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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Poly[aqua­hemi(μ4-oxalato)[μ3-5-(pyrazin-2-yl)tetra­zolato]cadmium(II)]

aSchool of Chemistry and Environment, South China Normal University, Guangzhou 510006, People's Republic of China, and bSchool of Chemistry and Chemical Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China
*Correspondence e-mail: zhangchen723@yahoo.com.cn

(Received 5 July 2010; accepted 10 July 2010; online 17 July 2010)

In the title polymeric complex, [Cd(C5H3N6)(C2O4)0.5(H2O)]n, the CdII ion is coordinated by four O atoms and three N atoms from two 5-(pyrazin-2-yl)tetra­zolate ligands, two oxalate ligands and one water mol­ecule, displaying a distorted monocapped octa­hedral geometry. The bridging ligands link metal centres, forming a three-dimensional network which is stabilized by inter­molecular O—H⋯N hydrogen-bonding inter­actions.

Related literature

For related structures, see: Deng et al. (2007[Deng, H., Qiu, Y.-C., Zeng, R.-H. & Sun, F. (2007). Acta Cryst. E63, m450-m451.]); Zeng et al. (2007[Zeng, R.-H., Qiu, Y.-C., Liu, Z.-H., Li, Y.-H. & Deng, H. (2007). Acta Cryst. E63, m1591.]). For graph-set notation, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • [Cd(C5H3N6)(C2O4)0.5(H2O)]

  • Mr = 321.56

  • Monoclinic, P 21 /n

  • a = 5.8801 (1) Å

  • b = 13.1286 (2) Å

  • c = 11.5647 (2) Å

  • β = 94.867 (1)°

  • V = 889.55 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 2.46 mm−1

  • T = 296 K

  • 0.24 × 0.22 × 0.19 mm

Data collection
  • Bruker APEXII area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2008a[Sheldrick, G. M. (2008a). SADABS. University of Göttingen, Germany.]) Tmin = 0.590, Tmax = 0.652

  • 7467 measured reflections

  • 1588 independent reflections

  • 1566 reflections with I > 2σ(I)

  • Rint = 0.031

Refinement
  • R[F2 > 2σ(F2)] = 0.023

  • wR(F2) = 0.056

  • S = 1.19

  • 1588 reflections

  • 151 parameters

  • 3 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.33 e Å−3

  • Δρmin = −0.77 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1W—H2W⋯N4i 0.82 (3) 2.08 (3) 2.897 (4) 174 (4)
O1W—H1W⋯N3ii 0.82 (3) 1.93 (3) 2.757 (4) 179 (5)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2004[Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2004[Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b[Sheldrick, G. M. (2008b). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b[Sheldrick, G. M. (2008b). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008b[Sheldrick, G. M. (2008b). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

In recent years, research on coordination polymers has made considerable progress in the fields of supramolecular chemistry and crystal engineering, because of their intriguing structural motifs and functional properties, such as molecular adsorption, magnetism, and luminescence. The reports on tetrazoles are expanding rapidly, since tetrazoles have an important role in coordination chemistry as ligands (Deng et al. 2007; Zeng et al. 2007). In the general reaction, tetrazoles are prepared by the addition of an azide to nitriles in water with the aid of a Lewis acid such a Zn2+. In this paper is reported the crystal structure of the title coordination polymer, which has been obtained under hydrothermal condition using 2-cyanopyrazine, NaN3, oxalic acid and the Lewis acid CdCl2 as reagents.

In the structure of the title compound (Fig. 1), each cadmium(II) centre is seven-coordinated by four O atoms and three N atoms from two 5-(2-pyrazinyl)tetrazolate ligands, two oxalate ligands and one water molecule, and can described as having a distorted monocapped octahedral geometry with Cd···O and Cd···N distances ranging from 2.312 (2) to 2.404 (2) Å and from 2.284 (3) to 2.700 (3) Å, respectively. The 5-(2-pyrazinyl)tetrazolate and oxalate ligands act as bridging ligands, linking the metal centres to assemble a three-dimensional motif (Fig. 2). Within the three-dimensional network, centrosymmetrically related water molecules interact with adjacent tetrazolate ligands through O—H···N hydrogen bonds to form ten-membered rings with R44(10) motifs (Bernstein et al., 1995).

Related literature top

For related structures, see: Deng et al. (2007); Zeng et al. (2007). For graph-set notation, see: Bernstein et al. (1995).

Experimental top

A mixture of CdCl2 (0.183 g; 1 mmol), 2-cyanopyrazine (0.105 g; 1 mmol), oxalic acid (0.09 g; 1 mmol) and NaN3 (0.065, 1 mmol) in water (10 ml) was stirred vigorously for 30 min and then sealed in a Teflon-lined stainless-steel autoclave (20 ml capacity). The autoclave was heated and maintained at 422 K for 50 h, and then cooled to room temperature at 5 K h-1. Colourless block crystals suitable for X-ray analysis were obtained.

Refinement top

Water H atoms were located in a difference Fourier map and were refined with distance restraints of O–H = 0.82 Å and H···H = 1.35 Å, and with Uiso(H) = 1.5 Ueq(O). Other H atoms were placed in calculated positions (C—H = 0.93 Å) and refined using a riding model, with Uiso(H) = 1.2Ueq(C)

Structure description top

In recent years, research on coordination polymers has made considerable progress in the fields of supramolecular chemistry and crystal engineering, because of their intriguing structural motifs and functional properties, such as molecular adsorption, magnetism, and luminescence. The reports on tetrazoles are expanding rapidly, since tetrazoles have an important role in coordination chemistry as ligands (Deng et al. 2007; Zeng et al. 2007). In the general reaction, tetrazoles are prepared by the addition of an azide to nitriles in water with the aid of a Lewis acid such a Zn2+. In this paper is reported the crystal structure of the title coordination polymer, which has been obtained under hydrothermal condition using 2-cyanopyrazine, NaN3, oxalic acid and the Lewis acid CdCl2 as reagents.

In the structure of the title compound (Fig. 1), each cadmium(II) centre is seven-coordinated by four O atoms and three N atoms from two 5-(2-pyrazinyl)tetrazolate ligands, two oxalate ligands and one water molecule, and can described as having a distorted monocapped octahedral geometry with Cd···O and Cd···N distances ranging from 2.312 (2) to 2.404 (2) Å and from 2.284 (3) to 2.700 (3) Å, respectively. The 5-(2-pyrazinyl)tetrazolate and oxalate ligands act as bridging ligands, linking the metal centres to assemble a three-dimensional motif (Fig. 2). Within the three-dimensional network, centrosymmetrically related water molecules interact with adjacent tetrazolate ligands through O—H···N hydrogen bonds to form ten-membered rings with R44(10) motifs (Bernstein et al., 1995).

For related structures, see: Deng et al. (2007); Zeng et al. (2007). For graph-set notation, see: Bernstein et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: SHELXTL (Sheldrick, 2008b); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title complound showing the atomic-numbering scheme and displacement ellipsoids drawn at the 50% probability level. Symmetry codes: (i) 1-x, 1-y, 2-z; (ii) -1+x, y, z; (iii) -0.5-x, -1/2+y, 1.5-z.
[Figure 2] Fig. 2. A view of the three-dimensional network of the title compound. Hydrogen bonds are shown as dashed lines.
Poly[aquahemi(µ4-oxalato)[µ3-5-(pyrazin-2-yl)tetrazolato]cadmium(II)] top
Crystal data top
[Cd(C5H3N6)(C2O4)0.5(H2O)]F(000) = 620
Mr = 321.56Dx = 2.401 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 1076 reflections
a = 5.8801 (1) Åθ = 1.4–28.0°
b = 13.1286 (2) ŵ = 2.46 mm1
c = 11.5647 (2) ÅT = 296 K
β = 94.867 (1)°Block, colourless
V = 889.55 (3) Å30.24 × 0.22 × 0.19 mm
Z = 4
Data collection top
Bruker APEXII area-detector
diffractometer
1588 independent reflections
Radiation source: fine-focus sealed tube1566 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.031
φ and ω scanθmax = 25.2°, θmin = 2.4°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008a)
h = 77
Tmin = 0.590, Tmax = 0.652k = 1315
7467 measured reflectionsl = 1213
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)] = 0.023Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.056H atoms treated by a mixture of independent and constrained refinement
S = 1.19 w = 1/[σ2(Fo2) + (0.0221P)2 + 1.3797P]
where P = (Fo2 + 2Fc2)/3
1588 reflections(Δ/σ)max = 0.001
151 parametersΔρmax = 0.33 e Å3
3 restraintsΔρmin = 0.77 e Å3
Crystal data top
[Cd(C5H3N6)(C2O4)0.5(H2O)]V = 889.55 (3) Å3
Mr = 321.56Z = 4
Monoclinic, P21/nMo Kα radiation
a = 5.8801 (1) ŵ = 2.46 mm1
b = 13.1286 (2) ÅT = 296 K
c = 11.5647 (2) Å0.24 × 0.22 × 0.19 mm
β = 94.867 (1)°
Data collection top
Bruker APEXII area-detector
diffractometer
1588 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2008a)
1566 reflections with I > 2σ(I)
Tmin = 0.590, Tmax = 0.652Rint = 0.031
7467 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0233 restraints
wR(F2) = 0.056H atoms treated by a mixture of independent and constrained refinement
S = 1.19Δρmax = 0.33 e Å3
1588 reflectionsΔρmin = 0.77 e Å3
151 parameters
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*/Ueq
Cd10.06773 (3)0.544930 (16)0.847068 (19)0.01725 (10)
C10.0857 (5)0.7869 (2)0.8871 (3)0.0205 (6)
C20.1305 (5)0.7892 (2)0.8144 (3)0.0199 (6)
C30.2443 (6)0.8798 (2)0.7882 (3)0.0246 (7)
H30.18540.94020.82030.029*
C40.5172 (6)0.7932 (3)0.6778 (3)0.0269 (7)
H40.65100.79190.62880.032*
C50.4074 (6)0.7024 (3)0.7069 (3)0.0250 (7)
H50.47240.64160.67930.030*
C60.5686 (5)0.5102 (2)0.9467 (3)0.0180 (6)
N10.1910 (5)0.6999 (2)0.9168 (2)0.0227 (6)
N20.3821 (5)0.7263 (2)0.9813 (3)0.0287 (7)
N30.3872 (5)0.8258 (2)0.9887 (3)0.0287 (6)
N40.2027 (5)0.8672 (2)0.9305 (3)0.0270 (6)
N50.2106 (5)0.69963 (19)0.7735 (2)0.0220 (6)
N60.4366 (5)0.8823 (2)0.7180 (2)0.0232 (6)
O10.4638 (4)0.51192 (18)0.84910 (19)0.0227 (5)
O20.7803 (4)0.52289 (17)0.9693 (2)0.0225 (5)
O1W0.1382 (5)0.56000 (19)0.6539 (2)0.0317 (6)
H1W0.062 (7)0.594 (2)0.605 (3)0.048*
H2W0.176 (7)0.5058 (18)0.626 (3)0.048*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Cd10.01395 (14)0.01826 (15)0.01932 (15)0.00172 (8)0.00015 (9)0.00031 (8)
C10.0230 (16)0.0187 (15)0.0206 (16)0.0008 (12)0.0063 (12)0.0033 (13)
C20.0198 (15)0.0194 (15)0.0214 (16)0.0016 (12)0.0067 (12)0.0020 (13)
C30.0279 (18)0.0195 (16)0.0268 (18)0.0002 (13)0.0052 (14)0.0011 (13)
C40.0233 (16)0.0327 (19)0.0247 (17)0.0013 (14)0.0020 (13)0.0040 (15)
C50.0245 (17)0.0231 (16)0.0279 (18)0.0063 (13)0.0051 (14)0.0011 (14)
C60.0140 (15)0.0176 (14)0.0224 (16)0.0027 (12)0.0022 (12)0.0030 (13)
N10.0203 (13)0.0204 (13)0.0269 (15)0.0005 (11)0.0007 (11)0.0007 (11)
N20.0237 (15)0.0298 (16)0.0319 (16)0.0002 (12)0.0017 (12)0.0028 (13)
N30.0304 (16)0.0283 (15)0.0270 (16)0.0070 (12)0.0008 (12)0.0015 (12)
N40.0296 (15)0.0201 (14)0.0306 (16)0.0028 (12)0.0022 (12)0.0012 (12)
N50.0241 (14)0.0200 (14)0.0226 (14)0.0005 (11)0.0063 (11)0.0028 (11)
N60.0221 (14)0.0233 (14)0.0245 (14)0.0038 (11)0.0042 (11)0.0025 (12)
O10.0159 (11)0.0330 (12)0.0190 (12)0.0023 (9)0.0005 (9)0.0025 (10)
O20.0116 (11)0.0316 (12)0.0242 (12)0.0016 (9)0.0016 (9)0.0070 (10)
O1W0.0432 (16)0.0285 (13)0.0229 (13)0.0128 (11)0.0003 (11)0.0006 (10)
Geometric parameters (Å, º) top
Cd1—N12.284 (3)C4—C51.383 (5)
Cd1—O2i2.312 (2)C4—H40.9300
Cd1—O1W2.315 (3)C5—N51.335 (4)
Cd1—O12.367 (2)C5—H50.9300
Cd1—N52.700 (3)C6—O11.239 (4)
Cd1—N6ii2.371 (3)C6—O21.261 (4)
Cd1—O2iii2.404 (2)C6—C6iii1.553 (6)
C1—N11.330 (4)N1—N21.341 (4)
C1—N41.333 (4)N2—N31.309 (4)
C1—C21.464 (4)N3—N41.342 (4)
C2—N51.338 (4)N6—Cd1iv2.371 (3)
C2—C31.385 (4)O2—Cd1v2.312 (2)
C3—N61.335 (4)O2—Cd1iii2.404 (2)
C3—H30.9300O1W—H1W0.82 (3)
C4—N61.332 (5)O1W—H2W0.82 (3)
N1—Cd1—O2i97.03 (9)N6—C4—H4119.1
N1—Cd1—O1W100.78 (10)C5—C4—H4119.1
O2i—Cd1—O1W143.20 (9)N5—C5—C4121.9 (3)
N1—Cd1—O182.94 (9)N5—C5—H5119.0
O2i—Cd1—O1137.80 (8)C4—C5—H5119.0
O1W—Cd1—O176.63 (9)O1—C6—O2126.3 (3)
N1—Cd1—N6ii177.81 (10)O1—C6—C6iii118.4 (3)
O2i—Cd1—N6ii81.17 (9)O2—C6—C6iii115.3 (3)
O1W—Cd1—N6ii81.40 (9)C1—N1—N2105.8 (3)
O1—Cd1—N6ii97.56 (9)C1—N1—Cd1123.2 (2)
N1—Cd1—O2iii86.28 (9)N2—N1—Cd1130.7 (2)
O2i—Cd1—O2iii69.50 (8)N3—N2—N1107.9 (3)
O1W—Cd1—O2iii143.19 (8)N2—N3—N4111.0 (3)
O1—Cd1—O2iii68.39 (7)C1—N4—N3103.8 (3)
N6ii—Cd1—O2iii91.92 (9)C5—N5—C2116.2 (3)
N1—C1—N4111.6 (3)C4—N6—C3116.7 (3)
N1—C1—C2121.9 (3)C4—N6—Cd1iv125.7 (2)
N4—C1—C2126.5 (3)C3—N6—Cd1iv116.8 (2)
N5—C2—C3121.9 (3)C6—O1—Cd1115.17 (19)
N5—C2—C1116.6 (3)C6—O2—Cd1v130.5 (2)
C3—C2—C1121.5 (3)C6—O2—Cd1iii114.90 (19)
N6—C3—C2121.5 (3)Cd1v—O2—Cd1iii110.50 (8)
N6—C3—H3119.3Cd1—O1W—H1W126 (3)
C2—C3—H3119.3Cd1—O1W—H2W112 (3)
N6—C4—C5121.8 (3)H1W—O1W—H2W110.4 (18)
Symmetry codes: (i) x1, y, z; (ii) x1/2, y1/2, z+3/2; (iii) x+1, y+1, z+2; (iv) x1/2, y+1/2, z+3/2; (v) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H2W···N4vi0.82 (3)2.08 (3)2.897 (4)174 (4)
O1W—H1W···N3vii0.82 (3)1.93 (3)2.757 (4)179 (5)
Symmetry codes: (vi) x+1/2, y1/2, z+3/2; (vii) x1/2, y+3/2, z1/2.

Experimental details

Crystal data
Chemical formula[Cd(C5H3N6)(C2O4)0.5(H2O)]
Mr321.56
Crystal system, space groupMonoclinic, P21/n
Temperature (K)296
a, b, c (Å)5.8801 (1), 13.1286 (2), 11.5647 (2)
β (°) 94.867 (1)
V3)889.55 (3)
Z4
Radiation typeMo Kα
µ (mm1)2.46
Crystal size (mm)0.24 × 0.22 × 0.19
Data collection
DiffractometerBruker APEXII area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2008a)
Tmin, Tmax0.590, 0.652
No. of measured, independent and
observed [I > 2σ(I)] reflections
7467, 1588, 1566
Rint0.031
(sin θ/λ)max1)0.599
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.023, 0.056, 1.19
No. of reflections1588
No. of parameters151
No. of restraints3
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.33, 0.77

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008b), SHELXL97 (Sheldrick, 2008b), SHELXTL (Sheldrick, 2008b).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1W—H2W···N4i0.82 (3)2.08 (3)2.897 (4)174 (4)
O1W—H1W···N3ii0.82 (3)1.93 (3)2.757 (4)179 (5)
Symmetry codes: (i) x+1/2, y1/2, z+3/2; (ii) x1/2, y+3/2, z1/2.
 

Acknowledgements

The author acknowledges South China Normal University for supporting this work.

References

First citationBernstein, 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
First citationBruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationDeng, H., Qiu, Y.-C., Zeng, R.-H. & Sun, F. (2007). Acta Cryst. E63, m450–m451.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationSheldrick, G. M. (2008a). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008b). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationZeng, R.-H., Qiu, Y.-C., Liu, Z.-H., Li, Y.-H. & Deng, H. (2007). Acta Cryst. E63, m1591.  Web of Science CSD CrossRef 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