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Acta Cryst. (2009). E65, m1412    [ doi:10.1107/S1600536809041440 ]

Poly[[bis([mu]2-6-methylpyrazin-2-carboxylato-[kappa]3N1,O:N4)copper(II)] dihydrate]

C. Fan, X.-T. Wei and L. Li

Abstract top

In the title compound, {[Cu(C6H5N2O2)2]·2H2O}n, the CuII ion (site symmetry \overline{1}) is coordinated by two N,O-bidentate ligands and two N-monodentate ligands in a distorted CuO2N4 octahedral geometry. Each anion acts as a bridge between two cations, thus forming a two-dimensional polymeric network parallel to the ab plane. The packing is consolidated by O-H...O hydrogen bonds. One of the O atoms of the ligand and both water molecules are disordered.

Comment top

In recent years,the construction of metal-organic coordination polymers (MOCPs) by metal-directed self- assembly is of great interest not only for their potential applications as functional materials in ion exchange, catalysis, hydrogen storage, and magnetic devices, but also for their aesthetic structural and host–guest chemistry associated with large central cavities. (Kesanli et al., 2003; Barnett et al., 2003). As an extension of this work,the 6-methyl-2- pyrazinecarboxylic acid was chosen due to its chelating coordinated effect leading to a linear metal center.

As shown in Fig.1. X-ray structural analyses of complex (1) reveal the core structure of (1) is the symmetric dinuclear unit of [Cu(L)2(H2O)2] (L = anion of 6-methyl-2- pyrazinecarboxylic acid). Each CuII atom is coordinated to two ligands as well as to the two N atoms of the other two ligands, forming a octahedral coordination conformation.

The ligand forms a coordination polymer with tridentate and monodentate binding of CuII ions at opposite ends of the ligand bridge neighboring units and yield a two-dimensional arrangement running in the ab plane (Fig. 2). Yigit et al. (2006) recently reported a coordination polymer featuring a similar head-to-tail arrangement of pyrazine-2,3,5,6-tetracarboxylic acid. There is intermolecular H-bonds (O3—H3···O4) showed as strong H bond, which link the molecular and water to form host–guest model.

Related literature top

For a related structure, see: Yigit et al. (2006). For background to coordination networks, see: Kesanli & Lin (2003); Barnett & Champness (2003).

Experimental top

4.00 g Potassium permanganate was to be dissolved in 30 ml pure water in a beaker and 1.0 ml 98% H2SO4 was added to the solution. After stiring 10 min, and then added 2,6-dimethylpyrazine to the mixture.The recation was keeping at room temperature for 24 h. The resulting solution was filtered, and the filtrate was left in a beaker, then 2.00 g copper(II) sulfate pentahydrate was added to the filtrate. After stirrng for 20 min s, the copper(II) sulfate pentahydrate was solved completely. The blue solution was kept at the room temperature for two weeks and blue blocks of (I) were obtained. Yield: 86percent, m.p. 551 K. Anal. Calc. for C12H14CuN4O6: C: 38.5567; H:3.7750; N:14.9881; Found:C: 37.67; H: 3.86; N: 14.32%. Selected IR (KBr, cm-1) 3439(w), 2889 (w), 1638(s), 1596 (s), 1536(w), 1409(s), 1364(m), 1275(m), 1149(s), 1151(s), 1034(s), 941(s), 820(m), 800(s), 712(w), 531(m), 471(w).

Refinement top

All H atoms were placed geometrically and treated as riding on their parent atoms with C—H 0.93(pyrazine), C—H 0.97 (methylene) Å [Uiso(H) = 1.2Ueq(C)] and O—H 0.82 Å (hydroxyl) [Uiso(H) = 1.5Ueq(O)].

Computing details top

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); 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. The molecular structure of (I) showing 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. The crystal packing of (I), viewed approximately along the c axis.
Poly[[bis(µ2-6-methylpyrazin-2-carboxylato- κ3N1,O:N4)copper(II)] dihydrate] top
Crystal data top
[Cu(C6H5N2O2)2]·2H2OF(000) = 382
Mr = 373.81Dx = 1.576 Mg m−3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1598 reflections
a = 8.371 (1) Åθ = 2.6–26.2°
b = 9.7901 (11) ŵ = 1.42 mm−1
c = 10.3849 (13) ÅT = 298 K
β = 112.277 (1)°Block, blue
V = 787.55 (16) Å30.34 × 0.32 × 0.30 mm
Z = 2
Data collection top
Bruker SMART CCD
diffractometer		1388 independent reflections
Radiation source: fine-focus sealed tube1094 reflections with I > 2σ(I)
graphiteRint = 0.027
ω scansθmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2003)		h = −9→9
Tmin = 0.644, Tmax = 0.675k = −11→11
3821 measured reflectionsl = −12→9
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)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.160H-atom parameters constrained
S = 1.06 w = 1/[σ2(Fo2) + (0.0987P)2 + 1.8186P]
where P = (Fo2 + 2Fc2)/3
1388 reflections(Δ/σ)max = 0.001
126 parametersΔρmax = 1.23 e Å−3
0 restraintsΔρmin = −0.47 e Å−3
Crystal data top
[Cu(C6H5N2O2)2]·2H2OV = 787.55 (16) Å3
Mr = 373.81Z = 2
Monoclinic, P21/cMo Kα radiation
a = 8.371 (1) ŵ = 1.42 mm−1
b = 9.7901 (11) ÅT = 298 K
c = 10.3849 (13) Å0.34 × 0.32 × 0.30 mm
β = 112.277 (1)°
Data collection top
Bruker SMART CCD
diffractometer		1388 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2003)		1094 reflections with I > 2σ(I)
Tmin = 0.644, Tmax = 0.675Rint = 0.027
3821 measured reflectionsθmax = 25.0°
Refinement top
R[F2 > 2σ(F2)] = 0.049H-atom parameters constrained
wR(F2) = 0.160Δρmax = 1.23 e Å−3
S = 1.06Δρmin = −0.47 e Å−3
1388 reflectionsAbsolute structure: ?
126 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

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)
Cu10.50000.50000.50000.0210 (3)
N10.5565 (5)0.3429 (4)0.3509 (4)0.0273 (9)
N20.5246 (5)0.1511 (4)0.1450 (4)0.0270 (9)
O10.2704 (4)0.4333 (3)0.3861 (3)0.0259 (7)
O20.1014 (18)0.343 (6)0.184 (5)0.049 (10)0.46 (9)
O2'0.1110 (16)0.279 (5)0.235 (4)0.049 (9)0.54 (9)
O30.8445 (18)0.5171 (12)0.0914 (16)0.097 (4)0.50
H3C0.93070.46390.12480.116*0.50
H3D0.86310.58770.14260.116*0.50
O40.499 (3)0.4908 (16)0.9398 (18)0.126 (6)0.50
H4D0.59040.50251.01210.152*0.50
H4E0.41220.49290.96280.152*0.50
C10.2469 (6)0.3484 (6)0.2899 (6)0.0411 (14)
C20.4033 (6)0.2942 (5)0.2678 (5)0.0302 (11)
C30.3863 (6)0.1987 (6)0.1653 (5)0.0337 (12)
H30.27710.16720.10960.040*
C40.6768 (6)0.1996 (5)0.2266 (5)0.0319 (11)
H4A0.77500.16820.21460.038*
C50.6955 (6)0.2969 (5)0.3308 (5)0.0301 (11)
C60.8676 (7)0.3506 (7)0.4211 (6)0.0496 (16)
H6A0.85320.42830.47210.074*
H6B0.93000.37750.36440.074*
H6C0.93090.28090.48500.074*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0214 (5)0.0226 (5)0.0193 (5)−0.0019 (3)0.0079 (3)0.0006 (3)
N10.023 (2)0.033 (2)0.026 (2)−0.0023 (17)0.0093 (16)−0.0047 (17)
N20.025 (2)0.031 (2)0.027 (2)−0.0020 (18)0.0120 (16)−0.0056 (17)
O10.0234 (16)0.0301 (18)0.0267 (17)−0.0018 (14)0.0124 (13)−0.0062 (15)
O20.025 (5)0.065 (19)0.054 (13)−0.004 (6)0.012 (5)−0.030 (15)
O2'0.025 (4)0.065 (17)0.054 (11)−0.004 (5)0.012 (5)−0.030 (12)
O30.074 (8)0.092 (10)0.115 (11)0.018 (6)0.026 (8)0.013 (7)
O40.120 (14)0.133 (15)0.129 (17)−0.002 (9)0.050 (14)0.000 (11)
C10.019 (3)0.058 (4)0.045 (3)−0.004 (2)0.010 (2)−0.019 (3)
C20.025 (3)0.033 (3)0.032 (3)−0.004 (2)0.010 (2)−0.010 (2)
C30.025 (3)0.041 (3)0.035 (3)−0.004 (2)0.011 (2)−0.012 (2)
C40.023 (3)0.040 (3)0.034 (3)0.002 (2)0.012 (2)−0.007 (2)
C50.026 (3)0.032 (3)0.033 (3)−0.002 (2)0.012 (2)−0.006 (2)
C60.024 (3)0.068 (4)0.054 (4)−0.001 (3)0.011 (3)−0.027 (3)
Geometric parameters (Å, °) top
Cu1—O1i1.949 (3)O3—H3C0.8500
Cu1—O11.949 (3)O3—H3D0.8500
Cu1—N2ii2.064 (4)O4—O4v1.26 (3)
Cu1—N2iii2.064 (4)O4—H4D0.8500
Cu1—N1i2.354 (4)O4—H4E0.8500
Cu1—N12.354 (4)C1—C21.509 (7)
N1—C21.333 (6)C2—C31.383 (7)
N1—C51.336 (6)C3—H30.9300
N2—C41.322 (6)C4—C51.405 (7)
N2—C31.337 (6)C4—H4A0.9300
N2—Cu1iv2.065 (4)C5—C61.486 (7)
O1—C11.256 (6)C6—H6A0.9600
O2—C11.30 (3)C6—H6B0.9600
O2'—C11.26 (2)C6—H6C0.9600
O1i—Cu1—O1180.0H4D—O4—H4E109.0
O1i—Cu1—N2ii89.70 (14)O1—C1—O2'124.0 (8)
O1—Cu1—N2ii90.30 (14)O1—C1—O2121.0 (11)
O1i—Cu1—N2iii90.30 (14)O2'—C1—O236.7 (6)
O1—Cu1—N2iii89.70 (14)O1—C1—C2118.1 (4)
N2ii—Cu1—N2iii180.0O2'—C1—C2115.3 (8)
O1i—Cu1—N1i77.27 (13)O2—C1—C2116.5 (8)
O1—Cu1—N1i102.73 (13)N1—C2—C3122.2 (5)
N2ii—Cu1—N1i88.74 (15)N1—C2—C1116.9 (4)
N2iii—Cu1—N1i91.26 (15)C3—C2—C1120.9 (4)
O1i—Cu1—N1102.73 (13)N2—C3—C2121.0 (4)
O1—Cu1—N177.27 (13)N2—C3—H3119.5
N2ii—Cu1—N191.26 (15)C2—C3—H3119.5
N2iii—Cu1—N188.74 (15)N2—C4—C5122.4 (4)
N1i—Cu1—N1180.0N2—C4—H4A118.8
C2—N1—C5117.4 (4)C5—C4—H4A118.8
C2—N1—Cu1106.0 (3)N1—C5—C4120.0 (4)
C5—N1—Cu1136.6 (3)N1—C5—C6118.4 (4)
C4—N2—C3117.1 (4)C4—C5—C6121.6 (4)
C4—N2—Cu1iv122.0 (3)C5—C6—H6A109.5
C3—N2—Cu1iv120.8 (3)C5—C6—H6B109.5
C1—O1—Cu1121.7 (3)H6A—C6—H6B109.5
H3C—O3—H3D108.5C5—C6—H6C109.5
O4v—O4—H4D55.8H6A—C6—H6C109.5
O4v—O4—H4E53.3H6B—C6—H6C109.5
O1i—Cu1—N1—C2−179.1 (3)C5—N1—C2—C1−179.1 (5)
O1—Cu1—N1—C20.9 (3)Cu1—N1—C2—C10.0 (5)
N2ii—Cu1—N1—C290.9 (3)O1—C1—C2—N1−1.4 (8)
N2iii—Cu1—N1—C2−89.1 (3)O2'—C1—C2—N1−164 (3)
N1i—Cu1—N1—C2168 (100)O2—C1—C2—N1155 (4)
O1i—Cu1—N1—C5−0.4 (5)O1—C1—C2—C3178.9 (5)
O1—Cu1—N1—C5179.6 (5)O2'—C1—C2—C317 (3)
N2ii—Cu1—N1—C5−90.4 (5)O2—C1—C2—C3−24 (4)
N2iii—Cu1—N1—C589.6 (5)C4—N2—C3—C2−0.2 (8)
N1i—Cu1—N1—C5−13 (100)Cu1iv—N2—C3—C2176.2 (4)
O1i—Cu1—O1—C15(100)N1—C2—C3—N2−0.1 (8)
N2ii—Cu1—O1—C1−93.0 (4)C1—C2—C3—N2179.6 (5)
N2iii—Cu1—O1—C187.0 (4)C3—N2—C4—C50.0 (8)
N1i—Cu1—O1—C1178.2 (4)Cu1iv—N2—C4—C5−176.3 (4)
N1—Cu1—O1—C1−1.8 (4)C2—N1—C5—C4−0.8 (7)
Cu1—O1—C1—O2'163 (3)Cu1—N1—C5—C4−179.5 (4)
Cu1—O1—C1—O2−153 (4)C2—N1—C5—C6179.4 (5)
Cu1—O1—C1—C22.4 (7)Cu1—N1—C5—C60.7 (8)
C5—N1—C2—C30.6 (7)N2—C4—C5—N10.5 (8)
Cu1—N1—C2—C3179.7 (4)N2—C4—C5—C6−179.7 (5)
Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x, −y+1/2, z+1/2; (iii) −x+1, y+1/2, −z+1/2; (iv) −x+1, y−1/2, −z+1/2; (v) −x+1, −y+1, −z+2.
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O3—H3C···O2vi0.851.782.624 (3)175
O3—H3C···O2'vi0.852.363.181 (3)163
O3—H3D···O2'iii0.852.233.074 (2)175
O4—H4D···O3vii0.851.972.73 (3)147
O4—H4E···O3i0.852.012.77 (2)150
Symmetry codes: (vi) x+1, y, z; (iii) −x+1, y+1/2, −z+1/2; (vii) x, y, z+1; (i) −x+1, −y+1, −z+1.
Table 1
Selected geometric parameters (Å) top
Cu1—O11.949 (3)Cu1—N12.354 (4)
Cu1—N2i2.064 (4)
Symmetry codes: (i) −x+1, y+1/2, −z+1/2.
Table 2
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O3—H3C···O2ii0.851.782.624 (3)175
O3—H3C···O2'ii0.852.363.181 (3)163
O3—H3D···O2'i0.852.233.074 (2)175
O4—H4D···O3iii0.851.972.73 (3)147
O4—H4E···O3iv0.852.012.77 (2)150
Symmetry codes: (ii) x+1, y, z; (i) −x+1, y+1/2, −z+1/2; (iii) x, y, z+1; (iv) −x+1, −y+1, −z+1.
references
References top

Barnett, S. A. & Champness, N. R. (2003). Coord. Chem. Rev. 246, 145–168.

Bruker (2003). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Kesanli, B. & Lin, W. B. (2003). Coord. Chem. Rev. 246, 305–326.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Yigit, M. V., Wang, Y., Moulton, B. & MacDonald, J. C. (2006). Cryst. Growth Des. 6, 829–832.