metal-organic compounds
Octaaquabis(μ2-1H-pyrazole-3,5-dicarboxylato)tricopper(II) tetrahydrate
aShenzhen Environmental Monitoring Center, Shenzhen 518008, People's Republic of China, bShenzhen Environmental Protecting Bureau, Shenzhen 518008, People's Republic of China, and cState Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
*Correspondence e-mail: jwxu@ciac.jl.cn
In the trinucler CuII complex molecule of the title compound, [Cu3(C5HN2O4)2(H2O)8]·4H2O, the central CuII atom is located on an inversion centre and is coordinated in a distorted octahedral geometry. The equatorial sites are occupied by two N and two O atoms from two pyrazole-3,5-dicarboxylate ligands and the axial positions are occupied by two water molecules. The two other symmetry-related CuII atoms are pentacoordinated and assume a square-pyramidal geometry. In the coordinated and uncoordinated water molecules and carboxylate O atoms are linked by O—H⋯O hydrogen bonds.
Related literature
For general background to coordination polymers, see: Yaghi et al. (2003); Kitagawa et al. (2004). For related structures, see: King et al. (2003); Li (2005). For graph-set motifs, see: Bernstein et al. (1995).
Experimental
Crystal data
|
Refinement
|
Data collection: SMART (Bruker, 1998); cell SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810001595/is2499sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810001595/is2499Isup2.hkl
The title complex was prepared by the addition of Cu(BF4)2 (20 mmol) and pyrazole-3,5-dicarboxylic acid (30 mmol) to 40 ml water. The mixture was stirred for 1 h, a blue precipitate was obtained. A minimum amount of ammonia (14 M) was added to give a blue solution. Suitable crystals were obtained after standing at room temperature for several days (yield 51% based on Cu).
Atom H2 was placed geometrically (C—H = 0.93 Å) and refined using a riding model, with Uiso(H) = Ueq(C). The H atoms bonded to O atoms of water molecules were located in a difference Fourier map and refined, with a bond distance restriction [O—H = 0.82 (2) Å], and with Uiso(H) = 1.2Ueq(O).
The design and synthesis of novel coordination architectures is a fertile field due to the intriguing network topologies and potential a pplications as new classes of materials (Yaghi et al., 2003; Kitagawa et al., 2004). The ligand of pyrazole-3,5-dicarboxylic acid has several potential coordination sites involving both two N atoms of the pyrazole ring and four carboxylate O atoms. These multifunctional coordination sites are highly accessible to metal ions, as such, the ligand can coordinate as a mono-, bi-, or tetradentate ligand and can act to link together metal centers through a number of bridging modes (Li, 2005). The divalent copper atoms are easily to precipitate with the OH- when the pyrazole-3,5-dicarboxylic acids are deprotoned in base water solution, the mixed solution can obtain coordianted polymer single crystals in hydrothermal condition (King et al., 2003). Nevertheless, when the ammonia was added to the mixed solution, because of the complexing action between the copper atoms and NH3, the turbid soltuion became clear. After the ammonia slowly evaporated, we obtained the blue crystals, compound (I), as shown in Fig.1, a copper(II) trimer.
The central copper atom, Cu1, lies on a crystallographic inversion center. The Cu1 atom has a six-coordinate octahedral geometry, in which two O atoms and two N atoms from two pyrazole-3,5-dicarboxylate ligands occupy the equatorial plane, and the axial coordination sites are occupied two water molecules; the Cu—N/O bond distances range from 2.003 (2) to 2.437 (3) Å. The other two symmetry-related copper atoms, Cu2, have a pentacoordinate square-pyramidal geometry, where a pyrazole nitrogen N2 and a carboxylate oxygen O3 from one pyrazole-3,5-dicarboxylate ligand occupy two coordination sites and the remaining three positions are occupied by water molecules; the Cu—N/O bond distances range from 1.984 (2) to 2.237 (2) Å. The pyrazole-3,5-dicarboxylate ligand is not strictly planar. Deviation from the mean plane defined by the pyrazole ring is seen for both carboxylate groups with values ranging from 0.034 (1) to 0.205 (1) Å. The dihedral angle between the two carboxylate mean planes is 11.3 (3)°. It can be seen that the ligand bite angle at the two different copper centers Cu1 and Cu2 is similar, 74.8 (4) and 80.6 (4)°, respectively. This implies that the pyrazole-3,5-dicarboxylate ligand is a fairly rigid ligand and retains its integrity on metal chelation.
In the
there are two lattice water molecules, four coordinated water molecules and carboxylate O atoms, which form complexed hydrogen-bonding interactions. Two lattice water molecules and its symmetric equivalents together with two carboxylate O atoms from two trimers form a hydrogen-bonded chair conformation, generating an R46(6) motif (Bernstein et al., 1995). Meanwhile, the four lattice water molecules in each R46(6) motif also bind four another trimers by O7—H7B···O4 hydrogen bond interaction, and O5—H5B···O8 hydrogen bond interaction. Those strong hydrogen-bonding interactions as well as some weaker interactions, such as O5—H5A···O1, O6—H6A···O8, O6—H6B···O2 and O9—H9A···O4, extend the into a three-dimensional supramolecular network (Fig. 2).For general background to coordination polymers, see: Yaghi et al. (2003); Kitagawa et al. (2004). For related structures, see: King et al. (2003); Li (2005). For graph-set motifs, see: Bernstein et al. (1995).
Data collection: SMART (Bruker, 1998); cell
SAINT-Plus (Bruker, 1998); data reduction: SAINT-Plus (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. A view of (I), with the atom-labeling scheme and 30% probability displacement ellipsoids. [Symmetry code: (A) 1 - x, 1 - y, -z.] | |
Fig. 2. Perspective view of packing structure of (I) along the c axis. For the sake of clarity, H atoms not involved in hydrogen bonds have been omitted. |
[Cu3(C5HN2O4)2(H2O)8]·4H2O | Z = 1 |
Mr = 712.97 | F(000) = 361 |
Triclinic, P1 | Dx = 1.869 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.9455 (6) Å | Cell parameters from 2128 reflections |
b = 9.1018 (7) Å | θ = 2.3–26.0° |
c = 9.1125 (7) Å | µ = 2.59 mm−1 |
α = 103.485 (1)° | T = 293 K |
β = 90.924 (1)° | Tabular, blue |
γ = 117.505 (1)° | 0.17 × 0.13 × 0.05 mm |
V = 633.31 (8) Å3 |
Bruker SMART APEX CCD area-detector diffractometer | 2412 independent reflections |
Radiation source: fine-focus sealed tube | 2198 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.010 |
φ and ω scans | θmax = 26.0°, θmin = 2.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −10→11 |
Tmin = 0.666, Tmax = 0.877 | k = −11→9 |
3535 measured reflections | l = −11→9 |
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)] = 0.036 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.095 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0495P)2 + 1.615P] where P = (Fo2 + 2Fc2)/3 |
2412 reflections | (Δ/σ)max = 0.042 |
205 parameters | Δρmax = 0.89 e Å−3 |
12 restraints | Δρmin = −0.54 e Å−3 |
[Cu3(C5HN2O4)2(H2O)8]·4H2O | γ = 117.505 (1)° |
Mr = 712.97 | V = 633.31 (8) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.9455 (6) Å | Mo Kα radiation |
b = 9.1018 (7) Å | µ = 2.59 mm−1 |
c = 9.1125 (7) Å | T = 293 K |
α = 103.485 (1)° | 0.17 × 0.13 × 0.05 mm |
β = 90.924 (1)° |
Bruker SMART APEX CCD area-detector diffractometer | 2412 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2198 reflections with I > 2σ(I) |
Tmin = 0.666, Tmax = 0.877 | Rint = 0.010 |
3535 measured reflections |
R[F2 > 2σ(F2)] = 0.036 | 12 restraints |
wR(F2) = 0.095 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.08 | Δρmax = 0.89 e Å−3 |
2412 reflections | Δρmin = −0.54 e Å−3 |
205 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 | ||
Cu1 | 0.5000 | 0.5000 | 0.0000 | 0.01250 (16) | |
Cu2 | 0.18693 (5) | 0.39943 (5) | 0.35269 (4) | 0.01365 (14) | |
O1 | 0.4661 (3) | 0.8149 (3) | 0.7106 (3) | 0.0205 (5) | |
O2 | 0.2463 (3) | 0.5801 (3) | 0.5590 (3) | 0.0180 (5) | |
O3 | 0.8061 (3) | 0.6833 (3) | 0.0762 (3) | 0.0187 (5) | |
O4 | 0.9786 (3) | 0.8716 (3) | 0.2903 (3) | 0.0198 (5) | |
O5 | 0.4555 (4) | 0.6959 (4) | −0.0015 (3) | 0.0319 (7) | |
H5A | 0.420 (6) | 0.690 (7) | −0.093 (3) | 0.038* | |
H5B | 0.541 (5) | 0.797 (4) | 0.040 (5) | 0.038* | |
O6 | −0.0225 (4) | 0.2439 (4) | 0.4269 (4) | 0.0318 (7) | |
H6A | −0.091 (5) | 0.148 (4) | 0.360 (5) | 0.038* | |
H6B | −0.083 (6) | 0.291 (6) | 0.468 (5) | 0.038* | |
O7 | 0.2443 (4) | 0.8545 (4) | 0.1630 (3) | 0.0268 (6) | |
H7A | 0.330 (4) | 0.923 (5) | 0.219 (5) | 0.032* | |
H7B | 0.159 (4) | 0.848 (6) | 0.198 (5) | 0.032* | |
O8 | 0.2631 (4) | 0.9378 (4) | 0.8781 (3) | 0.0280 (6) | |
H8A | 0.245 (6) | 0.913 (6) | 0.958 (3) | 0.034* | |
H8B | 0.316 (5) | 0.899 (6) | 0.826 (5) | 0.034* | |
O9 | 0.1851 (4) | 0.2020 (4) | 0.1939 (4) | 0.0335 (7) | |
H9A | 0.104 (5) | 0.102 (4) | 0.195 (6) | 0.040* | |
H9B | 0.282 (4) | 0.202 (7) | 0.197 (6) | 0.040* | |
O10 | 0.0459 (4) | 0.4770 (5) | 0.2092 (4) | 0.0415 (8) | |
H10A | 0.102 (6) | 0.580 (4) | 0.202 (6) | 0.050* | |
H10B | −0.052 (4) | 0.452 (7) | 0.238 (6) | 0.050* | |
N1 | 0.5326 (3) | 0.5804 (4) | 0.2330 (3) | 0.0135 (6) | |
N2 | 0.4214 (3) | 0.5670 (4) | 0.3334 (3) | 0.0136 (6) | |
C1 | 0.5045 (4) | 0.6944 (4) | 0.4637 (4) | 0.0136 (6) | |
C2 | 0.6742 (4) | 0.7934 (4) | 0.4484 (4) | 0.0151 (7) | |
H2 | 0.7597 | 0.8884 | 0.5196 | 0.015* | |
C3 | 0.6852 (4) | 0.7162 (4) | 0.3012 (4) | 0.0125 (6) | |
C4 | 0.4011 (4) | 0.6993 (4) | 0.5882 (4) | 0.0153 (7) | |
C5 | 0.8344 (4) | 0.7607 (4) | 0.2152 (4) | 0.0136 (7) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0145 (3) | 0.0118 (3) | 0.0090 (3) | 0.0055 (2) | 0.0011 (2) | 0.0007 (2) |
Cu2 | 0.0111 (2) | 0.0123 (2) | 0.0137 (2) | 0.00298 (17) | 0.00279 (15) | 0.00235 (16) |
O1 | 0.0194 (12) | 0.0210 (13) | 0.0134 (12) | 0.0060 (11) | 0.0028 (10) | −0.0012 (10) |
O2 | 0.0141 (12) | 0.0167 (12) | 0.0181 (12) | 0.0045 (10) | 0.0046 (9) | 0.0018 (10) |
O3 | 0.0171 (12) | 0.0216 (13) | 0.0122 (12) | 0.0056 (10) | 0.0040 (9) | 0.0030 (10) |
O4 | 0.0116 (11) | 0.0210 (13) | 0.0172 (12) | 0.0012 (10) | 0.0018 (9) | 0.0026 (10) |
O5 | 0.0366 (17) | 0.0299 (16) | 0.0294 (16) | 0.0160 (14) | 0.0037 (13) | 0.0082 (13) |
O6 | 0.0251 (15) | 0.0303 (16) | 0.0354 (17) | 0.0099 (13) | 0.0063 (12) | 0.0076 (13) |
O7 | 0.0209 (14) | 0.0209 (14) | 0.0335 (16) | 0.0080 (12) | 0.0098 (12) | 0.0025 (12) |
O8 | 0.0286 (15) | 0.0294 (16) | 0.0257 (15) | 0.0154 (13) | 0.0053 (12) | 0.0033 (12) |
O9 | 0.0323 (16) | 0.0270 (16) | 0.0358 (17) | 0.0100 (13) | 0.0082 (13) | 0.0076 (13) |
O10 | 0.0351 (18) | 0.0381 (19) | 0.054 (2) | 0.0156 (16) | 0.0024 (16) | 0.0220 (16) |
N1 | 0.0125 (13) | 0.0140 (14) | 0.0123 (13) | 0.0050 (11) | 0.0035 (10) | 0.0035 (11) |
N2 | 0.0119 (13) | 0.0146 (14) | 0.0112 (13) | 0.0044 (11) | 0.0020 (10) | 0.0018 (11) |
C1 | 0.0136 (15) | 0.0139 (16) | 0.0119 (15) | 0.0057 (13) | 0.0014 (12) | 0.0032 (12) |
C2 | 0.0125 (15) | 0.0157 (17) | 0.0132 (16) | 0.0039 (13) | 0.0005 (12) | 0.0031 (13) |
C3 | 0.0127 (15) | 0.0126 (16) | 0.0103 (15) | 0.0047 (13) | −0.0010 (12) | 0.0027 (12) |
C4 | 0.0149 (16) | 0.0166 (17) | 0.0152 (16) | 0.0081 (14) | 0.0031 (13) | 0.0047 (13) |
C5 | 0.0150 (16) | 0.0130 (17) | 0.0133 (16) | 0.0064 (14) | 0.0037 (13) | 0.0048 (13) |
Cu1—O5 | 2.001 (3) | O6—H6B | 0.87 (6) |
Cu1—O5i | 2.001 (3) | O7—H7A | 0.80 (2) |
Cu1—N1 | 2.047 (3) | O7—H7B | 0.81 (2) |
Cu1—N1i | 2.047 (3) | O8—H8A | 0.81 (2) |
Cu1—O3i | 2.437 (2) | O8—H8B | 0.81 (5) |
Cu1—O3 | 2.437 (2) | O9—H9A | 0.87 (2) |
Cu2—N2 | 1.985 (3) | O9—H9B | 0.87 (5) |
Cu2—O6 | 2.002 (3) | O10—H10A | 0.85 (2) |
Cu2—O9 | 2.021 (3) | O10—H10B | 0.86 (5) |
Cu2—O2 | 2.059 (2) | N1—N2 | 1.345 (4) |
Cu2—O10 | 2.236 (3) | N1—C3 | 1.354 (4) |
O1—C4 | 1.247 (4) | N2—C1 | 1.357 (4) |
O2—C4 | 1.277 (4) | C1—C2 | 1.392 (5) |
O3—C5 | 1.255 (4) | C1—C4 | 1.481 (5) |
O4—C5 | 1.264 (4) | C2—C3 | 1.390 (5) |
O5—H5A | 0.87 (2) | C2—H2 | 0.9300 |
O5—H5B | 0.87 (2) | C3—C5 | 1.497 (4) |
O6—H6A | 0.87 (2) | ||
O5—Cu1—O5i | 180.0 | Cu2—O6—H6B | 116 (3) |
O5—Cu1—N1 | 87.36 (12) | H6A—O6—H6B | 108 (5) |
O5i—Cu1—N1 | 92.64 (12) | H7A—O7—H7B | 113 (5) |
O5—Cu1—N1i | 92.64 (12) | H8A—O8—H8B | 117 (5) |
O5i—Cu1—N1i | 87.36 (12) | Cu2—O9—H9A | 114 (3) |
N1—Cu1—N1i | 180.00 (18) | Cu2—O9—H9B | 114 (3) |
O5—Cu1—O3i | 85.89 (11) | H9A—O9—H9B | 110 (5) |
O5i—Cu1—O3i | 94.11 (11) | Cu2—O10—H10A | 115 (4) |
N1—Cu1—O3i | 105.11 (9) | Cu2—O10—H10B | 109 (4) |
N1i—Cu1—O3i | 74.89 (9) | H10A—O10—H10B | 114 (6) |
O5—Cu1—O3 | 94.11 (11) | N2—N1—C3 | 107.6 (3) |
O5i—Cu1—O3 | 85.89 (11) | N2—N1—Cu1 | 132.2 (2) |
N1—Cu1—O3 | 74.89 (9) | C3—N1—Cu1 | 116.3 (2) |
N1i—Cu1—O3 | 105.11 (9) | N1—N2—C1 | 108.4 (3) |
O3i—Cu1—O3 | 180.0 | N1—N2—Cu2 | 137.8 (2) |
N2—Cu2—O6 | 165.29 (12) | C1—N2—Cu2 | 113.2 (2) |
N2—Cu2—O9 | 93.98 (12) | N2—C1—C2 | 110.0 (3) |
O6—Cu2—O9 | 92.94 (13) | N2—C1—C4 | 115.9 (3) |
N2—Cu2—O2 | 80.69 (10) | C2—C1—C4 | 134.1 (3) |
O6—Cu2—O2 | 88.18 (11) | C3—C2—C1 | 103.4 (3) |
O9—Cu2—O2 | 158.66 (12) | C3—C2—H2 | 128.3 |
N2—Cu2—O10 | 97.78 (12) | C1—C2—H2 | 128.3 |
O6—Cu2—O10 | 93.87 (13) | N1—C3—C2 | 110.6 (3) |
O9—Cu2—O10 | 99.41 (14) | N1—C3—C5 | 119.3 (3) |
O2—Cu2—O10 | 101.78 (12) | C2—C3—C5 | 130.1 (3) |
C4—O2—Cu2 | 114.3 (2) | O1—C4—O2 | 124.6 (3) |
C5—O3—Cu1 | 109.0 (2) | O1—C4—C1 | 120.1 (3) |
Cu1—O5—H5A | 111 (3) | O2—C4—C1 | 115.2 (3) |
Cu1—O5—H5B | 115 (3) | O3—C5—O4 | 125.8 (3) |
H5A—O5—H5B | 110 (5) | O3—C5—C3 | 117.4 (3) |
Cu2—O6—H6A | 115 (3) | O4—C5—C3 | 116.8 (3) |
Symmetry code: (i) −x+1, −y+1, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5A···O1ii | 0.87 (3) | 2.28 (4) | 3.050 (4) | 148 (4) |
O5—H5B···O8iii | 0.87 (4) | 2.16 (4) | 3.021 (5) | 172 (4) |
O6—H6A···O8iv | 0.87 (4) | 2.38 (5) | 3.078 (4) | 137 (4) |
O6—H6B···O2iv | 0.87 (6) | 2.30 (6) | 3.077 (4) | 149 (4) |
O7—H7A···O1iii | 0.80 (4) | 2.16 (4) | 2.860 (4) | 147 (4) |
O7—H7B···O4v | 0.81 (4) | 1.91 (4) | 2.715 (4) | 171 (4) |
O8—H8A···O7vi | 0.81 (3) | 2.06 (3) | 2.854 (4) | 169 (4) |
O8—H8B···O1 | 0.81 (5) | 2.03 (5) | 2.836 (4) | 175 (4) |
O9—H9A···O4vii | 0.87 (4) | 2.26 (4) | 3.061 (4) | 154 (4) |
Symmetry codes: (ii) x, y, z−1; (iii) −x+1, −y+2, −z+1; (iv) −x, −y+1, −z+1; (v) x−1, y, z; (vi) x, y, z+1; (vii) x−1, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu3(C5HN2O4)2(H2O)8]·4H2O |
Mr | 712.97 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 8.9455 (6), 9.1018 (7), 9.1125 (7) |
α, β, γ (°) | 103.485 (1), 90.924 (1), 117.505 (1) |
V (Å3) | 633.31 (8) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 2.59 |
Crystal size (mm) | 0.17 × 0.13 × 0.05 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.666, 0.877 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3535, 2412, 2198 |
Rint | 0.010 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.036, 0.095, 1.08 |
No. of reflections | 2412 |
No. of parameters | 205 |
No. of restraints | 12 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.89, −0.54 |
Computer programs: SMART (Bruker, 1998), SAINT-Plus (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O5—H5A···O1i | 0.87 (3) | 2.28 (4) | 3.050 (4) | 148 (4) |
O5—H5B···O8ii | 0.87 (4) | 2.16 (4) | 3.021 (5) | 172 (4) |
O6—H6A···O8iii | 0.87 (4) | 2.38 (5) | 3.078 (4) | 137 (4) |
O6—H6B···O2iii | 0.87 (6) | 2.30 (6) | 3.077 (4) | 149 (4) |
O7—H7A···O1ii | 0.80 (4) | 2.16 (4) | 2.860 (4) | 147 (4) |
O7—H7B···O4iv | 0.81 (4) | 1.91 (4) | 2.715 (4) | 171 (4) |
O8—H8A···O7v | 0.81 (3) | 2.06 (3) | 2.854 (4) | 169 (4) |
O8—H8B···O1 | 0.81 (5) | 2.03 (5) | 2.836 (4) | 175 (4) |
O9—H9A···O4vi | 0.87 (4) | 2.26 (4) | 3.061 (4) | 154 (4) |
Symmetry codes: (i) x, y, z−1; (ii) −x+1, −y+2, −z+1; (iii) −x, −y+1, −z+1; (iv) x−1, y, z; (v) x, y, z+1; (vi) x−1, y−1, z. |
Acknowledgements
This work was supported by the National Analytical Research Center of Electrochemistry and Spectroscopy, Changchun Institute of Applied Chemistry.
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (1998). SMART and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
King, P., Clerac, R., Anson, C. E., Coulon, C. & Powell, A. K. (2003). Inorg. Chem. 423, 705–714. Google Scholar
Kitagawa, S., Kitaura, R. & Noro, S. (2004). Angew. Chem. Int. Ed. 43, 2334–2375. Web of Science CrossRef CAS Google Scholar
Li, X.-H. (2005). Acta Cryst. E61, m2405–m2407. Web of Science CSD CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yaghi, O. M., O'Keeffe, M., Ockwig, N. W., Chae, H. K., Eddaoudi, M. & Kim, J. (2003). Nature (London), 423, 705–714. Web of Science CrossRef PubMed CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
The design and synthesis of novel coordination architectures is a fertile field due to the intriguing network topologies and potential a pplications as new classes of materials (Yaghi et al., 2003; Kitagawa et al., 2004). The ligand of pyrazole-3,5-dicarboxylic acid has several potential coordination sites involving both two N atoms of the pyrazole ring and four carboxylate O atoms. These multifunctional coordination sites are highly accessible to metal ions, as such, the ligand can coordinate as a mono-, bi-, or tetradentate ligand and can act to link together metal centers through a number of bridging modes (Li, 2005). The divalent copper atoms are easily to precipitate with the OH- when the pyrazole-3,5-dicarboxylic acids are deprotoned in base water solution, the mixed solution can obtain coordianted polymer single crystals in hydrothermal condition (King et al., 2003). Nevertheless, when the ammonia was added to the mixed solution, because of the complexing action between the copper atoms and NH3, the turbid soltuion became clear. After the ammonia slowly evaporated, we obtained the blue crystals, compound (I), as shown in Fig.1, a copper(II) trimer.
The central copper atom, Cu1, lies on a crystallographic inversion center. The Cu1 atom has a six-coordinate octahedral geometry, in which two O atoms and two N atoms from two pyrazole-3,5-dicarboxylate ligands occupy the equatorial plane, and the axial coordination sites are occupied two water molecules; the Cu—N/O bond distances range from 2.003 (2) to 2.437 (3) Å. The other two symmetry-related copper atoms, Cu2, have a pentacoordinate square-pyramidal geometry, where a pyrazole nitrogen N2 and a carboxylate oxygen O3 from one pyrazole-3,5-dicarboxylate ligand occupy two coordination sites and the remaining three positions are occupied by water molecules; the Cu—N/O bond distances range from 1.984 (2) to 2.237 (2) Å. The pyrazole-3,5-dicarboxylate ligand is not strictly planar. Deviation from the mean plane defined by the pyrazole ring is seen for both carboxylate groups with values ranging from 0.034 (1) to 0.205 (1) Å. The dihedral angle between the two carboxylate mean planes is 11.3 (3)°. It can be seen that the ligand bite angle at the two different copper centers Cu1 and Cu2 is similar, 74.8 (4) and 80.6 (4)°, respectively. This implies that the pyrazole-3,5-dicarboxylate ligand is a fairly rigid ligand and retains its integrity on metal chelation.
In the asymmetric unit, there are two lattice water molecules, four coordinated water molecules and carboxylate O atoms, which form complexed hydrogen-bonding interactions. Two lattice water molecules and its symmetric equivalents together with two carboxylate O atoms from two trimers form a hydrogen-bonded chair conformation, generating an R46(6) motif (Bernstein et al., 1995). Meanwhile, the four lattice water molecules in each R46(6) motif also bind four another trimers by O7—H7B···O4 hydrogen bond interaction, and O5—H5B···O8 hydrogen bond interaction. Those strong hydrogen-bonding interactions as well as some weaker interactions, such as O5—H5A···O1, O6—H6A···O8, O6—H6B···O2 and O9—H9A···O4, extend the crystal structure into a three-dimensional supramolecular network (Fig. 2).