metal-organic compounds
Tetraaquabis[5-(3-pyridyl)tetrazolido-κN5]zinc(II) tetrahydrate
aCollege of Mechanical & Material Engineering, China Three Gorges University, Yichang, Hubei 443002, People's Republic of China
*Correspondence e-mail: junzhao08@126.com
The title compound, [Zn(C6H4N5)2(H2O)4]·4H2O, was synthesized by the hydrothermal reaction of Zn(CH3COO)2·2H2O with 3-(2H-tetrazol-5-yl)pyridine. The ZnII ion is located on an inversion center and is coordinated by two pyridine N atoms from two 5-(3-pyridyl)tetrazolide ligands and four coordinated water molecules in a slightly distorted octahedral geometry. The dihedral angle between the pyridine and tetrazole rings is 9.920 (7)°. In the crystal, molecules are linked into a three-dimensional network by intermolecular O—H⋯O and O—H⋯N hydrogen bonds involving the tetrazole group N atoms, the aqua ligands and solvent water molecules.
Related literature
For background to 5-(3-pyridyl)tetrazolate complexes, see: Xiong et al. (2002); Wang et al. (2005). For a related structure, see: Zhang et al. (2006). For hydrogen-bond motifs, see: Bernstein et al. (1995).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536810048464/lh5162sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810048464/lh5162Isup2.hkl
A mixture of 3-(2H-tetrazol-5-yl)pyridine (0.2 mmol,0.0294 g), Zn(CH3COO)2.2H2O (0.1 mmol, 0.0219 g), methanol (5 ml) and distilled water (10 ml) were sealed in a 25 ml Teflon-lined stainless steel reactor and heated at 393 K for three days, and then cooled slowly to 298 K at which time colorless crystals were obtained.
All the H atoms were positioned geometrically (C—H = 0.93 Å, O—H = 0.85 Å), and allowed to ride on their parent atoms, with Uiso(H) = 1.2 Ueq(C) or 1.5Ueq(O).
Nowadays much attention is focused on the design and synthesis of functional materials based on metal-organic coordination polymers due to their intriguing topological structures and tremendous range of potential applications. Tetrazole compounds are a class of excellent ligands for construction of novel metal-organic frameworks and for the medical applications, because of their various coordination modes (Xiong et al., 2002; Wang et al., 2005; Zhang et al., 2006). We report herein the
of the title compound. The contains one half of a ZnII ion, one 5-(3-pyridyl)tetrazolide (3-ptz) ligand, two coordinated water and two solvent water molecules. The ZnII ion is in a slightly distorted octahedral geometry surrounded by two N atoms from two 5-(3-pyridyl)tetrazolide ligands and four coordinated water molecules (Fig. 1). The dihedral angle between the pyridine and tetrazole rings is 9.920 (7)°. In the crystal, molecules are linked into a three-dimensional network by intermolecular O—H···O, O—H···N hydrogen bonds involving the tetrazole group N atoms, the aqua ligands and solvent water molecules (Fig. 2). The hydrogen bond network contains R24(10), R44(10) and R44(22) rings (Bernstein et al., 1995).For background to 5-(3-pyridyl)tetrazolate complexes, see: Xiong et al. (2002); Wang et al. (2005). For a related structure, see Zhang et al. (2006). For hydrogen-bond motifs, see: Bernstein et al. (1995).
Data collection: SMART (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).Fig. 1. View of the title complex with the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are omitted for clarity. [Symmetry code: (A) 2 - x, 1 - y, -z.]. | |
Fig. 2. Part of the crystal structure with hydrogen bonds shown as dashed lines. H atoms not involved in hydrogen bonding have been omitted for clarity. |
[Zn(C6H4N5)2(H2O)4]·4H2O | Z = 1 |
Mr = 501.78 | F(000) = 260 |
Triclinic, P1 | Dx = 1.597 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 8.0930 (13) Å | Cell parameters from 2640 reflections |
b = 8.5836 (14) Å | θ = 2.5–25.0° |
c = 8.7082 (14) Å | µ = 1.24 mm−1 |
α = 85.942 (2)° | T = 296 K |
β = 65.075 (2)° | Prism, colorless |
γ = 72.369 (2)° | 0.35 × 0.23 × 0.18 mm |
V = 521.69 (15) Å3 |
Bruker SMART CCD diffractometer | 1814 independent reflections |
Radiation source: fine-focus sealed tube | 1788 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.018 |
φ and ω scans | θmax = 25.0°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −8→9 |
Tmin = 0.717, Tmax = 0.800 | k = −10→9 |
2640 measured reflections | l = −9→10 |
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)] = 0.026 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.00 | w = 1/[σ2(Fo2) + (0.038P)2 + 0.3832P] where P = (Fo2 + 2Fc2)/3 |
1814 reflections | (Δ/σ)max < 0.001 |
142 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.48 e Å−3 |
[Zn(C6H4N5)2(H2O)4]·4H2O | γ = 72.369 (2)° |
Mr = 501.78 | V = 521.69 (15) Å3 |
Triclinic, P1 | Z = 1 |
a = 8.0930 (13) Å | Mo Kα radiation |
b = 8.5836 (14) Å | µ = 1.24 mm−1 |
c = 8.7082 (14) Å | T = 296 K |
α = 85.942 (2)° | 0.35 × 0.23 × 0.18 mm |
β = 65.075 (2)° |
Bruker SMART CCD diffractometer | 1814 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1788 reflections with I > 2σ(I) |
Tmin = 0.717, Tmax = 0.800 | Rint = 0.018 |
2640 measured reflections |
R[F2 > 2σ(F2)] = 0.026 | 0 restraints |
wR(F2) = 0.071 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.25 e Å−3 |
1814 reflections | Δρmin = −0.48 e Å−3 |
142 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 | ||
Zn1 | 1.0000 | 0.5000 | 0.0000 | 0.02415 (12) | |
N1 | 0.9006 (2) | 0.5872 (2) | 0.2605 (2) | 0.0253 (3) | |
N2 | 1.2471 (2) | 0.8188 (2) | 0.3456 (2) | 0.0295 (4) | |
N3 | 1.3341 (2) | 0.8789 (2) | 0.4176 (2) | 0.0323 (4) | |
N4 | 1.2417 (3) | 0.8856 (2) | 0.5824 (2) | 0.0316 (4) | |
N5 | 1.0910 (2) | 0.8308 (2) | 0.6230 (2) | 0.0277 (4) | |
O1 | 1.2917 (2) | 0.49525 (18) | −0.06216 (18) | 0.0332 (3) | |
H1A | 1.3635 | 0.4132 | −0.0366 | 0.050* | |
H1B | 1.3182 | 0.5786 | −0.0438 | 0.050* | |
O2 | 0.9302 (2) | 0.74166 (18) | −0.05239 (19) | 0.0431 (4) | |
H2A | 0.9749 | 0.7802 | −0.1488 | 0.052* | |
H2B | 0.8479 | 0.8183 | 0.0214 | 0.065* | |
O3 | 0.5798 (2) | 0.25397 (19) | 1.00465 (19) | 0.0359 (3) | |
H3B | 0.5938 | 0.1703 | 1.0616 | 0.054* | |
H3A | 0.6317 | 0.2165 | 0.9019 | 0.054* | |
O4 | 0.6545 (2) | −0.01658 (18) | 0.19326 (18) | 0.0337 (3) | |
H4A | 0.6930 | 0.0211 | 0.2554 | 0.051* | |
H4B | 0.5598 | −0.0480 | 0.2593 | 0.051* | |
C1 | 1.0065 (3) | 0.6594 (2) | 0.2951 (2) | 0.0280 (4) | |
H1 | 1.1170 | 0.6696 | 0.2055 | 0.034* | |
C2 | 0.9644 (3) | 0.7203 (2) | 0.4543 (2) | 0.0233 (4) | |
C3 | 0.7977 (3) | 0.7081 (3) | 0.5869 (2) | 0.0284 (4) | |
H3 | 0.7630 | 0.7474 | 0.6965 | 0.034* | |
C4 | 0.6849 (3) | 0.6368 (3) | 0.5532 (3) | 0.0332 (5) | |
H4 | 0.5716 | 0.6286 | 0.6401 | 0.040* | |
C5 | 0.7393 (3) | 0.5773 (2) | 0.3904 (2) | 0.0283 (4) | |
H5 | 0.6616 | 0.5287 | 0.3700 | 0.034* | |
C6 | 1.0978 (3) | 0.7907 (2) | 0.4753 (2) | 0.0234 (4) |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.02550 (18) | 0.02944 (19) | 0.01939 (18) | −0.01032 (13) | −0.00976 (13) | 0.00137 (12) |
N1 | 0.0254 (8) | 0.0299 (8) | 0.0232 (8) | −0.0103 (7) | −0.0113 (7) | 0.0027 (6) |
N2 | 0.0297 (9) | 0.0378 (9) | 0.0237 (8) | −0.0157 (7) | −0.0099 (7) | 0.0023 (7) |
N3 | 0.0321 (9) | 0.0394 (10) | 0.0304 (9) | −0.0173 (8) | −0.0134 (7) | 0.0026 (7) |
N4 | 0.0353 (9) | 0.0353 (9) | 0.0318 (9) | −0.0161 (8) | −0.0176 (8) | 0.0031 (7) |
N5 | 0.0331 (9) | 0.0313 (9) | 0.0231 (8) | −0.0147 (7) | −0.0127 (7) | 0.0033 (7) |
O1 | 0.0273 (7) | 0.0398 (8) | 0.0351 (8) | −0.0100 (6) | −0.0148 (6) | −0.0026 (6) |
O2 | 0.0585 (10) | 0.0300 (8) | 0.0218 (7) | −0.0056 (7) | −0.0051 (7) | 0.0046 (6) |
O3 | 0.0379 (8) | 0.0388 (8) | 0.0276 (8) | −0.0126 (7) | −0.0099 (6) | 0.0030 (6) |
O4 | 0.0364 (8) | 0.0421 (8) | 0.0248 (7) | −0.0187 (7) | −0.0099 (6) | 0.0004 (6) |
C1 | 0.0277 (10) | 0.0370 (11) | 0.0201 (9) | −0.0155 (8) | −0.0067 (8) | 0.0013 (8) |
C2 | 0.0246 (9) | 0.0236 (9) | 0.0229 (9) | −0.0071 (7) | −0.0115 (7) | 0.0034 (7) |
C3 | 0.0274 (10) | 0.0355 (10) | 0.0202 (9) | −0.0096 (8) | −0.0076 (8) | −0.0004 (8) |
C4 | 0.0254 (10) | 0.0461 (12) | 0.0258 (10) | −0.0154 (9) | −0.0055 (8) | 0.0021 (9) |
C5 | 0.0253 (10) | 0.0357 (11) | 0.0275 (10) | −0.0128 (8) | −0.0123 (8) | 0.0033 (8) |
C6 | 0.0260 (9) | 0.0231 (9) | 0.0227 (9) | −0.0086 (7) | −0.0111 (7) | 0.0037 (7) |
Zn1—O2i | 2.0503 (15) | O2—H2A | 0.8498 |
Zn1—O2 | 2.0503 (15) | O2—H2B | 0.8498 |
Zn1—N1i | 2.1662 (16) | O3—H3B | 0.8499 |
Zn1—N1 | 2.1662 (16) | O3—H3A | 0.8499 |
Zn1—O1i | 2.1760 (14) | O4—H4A | 0.8498 |
Zn1—O1 | 2.1760 (14) | O4—H4B | 0.8498 |
N1—C1 | 1.333 (3) | C1—C2 | 1.381 (3) |
N1—C5 | 1.341 (2) | C1—H1 | 0.9300 |
N2—C6 | 1.335 (2) | C2—C3 | 1.385 (3) |
N2—N3 | 1.339 (2) | C2—C6 | 1.463 (3) |
N3—N4 | 1.305 (3) | C3—C4 | 1.373 (3) |
N4—N5 | 1.339 (2) | C3—H3 | 0.9300 |
N5—C6 | 1.329 (3) | C4—C5 | 1.380 (3) |
O1—H1A | 0.8499 | C4—H4 | 0.9300 |
O1—H1B | 0.8500 | C5—H5 | 0.9300 |
O2i—Zn1—O2 | 180.0 | H1A—O1—H1B | 106.1 |
O2i—Zn1—N1i | 86.61 (6) | Zn1—O2—H2A | 126.3 |
O2—Zn1—N1i | 93.39 (6) | Zn1—O2—H2B | 123.6 |
O2i—Zn1—N1 | 93.39 (6) | H2A—O2—H2B | 110.0 |
O2—Zn1—N1 | 86.61 (6) | H3B—O3—H3A | 105.1 |
N1i—Zn1—N1 | 180.0 | H4A—O4—H4B | 107.1 |
O2i—Zn1—O1i | 91.09 (7) | N1—C1—C2 | 124.80 (17) |
O2—Zn1—O1i | 88.91 (7) | N1—C1—H1 | 117.6 |
N1i—Zn1—O1i | 92.52 (6) | C2—C1—H1 | 117.6 |
N1—Zn1—O1i | 87.48 (6) | C1—C2—C3 | 117.46 (17) |
O2i—Zn1—O1 | 88.91 (7) | C1—C2—C6 | 119.00 (17) |
O2—Zn1—O1 | 91.09 (7) | C3—C2—C6 | 123.53 (17) |
N1i—Zn1—O1 | 87.48 (6) | C4—C3—C2 | 118.58 (18) |
N1—Zn1—O1 | 92.52 (6) | C4—C3—H3 | 120.7 |
O1i—Zn1—O1 | 180.00 (8) | C2—C3—H3 | 120.7 |
C1—N1—C5 | 116.84 (17) | C3—C4—C5 | 120.07 (18) |
C1—N1—Zn1 | 117.54 (12) | C3—C4—H4 | 120.0 |
C5—N1—Zn1 | 125.61 (13) | C5—C4—H4 | 120.0 |
C6—N2—N3 | 104.97 (16) | N1—C5—C4 | 122.24 (18) |
N4—N3—N2 | 109.42 (16) | N1—C5—H5 | 118.9 |
N3—N4—N5 | 109.47 (16) | C4—C5—H5 | 118.9 |
C6—N5—N4 | 105.07 (15) | N5—C6—N2 | 111.07 (16) |
Zn1—O1—H1A | 118.6 | N5—C6—C2 | 125.41 (17) |
Zn1—O1—H1B | 122.1 | N2—C6—C2 | 123.50 (17) |
O2i—Zn1—N1—C1 | 109.54 (15) | N1—C1—C2—C6 | 177.49 (18) |
O2—Zn1—N1—C1 | −70.46 (15) | C1—C2—C3—C4 | 0.0 (3) |
N1i—Zn1—N1—C1 | −69 (100) | C6—C2—C3—C4 | −178.70 (19) |
O1i—Zn1—N1—C1 | −159.52 (15) | C2—C3—C4—C5 | 0.8 (3) |
O1—Zn1—N1—C1 | 20.48 (15) | C1—N1—C5—C4 | −0.7 (3) |
O2i—Zn1—N1—C5 | −71.60 (16) | Zn1—N1—C5—C4 | −179.59 (15) |
O2—Zn1—N1—C5 | 108.40 (16) | C3—C4—C5—N1 | −0.5 (3) |
N1i—Zn1—N1—C5 | 110 (100) | N4—N5—C6—N2 | 0.0 (2) |
O1i—Zn1—N1—C5 | 19.35 (16) | N4—N5—C6—C2 | 178.35 (17) |
O1—Zn1—N1—C5 | −160.65 (16) | N3—N2—C6—N5 | −0.2 (2) |
C6—N2—N3—N4 | 0.2 (2) | N3—N2—C6—C2 | −178.53 (17) |
N2—N3—N4—N5 | −0.2 (2) | C1—C2—C6—N5 | −169.29 (19) |
N3—N4—N5—C6 | 0.1 (2) | C3—C2—C6—N5 | 9.4 (3) |
C5—N1—C1—C2 | 1.6 (3) | C1—C2—C6—N2 | 8.8 (3) |
Zn1—N1—C1—C2 | −179.40 (15) | C3—C2—C6—N2 | −172.44 (19) |
N1—C1—C2—C3 | −1.3 (3) |
Symmetry code: (i) −x+2, −y+1, −z. |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O3ii | 0.85 | 2.02 | 2.848 (2) | 165 |
O1—H1B···O3iii | 0.85 | 1.97 | 2.813 (2) | 171 |
O2—H2A···N5iv | 0.85 | 1.89 | 2.733 (2) | 171 |
O2—H2B···O4v | 0.85 | 1.92 | 2.768 (2) | 177 |
O3—H3B···O4vi | 0.85 | 1.97 | 2.811 (2) | 173 |
O3—H3A···N2iii | 0.85 | 1.96 | 2.792 (2) | 167 |
O4—H4A···N4iii | 0.85 | 1.99 | 2.838 (2) | 175 |
O4—H4B···N3vii | 0.85 | 2.02 | 2.870 (2) | 180 |
Symmetry codes: (ii) x+1, y, z−1; (iii) −x+2, −y+1, −z+1; (iv) x, y, z−1; (v) x, y+1, z; (vi) x, y, z+1; (vii) x−1, y−1, z. |
Experimental details
Crystal data | |
Chemical formula | [Zn(C6H4N5)2(H2O)4]·4H2O |
Mr | 501.78 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 296 |
a, b, c (Å) | 8.0930 (13), 8.5836 (14), 8.7082 (14) |
α, β, γ (°) | 85.942 (2), 65.075 (2), 72.369 (2) |
V (Å3) | 521.69 (15) |
Z | 1 |
Radiation type | Mo Kα |
µ (mm−1) | 1.24 |
Crystal size (mm) | 0.35 × 0.23 × 0.18 |
Data collection | |
Diffractometer | Bruker SMART CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.717, 0.800 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2640, 1814, 1788 |
Rint | 0.018 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.026, 0.071, 1.00 |
No. of reflections | 1814 |
No. of parameters | 142 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.25, −0.48 |
Computer programs: SMART (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 1999), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1A···O3i | 0.85 | 2.02 | 2.848 (2) | 165.3 |
O1—H1B···O3ii | 0.85 | 1.97 | 2.813 (2) | 170.5 |
O2—H2A···N5iii | 0.85 | 1.89 | 2.733 (2) | 170.8 |
O2—H2B···O4iv | 0.85 | 1.92 | 2.768 (2) | 177.0 |
O3—H3B···O4v | 0.85 | 1.97 | 2.811 (2) | 172.7 |
O3—H3A···N2ii | 0.85 | 1.96 | 2.792 (2) | 166.9 |
O4—H4A···N4ii | 0.85 | 1.99 | 2.838 (2) | 174.6 |
O4—H4B···N3vi | 0.85 | 2.02 | 2.870 (2) | 179.5 |
Symmetry codes: (i) x+1, y, z−1; (ii) −x+2, −y+1, −z+1; (iii) x, y, z−1; (iv) x, y+1, z; (v) x, y, z+1; (vi) x−1, y−1, z. |
Acknowledgements
This work was supported financially by the Important Project of Hubei Provincial Education Office (Q20101203).
References
Bernstein, 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
Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2007). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. 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
Wang, X.-S., Tang, Y.-Z., Huang, X.-F., Qu, Z.-R., Che, C.-M., Chan, C. W. H. & Xiong, R.-G. (2005). Inorg. Chem. 44, 5278–5285. Web of Science CSD CrossRef PubMed CAS Google Scholar
Xiong, R.-G., Xue, X., Zhao, H., You, X.-Z., Abrahams, B. F. & Xue, Z.-L. (2002). Angew. Chem. Int. Ed. Engl. 41, 3800–3803. CrossRef PubMed CAS Google Scholar
Zhang, C., Ai, H.-Q. & Ng, S. W. (2006). Acta Cryst. E62, m2908–m2909. Web of Science CSD CrossRef IUCr Journals Google Scholar
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Nowadays much attention is focused on the design and synthesis of functional materials based on metal-organic coordination polymers due to their intriguing topological structures and tremendous range of potential applications. Tetrazole compounds are a class of excellent ligands for construction of novel metal-organic frameworks and for the medical applications, because of their various coordination modes (Xiong et al., 2002; Wang et al., 2005; Zhang et al., 2006). We report herein the crystal structure of the title compound. The asymmetric unit contains one half of a ZnII ion, one 5-(3-pyridyl)tetrazolide (3-ptz) ligand, two coordinated water and two solvent water molecules. The ZnII ion is in a slightly distorted octahedral geometry surrounded by two N atoms from two 5-(3-pyridyl)tetrazolide ligands and four coordinated water molecules (Fig. 1). The dihedral angle between the pyridine and tetrazole rings is 9.920 (7)°. In the crystal, molecules are linked into a three-dimensional network by intermolecular O—H···O, O—H···N hydrogen bonds involving the tetrazole group N atoms, the aqua ligands and solvent water molecules (Fig. 2). The hydrogen bond network contains R24(10), R44(10) and R44(22) rings (Bernstein et al., 1995).