metal-organic compounds
Poly[(μ-3,5-dinitro-2-oxidobenzoato)(μ-3-hydroxypyridine)copper(II)]
aCollege of Science, Guang Dong Ocean University, Zhanjiang 524088, People's Republic of China
*Correspondence e-mail: songwd60@126.com
A new coordination polymer, [Cu(C7H2N2O7)(C5H5NO)]n, exhibits a double-chain structure, in which 3,5-dinitro-2-oxidobenzoate and 3-hydroxypyridine both act as bridging ligands, connecting adjacent copper(II) centers to form an infinite double-stranded chain. The contains one CuII ion, one 3,5-dinitro-2-oxidobenzoate ligand and a 3-hydroxypyridine ligand. Coordination by one N atom and three O atoms from two different 3,5-dinitro-2-oxidobenzoate ligands and a 3-hydroxypyridine ligand creates a square-planar CuII center, which is augmented by a less tightly bonded fifth phenol O atom to form a square-pyramidal five-coordinate complex with an essentially planar base. The double-stranded chains are stabilized by intrachain π–π interactions [the centroid-to-centroid distance between adjacent aromatic rings is 3.719 (7) Å], and further linked through O—H⋯O hydrogen bonds, forming a three-dimensional supramolecular network.
Related literature
For related literature, see: Bradshaw et al. (2005); Eddaoudi et al. (2001); Fujita et al. (1994); Gable et al. (1990); Gao et al. (2005); He et al. (2006); Li et al. (1999); Losier & Zaworotko (1996); Moulton & Zaworotko (2001); Song & Xi (2006) Song et al., 2006; Song, Guo & Guo, 2007; Song, Guo & He, 2007; Song, Guo & Zhang, 2007; Song, Yan et al., 2007); Stang & Olenyuk (1997); Withersby et al. (1999); Yaghi & Li (1995).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2004); cell SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
Supporting information
10.1107/S1600536808009392/zl2099sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536808009392/zl2099Isup2.hkl
A mixture of CuCl2 (0.134 g; 1 mmol), 3,5-dinitrosalicylic acid (0.228 g; 1 mmol), 3-hydroxypyridine (0.095 g; 1 mmol) and H2O (10 ml) was stirred vigorously for 20 min and then sealed in a Teflon-lined stainless-steel autoclave (20 ml, capacity). The autoclave was heated to and maintained at 433 K for 5 days, and then cooled to room temperature at 5 K h-1. The blue plate single crystals were obtained in ca 78% yield based on CuCl2.
Aromatic and hydroxyl H atoms were placed in calculated positions and were treated as riding on the parent C atoms with C—H = 0.93 Å, O—H = 0.82 Å (hydroxyl group) and with Uiso(H) = 1.2 or 1.5 Ueq(C, O). Hydroxyl H atoms were allowed to rotate around the C—O direction to best fit the experimental electron denisty.
Data collection: APEX2 (Bruker, 2004); cell
SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2001); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).[Cu(C7H2N2O7)(C5H5NO)] | F(000) = 772 |
Mr = 384.75 | Dx = 1.883 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 2895 reflections |
a = 8.1055 (3) Å | θ = 2.4–27.9° |
b = 6.2208 (2) Å | µ = 1.66 mm−1 |
c = 26.9837 (9) Å | T = 296 K |
β = 94.030 (3)° | Plate, blue |
V = 1357.23 (8) Å3 | 0.25 × 0.16 × 0.09 mm |
Z = 4 |
Bruker APEXII area-detector diffractometer | 3094 independent reflections |
Radiation source: fine-focus sealed tube | 2275 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.061 |
ϕ and ω scans | θmax = 27.5°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −10→10 |
Tmin = 0.681, Tmax = 0.865 | k = −8→8 |
12917 measured reflections | l = −31→34 |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.092 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0416P)2] where P = (Fo2 + 2Fc2)/3 |
3094 reflections | (Δ/σ)max < 0.001 |
218 parameters | Δρmax = 0.38 e Å−3 |
0 restraints | Δρmin = −0.45 e Å−3 |
[Cu(C7H2N2O7)(C5H5NO)] | V = 1357.23 (8) Å3 |
Mr = 384.75 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 8.1055 (3) Å | µ = 1.66 mm−1 |
b = 6.2208 (2) Å | T = 296 K |
c = 26.9837 (9) Å | 0.25 × 0.16 × 0.09 mm |
β = 94.030 (3)° |
Bruker APEXII area-detector diffractometer | 3094 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 2275 reflections with I > 2σ(I) |
Tmin = 0.681, Tmax = 0.865 | Rint = 0.061 |
12917 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.092 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.38 e Å−3 |
3094 reflections | Δρmin = −0.45 e Å−3 |
218 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 | 0.12663 (5) | 0.27589 (5) | 0.187438 (14) | 0.02720 (13) | |
O1 | 0.2121 (3) | 0.3893 (3) | 0.12851 (7) | 0.0336 (5) | |
C3 | 0.4627 (4) | 0.8652 (4) | 0.15767 (12) | 0.0300 (7) | |
H3 | 0.5168 | 0.9353 | 0.1846 | 0.036* | |
C7 | 0.2967 (4) | 0.5637 (4) | 0.12445 (11) | 0.0266 (6) | |
C2 | 0.3785 (4) | 0.6762 (4) | 0.16517 (11) | 0.0257 (6) | |
C6 | 0.3114 (4) | 0.6587 (4) | 0.07688 (11) | 0.0303 (7) | |
C5 | 0.3921 (4) | 0.8497 (5) | 0.06963 (12) | 0.0339 (7) | |
H5 | 0.3957 | 0.9089 | 0.0381 | 0.041* | |
C4 | 0.4673 (4) | 0.9503 (4) | 0.11085 (12) | 0.0319 (7) | |
N2 | 0.2313 (3) | 0.5572 (4) | 0.03232 (10) | 0.0383 (7) | |
N3 | 0.5560 (3) | 1.1514 (4) | 0.10454 (13) | 0.0432 (7) | |
O5 | 0.5735 (3) | 1.2190 (4) | 0.06299 (10) | 0.0593 (8) | |
O4 | 0.6093 (3) | 1.2453 (3) | 0.14266 (11) | 0.0569 (7) | |
O6 | 0.1611 (3) | 0.6731 (4) | 0.00078 (10) | 0.0580 (7) | |
O7 | 0.2381 (4) | 0.3631 (4) | 0.02875 (9) | 0.0591 (7) | |
N1 | 0.0150 (3) | 0.0378 (3) | 0.14852 (9) | 0.0280 (6) | |
C10 | −0.1449 (4) | −0.2943 (4) | 0.09616 (13) | 0.0354 (8) | |
H10 | −0.1983 | −0.4056 | 0.0785 | 0.043* | |
C8 | −0.0260 (4) | −0.1437 (4) | 0.17174 (12) | 0.0308 (7) | |
H8 | −0.0007 | −0.1566 | 0.2058 | 0.037* | |
C9 | −0.1048 (4) | −0.3115 (4) | 0.14630 (12) | 0.0294 (7) | |
C12 | −0.0227 (4) | 0.0547 (4) | 0.09966 (12) | 0.0335 (7) | |
H12 | 0.0064 | 0.1790 | 0.0832 | 0.040* | |
C11 | −0.1036 (4) | −0.1078 (5) | 0.07304 (13) | 0.0377 (8) | |
H11 | −0.1303 | −0.0907 | 0.0392 | 0.045* | |
O8 | −0.1323 (3) | −0.4927 (3) | 0.17369 (9) | 0.0429 (6) | |
H8A | −0.2046 | −0.5657 | 0.1591 | 0.064* | |
C1 | 0.3686 (4) | 0.6059 (4) | 0.21742 (11) | 0.0272 (7) | |
O2 | 0.2620 (3) | 0.4681 (3) | 0.22901 (8) | 0.0378 (5) | |
O3 | 0.4641 (2) | 0.6940 (3) | 0.25017 (8) | 0.0290 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Cu1 | 0.0369 (2) | 0.02288 (17) | 0.0209 (2) | −0.00557 (14) | −0.00425 (16) | 0.00164 (14) |
O1 | 0.0472 (14) | 0.0299 (10) | 0.0231 (12) | −0.0138 (9) | −0.0003 (10) | −0.0021 (8) |
C3 | 0.0300 (17) | 0.0254 (13) | 0.034 (2) | −0.0014 (11) | −0.0011 (14) | −0.0047 (12) |
C7 | 0.0291 (17) | 0.0262 (13) | 0.0241 (17) | −0.0016 (11) | −0.0008 (13) | −0.0019 (11) |
C2 | 0.0298 (17) | 0.0255 (13) | 0.0215 (17) | −0.0004 (11) | −0.0002 (13) | −0.0009 (11) |
C6 | 0.0342 (18) | 0.0365 (15) | 0.0195 (18) | −0.0052 (12) | −0.0021 (14) | −0.0005 (12) |
C5 | 0.0335 (19) | 0.0391 (15) | 0.0294 (19) | −0.0064 (13) | 0.0038 (15) | 0.0076 (14) |
C4 | 0.0291 (17) | 0.0282 (13) | 0.038 (2) | −0.0066 (12) | 0.0038 (15) | 0.0039 (13) |
N2 | 0.0425 (17) | 0.0507 (16) | 0.0216 (16) | −0.0148 (13) | 0.0006 (13) | −0.0006 (12) |
N3 | 0.0349 (17) | 0.0343 (13) | 0.060 (2) | −0.0077 (12) | 0.0038 (16) | 0.0058 (14) |
O5 | 0.0653 (19) | 0.0535 (14) | 0.060 (2) | −0.0221 (12) | 0.0112 (15) | 0.0213 (13) |
O4 | 0.0575 (17) | 0.0447 (13) | 0.068 (2) | −0.0267 (11) | 0.0005 (15) | −0.0063 (12) |
O6 | 0.0634 (19) | 0.0757 (17) | 0.0321 (16) | −0.0060 (14) | −0.0154 (13) | 0.0153 (13) |
O7 | 0.090 (2) | 0.0474 (14) | 0.0379 (17) | −0.0132 (13) | −0.0070 (15) | −0.0116 (12) |
N1 | 0.0331 (15) | 0.0236 (11) | 0.0265 (15) | −0.0028 (9) | −0.0037 (11) | 0.0018 (10) |
C10 | 0.0395 (19) | 0.0282 (14) | 0.037 (2) | −0.0087 (12) | −0.0082 (16) | −0.0089 (13) |
C8 | 0.0362 (18) | 0.0258 (13) | 0.0291 (19) | −0.0049 (12) | −0.0072 (15) | 0.0043 (12) |
C9 | 0.0279 (17) | 0.0246 (13) | 0.035 (2) | −0.0017 (11) | −0.0038 (14) | 0.0030 (12) |
C12 | 0.0430 (19) | 0.0294 (14) | 0.0269 (19) | −0.0071 (13) | −0.0052 (15) | −0.0006 (12) |
C11 | 0.045 (2) | 0.0382 (16) | 0.0282 (19) | −0.0047 (14) | −0.0052 (16) | −0.0036 (14) |
O8 | 0.0481 (16) | 0.0281 (10) | 0.0501 (16) | −0.0143 (9) | −0.0124 (12) | 0.0091 (10) |
C1 | 0.0321 (17) | 0.0246 (13) | 0.0242 (18) | 0.0024 (11) | −0.0024 (14) | −0.0046 (11) |
O2 | 0.0511 (15) | 0.0399 (11) | 0.0214 (12) | −0.0187 (10) | −0.0040 (10) | 0.0005 (9) |
O3 | 0.0315 (12) | 0.0313 (10) | 0.0231 (12) | −0.0031 (8) | −0.0055 (9) | −0.0073 (8) |
Cu1—O1 | 1.9132 (19) | N3—O5 | 1.215 (4) |
Cu1—O2 | 1.929 (2) | N3—O4 | 1.234 (4) |
Cu1—O3i | 1.952 (2) | N1—C12 | 1.336 (4) |
Cu1—N1 | 1.996 (2) | N1—C8 | 1.344 (3) |
O1—C7 | 1.292 (3) | C10—C11 | 1.370 (4) |
C3—C4 | 1.373 (4) | C10—C9 | 1.373 (5) |
C3—C2 | 1.382 (4) | C10—H10 | 0.9300 |
C3—H3 | 0.9300 | C8—C9 | 1.381 (4) |
C7—C6 | 1.426 (4) | C8—H8 | 0.9300 |
C7—C2 | 1.426 (4) | C9—O8 | 1.375 (3) |
C2—C1 | 1.484 (4) | C12—C11 | 1.379 (4) |
C6—C5 | 1.377 (4) | C12—H12 | 0.9300 |
C6—N2 | 1.468 (4) | C11—H11 | 0.9300 |
C5—C4 | 1.380 (4) | O8—H8A | 0.8200 |
C5—H5 | 0.9300 | C1—O3 | 1.259 (3) |
C4—N3 | 1.459 (3) | C1—O2 | 1.271 (3) |
N2—O7 | 1.213 (3) | O3—Cu1ii | 1.952 (2) |
N2—O6 | 1.224 (3) | ||
O1—Cu1—O2 | 91.74 (8) | O5—N3—O4 | 123.3 (3) |
O1—Cu1—O3i | 173.49 (8) | O5—N3—C4 | 119.7 (3) |
O2—Cu1—O3i | 83.90 (8) | O4—N3—C4 | 117.1 (3) |
O1—Cu1—N1 | 90.78 (9) | C12—N1—C8 | 118.6 (2) |
O2—Cu1—N1 | 169.99 (10) | C12—N1—Cu1 | 121.62 (18) |
O3i—Cu1—N1 | 94.34 (9) | C8—N1—Cu1 | 119.7 (2) |
C7—O1—Cu1 | 127.25 (19) | C11—C10—C9 | 117.8 (3) |
C4—C3—C2 | 120.6 (3) | C11—C10—H10 | 121.1 |
C4—C3—H3 | 119.7 | C9—C10—H10 | 121.1 |
C2—C3—H3 | 119.7 | N1—C8—C9 | 121.6 (3) |
O1—C7—C6 | 120.2 (3) | N1—C8—H8 | 119.2 |
O1—C7—C2 | 124.6 (3) | C9—C8—H8 | 119.2 |
C6—C7—C2 | 115.2 (2) | C10—C9—O8 | 123.9 (3) |
C3—C2—C7 | 120.8 (3) | C10—C9—C8 | 120.0 (3) |
C3—C2—C1 | 116.8 (3) | O8—C9—C8 | 116.1 (3) |
C7—C2—C1 | 122.3 (2) | N1—C12—C11 | 121.6 (3) |
C5—C6—C7 | 123.8 (3) | N1—C12—H12 | 119.2 |
C5—C6—N2 | 116.2 (3) | C11—C12—H12 | 119.2 |
C7—C6—N2 | 119.9 (2) | C10—C11—C12 | 120.4 (3) |
C6—C5—C4 | 117.7 (3) | C10—C11—H11 | 119.8 |
C6—C5—H5 | 121.2 | C12—C11—H11 | 119.8 |
C4—C5—H5 | 121.2 | C9—O8—H8A | 109.5 |
C3—C4—C5 | 121.8 (3) | O3—C1—O2 | 121.0 (3) |
C3—C4—N3 | 118.9 (3) | O3—C1—C2 | 117.9 (3) |
C5—C4—N3 | 119.2 (3) | O2—C1—C2 | 121.0 (3) |
O7—N2—O6 | 123.5 (3) | C1—O2—Cu1 | 130.1 (2) |
O7—N2—C6 | 118.2 (3) | C1—O3—Cu1ii | 117.95 (19) |
O6—N2—C6 | 118.2 (3) |
Symmetry codes: (i) −x+1/2, y−1/2, −z+1/2; (ii) −x+1/2, y+1/2, −z+1/2. |
D—H···A | D—H | H···A | D···A | D—H···A |
O8—H8A···O4iii | 0.82 | 1.94 | 2.738 (3) | 165 |
Symmetry code: (iii) x−1, y−2, z. |
Experimental details
Crystal data | |
Chemical formula | [Cu(C7H2N2O7)(C5H5NO)] |
Mr | 384.75 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 296 |
a, b, c (Å) | 8.1055 (3), 6.2208 (2), 26.9837 (9) |
β (°) | 94.030 (3) |
V (Å3) | 1357.23 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.66 |
Crystal size (mm) | 0.25 × 0.16 × 0.09 |
Data collection | |
Diffractometer | Bruker APEXII area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.681, 0.865 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12917, 3094, 2275 |
Rint | 0.061 |
(sin θ/λ)max (Å−1) | 0.650 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.092, 1.03 |
No. of reflections | 3094 |
No. of parameters | 218 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.38, −0.45 |
Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2001), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O8—H8A···O4i | 0.82 | 1.94 | 2.738 (3) | 164.5 |
Symmetry code: (i) x−1, y−2, z. |
Acknowledgements
The authors thank Guang Dong Ocean University for supporting this study.
References
Bradshaw, D., Claridge, J. B., Cussen, E. J., Prior, T. J. & Rosseinsky, M. J. (2005). Acc. Chem. Res. 38, 273–282. Web of Science CrossRef PubMed CAS Google Scholar
Brandenburg, K. (2001). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2004). APEX2 and SAINT. Bruker AXS Inc, Madison, Wisconsin, USA. Google Scholar
Eddaoudi, M., Moler, D. B., Li, H. L., Chen, B. L., Reineke, T. M., O'Keeffe, M. & Yaghi, O. M. (2001). Acc. Chem. Res. 34, 319–330. Web of Science CrossRef PubMed CAS Google Scholar
Fujita, M., Kwon, Y. J., Washizu, S. & Ogura, K. (1994). J. Am. Chem. Soc. 116, 1151–1152. CSD CrossRef CAS Web of Science Google Scholar
Gable, R. W., Hoskins, B. F. & Robson, R. (1990). J. Chem. Soc. Chem. Commun. pp. 1677–1678. CrossRef Web of Science Google Scholar
Gao, S., Zhang, X.-F., Huo, L.-H. & Zhao, H. (2005). Acta Cryst. C61, m133–m135. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
He, X., Bi, M. H., Ye, K. Q., Fang, Q. R., Zhang, P., Xu, J. N. & Wang, Y. (2006). Inorg. Chem. Commun. 9, 1165–1168. Web of Science CSD CrossRef CAS Google Scholar
Li, H., Eddaoudi, M., O'Keeffe, M. & Yaghi, O. M. (1999). Nature (London), 402, 276–279. CAS Google Scholar
Losier, P. & Zaworotko, M. J. (1996). Angew. Chem. Int. Ed. Engl. 35, 2779–2782. CSD CrossRef CAS Web of Science Google Scholar
Moulton, B. & Zaworotko, M. J. (2001). Chem. Rev. 101, 1629–1658. Web of Science CrossRef PubMed CAS 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
Song, W.-D., Guo, X.-X. & Rong-Fa, G. (2007). Acta Cryst. E63, m737–m739. Web of Science CSD CrossRef IUCr Journals Google Scholar
Song, W.-D., Guo, X.-X. & He, H. (2007). Acta Cryst. E63, m610–m612. Web of Science CSD CrossRef IUCr Journals Google Scholar
Song, W.-D., Guo, X.-X. & Zhang, C.-H. (2007). Acta Cryst. E63, m399–m401. Web of Science CSD CrossRef IUCr Journals Google Scholar
Song, W.-D. & Xi, D.-L. (2006). Acta Cryst. E62, m3083–m3085. Web of Science CSD CrossRef IUCr Journals Google Scholar
Song, W.-D., Yan, J.-B., Guo, X.-X. & Ng, S. W. (2007). Acta Cryst. E63, m1307–m1308. Web of Science CSD CrossRef IUCr Journals Google Scholar
Stang, P. J. & Olenyuk, B. (1997). Acc. Chem. Res. 30, 502–518. Web of Science CrossRef CAS Google Scholar
Withersby, M. A., Blake, A. J., Champness, N. R., Cooke, P. A., Hubberstey, P. & Schroder, M. (1999). New J. Chem. 23, 573–576. Web of Science CSD CrossRef CAS Google Scholar
Yaghi, O. M. & Li, H. (1995). J. Am. Chem. Soc. 117, 10401–10402. CSD CrossRef CAS Web of Science 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.
Inorganic-organic coordination polymers have been a focus of contemporary research interest not only because of the intriguing variety of architectures and topologies but also because of their potential application in gas storage, catalysis, as molecular magnets, in molecular recognition and photoluminescene (Stang & Olenyuk,1997; Moulton & Zaworotko, 2001; Eddaoudi et al., 2001; Bradshaw et al., 2005). Over the past few decades considerable efforts have documented many networks with various structural motifs including honeycomb, brick-wall, rectangular grid, bilayer, ladder, herringbone, diamondoid and octahedral geometries (Gable et al., 1990; Fujita et al., 1994; Yaghi & Li, 1995; Losier & Zaworotko, 1996; Withersby et al., 1999; Li et al., 1999). Building blocks based on aromatic acids, such as benzoic acid and/or its substituted derivatives, have been used in the construction of coordination polymers. However, there are few examples of metal derivatives of 3,5-dinitrosalicylic acid, and examples of crystal structure reports are limited to silver and tin complexes only. 3,5-Dinitrosalicylic acid is, owing to its versatile coordination modes, an important multidentate ligand for metal complexes (He et al., 2006). Recently, some new structures with the 3,5-dinitrosalicylicate have been synthesized by our group (Song & Xi (2006), 2006; Song, Guo & Guo, 2007; Song, Guo & He, 2007; Song,Guo & Zhang, 2007; Song, Yan et al., 2007).
With the intention of studying the influences of aromatic bridging ligands on the frameworks of possible structures, we chose another non-chelating ligand, 3-hydroxyprridine, as a second ligand (Gao et al., 2005), and a new coordination polymer, [Cu(C7H3N2O7)(C5H5NO)]n, (I), was successfully synthesized.
The coordination environment of the copper center in complex (I) is depicted in Fig. 1. The asymmetric unit contains one CuII ion, one 3,5-dinitro-2-oxidobenzoate ligand and a 3-hydroxypyridine ligand. Coordination by one N atom and three O atoms from two different 3,5-dinitro-2-oxidobenzoate ligands and 3-hydroxypyridine ligand create a square planar CuII center, which is augmented by a less tightly bonded fifth phenol oxygen atom to form a square pyramidal five-coordinated complex with a basically flat base. The compound exhibits a double chain structure, in which the 3,5-dinitro-2-oxidobenzoate and 3-hydroxypyridine both act as bridging ligands interconnecting adjacent copper(II) centers to form an infinite double stranded chain along the b axis of the unit cell (Fig 2.). These double stranded chains are stabilized by intra-chain π-π interactions, and further linked through O—H···O hydrogen bonding interaction involving the hydroxyl group of the 3-hydroxypyridine ligand as the H-donor and a nitryl group of the 3,5-dinitro-2-oxidobenzoate ligand as the acceptor, thus forming a three-dimensional supramolecular network (Fig. 3). The centroid-to-centroid distance of adjacent aromatic rings is 3.719 (7) Å.