metal-organic compounds
Diaquabis(1H-imidazole-4-carboxylato-κ2N3,O)zinc
aGuangdong Test Center for Green Labelling, Guangzhou 510440, People's Republic of China, and bSchool of Chemistry and Environment, South China Normal University, Guangzhou 510006, People's Republic of China
*Correspondence e-mail: S2371386@yahoo.com.cn
In the title compound, [Zn(C4H3N2O2)2(H2O)2], the ZnII ion is situated on a twofold rotation axis and exhibits a distorted octahedral coordination configuration. The equatorial plane contains two cis-oriented bidentate 1H-imidazole-4-carboxylate ligands and the axial positions are occupied by two coordinated water molecules. In the intermolecular O—H⋯O and N—H⋯O hydrogen bonds link the molecules into a three-dimensional supramolecular network. There are π–π interactions between the imidazole rings, with a centroid-to-centroid distance of 3.504 (3) Å.
Related literature
For general background, see: Yin et al. (2009); Zheng et al. (2011); Alkordi et al. (2009); Lu et al. (2009). For related structures, see: Haggag (2005); Starosta & Leciejewicz (2006); Gryz et al. (2007); Yin et al. (2009).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2004); cell APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536811020800/cv5098sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811020800/cv5098Isup2.hkl
13.6 mg ZnCl2 (0.10 mmol) and 16.8 mg H2imc (0.20 mmol) were mixed in 6 ml EtOH/H2O (1:1). The aqueous NaOH (0.20 M) solution was dropwise added to the above solution and the pH was adjusted to about 7. Then, the resulting mixture was sealed into a 10 ml Teflon-lined stainless-steel reactor, which was heated at 100°C for 48 h under autogenous pressure, and then slowly cooled to room temperature at a rate of 2°C/h. Colorless block crystals of (I) were isolated, washed with distilled water, and dried in air (yield: 56%). IR (KBr, n/cm-1): 3382m, 3147 s, 2997w, 2941w, 2849w, 1688m, 1584 s, 15581m, 1462m, 1402w, 1395 s, 1237 s, 1094m, 1003 s, 931w, 847w, 820w, 793m, 713w, 656m, 610w, 494m.
C- and N-bound H atoms were positioned geometrically and refined using a riding model, with C—H = 0.93 and N—H = 0.86 Å and with Uiso(H) = 1.2Ueq(C,N). H atoms of the water molecule were located from a difference Fourier map and isotropically refined with O—H bond lenghts restrained to 0.82 (2) Å.
Data collection: APEX2 (Bruker, 2004); cell
APEX2 (Bruker, 2004); data reduction: APEX2 (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).[Zn(C4H3N2O2)2(H2O)2] | Dx = 1.895 Mg m−3 |
Mr = 323.57 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pccn | Cell parameters from 2272 reflections |
a = 7.1399 (19) Å | θ = 3.3–27.3° |
b = 11.757 (3) Å | µ = 2.20 mm−1 |
c = 13.508 (4) Å | T = 298 K |
V = 1133.9 (5) Å3 | Block, colourless |
Z = 4 | 0.35 × 0.32 × 0.30 mm |
F(000) = 656 |
Bruker SMART APEXII CCD area-detector diffractometer | 1037 independent reflections |
Radiation source: fine-focus sealed tube | 913 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.021 |
ϕ and ω scans | θmax = 25.2°, θmin = 3.0° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −7→8 |
Tmin = 0.513, Tmax = 0.558 | k = −8→14 |
5336 measured reflections | l = −14→16 |
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)] = 0.023 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.066 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0338P)2 + 0.618P] where P = (Fo2 + 2Fc2)/3 |
1037 reflections | (Δ/σ)max < 0.001 |
95 parameters | Δρmax = 0.29 e Å−3 |
2 restraints | Δρmin = −0.33 e Å−3 |
[Zn(C4H3N2O2)2(H2O)2] | V = 1133.9 (5) Å3 |
Mr = 323.57 | Z = 4 |
Orthorhombic, Pccn | Mo Kα radiation |
a = 7.1399 (19) Å | µ = 2.20 mm−1 |
b = 11.757 (3) Å | T = 298 K |
c = 13.508 (4) Å | 0.35 × 0.32 × 0.30 mm |
Bruker SMART APEXII CCD area-detector diffractometer | 1037 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 913 reflections with I > 2σ(I) |
Tmin = 0.513, Tmax = 0.558 | Rint = 0.021 |
5336 measured reflections |
R[F2 > 2σ(F2)] = 0.023 | 2 restraints |
wR(F2) = 0.066 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | Δρmax = 0.29 e Å−3 |
1037 reflections | Δρmin = −0.33 e Å−3 |
95 parameters |
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 | ||
Zn1 | 1.2500 | 0.7500 | 0.37215 (2) | 0.02665 (15) | |
N1 | 1.0565 (2) | 0.81059 (14) | 0.47393 (11) | 0.0263 (4) | |
N2 | 0.8608 (2) | 0.87069 (15) | 0.58685 (12) | 0.0318 (4) | |
H2 | 0.8123 | 0.8836 | 0.6440 | 0.038* | |
C2 | 0.9100 (3) | 0.86538 (16) | 0.42860 (13) | 0.0229 (4) | |
C1 | 0.9084 (3) | 0.87026 (16) | 0.31884 (14) | 0.0229 (4) | |
C3 | 0.7885 (3) | 0.90319 (19) | 0.49823 (15) | 0.0291 (4) | |
H3 | 0.6781 | 0.9433 | 0.4875 | 0.035* | |
C4 | 1.0207 (3) | 0.81514 (18) | 0.56937 (14) | 0.0322 (5) | |
H4 | 1.0966 | 0.7838 | 0.6182 | 0.039* | |
O1 | 1.04760 (19) | 0.82909 (12) | 0.27495 (9) | 0.0304 (3) | |
O2 | 0.76821 (19) | 0.91520 (13) | 0.27745 (10) | 0.0303 (4) | |
O1W | 1.0979 (2) | 0.59370 (14) | 0.34656 (12) | 0.0356 (4) | |
H1WA | 1.150 (4) | 0.550 (2) | 0.3077 (18) | 0.062 (9)* | |
H1WB | 0.989 (3) | 0.595 (3) | 0.328 (2) | 0.072 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.0242 (2) | 0.0358 (2) | 0.0200 (2) | 0.00824 (13) | 0.000 | 0.000 |
N1 | 0.0267 (9) | 0.0336 (10) | 0.0187 (8) | 0.0059 (7) | 0.0010 (7) | 0.0021 (7) |
N2 | 0.0338 (10) | 0.0426 (11) | 0.0189 (8) | 0.0024 (8) | 0.0070 (7) | −0.0012 (7) |
C2 | 0.0220 (10) | 0.0252 (10) | 0.0214 (10) | 0.0008 (8) | 0.0003 (8) | 0.0002 (8) |
C1 | 0.0246 (10) | 0.0238 (10) | 0.0205 (9) | −0.0028 (8) | −0.0016 (8) | 0.0009 (8) |
C3 | 0.0254 (10) | 0.0344 (11) | 0.0275 (11) | 0.0040 (9) | 0.0007 (9) | −0.0018 (9) |
C4 | 0.0344 (12) | 0.0421 (13) | 0.0203 (10) | 0.0044 (9) | −0.0009 (9) | 0.0046 (9) |
O1 | 0.0283 (8) | 0.0434 (9) | 0.0194 (7) | 0.0063 (6) | 0.0021 (6) | −0.0011 (6) |
O2 | 0.0249 (8) | 0.0433 (9) | 0.0227 (7) | 0.0044 (6) | −0.0045 (6) | 0.0051 (6) |
O1W | 0.0264 (8) | 0.0386 (9) | 0.0417 (9) | 0.0049 (7) | −0.0033 (7) | −0.0108 (7) |
Zn1—N1 | 2.0751 (16) | N2—H2 | 0.8600 |
Zn1—N1i | 2.0751 (16) | C2—C3 | 1.354 (3) |
Zn1—O1 | 2.1626 (14) | C2—C1 | 1.484 (3) |
Zn1—O1i | 2.1626 (14) | C1—O1 | 1.255 (2) |
Zn1—O1Wi | 2.1623 (17) | C1—O2 | 1.262 (2) |
Zn1—O1W | 2.1623 (17) | C3—H3 | 0.9300 |
N1—C4 | 1.315 (2) | C4—H4 | 0.9300 |
N1—C2 | 1.373 (2) | O1W—H1WA | 0.828 (17) |
N2—C4 | 1.336 (3) | O1W—H1WB | 0.818 (18) |
N2—C3 | 1.358 (3) | ||
N1—Zn1—N1i | 97.01 (9) | C4—N2—H2 | 126.1 |
N1—Zn1—O1 | 79.04 (6) | C3—N2—H2 | 126.1 |
N1i—Zn1—O1 | 174.10 (5) | C3—C2—N1 | 109.40 (16) |
N1—Zn1—O1i | 174.10 (5) | C3—C2—C1 | 132.55 (17) |
N1i—Zn1—O1i | 79.04 (6) | N1—C2—C1 | 118.02 (15) |
O1—Zn1—O1i | 105.24 (7) | O1—C1—O2 | 125.47 (17) |
N1—Zn1—O1Wi | 98.53 (7) | O1—C1—C2 | 116.81 (15) |
N1i—Zn1—O1Wi | 93.64 (7) | O2—C1—C2 | 117.71 (16) |
O1—Zn1—O1Wi | 82.71 (6) | C2—C3—N2 | 106.05 (18) |
O1i—Zn1—O1Wi | 86.15 (6) | C2—C3—H3 | 127.0 |
N1—Zn1—O1W | 93.64 (7) | N2—C3—H3 | 127.0 |
N1i—Zn1—O1W | 98.54 (7) | N1—C4—N2 | 111.05 (18) |
O1—Zn1—O1W | 86.15 (6) | N1—C4—H4 | 124.5 |
O1i—Zn1—O1W | 82.71 (6) | N2—C4—H4 | 124.5 |
O1Wi—Zn1—O1W | 161.60 (9) | C1—O1—Zn1 | 114.11 (11) |
C4—N1—C2 | 105.65 (16) | Zn1—O1W—H1WA | 114 (2) |
C4—N1—Zn1 | 142.45 (15) | Zn1—O1W—H1WB | 121 (2) |
C2—N1—Zn1 | 111.89 (12) | H1WA—O1W—H1WB | 104 (3) |
C4—N2—C3 | 107.84 (17) | ||
N1i—Zn1—N1—C4 | −5.0 (2) | C3—C2—C1—O2 | −1.8 (3) |
O1—Zn1—N1—C4 | 179.4 (3) | N1—C2—C1—O2 | 176.18 (18) |
O1i—Zn1—N1—C4 | 42.6 (7) | N1—C2—C3—N2 | −0.3 (2) |
O1Wi—Zn1—N1—C4 | −99.8 (2) | C1—C2—C3—N2 | 177.80 (19) |
O1W—Zn1—N1—C4 | 94.1 (3) | C4—N2—C3—C2 | 0.0 (2) |
N1i—Zn1—N1—C2 | 175.82 (16) | C2—N1—C4—N2 | −0.6 (2) |
O1—Zn1—N1—C2 | 0.25 (13) | Zn1—N1—C4—N2 | −179.84 (17) |
O1i—Zn1—N1—C2 | −136.6 (5) | C3—N2—C4—N1 | 0.4 (3) |
O1Wi—Zn1—N1—C2 | 81.05 (14) | O2—C1—O1—Zn1 | −176.15 (15) |
O1W—Zn1—N1—C2 | −85.11 (14) | C2—C1—O1—Zn1 | 3.9 (2) |
C4—N1—C2—C3 | 0.6 (2) | N1—Zn1—O1—C1 | −2.39 (14) |
Zn1—N1—C2—C3 | −179.92 (14) | N1i—Zn1—O1—C1 | −50.7 (6) |
C4—N1—C2—C1 | −177.86 (17) | O1i—Zn1—O1—C1 | 173.43 (15) |
Zn1—N1—C2—C1 | 1.6 (2) | O1Wi—Zn1—O1—C1 | −102.60 (14) |
C3—C2—C1—O1 | 178.1 (2) | O1W—Zn1—O1—C1 | 92.07 (14) |
N1—C2—C1—O1 | −3.9 (2) |
Symmetry code: (i) −x+5/2, −y+3/2, z. |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2ii | 0.86 | 1.93 | 2.784 (2) | 174 |
O1W—H1WA···O2iii | 0.83 (2) | 2.04 (2) | 2.850 (2) | 167 (3) |
O1W—H1WB···O2iv | 0.82 (2) | 1.96 (2) | 2.778 (2) | 175 (3) |
Symmetry codes: (ii) −x+3/2, y, z+1/2; (iii) −x+2, y−1/2, −z+1/2; (iv) −x+3/2, −y+3/2, z. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C4H3N2O2)2(H2O)2] |
Mr | 323.57 |
Crystal system, space group | Orthorhombic, Pccn |
Temperature (K) | 298 |
a, b, c (Å) | 7.1399 (19), 11.757 (3), 13.508 (4) |
V (Å3) | 1133.9 (5) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.20 |
Crystal size (mm) | 0.35 × 0.32 × 0.30 |
Data collection | |
Diffractometer | Bruker SMART APEXII CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.513, 0.558 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5336, 1037, 913 |
Rint | 0.021 |
(sin θ/λ)max (Å−1) | 0.600 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.023, 0.066, 1.08 |
No. of reflections | 1037 |
No. of parameters | 95 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.29, −0.33 |
Computer programs: APEX2 (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···O2i | 0.86 | 1.93 | 2.784 (2) | 173.6 |
O1W—H1WA···O2ii | 0.828 (17) | 2.039 (18) | 2.850 (2) | 167 (3) |
O1W—H1WB···O2iii | 0.818 (18) | 1.962 (19) | 2.778 (2) | 175 (3) |
Symmetry codes: (i) −x+3/2, y, z+1/2; (ii) −x+2, y−1/2, −z+1/2; (iii) −x+3/2, −y+3/2, z. |
Acknowledgements
This work was financially supported by the National Natural Science Foundation of China (grant No. 21003053) and the Natural Science Foundation of Guang Dong (grant No. 10451063101004667).
References
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Recently, we were interested in constructing coordination polymers based on N-heterocyclic carboxylic acids (Zheng et al., 2011). The imidazole-4-carboxylatic acid (H2imc), which contains two N atoms of an imidazole group and one carboxylate group, remains largely unexplored, compared with its analogue imidazole-4,5-dicarboxylic acid (Alkordi et al., 2009; Lu et al., 2009). To date, only a few mononuclear complexes based on the H2imc ligand have been documented (Haggag, 2005; Starosta & Leciejewicz, 2006; Gryz et al., 2007; Yin et al., 2009). For instance, Yin et al. (2009) reported the structure of a mononuclear complex [Cd(Himc)2(H2O)2], which was prepared by the solvent evaporation method. Herein, we report a new ZnII coordination polymer [Zn(Himc)2(H2O)2], (I), which is isomorphous with the CdII analog.
The asymmetric unit of (I) contains a half of [Zn(Himc)2(H2O)2] formula unit. The ZnII ion exhibits a distorted octahedral geometry (Fig. 1), in which two cis-oriented bidentate chelating Himc- ligands are located in the equatorial plane, forming two stable five-membered rings with metal ion, and the axial sites are occupied by two coordinated water molecules (Fig. 1). The Zn—O distances range from 2.1623 (17) to 2.1626 (14) Å and Zn—N bonds have the value of 2.0751 (16) Å. All Zn—O and Zn—N bond distances are shorter than those of CdII analog [the axial Cd—O, the equatorial Cd—O and Cd—N bond distances are 2.343 (2), 2.325 (2) and 2.274 (2) Å, respectively].
In the crystal structure, intermolecular O—H···O and N—H···O hydrogen bonds (Table 1) link the molecules into a three-dimensional supramolecular network, which demonstrate π–π interactions between the imidazole rings (Fig. 2) with the centroid-to-centroid distance of 3.504 (3) Å.