supplementary materials


hy2493 scheme

Acta Cryst. (2012). E68, m46    [ doi:10.1107/S1600536811052949 ]

Diaquabis(4-hydroxy-5-nitropyridine-2-carboxylato-[kappa]2N1,O2)copper(II)

F. Shi, J. Deng and H. Dai

Abstract top

In the title compound, [Cu(C6H3N2O5)2(H2O)2], the CuII ion, lying on an inversion center, is coordinated by two pyridine N atoms and two carboxylate O atoms from symmetry-related two 4-hydroxy-5-nitropyridine-2-carboxylate ligands, and two water molecules, forming a distorted octahedral geometry. In the crystal, O-H...O hydrogen bonds link the complex molecules. One of the H atoms of the water molecule is disordered over two sites of equal occupancy.

Comment top

Carboxylate ligands play an important role in constructing novel metal-organic frameworks (MOFs) in coordination chemistry. Especially, a large number of MOFs based on pyridyl dicarboxylic acid ligands containing N- and O-donors with multi-connecting ability have been constructed. 4-Hydroxyl-pyridine-2,6-dicarboxylic acid has been widely used in the construction of high-dimensional structures with large pores. It usually adopts diverse coordination binding modes such as chelating to one metal center, bridging bidentate in synsyn or synanti configuration to two or three metal centers. A systematic study of 3d–4f, 4d–4f and 3d–4d–4f complexes based on 4-hydroxyl-pyridine-2,6-dicarboxylic acid ligand has been undertaken (Zhao et al., 2006, 2009, 2011). However, to the best of our knowledge, no reports on the synthesis of the title compound have been seen in literature. In this paper, we report the synthesis and crystal structure of the title compound using a hydrothermal method with 4-hydroxyl-pyridine-2,6-dicarboxylic acid as ligand.

The title compound features a 3-nitro-4-hydroxyl-pyridine-6-carboxylate ligand, which was in situ generated by decarboxylation and nitration of 4-hydroxyl-pyridine-2,6-dicarboxylic acid under the hydrothermal conditions. A similar reaction has been reported (Xu et al., 2011). Structure analysis shows that the CuII ion is centrosymmetrically coordinated by two N atoms [Cu—N = 1.9685 (16) Å] and two carboxylate O atoms [Cu—O = 1.9667 (15) Å] from two 3-nitro-4-hydroxyl-pyridine-6-carboxylate ligands and two water molecules [Cu—O = 2.479 (2) Å], forming a distorted octahedral geometry, as shown in Fig. 1. O—H···O hydrogen bonds link the complex molecules (Table 1).

Related literature top

For complexes based on the 4-hydroxylpyridine-2,6-dicarboxylic acid ligand, see: Zhao et al. (2006, 2009, 2011). For a similar reaction to the formation of the ligand, see: Xu et al. (2011).

Experimental top

A mixture of 4-hydroxyl-pyridine-2,6-dicarboxylic acid (366 mg, 2.0 mmol), copper nitrate trihydrate (242 mg, 1.0 mmol), lanthanide nitrate hexahydrate (Ln = Eu, Sm, Pr, Tb) (1.0 mmol) and deionized water (10 ml) was placed in a 25 ml Teflon-lined steel autoclave, which was kept at 433 K for 3 days. The resuling blue prismatic crystals suitable for X-ray diffraction experiment were collected after washing with deionized water and diethyl ether (yield: 43% based on the mass of copper nitrate trihydrate).

Refinement top

H atoms bound to C atoms were positioned geometrically and refined as riding atoms, with C—H = 0.95 Å and with Uiso(H) = 1.2Ueq(C). H atoms bound to O atoms were located from a difference Fourier map and refined isotropically. One of H atoms of the water molecule is disordered over two sites with equal occupancy factors.

Computing details top

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 (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level. One of the disordered H atom sites on water molecule is not shown. [Symmetry code: (A) -x, 1-y, 1-z.]
Diaquabis(4-hydroxy-5-nitropyridine-2-carboxylato- κ2N1,O2)copper(II) top
Crystal data top
[Cu(C6H3N2O5)2(H2O)2]F(000) = 470
Mr = 465.79Dx = 2.023 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 3085 reflections
a = 6.5327 (7) Åθ = 2.1–27.9°
b = 9.7963 (10) ŵ = 1.52 mm1
c = 12.2562 (12) ÅT = 113 K
β = 102.86 (2)°Prism, colorless
V = 764.68 (15) Å30.20 × 0.18 × 0.10 mm
Z = 2
Data collection top
Rigaku Saturn 724 CCD
diffractometer
1829 independent reflections
Radiation source: rotating anode1466 reflections with I > 2σ(I)
multilayerRint = 0.053
Detector resolution: 14.22 pixels mm-1θmax = 27.9°, θmin = 2.7°
ω scansh = 87
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
k = 1212
Tmin = 0.752, Tmax = 0.863l = 1516
9563 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.029Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.077H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.036P)2]
where P = (Fo2 + 2Fc2)/3
1829 reflections(Δ/σ)max < 0.001
149 parametersΔρmax = 0.39 e Å3
6 restraintsΔρmin = 0.49 e Å3
Crystal data top
[Cu(C6H3N2O5)2(H2O)2]V = 764.68 (15) Å3
Mr = 465.79Z = 2
Monoclinic, P21/nMo Kα radiation
a = 6.5327 (7) ŵ = 1.52 mm1
b = 9.7963 (10) ÅT = 113 K
c = 12.2562 (12) Å0.20 × 0.18 × 0.10 mm
β = 102.86 (2)°
Data collection top
Rigaku Saturn 724 CCD
diffractometer
1829 independent reflections
Absorption correction: multi-scan
(CrystalClear; Rigaku, 2005)
1466 reflections with I > 2σ(I)
Tmin = 0.752, Tmax = 0.863Rint = 0.053
9563 measured reflectionsθmax = 27.9°
Refinement top
R[F2 > 2σ(F2)] = 0.029H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.077Δρmax = 0.39 e Å3
S = 1.04Δρmin = 0.49 e Å3
1829 reflectionsAbsolute structure: ?
149 parametersFlack parameter: ?
6 restraintsRogers parameter: ?
Special details top

Experimental. Rigaku CrystalClear-SM Expert 2.0 r2

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
Cu10.00000.50000.50000.01573 (13)
O10.0540 (2)0.53885 (14)0.66132 (12)0.0145 (3)
O20.1475 (2)0.70789 (14)0.78407 (11)0.0150 (3)
O30.3093 (2)1.08681 (14)0.52856 (13)0.0144 (3)
H30.331 (5)1.107 (3)0.592 (2)0.058 (11)*
O40.2830 (3)1.07679 (17)0.31323 (14)0.0291 (4)
O50.0819 (3)0.9216 (2)0.22215 (13)0.0408 (5)
O60.3578 (3)0.40247 (18)0.52615 (15)0.0253 (4)
H6A0.371 (5)0.381 (3)0.5936 (10)0.060 (11)*
H6B0.454 (7)0.455 (5)0.516 (3)0.06 (2)*0.50
H6C0.348 (10)0.332 (3)0.484 (3)0.09 (3)*0.50
N10.1030 (3)0.68775 (16)0.49202 (13)0.0113 (4)
C10.1142 (3)0.6591 (2)0.68823 (16)0.0121 (4)
C20.1493 (3)0.7498 (2)0.59364 (16)0.0108 (4)
C30.2222 (3)0.8799 (2)0.61022 (16)0.0109 (4)
H3A0.25760.91690.68370.013*
C40.2450 (3)0.9596 (2)0.51800 (17)0.0106 (4)
C50.1881 (3)0.8957 (2)0.41301 (16)0.0114 (4)
C60.1219 (3)0.7610 (2)0.40323 (16)0.0119 (4)
H60.08910.71970.33130.014*
N20.1874 (3)0.97025 (17)0.30795 (15)0.0150 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0276 (2)0.00876 (18)0.0110 (2)0.00692 (15)0.00460 (15)0.00212 (14)
O10.0212 (8)0.0095 (7)0.0123 (8)0.0040 (6)0.0028 (6)0.0002 (5)
O20.0251 (8)0.0103 (7)0.0088 (7)0.0004 (6)0.0021 (6)0.0006 (6)
O30.0201 (8)0.0090 (7)0.0146 (8)0.0040 (6)0.0052 (7)0.0001 (6)
O40.0442 (11)0.0199 (9)0.0253 (9)0.0091 (8)0.0124 (8)0.0029 (7)
O50.0523 (13)0.0497 (12)0.0151 (9)0.0240 (10)0.0036 (9)0.0070 (8)
O60.0271 (10)0.0238 (9)0.0234 (10)0.0057 (8)0.0019 (8)0.0029 (8)
N10.0125 (9)0.0104 (8)0.0100 (8)0.0010 (7)0.0004 (7)0.0013 (6)
C10.0107 (10)0.0107 (10)0.0149 (11)0.0005 (8)0.0027 (8)0.0031 (8)
C20.0123 (10)0.0102 (9)0.0091 (10)0.0006 (8)0.0006 (8)0.0012 (7)
C30.0109 (10)0.0116 (10)0.0093 (10)0.0000 (8)0.0007 (8)0.0011 (7)
C40.0077 (9)0.0100 (9)0.0145 (10)0.0007 (7)0.0030 (8)0.0003 (7)
C50.0104 (10)0.0139 (10)0.0105 (10)0.0004 (8)0.0034 (8)0.0030 (8)
C60.0117 (11)0.0149 (10)0.0099 (10)0.0002 (8)0.0036 (8)0.0028 (8)
N20.0150 (9)0.0165 (9)0.0136 (9)0.0015 (7)0.0033 (8)0.0011 (7)
Geometric parameters (Å, °) top
Cu1—N11.9685 (16)O6—H6C0.85 (1)
Cu1—O11.9667 (15)N1—C61.332 (2)
Cu1—O62.479 (2)N1—C21.358 (2)
O1—C11.263 (2)C1—C21.518 (3)
O2—C11.242 (2)C2—C31.360 (3)
O3—C41.312 (2)C3—C41.409 (3)
O3—H30.79 (3)C3—H3A0.9500
O4—N21.211 (2)C4—C51.405 (3)
O5—N21.219 (2)C5—C61.385 (3)
O6—H6A0.84 (1)C5—N21.480 (2)
O6—H6B0.85 (1)C6—H60.9500
O1—Cu1—O1i180.0O2—C1—C2118.24 (17)
O1—Cu1—N183.24 (6)O1—C1—C2115.97 (17)
O1i—Cu1—N196.76 (6)N1—C2—C3123.75 (18)
O1—Cu1—N1i96.76 (6)N1—C2—C1113.45 (17)
O1i—Cu1—N1i83.24 (6)C3—C2—C1122.80 (18)
N1—Cu1—N1i180.0C2—C3—C4119.73 (18)
O1—Cu1—O689.52 (6)C2—C3—H3A120.1
O1—Cu1—O6i90.48 (6)C4—C3—H3A120.1
N1—Cu1—O6i87.50 (7)O3—C4—C5121.85 (18)
O6—Cu1—N192.50 (7)O3—C4—C3122.42 (18)
O6—Cu1—O6i180.00C5—C4—C3115.70 (18)
C1—O1—Cu1114.76 (13)C6—C5—C4121.20 (18)
C4—O3—H3109 (2)C6—C5—N2117.04 (17)
H6A—O6—H6B112.7 (17)C4—C5—N2121.71 (17)
H6A—O6—H6C111.5 (17)N1—C6—C5121.74 (18)
H6B—O6—H6C111.2 (17)N1—C6—H6119.1
C6—N1—C2117.79 (17)C5—C6—H6119.1
C6—N1—Cu1129.69 (14)O4—N2—O5124.71 (18)
C2—N1—Cu1112.42 (13)O4—N2—C5118.54 (17)
O2—C1—O1125.79 (19)O5—N2—C5116.68 (17)
N1—Cu1—O1—C13.72 (14)N1—C2—C3—C42.6 (3)
N1i—Cu1—O1—C1176.28 (14)C1—C2—C3—C4178.09 (18)
O1—Cu1—N1—C6178.60 (18)C2—C3—C4—O3178.19 (18)
O1i—Cu1—N1—C61.40 (18)C2—C3—C4—C50.1 (3)
O1—Cu1—N1—C22.41 (13)O3—C4—C5—C6179.52 (18)
O1i—Cu1—N1—C2177.59 (13)C3—C4—C5—C62.4 (3)
Cu1—O1—C1—O2176.32 (16)O3—C4—C5—N23.1 (3)
Cu1—O1—C1—C24.1 (2)C3—C4—C5—N2175.00 (17)
C6—N1—C2—C33.0 (3)C2—N1—C6—C50.5 (3)
Cu1—N1—C2—C3179.66 (16)Cu1—N1—C6—C5176.56 (14)
C6—N1—C2—C1177.69 (16)C4—C5—C6—N12.1 (3)
Cu1—N1—C2—C11.0 (2)N2—C5—C6—N1175.38 (17)
O2—C1—C2—N1178.33 (17)C6—C5—N2—O4165.03 (19)
O1—C1—C2—N12.1 (3)C4—C5—N2—O417.5 (3)
O2—C1—C2—C32.3 (3)C6—C5—N2—O518.0 (3)
O1—C1—C2—C3177.27 (18)C4—C5—N2—O5159.5 (2)
Symmetry codes: (i) −x, −y+1, −z+1.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O3—H3···O2ii0.79 (3)1.79 (3)2.544 (2)160 (3)
O6—H6A···O2iii0.84 (1)2.28 (2)3.014 (2)146 (3)
O6—H6B···O6iv0.85 (1)2.00 (1)2.836 (3)170 (5)
O6—H6C···O3v0.85 (1)2.49 (3)3.109 (2)130 (3)
Symmetry codes: (ii) −x+1/2, y+1/2, −z+3/2; (iii) −x+1/2, y−1/2, −z+3/2; (iv) −x+1, −y+1, −z+1; (v) x, y−1, z.
Table 1
Hydrogen-bond geometry (Å, °)
top
D—H···AD—HH···AD···AD—H···A
O3—H3···O2i0.79 (3)1.79 (3)2.544 (2)160 (3)
O6—H6A···O2ii0.84 (1)2.28 (2)3.014 (2)146 (3)
O6—H6B···O6iii0.85 (1)2.00 (1)2.836 (3)170 (5)
O6—H6C···O3iv0.85 (1)2.49 (3)3.109 (2)130 (3)
Symmetry codes: (i) −x+1/2, y+1/2, −z+3/2; (ii) −x+1/2, y−1/2, −z+3/2; (iii) −x+1, −y+1, −z+1; (iv) x, y−1, z.
Acknowledgements top

This work was supported by the National High Technology Research and Development (863) Key Program of the Ministry of Science and Technology of China (No. 2009AA063201).

references
References top

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