metal-organic compounds
A dimeric zinc(II) complex: bis[μ-1,2-bis(1,2,4-triazol-4-yl)ethane-κ2N1:N1′]bis[dinitritozinc(II)]
aSchool of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013, People's Republic of China, and bSchool of Pharmacy, Jiangsu University, Zhenjiang 212013, People's Republic of China
*Correspondence e-mail: rong@ujs.edu.cn
The coordination geometry of the ZnII atom in the title complex, [Zn2(NO2)4(C6H8N6)2], is distorted octahedral, in which the ZnII atom is coordinated by two N atoms from the triazole rings of two symmetry-related 1,2-bis(1,2,4-triazol-4-yl)ethane ligands and four O atoms from two nitrite ligands. Two ZnII atoms are bridged by two organic ligands, forming a centrosymmetric dimer. Weak C—H⋯N and C—H⋯O hydrogen bonds play an important role in the intermolecular packing.
Related literature
For background to 1,2,4-triazole and its derivatives, see: Haasnoot (2000). For a related structure, see: Habit et al. (2009). For hydrogen bonding, see: Mascal (1998).
Experimental
Crystal data
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Refinement
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Data collection: CrystalClear (Rigaku, 2000); cell CrystalClear; data reduction: CrystalClear; 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.
Supporting information
10.1107/S1600536810034203/bv2153sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810034203/bv2153Isup2.hkl
A 10 ml aqueous solution of Zn(NO2)2 (1 mmol) was added to a tube, and a 10 ml MeOH solution of 1,2-bis(1,2,4-triazol-4-yl)ethane (btre) (1.0 mmol) was carefully added above the aqueous solution. Colourless crystal were obtained after about two weeks. Anal. Calcd. for C12H16N16O8Zn2: C, 22.41; H, 2.51; N, 34.85%. Found: C, 22.36; H, 2.44; N, 34.69%.
H atom were placed in idealized positions and refined as riding, with C—H distances of 0.93 (triazole) and 0.97Å (ethane), and with Uiso(H) = 1.2Ueq(C).
Data collection: CrystalClear (Rigaku, 2000); cell
CrystalClear (Rigaku, 2000); data reduction: CrystalClear (Rigaku, 2000); 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).[Zn2(NO2)4(C6H8N6)2] | F(000) = 1296 |
Mr = 643.15 | Dx = 1.811 Mg m−3 |
Monoclinic, C2/c | Mo Kα radiation, λ = 0.71070 Å |
Hall symbol: -c 2yc | Cell parameters from 4261 reflections |
a = 20.491 (4) Å | θ = 3.2–25.4° |
b = 6.7087 (13) Å | µ = 2.11 mm−1 |
c = 17.289 (4) Å | T = 293 K |
β = 97.125 (5)° | Block, colorless |
V = 2358.3 (8) Å3 | 0.60 × 0.20 × 0.20 mm |
Z = 4 |
Rigaku Mercury CCD diffractometer | 2144 independent reflections |
Radiation source: fine-focus sealed tube | 1945 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
ω scans | θmax = 25.3°, θmin = 3.2° |
Absorption correction: multi-scan (Blessing, 1995, 1997) | h = −24→24 |
Tmin = 0.364, Tmax = 0.678 | k = −7→8 |
10892 measured reflections | l = −20→20 |
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)] = 0.040 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.104 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0627P)2 + 2.1848P] where P = (Fo2 + 2Fc2)/3 |
2144 reflections | (Δ/σ)max = 0.001 |
172 parameters | Δρmax = 0.47 e Å−3 |
0 restraints | Δρmin = −0.61 e Å−3 |
[Zn2(NO2)4(C6H8N6)2] | V = 2358.3 (8) Å3 |
Mr = 643.15 | Z = 4 |
Monoclinic, C2/c | Mo Kα radiation |
a = 20.491 (4) Å | µ = 2.11 mm−1 |
b = 6.7087 (13) Å | T = 293 K |
c = 17.289 (4) Å | 0.60 × 0.20 × 0.20 mm |
β = 97.125 (5)° |
Rigaku Mercury CCD diffractometer | 2144 independent reflections |
Absorption correction: multi-scan (Blessing, 1995, 1997) | 1945 reflections with I > 2σ(I) |
Tmin = 0.364, Tmax = 0.678 | Rint = 0.036 |
10892 measured reflections |
R[F2 > 2σ(F2)] = 0.040 | 0 restraints |
wR(F2) = 0.104 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.47 e Å−3 |
2144 reflections | Δρmin = −0.61 e Å−3 |
172 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 | 0.377036 (17) | 0.06273 (5) | 0.900523 (19) | 0.03325 (17) | |
O1 | 0.42015 (16) | 0.3236 (5) | 0.8755 (2) | 0.0767 (10) | |
O2 | 0.3646 (2) | 0.3909 (5) | 0.96266 (18) | 0.0876 (12) | |
O3 | 0.40736 (13) | −0.1027 (4) | 0.81217 (16) | 0.0581 (7) | |
O4 | 0.48542 (14) | −0.1050 (5) | 0.90120 (16) | 0.0662 (8) | |
N1 | 0.28080 (13) | 0.0744 (4) | 0.85410 (15) | 0.0353 (6) | |
N2 | 0.26438 (14) | 0.0921 (4) | 0.77408 (15) | 0.0401 (7) | |
N3 | 0.17452 (13) | 0.0807 (4) | 0.83012 (15) | 0.0325 (6) | |
N4 | 0.12627 (14) | −0.4368 (4) | 0.99508 (15) | 0.0353 (6) | |
N5 | 0.17231 (16) | −0.4949 (5) | 0.94714 (18) | 0.0499 (8) | |
N6 | 0.10563 (13) | −0.2736 (4) | 0.88654 (14) | 0.0355 (6) | |
N7 | 0.4027 (2) | 0.4550 (5) | 0.9200 (2) | 0.0712 (11) | |
N8 | 0.46565 (16) | −0.1617 (6) | 0.83561 (19) | 0.0568 (8) | |
C1 | 0.10463 (16) | 0.0757 (5) | 0.8402 (2) | 0.0413 (8) | |
H1A | 0.0807 | 0.1668 | 0.8034 | 0.050* | |
H1B | 0.0992 | 0.1202 | 0.8924 | 0.050* | |
C2 | 0.07634 (16) | −0.1309 (6) | 0.82762 (19) | 0.0448 (8) | |
H2A | 0.0292 | −0.1254 | 0.8292 | 0.054* | |
H2B | 0.0837 | −0.1775 | 0.7763 | 0.054* | |
C3 | 0.22636 (17) | 0.0689 (5) | 0.88560 (19) | 0.0360 (7) | |
H3A | 0.2237 | 0.0584 | 0.9388 | 0.043* | |
C4 | 0.20115 (17) | 0.0957 (5) | 0.76274 (18) | 0.0392 (8) | |
H4A | 0.1767 | 0.1072 | 0.7139 | 0.047* | |
C5 | 0.08740 (15) | −0.3056 (5) | 0.95728 (17) | 0.0330 (7) | |
H5A | 0.0522 | −0.2435 | 0.9766 | 0.040* | |
C6 | 0.15788 (19) | −0.3936 (6) | 0.8829 (2) | 0.0468 (9) | |
H6A | 0.1808 | −0.4031 | 0.8399 | 0.056* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.0323 (3) | 0.0385 (3) | 0.0298 (2) | −0.00378 (14) | 0.00707 (16) | 0.00015 (14) |
O1 | 0.080 (2) | 0.0613 (18) | 0.098 (2) | −0.0275 (16) | 0.0486 (19) | −0.0208 (18) |
O2 | 0.142 (4) | 0.071 (2) | 0.0574 (19) | −0.033 (2) | 0.041 (2) | −0.0132 (16) |
O3 | 0.0422 (16) | 0.0766 (18) | 0.0542 (16) | 0.0062 (13) | 0.0013 (12) | −0.0270 (14) |
O4 | 0.0506 (18) | 0.098 (2) | 0.0485 (16) | −0.0159 (16) | 0.0018 (13) | −0.0053 (15) |
N1 | 0.0298 (15) | 0.0439 (16) | 0.0322 (14) | −0.0011 (11) | 0.0038 (11) | 0.0003 (11) |
N2 | 0.0341 (16) | 0.0556 (17) | 0.0321 (14) | 0.0014 (13) | 0.0100 (12) | 0.0078 (12) |
N3 | 0.0279 (14) | 0.0353 (14) | 0.0354 (14) | 0.0019 (10) | 0.0083 (11) | 0.0064 (11) |
N4 | 0.0377 (15) | 0.0387 (15) | 0.0309 (14) | −0.0026 (11) | 0.0097 (12) | −0.0004 (11) |
N5 | 0.052 (2) | 0.0539 (17) | 0.0480 (18) | 0.0126 (15) | 0.0243 (15) | 0.0090 (15) |
N6 | 0.0336 (14) | 0.0440 (15) | 0.0293 (13) | −0.0075 (12) | 0.0056 (11) | 0.0035 (11) |
N7 | 0.110 (3) | 0.0459 (19) | 0.062 (2) | −0.022 (2) | 0.028 (2) | −0.0096 (17) |
N8 | 0.0402 (18) | 0.078 (2) | 0.0531 (19) | 0.0002 (17) | 0.0121 (15) | −0.0140 (17) |
C1 | 0.0286 (17) | 0.056 (2) | 0.0415 (18) | 0.0098 (14) | 0.0106 (14) | 0.0181 (15) |
C2 | 0.0274 (17) | 0.074 (2) | 0.0320 (17) | −0.0075 (17) | −0.0009 (13) | 0.0115 (17) |
C3 | 0.0348 (18) | 0.0455 (19) | 0.0287 (15) | 0.0005 (14) | 0.0082 (13) | −0.0004 (13) |
C4 | 0.0374 (19) | 0.0522 (19) | 0.0285 (16) | 0.0049 (15) | 0.0060 (14) | 0.0088 (14) |
C5 | 0.0317 (17) | 0.0392 (16) | 0.0290 (15) | −0.0046 (14) | 0.0072 (12) | −0.0003 (13) |
C6 | 0.053 (2) | 0.053 (2) | 0.0378 (18) | 0.0008 (17) | 0.0219 (16) | 0.0017 (16) |
Zn1—N4i | 2.002 (3) | N4—C5 | 1.307 (4) |
Zn1—O1 | 2.031 (3) | N4—N5 | 1.386 (4) |
Zn1—N1 | 2.036 (3) | N4—Zn1i | 2.002 (3) |
Zn1—O3 | 2.046 (3) | N5—C6 | 1.304 (5) |
Zn1—O2 | 2.477 (3) | N6—C5 | 1.340 (4) |
Zn1—O4 | 2.488 (3) | N6—C6 | 1.347 (5) |
O1—N7 | 1.251 (4) | N6—C2 | 1.471 (4) |
O2—N7 | 1.218 (5) | C1—C2 | 1.508 (5) |
O3—N8 | 1.276 (4) | C1—H1A | 0.9700 |
O4—N8 | 1.217 (4) | C1—H1B | 0.9700 |
N1—C3 | 1.301 (4) | C2—H2A | 0.9700 |
N1—N2 | 1.388 (4) | C2—H2B | 0.9700 |
N2—C4 | 1.286 (4) | C3—H3A | 0.9300 |
N3—C3 | 1.342 (4) | C4—H4A | 0.9300 |
N3—C4 | 1.350 (4) | C5—H5A | 0.9300 |
N3—C1 | 1.464 (4) | C6—H6A | 0.9300 |
N4i—Zn1—O1 | 128.32 (12) | C5—N6—C6 | 105.1 (3) |
N4i—Zn1—N1 | 103.43 (11) | C5—N6—C2 | 126.9 (3) |
O1—Zn1—N1 | 107.96 (13) | C6—N6—C2 | 128.0 (3) |
N4i—Zn1—O3 | 119.46 (12) | O2—N7—O1 | 112.2 (3) |
O1—Zn1—O3 | 97.34 (12) | O4—N8—O3 | 112.9 (3) |
N1—Zn1—O3 | 95.48 (11) | N3—C1—C2 | 111.6 (3) |
N4i—Zn1—O2 | 88.11 (11) | N3—C1—H1A | 109.3 |
O1—Zn1—O2 | 52.96 (11) | C2—C1—H1A | 109.3 |
N1—Zn1—O2 | 89.42 (13) | N3—C1—H1B | 109.3 |
O3—Zn1—O2 | 149.67 (12) | C2—C1—H1B | 109.3 |
N4i—Zn1—O4 | 86.27 (10) | H1A—C1—H1B | 108.0 |
O1—Zn1—O4 | 88.80 (12) | N6—C2—C1 | 112.5 (3) |
N1—Zn1—O4 | 147.07 (10) | N6—C2—H2A | 109.1 |
O3—Zn1—O4 | 53.47 (10) | C1—C2—H2A | 109.1 |
O2—Zn1—O4 | 122.68 (12) | N6—C2—H2B | 109.1 |
N7—O1—Zn1 | 108.1 (2) | C1—C2—H2B | 109.1 |
N7—O2—Zn1 | 86.7 (2) | H2A—C2—H2B | 107.8 |
N8—O3—Zn1 | 106.9 (2) | N1—C3—N3 | 110.1 (3) |
N8—O4—Zn1 | 86.7 (2) | N1—C3—H3A | 125.0 |
C3—N1—N2 | 107.8 (3) | N3—C3—H3A | 125.0 |
C3—N1—Zn1 | 132.3 (2) | N2—C4—N3 | 112.0 (3) |
N2—N1—Zn1 | 120.0 (2) | N2—C4—H4A | 124.0 |
C4—N2—N1 | 105.6 (3) | N3—C4—H4A | 124.0 |
C3—N3—C4 | 104.6 (3) | N4—C5—N6 | 110.0 (3) |
C3—N3—C1 | 127.8 (3) | N4—C5—H5A | 125.0 |
C4—N3—C1 | 127.6 (3) | N6—C5—H5A | 125.0 |
C5—N4—N5 | 107.9 (3) | N5—C6—N6 | 111.6 (3) |
C5—N4—Zn1i | 130.4 (2) | N5—C6—H6A | 124.2 |
N5—N4—Zn1i | 121.5 (2) | N6—C6—H6A | 124.2 |
C6—N5—N4 | 105.3 (3) | ||
N4i—Zn1—O1—N7 | −48.4 (4) | O4—Zn1—N1—N2 | −55.0 (3) |
N1—Zn1—O1—N7 | 76.1 (3) | C3—N1—N2—C4 | −0.1 (4) |
O3—Zn1—O1—N7 | 174.4 (3) | Zn1—N1—N2—C4 | −180.0 (2) |
O2—Zn1—O1—N7 | 1.1 (3) | C5—N4—N5—C6 | 0.0 (4) |
O4—Zn1—O1—N7 | −132.7 (3) | Zn1i—N4—N5—C6 | 176.0 (2) |
N4i—Zn1—O2—N7 | 142.3 (3) | Zn1—O2—N7—O1 | 1.5 (4) |
O1—Zn1—O2—N7 | −1.1 (3) | Zn1—O1—N7—O2 | −1.9 (5) |
N1—Zn1—O2—N7 | −114.3 (3) | Zn1—O4—N8—O3 | −0.1 (3) |
O3—Zn1—O2—N7 | −14.4 (5) | Zn1—O3—N8—O4 | 0.1 (4) |
O4—Zn1—O2—N7 | 57.9 (3) | C3—N3—C1—C2 | −96.2 (4) |
N4i—Zn1—O3—N8 | −59.3 (3) | C4—N3—C1—C2 | 82.9 (4) |
O1—Zn1—O3—N8 | 82.9 (3) | C5—N6—C2—C1 | 84.7 (4) |
N1—Zn1—O3—N8 | −168.1 (3) | C6—N6—C2—C1 | −92.2 (4) |
O2—Zn1—O3—N8 | 93.6 (3) | N3—C1—C2—N6 | 64.9 (4) |
O4—Zn1—O3—N8 | −0.1 (2) | N2—N1—C3—N3 | 0.4 (3) |
N4i—Zn1—O4—N8 | 131.5 (2) | Zn1—N1—C3—N3 | −179.7 (2) |
O1—Zn1—O4—N8 | −100.0 (3) | C4—N3—C3—N1 | −0.6 (3) |
N1—Zn1—O4—N8 | 22.4 (3) | C1—N3—C3—N1 | 178.7 (3) |
O3—Zn1—O4—N8 | 0.1 (2) | N1—N2—C4—N3 | −0.2 (4) |
O2—Zn1—O4—N8 | −143.1 (2) | C3—N3—C4—N2 | 0.5 (4) |
N4i—Zn1—N1—C3 | 21.0 (3) | C1—N3—C4—N2 | −178.7 (3) |
O1—Zn1—N1—C3 | −117.4 (3) | N5—N4—C5—N6 | −0.1 (4) |
O3—Zn1—N1—C3 | 143.0 (3) | Zn1i—N4—C5—N6 | −175.7 (2) |
O2—Zn1—N1—C3 | −67.0 (3) | C6—N6—C5—N4 | 0.3 (4) |
O4—Zn1—N1—C3 | 125.2 (3) | C2—N6—C5—N4 | −177.2 (3) |
N4i—Zn1—N1—N2 | −159.2 (2) | N4—N5—C6—N6 | 0.2 (4) |
O1—Zn1—N1—N2 | 62.4 (2) | C5—N6—C6—N5 | −0.3 (4) |
O3—Zn1—N1—N2 | −37.2 (2) | C2—N6—C6—N5 | 177.1 (3) |
O2—Zn1—N1—N2 | 112.8 (2) |
Symmetry code: (i) −x+1/2, −y−1/2, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1B···O2ii | 0.97 | 2.53 | 3.396 (5) | 149 |
C2—H2A···O1iii | 0.97 | 2.49 | 3.417 (4) | 160 |
C3—H3A···O2ii | 0.93 | 2.66 | 3.412 (5) | 139 |
C6—H6A···N2iv | 0.93 | 2.39 | 3.314 (4) | 176 |
Symmetry codes: (ii) −x+1/2, −y+1/2, −z+2; (iii) x−1/2, y−1/2, z; (iv) −x+1/2, y−1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | [Zn2(NO2)4(C6H8N6)2] |
Mr | 643.15 |
Crystal system, space group | Monoclinic, C2/c |
Temperature (K) | 293 |
a, b, c (Å) | 20.491 (4), 6.7087 (13), 17.289 (4) |
β (°) | 97.125 (5) |
V (Å3) | 2358.3 (8) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 2.11 |
Crystal size (mm) | 0.60 × 0.20 × 0.20 |
Data collection | |
Diffractometer | Rigaku Mercury CCD diffractometer |
Absorption correction | Multi-scan (Blessing, 1995, 1997) |
Tmin, Tmax | 0.364, 0.678 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 10892, 2144, 1945 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.602 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.104, 1.06 |
No. of reflections | 2144 |
No. of parameters | 172 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.47, −0.61 |
Computer programs: CrystalClear (Rigaku, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
Zn1—N4i | 2.002 (3) | Zn1—O3 | 2.046 (3) |
Zn1—O1 | 2.031 (3) | Zn1—O2 | 2.477 (3) |
Zn1—N1 | 2.036 (3) | Zn1—O4 | 2.488 (3) |
N4i—Zn1—O1 | 128.32 (12) | N1—Zn1—O2 | 89.42 (13) |
N4i—Zn1—N1 | 103.43 (11) | O3—Zn1—O2 | 149.67 (12) |
O1—Zn1—N1 | 107.96 (13) | N4i—Zn1—O4 | 86.27 (10) |
N4i—Zn1—O3 | 119.46 (12) | O1—Zn1—O4 | 88.80 (12) |
O1—Zn1—O3 | 97.34 (12) | N1—Zn1—O4 | 147.07 (10) |
N1—Zn1—O3 | 95.48 (11) | O3—Zn1—O4 | 53.47 (10) |
N4i—Zn1—O2 | 88.11 (11) | O2—Zn1—O4 | 122.68 (12) |
O1—Zn1—O2 | 52.96 (11) |
Symmetry code: (i) −x+1/2, −y−1/2, −z+2. |
D—H···A | D—H | H···A | D···A | D—H···A |
C1—H1B···O2ii | 0.97 | 2.53 | 3.396 (5) | 149.4 |
C2—H2A···O1iii | 0.97 | 2.49 | 3.417 (4) | 160.1 |
C3—H3A···O2ii | 0.93 | 2.66 | 3.412 (5) | 138.7 |
C6—H6A···N2iv | 0.93 | 2.39 | 3.314 (4) | 176.1 |
Symmetry codes: (ii) −x+1/2, −y+1/2, −z+2; (iii) x−1/2, y−1/2, z; (iv) −x+1/2, y−1/2, −z+3/2. |
References
Blessing, R. H. (1995). Acta Cryst. A51, 33–38. CrossRef CAS Web of Science IUCr Journals Google Scholar
Blessing, R. H. (1997). J. Appl. Cryst. 30, 421–426. CrossRef CAS Web of Science IUCr Journals Google Scholar
Haasnoot, J. G. (2000). Coord. Chem. Rev. 200–202, 131–185. Web of Science CrossRef CAS Google Scholar
Habit, H. A., Hoffmann, A., Hoppe, H. A., Steinfeld, G. & Janiak, C. (2009). Inorg. Chem. 48, 2166–2180. Web of Science PubMed Google Scholar
Mascal, M. (1998). Chem. Commun. pp. 303–304. Web of Science CrossRef Google Scholar
Rigaku (2000). CrystalClear. Rigaku Corporation, Tokyo, Japan. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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1,2,4-Triazole and its derivatives are very interesting ligands, because they combine the coordination geometry of both pyrazole and imidazole with regard to the arrangement of their three heteroatoms. A large number of mononuclear, oligonuclear and polynuclear transition metal complexes of 1,2,4-triazole derivatives have been synthesized and characterized because of their magnetic properties and novel topologies (Haasnoot, 2000).
In the present work, we report here the preparation and crystal structure of a dimeric zincII complex, namely, [Zn(btre)NO2)2]2 (I) (btre = 1,2-bis(1,2,4-triazol-4-yl)ethane.
In the complex (I), the coordination geometry of the zincII atom in the title complex, [Zn(C6H8N6)(NO2)2]2 or [Zn(btre)(NO2)2]2, where btre is µ-[1,2-bis(1,2,4-triazol-4-yl)ethane], is a distorted octahedron, in which the ZnII atom is coordinated by two N atoms from the triazole rings of two symmetry-related btre ligands and four O atoms from two NO2- ligands. Two ZnII atoms are bridged by two organic ligands to form a dimer. Each NO2- anion acts as a chelating coordination mode.
The crystal structure of (I) is built up from a neutral dimeric metallocycle. The dimer is centrosymmetric. As shown in Fig.1, in each dimer, two zincII centres are connected by two btre ligands resulting in a discrete Zn2(btre)2 18-membered binuclear metallocycle.
Each zincII centre is six-coordinated by two N atoms of btre ligands and four O atoms from two NO2- ligands (Table 1), forming a distorted octahedral geometry. Each btre exhibits a gauche conformation in (I). The N3—C1—C2—N6 torsion angle is 64.9 (4)°. The dihedral angle between the two triazole ring is 40.1 (2)°. The Zn···Zn separation via the bridging btre ligand is 7.809 (2)Å in (I), compared with the corresponding values 7.8750 (2)Å in [Zn(btre)Cl2]2 and 7.7980 (5)Å in [Zn(btre)I2]2 (Habit et al., 2009).
Weak hydrogen bonds play an important role in the formation of the crystal structure. The intermolecular packing is organized by C—H···N and C—H···O hydrogen bonds (Table 2 and Figure 2; Mascal 1998).