of metal complexes with N-heterocyclic carboxylic acids has been given considerable attention ((Nie et al., 2007; Liang et al., 2002; Net et al., 1989; Zeng et al., 2008). In this paper, we report on the synthesis and structure of the title compound, which was obtained by the hydrothermal reaction of CuCl2 with 2-methyl-1H-imidazole-4,5-dicarboxylic acid.
Figure 1 shows the monomeric complex molecule along with the atom-labelling scheme. The copper(II) metal lies on an inversion centre and is in an N2O2 four-coordinate environment with a regular square-planar geometry. The Cu—O distance is 1.9633 (15) Å and the Cu—N distance is 1.9830 (14) Å. The five-membered chelating ring assumes an approximately planar conformation (maximum deviation -0.033 (1) Å for atom N1). The crystal structure is stabilized by an intramolecular O—H···O hydrogen bond, and by intermolecular N—H···O and C—H···O hydrogen interactions (Table 1), forming an extended three-dimensional network (Fig. 2).