metal-organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

A polymorph of di­aqua­bis­(pyrazine-2-carboxyl­ato-κ2N1,O)copper(II)

aThe State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China
*Correspondence e-mail: hunh@ciac.jl.cn, jwxu@ciac.jl.cn

(Received 26 October 2009; accepted 29 October 2009; online 4 November 2009)

The title compound, [Cu(C5H3N2O2)2(H2O)2], is a new polymorph of the previously reported compound [Klein et al. (1982[Klein, C. L., Majeste, R. J., Trefonas, L. M. & O'Connor, C. J. (1982). Inorg. Chem. 21, 1891-1897.]). Inorg. Chem. 21, 1891–1897]. The CuII atom, lying on an inversion center, is coordinated by two N atoms and two O atoms from two pyrazine-2-carboxyl­ate ligands and by two water mol­ecules in a distorted octa­hedral geometry with the water mol­ecules occupying the axial sites. Inter­molecular O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds connect the complex mol­ecules into a two-dimensional layer parallel to (10[\overline{1}]), whereas the previously reported polymorph exhibits a three-dimensional hydrogen-bonded network.

Related literature

For general background to metal complexes of pyrazine­carboxyl­ates, see: Dong et al. (2000[Dong, Y.-B., Smith, M. D. & zur Loye, H.-C. (2000). Inorg. Chem. 39, 1943-1949.]); Kubota et al. (2006[Kubota, Y., Takata, M., Matsuda, R., Kitaura, R., Kitagawa, S. & Kobayashi, T. C. (2006). Angew. Chem. Int. Ed. 45, 4932-4936.]); Luo et al. (2004[Luo, J., Alexander, B., Wagner, T. R. & Maggard, P. A. (2004). Inorg. Chem. 43, 5537-5542.]); Ptasiewicz-Bak et al. (1995[Ptasiewicz-Bak, H., Leciejewicz, J. & Zachara, J. (1995). J. Coord. Chem. 36, 317-326.]). For the previously reported polymorph, see: Klein et al. (1982[Klein, C. L., Majeste, R. J., Trefonas, L. M. & O'Connor, C. J. (1982). Inorg. Chem. 21, 1891-1897.]). For a related structure, see: Chutia et al. (2009[Chutia, P., Kato, S., Kojima, T. & Satokawa, S. (2009). Polyhedron, 28, 370-380.]).

[Scheme 1]

Experimental

Crystal data
  • [Cu(C5H3N2O2)2(H2O)2]

  • Mr = 345.76

  • Monoclinic, P 21 /n

  • a = 6.7066 (12) Å

  • b = 7.9041 (14) Å

  • c = 12.030 (2) Å

  • β = 105.036 (2)°

  • V = 615.88 (19) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 1.81 mm−1

  • T = 293 K

  • 0.29 × 0.25 × 0.20 mm

Data collection
  • Bruker SMART APEX CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.626, Tmax = 0.711

  • 3322 measured reflections

  • 1212 independent reflections

  • 1119 reflections with I > 2σ(I)

  • Rint = 0.014

Refinement
  • R[F2 > 2σ(F2)] = 0.024

  • wR(F2) = 0.071

  • S = 1.10

  • 1212 reflections

  • 98 parameters

  • H-atom parameters constrained

  • Δρmax = 0.24 e Å−3

  • Δρmin = −0.27 e Å−3

Table 1
Selected bond lengths (Å)

Cu1—O1 1.9486 (12)
Cu1—N1 1.9753 (14)
Cu1—O1W 2.6143 (14)

Table 2
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1W—H1A⋯O2i 0.82 1.99 2.796 (2) 168
O1W—H1B⋯N2ii 0.82 2.33 3.041 (2) 145
C1—H1⋯O2ii 0.93 2.42 3.226 (2) 144
Symmetry codes: (i) [x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]; (ii) [x+{\script{1\over 2}}, -y+{\script{1\over 2}}, z+{\script{1\over 2}}].

Data collection: SMART (Bruker, 2007[Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2007[Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Pyrazinecarboxylates have been extensively studied as excellent bridging ligands in the coordination chemistry research (Dong et al., 2000; Kubota et al., 2006; Luo et al., 2004; Ptasiewicz-Bak et al., 1995). The structure and magnetic properties of a copper(II) complex with the pyrazine-2-carboxylate (pzc) ligand (polymorph I) has been reported by Klein et al. (1982). We report here the structure of a new polymorph (polymorph II) of the title compound.

The polymorph II crystallizes in the monoclinic space group P21/n (polymorph I in P21/c). The CuII atom, lying on an inversion center, is six-coordinated in a distorted octahedral geometry, defined by two O atoms and two N atoms from two pzc ligands in the equatorial plane and two water molecules in the axial positions (Table 1 and Fig. 1). Weak coordination exists between the CuII center and the coordinated water molecule, with a Cu—O distance of 2.6143 (14) Å, due to Jahn-Teller effects. The bond lengths and angles are in normal ranges (Chutia et al., 2009; Klein et al., 1982). The coordinated water molecule donates its two H atoms to an uncoordinated carboxylate O atom and a pyrazine N atom of the neighboring molecules (Table 2 and Fig. 2). One complex molecule is linked to four neighboring molecules through these O—H···O and O—H···N hydrogen bonds, forming a two-dimensional layer in the (1 0 1) plane. Weak C—H···O hydrogen bond (Table 2) stabilizes the layer structure. In the previously reported polymorph I, the water molecule forms two O—H···O hydrogen bonds with a coordinated carboxylate O atom and an uncoordinated carboxylate O atom. One complex molecule is linked to six neighboring molecules, leading to a three-dimensional network.

Related literature top

For general background to metal complexes of pyrazinecarboxylates, see: Dong et al. (2000); Kubota et al. (2006); Luo et al. (2004); Ptasiewicz-Bak et al. (1995). For the previously reported polymorph, see: Klein et al. (1982). For a related structure, see: Chutia et al. (2009).

Experimental top

Aqueous triethylamine (0.05 ml) was added to a suspending solution of Hpzc (0.012 g, 0.1 mmol) in H2O (7 ml), followed by dropwise addition of a solution of Cu(NO3)2.3H2O (0.024 g, 0.1 mmol) in H2O (3 ml). The mixture was stirred and sealed in a 15 ml Teflon-lined stainless steel autoclave and heated at 413 K for 3 d under autogenous pressure. When the mixture was cooled to room temperature, blue block crystals of the title compound were obtained (yield 0.029 g, 85% based on Cu).

Refinement top

H atoms of the pyrazine ring were positioned geometrically and refined as riding atoms, with C—H = 0.93 Å and with Uiso(H) = 1.2Ueq(C). H atoms of the water molecule were located in a difference Fourier map and refined as riding, with O—H = 0.82 Å and with Uiso(H) = 1.2Ueq(O).

Computing details top

Data collection: SMART (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound. Displacement ellipsoids are drawn at the 30% probability level. [Symmetry code: (i) -x, 1 - y, 2 - z.]
[Figure 2] Fig. 2. A part of the two-dimensional layer structure in the title compound. Dashed lines denote hydrogen bonds.
diaquabis(pyrazine-2-carboxylato-κ2N1,O)copper(II) top
Crystal data top
[Cu(C5H3N2O2)2(H2O)2]F(000) = 350
Mr = 345.76Dx = 1.864 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2148 reflections
a = 6.7066 (12) Åθ = 3.1–26.1°
b = 7.9041 (14) ŵ = 1.81 mm1
c = 12.030 (2) ÅT = 293 K
β = 105.036 (2)°Block, blue
V = 615.88 (19) Å30.29 × 0.25 × 0.20 mm
Z = 2
Data collection top
Bruker SMART APEX CCD
diffractometer
1212 independent reflections
Radiation source: sealed tube1119 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.014
ϕ and ω scansθmax = 26.1°, θmin = 3.1°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 88
Tmin = 0.626, Tmax = 0.711k = 89
3322 measured reflectionsl = 714
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.024H-atom parameters constrained
wR(F2) = 0.071 w = 1/[σ2(Fo2) + (0.0427P)2 + 0.1736P]
where P = (Fo2 + 2Fc2)/3
S = 1.10(Δ/σ)max < 0.001
1212 reflectionsΔρmax = 0.24 e Å3
98 parametersΔρmin = 0.27 e Å3
0 restraintsExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.015 (3)
Crystal data top
[Cu(C5H3N2O2)2(H2O)2]V = 615.88 (19) Å3
Mr = 345.76Z = 2
Monoclinic, P21/nMo Kα radiation
a = 6.7066 (12) ŵ = 1.81 mm1
b = 7.9041 (14) ÅT = 293 K
c = 12.030 (2) Å0.29 × 0.25 × 0.20 mm
β = 105.036 (2)°
Data collection top
Bruker SMART APEX CCD
diffractometer
1212 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1119 reflections with I > 2σ(I)
Tmin = 0.626, Tmax = 0.711Rint = 0.014
3322 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0240 restraints
wR(F2) = 0.071H-atom parameters constrained
S = 1.10Δρmax = 0.24 e Å3
1212 reflectionsΔρmin = 0.27 e Å3
98 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Cu10.00000.50001.00000.03498 (16)
O10.0727 (2)0.61455 (15)0.85150 (10)0.0366 (3)
O20.1196 (2)0.56084 (18)0.66400 (11)0.0410 (3)
N10.0637 (2)0.30822 (17)0.90970 (11)0.0281 (3)
N20.0994 (2)0.0660 (2)0.74999 (14)0.0379 (4)
C10.1310 (3)0.1525 (2)0.94293 (15)0.0323 (4)
H10.16850.12521.02080.039*
C20.1451 (3)0.0321 (2)0.86246 (19)0.0388 (4)
H20.18800.07650.88740.047*
C30.0352 (3)0.2226 (2)0.71834 (15)0.0334 (4)
H30.00330.25090.64070.040*
C40.0146 (2)0.3439 (2)0.79692 (14)0.0277 (4)
C50.0665 (3)0.5207 (2)0.76592 (16)0.0299 (4)
O1W0.3669 (2)0.63676 (18)1.04173 (12)0.0483 (4)
H1A0.35510.72071.07960.058*
H1B0.46360.57881.07810.058*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cu10.0529 (2)0.0279 (2)0.0235 (2)0.00894 (12)0.00891 (15)0.00016 (10)
O10.0516 (8)0.0285 (6)0.0285 (7)0.0070 (5)0.0085 (5)0.0008 (5)
O20.0550 (8)0.0383 (7)0.0252 (7)0.0039 (6)0.0022 (6)0.0042 (6)
N10.0298 (7)0.0275 (7)0.0256 (7)0.0002 (5)0.0050 (5)0.0003 (6)
N20.0438 (9)0.0331 (8)0.0380 (9)0.0012 (7)0.0127 (7)0.0059 (7)
C10.0343 (9)0.0327 (9)0.0287 (9)0.0030 (7)0.0059 (7)0.0043 (7)
C20.0417 (10)0.0292 (9)0.0468 (12)0.0066 (7)0.0139 (9)0.0022 (8)
C30.0356 (9)0.0352 (9)0.0287 (9)0.0023 (7)0.0073 (7)0.0023 (7)
C40.0271 (8)0.0292 (8)0.0258 (8)0.0022 (6)0.0049 (6)0.0005 (6)
C50.0299 (8)0.0287 (8)0.0292 (10)0.0006 (6)0.0039 (7)0.0010 (7)
O1W0.0578 (9)0.0406 (8)0.0456 (8)0.0054 (6)0.0116 (7)0.0037 (6)
Geometric parameters (Å, º) top
Cu1—O11.9486 (12)C1—C21.378 (3)
Cu1—N11.9753 (14)C1—H10.9300
Cu1—O1W2.6143 (14)C2—H20.9300
O1—C51.279 (2)C3—C41.379 (2)
O2—C51.227 (2)C3—H30.9300
N1—C11.336 (2)C4—C51.510 (2)
N1—C41.340 (2)O1W—H1A0.82
N2—C31.333 (3)O1W—H1B0.82
N2—C21.335 (3)
O1i—Cu1—O1180.0N1—C1—H1119.8
O1i—Cu1—N1i83.73 (5)C2—C1—H1119.8
O1—Cu1—N1i96.27 (5)N2—C2—C1122.29 (18)
O1i—Cu1—N196.27 (5)N2—C2—H2118.9
O1—Cu1—N183.73 (5)C1—C2—H2118.9
N1i—Cu1—N1180.0N2—C3—C4122.17 (16)
O1W—Cu1—N195.50 (5)N2—C3—H3118.9
O1W—Cu1—O189.03 (5)C4—C3—H3118.9
O1W—Cu1—N1i84.50 (5)N1—C4—C3120.37 (16)
O1W—Cu1—O1i90.97 (5)N1—C4—C5115.01 (15)
C5—O1—Cu1114.57 (11)C3—C4—C5124.60 (16)
C1—N1—C4118.16 (14)O2—C5—O1126.37 (16)
C1—N1—Cu1130.31 (12)O2—C5—C4118.61 (16)
C4—N1—Cu1111.33 (11)O1—C5—C4115.02 (15)
C3—N2—C2116.61 (16)H1A—O1W—H1B109
N1—C1—C2120.36 (16)
Symmetry code: (i) x, y+1, z+2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1A···O2ii0.821.992.796 (2)168
O1W—H1B···N2iii0.822.333.041 (2)145
C1—H1···O2iii0.932.423.226 (2)144
Symmetry codes: (ii) x+1/2, y+3/2, z+1/2; (iii) x+1/2, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formula[Cu(C5H3N2O2)2(H2O)2]
Mr345.76
Crystal system, space groupMonoclinic, P21/n
Temperature (K)293
a, b, c (Å)6.7066 (12), 7.9041 (14), 12.030 (2)
β (°) 105.036 (2)
V3)615.88 (19)
Z2
Radiation typeMo Kα
µ (mm1)1.81
Crystal size (mm)0.29 × 0.25 × 0.20
Data collection
DiffractometerBruker SMART APEX CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.626, 0.711
No. of measured, independent and
observed [I > 2σ(I)] reflections
3322, 1212, 1119
Rint0.014
(sin θ/λ)max1)0.618
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.024, 0.071, 1.10
No. of reflections1212
No. of parameters98
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.24, 0.27

Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2006), SHELXTL (Sheldrick, 2008).

Selected bond lengths (Å) top
Cu1—O11.9486 (12)Cu1—O1W2.6143 (14)
Cu1—N11.9753 (14)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H1A···O2i0.821.992.796 (2)168
O1W—H1B···N2ii0.822.333.041 (2)145
C1—H1···O2ii0.932.423.226 (2)144
Symmetry codes: (i) x+1/2, y+3/2, z+1/2; (ii) x+1/2, y+1/2, z+1/2.
 

Acknowledgements

The authors thank Changchun Institute of Applied Chemistry for supporting this work.

References

First citationBruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationChutia, P., Kato, S., Kojima, T. & Satokawa, S. (2009). Polyhedron, 28, 370–380.  Web of Science CSD CrossRef CAS Google Scholar
First citationDong, Y.-B., Smith, M. D. & zur Loye, H.-C. (2000). Inorg. Chem. 39, 1943–1949.  Web of Science CSD CrossRef PubMed CAS Google Scholar
First citationKlein, C. L., Majeste, R. J., Trefonas, L. M. & O'Connor, C. J. (1982). Inorg. Chem. 21, 1891–1897.  CSD CrossRef CAS Web of Science Google Scholar
First citationKubota, Y., Takata, M., Matsuda, R., Kitaura, R., Kitagawa, S. & Kobayashi, T. C. (2006). Angew. Chem. Int. Ed. 45, 4932–4936.  Web of Science CSD CrossRef CAS Google Scholar
First citationLuo, J., Alexander, B., Wagner, T. R. & Maggard, P. A. (2004). Inorg. Chem. 43, 5537–5542.  Web of Science CrossRef PubMed CAS Google Scholar
First citationMacrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationPtasiewicz-Bak, H., Leciejewicz, J. & Zachara, J. (1995). J. Coord. Chem. 36, 317–326.  CrossRef CAS Web of Science Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals 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.

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds