Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270113010809/sf3195sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270113010809/sf3195Isup2.hkl |
CCDC reference: 893243
All chemicals were of analytical grade (Aldrich) and were used without further purification. CHN microanalyses were performed using a Vario Micro Cube elemental analyser. The IR spectrum was recorded on a Nicolet iS5 55 FT–IR spectrophotometer. Diffuse reflectance spectra were measured in BaSO4 pellets with BaSO4 as a reference using a Shimadzu UV-3600 equipped with an ISR-3100 attachment.
ZnCl2 (0.645 g, 5.0 mmol), NaN3 (0.65 g, 10.0 mmol) and pyridine-2-carbonitrile (1.04 g, 10.0 mmol) were dissolved in water (150 ml) and the mixture was stirred for 4 d at room temperature. After that time, a white compound was filtered off, washed with water and dried in air (yield: 0.76 g, 35%). 2 M HCl was then added dropwise to the compound (0.25 g) until the solid dissolved, and the solution was extracted with CH2Cl2 (ca 5 ml). The organic phase was separated from the inorganic phase and the inorganic phase was left aside for crystallization. The product, (I), was filtered off and dried in air (yield 0.10 g, 30%). Analysis, calculated for C12H12Cl4N10Zn: C 28.62, H 2.40, N 27.82%; found: C 28.33, H 2.39, N 27.14%. Spectroscopic analysis: IR (Medium?, ν, cm-1): 3250, 3081, 3053, 2988, 1705, 1636, 1611, 1458, 1282, 1035, 805, 792, 748, 713, 621; UV–Vis (BaSO4 pellet, λ, nm): 277, 237.
All C-bound H atoms were positioned with an idealized geometry, with C—H = 0.93 Å [Added text OK?] and refined using a riding model, with Uiso(H) = 1.5Ueq(C) for methyl groups and 1.2Ueq(C) otherwise. N-bound H atoms were found in difference Fourier maps and refined without any restraints.
Data collection: CrysAlis RED (Oxford Diffraction, 2011); cell refinement: CrysAlis RED (Oxford Diffraction, 2011); data reduction: CrysAlis PRO (Oxford Diffraction, 2011); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: WinGX (Farrugia, 2012).
(C6H6N5)2[ZnCl4] | Z = 2 |
Mr = 503.49 | F(000) = 504 |
Triclinic, P1 | Dx = 1.687 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71069 Å |
a = 9.196 (5) Å | Cell parameters from 0 reflections |
b = 10.491 (5) Å | θ = 0–0° |
c = 11.186 (5) Å | µ = 1.80 mm−1 |
α = 102.407 (5)° | T = 293 K |
β = 98.185 (5)° | Prism, colourless |
γ = 105.697 (5)° | 0.55 × 0.49 × 0.21 mm |
V = 991.3 (8) Å3 |
Oxford SuperNova diffractometer | 4101 independent reflections |
Radiation source: SuperNova (Mo) X-ray Source | 3266 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.032 |
Detector resolution: 10.3756 pixels mm-1 | θmax = 26.5°, θmin = 3.2° |
ω scans | h = −11→11 |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2011) | k = −13→13 |
Tmin = 0.438, Tmax = 0.704 | l = −14→14 |
12476 measured reflections |
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)] = 0.029 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0302P)2] where P = (Fo2 + 2Fc2)/3 |
4101 reflections | (Δ/σ)max = 0.001 |
260 parameters | Δρmax = 0.30 e Å−3 |
0 restraints | Δρmin = −0.27 e Å−3 |
(C6H6N5)2[ZnCl4] | γ = 105.697 (5)° |
Mr = 503.49 | V = 991.3 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 9.196 (5) Å | Mo Kα radiation |
b = 10.491 (5) Å | µ = 1.80 mm−1 |
c = 11.186 (5) Å | T = 293 K |
α = 102.407 (5)° | 0.55 × 0.49 × 0.21 mm |
β = 98.185 (5)° |
Oxford SuperNova diffractometer | 4101 independent reflections |
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2011) | 3266 reflections with I > 2σ(I) |
Tmin = 0.438, Tmax = 0.704 | Rint = 0.032 |
12476 measured reflections |
R[F2 > 2σ(F2)] = 0.029 | 0 restraints |
wR(F2) = 0.070 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.03 | Δρmax = 0.30 e Å−3 |
4101 reflections | Δρmin = −0.27 e Å−3 |
260 parameters |
Experimental. CrysAlisPro, Agilent Technologies, Version 1.171.35.15 (release 03-08-2011 CrysAlis171 .NET) (compiled Aug 3 2011,13:03:54) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm. |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s involving l.s. planes. |
Refinement. Positions of all of non-hydrogen atoms were determined by direct methods using SIR97 (Altomare et al., 1999). All non-hydrogen atoms were refined anisotropically using weighted full-matrix least-squares on F2. Refinement and further calculations were carried out using SHELXL97 (Sheldrick, 2008). 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 > 2σ(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 | 0.26396 (3) | 0.75957 (2) | 0.25111 (2) | 0.04205 (10) | |
Cl1 | 0.47346 (6) | 0.76958 (5) | 0.40002 (5) | 0.04462 (14) | |
Cl2 | 0.13410 (6) | 0.89224 (5) | 0.34664 (6) | 0.04824 (15) | |
Cl3 | 0.35100 (8) | 0.82995 (7) | 0.09271 (6) | 0.06294 (18) | |
Cl4 | 0.10036 (7) | 0.53960 (6) | 0.20200 (6) | 0.05392 (17) | |
N1 | 0.1412 (2) | 0.2519 (2) | 0.4684 (2) | 0.0555 (5) | |
N2 | 0.0982 (3) | 0.3215 (2) | 0.5622 (2) | 0.0604 (6) | |
N3 | 0.1638 (3) | 0.4555 (2) | 0.5919 (2) | 0.0712 (6) | |
N4 | 0.2549 (3) | 0.4764 (2) | 0.5123 (2) | 0.0639 (6) | |
C5 | 0.2385 (3) | 0.3523 (2) | 0.4392 (2) | 0.0452 (5) | |
C6 | 0.3207 (2) | 0.3323 (2) | 0.3387 (2) | 0.0426 (5) | |
C7 | 0.3255 (3) | 0.2076 (2) | 0.2712 (2) | 0.0559 (6) | |
H7 | 0.2725 | 0.1265 | 0.2878 | 0.067* | |
C8 | 0.4101 (3) | 0.2046 (3) | 0.1783 (3) | 0.0610 (7) | |
H8 | 0.4127 | 0.1208 | 0.1316 | 0.073* | |
C9 | 0.4906 (3) | 0.3246 (3) | 0.1543 (2) | 0.0579 (7) | |
H9 | 0.549 | 0.3229 | 0.0929 | 0.069* | |
C10 | 0.4823 (3) | 0.4460 (3) | 0.2231 (2) | 0.0528 (6) | |
H10 | 0.5345 | 0.5283 | 0.2081 | 0.063* | |
N11 | 0.3997 (2) | 0.4464 (2) | 0.31149 (19) | 0.0447 (5) | |
H2 | 0.031 (3) | 0.275 (3) | 0.603 (3) | 0.098 (11)* | |
H11 | 0.400 (3) | 0.520 (2) | 0.355 (2) | 0.059 (8)* | |
N12 | 0.1239 (2) | 0.2044 (2) | 0.95795 (18) | 0.0517 (5) | |
N13 | 0.1579 (3) | 0.3387 (2) | 0.9786 (2) | 0.0582 (6) | |
N14 | 0.2489 (3) | 0.3944 (2) | 0.9113 (2) | 0.0641 (6) | |
N15 | 0.2768 (2) | 0.2908 (2) | 0.83919 (19) | 0.0546 (5) | |
C16 | 0.2007 (2) | 0.1774 (2) | 0.8692 (2) | 0.0428 (5) | |
C17 | 0.2047 (2) | 0.0418 (2) | 0.8078 (2) | 0.0414 (5) | |
C18 | 0.1395 (3) | −0.0782 (3) | 0.8379 (2) | 0.0561 (6) | |
H18 | 0.0847 | −0.0784 | 0.9016 | 0.067* | |
C19 | 0.1568 (3) | −0.1988 (3) | 0.7717 (3) | 0.0672 (7) | |
H19 | 0.1141 | −0.2803 | 0.7921 | 0.081* | |
C20 | 0.2353 (3) | −0.2001 (3) | 0.6771 (3) | 0.0610 (7) | |
H20 | 0.2448 | −0.2819 | 0.632 | 0.073* | |
C21 | 0.2999 (3) | −0.0793 (2) | 0.6495 (2) | 0.0537 (6) | |
H21 | 0.355 | −0.0776 | 0.586 | 0.064* | |
N22 | 0.2829 (2) | 0.0360 (2) | 0.71483 (18) | 0.0447 (5) | |
H13 | 0.127 (2) | 0.386 (2) | 1.032 (2) | 0.043 (7)* | |
H22 | 0.326 (3) | 0.107 (2) | 0.700 (2) | 0.058 (8)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Zn1 | 0.04800 (17) | 0.03893 (16) | 0.04320 (16) | 0.01448 (12) | 0.01712 (12) | 0.01306 (12) |
Cl1 | 0.0479 (3) | 0.0422 (3) | 0.0453 (3) | 0.0127 (2) | 0.0125 (3) | 0.0147 (2) |
Cl2 | 0.0553 (3) | 0.0382 (3) | 0.0594 (4) | 0.0185 (3) | 0.0259 (3) | 0.0159 (3) |
Cl3 | 0.0851 (5) | 0.0702 (4) | 0.0479 (4) | 0.0301 (4) | 0.0316 (3) | 0.0263 (3) |
Cl4 | 0.0527 (4) | 0.0381 (3) | 0.0653 (4) | 0.0091 (3) | 0.0185 (3) | 0.0047 (3) |
N1 | 0.0540 (12) | 0.0517 (12) | 0.0677 (14) | 0.0125 (10) | 0.0245 (11) | 0.0273 (11) |
N2 | 0.0571 (14) | 0.0657 (16) | 0.0637 (15) | 0.0095 (12) | 0.0224 (12) | 0.0342 (12) |
N3 | 0.0846 (17) | 0.0639 (16) | 0.0650 (15) | 0.0115 (13) | 0.0357 (13) | 0.0187 (12) |
N4 | 0.0827 (16) | 0.0516 (13) | 0.0587 (13) | 0.0088 (11) | 0.0378 (12) | 0.0182 (11) |
C5 | 0.0457 (13) | 0.0444 (13) | 0.0489 (14) | 0.0111 (11) | 0.0110 (11) | 0.0225 (11) |
C6 | 0.0432 (13) | 0.0393 (12) | 0.0497 (13) | 0.0133 (10) | 0.0106 (11) | 0.0200 (10) |
C7 | 0.0649 (16) | 0.0394 (13) | 0.0654 (17) | 0.0147 (12) | 0.0127 (14) | 0.0206 (12) |
C8 | 0.0731 (18) | 0.0528 (16) | 0.0618 (17) | 0.0324 (14) | 0.0123 (14) | 0.0102 (13) |
C9 | 0.0605 (16) | 0.0672 (17) | 0.0577 (16) | 0.0308 (14) | 0.0230 (13) | 0.0199 (13) |
C10 | 0.0566 (15) | 0.0532 (15) | 0.0584 (15) | 0.0188 (12) | 0.0258 (13) | 0.0239 (12) |
N11 | 0.0520 (12) | 0.0384 (11) | 0.0513 (12) | 0.0172 (10) | 0.0208 (10) | 0.0172 (10) |
N12 | 0.0534 (12) | 0.0590 (13) | 0.0493 (12) | 0.0218 (10) | 0.0193 (10) | 0.0173 (10) |
N13 | 0.0661 (15) | 0.0639 (15) | 0.0563 (14) | 0.0326 (12) | 0.0286 (12) | 0.0140 (12) |
N14 | 0.0735 (15) | 0.0576 (14) | 0.0729 (15) | 0.0276 (12) | 0.0330 (13) | 0.0210 (12) |
N15 | 0.0632 (13) | 0.0484 (12) | 0.0623 (13) | 0.0228 (10) | 0.0300 (11) | 0.0175 (10) |
C16 | 0.0411 (12) | 0.0520 (14) | 0.0390 (12) | 0.0153 (11) | 0.0133 (10) | 0.0159 (11) |
C17 | 0.0382 (12) | 0.0491 (13) | 0.0366 (12) | 0.0101 (10) | 0.0079 (10) | 0.0151 (10) |
C18 | 0.0572 (16) | 0.0578 (16) | 0.0573 (16) | 0.0109 (13) | 0.0206 (13) | 0.0270 (13) |
C19 | 0.0677 (18) | 0.0463 (15) | 0.080 (2) | 0.0030 (13) | 0.0075 (16) | 0.0253 (14) |
C20 | 0.0666 (18) | 0.0425 (14) | 0.0659 (18) | 0.0150 (13) | 0.0056 (14) | 0.0059 (13) |
C21 | 0.0572 (15) | 0.0526 (15) | 0.0470 (14) | 0.0175 (12) | 0.0106 (12) | 0.0043 (12) |
N22 | 0.0497 (12) | 0.0392 (11) | 0.0447 (11) | 0.0092 (10) | 0.0151 (9) | 0.0128 (9) |
Zn1—Cl1 | 2.3236 (11) | C10—H10 | 0.93 |
Zn1—Cl2 | 2.2648 (9) | N11—H11 | 0.82 (2) |
Zn1—Cl3 | 2.2297 (10) | N12—N13 | 1.318 (3) |
Zn1—Cl4 | 2.2873 (11) | N12—C16 | 1.323 (3) |
N1—C5 | 1.318 (3) | N13—N14 | 1.308 (3) |
N1—N2 | 1.317 (3) | N13—H13 | 0.83 (2) |
N2—N3 | 1.317 (3) | N14—N15 | 1.317 (2) |
N2—H2 | 0.92 (3) | N15—C16 | 1.343 (3) |
N3—N4 | 1.318 (3) | C16—C17 | 1.453 (3) |
N4—C5 | 1.337 (3) | C17—N22 | 1.347 (3) |
C5—C6 | 1.451 (3) | C17—C18 | 1.374 (3) |
C6—N11 | 1.342 (3) | C18—C19 | 1.383 (3) |
C6—C7 | 1.379 (3) | C18—H18 | 0.93 |
C7—C8 | 1.384 (3) | C19—C20 | 1.364 (4) |
C7—H7 | 0.93 | C19—H19 | 0.93 |
C8—C9 | 1.379 (3) | C20—C21 | 1.366 (4) |
C8—H8 | 0.93 | C20—H20 | 0.93 |
C9—C10 | 1.367 (3) | C21—N22 | 1.333 (3) |
C9—H9 | 0.93 | C21—H21 | 0.93 |
C10—N11 | 1.331 (3) | N22—H22 | 0.81 (2) |
Cl3—Zn1—Cl2 | 112.68 (3) | C10—N11—C6 | 123.8 (2) |
Cl3—Zn1—Cl4 | 116.09 (3) | C10—N11—H11 | 118.8 (18) |
Cl2—Zn1—Cl4 | 105.13 (4) | C6—N11—H11 | 117.3 (18) |
Cl3—Zn1—Cl1 | 108.78 (4) | N13—N12—C16 | 100.4 (2) |
Cl2—Zn1—Cl1 | 107.68 (4) | N14—N13—N12 | 115.7 (2) |
Cl4—Zn1—Cl1 | 106.00 (3) | N14—N13—H13 | 121.4 (16) |
C5—N1—N2 | 100.9 (2) | N12—N13—H13 | 122.8 (16) |
N3—N2—N1 | 114.8 (2) | N13—N14—N15 | 104.8 (2) |
N3—N2—H2 | 125.5 (18) | N14—N15—C16 | 106.38 (19) |
N1—N2—H2 | 119.6 (18) | N12—C16—N15 | 112.6 (2) |
N2—N3—N4 | 105.2 (2) | N12—C16—C17 | 125.4 (2) |
N3—N4—C5 | 106.1 (2) | N15—C16—C17 | 122.0 (2) |
N1—C5—N4 | 113.1 (2) | N22—C17—C18 | 118.0 (2) |
N1—C5—C6 | 124.2 (2) | N22—C17—C16 | 115.8 (2) |
N4—C5—C6 | 122.7 (2) | C18—C17—C16 | 126.1 (2) |
N11—C6—C7 | 118.1 (2) | C17—C18—C19 | 118.9 (2) |
N11—C6—C5 | 116.25 (19) | C17—C18—H18 | 120.6 |
C7—C6—C5 | 125.6 (2) | C19—C18—H18 | 120.6 |
C6—C7—C8 | 119.1 (2) | C20—C19—C18 | 121.1 (3) |
C6—C7—H7 | 120.4 | C20—C19—H19 | 119.5 |
C8—C7—H7 | 120.4 | C18—C19—H19 | 119.5 |
C9—C8—C7 | 120.8 (2) | C19—C20—C21 | 119.0 (2) |
C9—C8—H8 | 119.6 | C19—C20—H20 | 120.5 |
C7—C8—H8 | 119.6 | C21—C20—H20 | 120.5 |
C10—C9—C8 | 118.2 (2) | N22—C21—C20 | 119.1 (2) |
C10—C9—H9 | 120.9 | N22—C21—H21 | 120.4 |
C8—C9—H9 | 120.9 | C20—C21—H21 | 120.4 |
N11—C10—C9 | 120.0 (2) | C21—N22—C17 | 124.0 (2) |
N11—C10—H10 | 120 | C21—N22—H22 | 117.8 (17) |
C9—C10—H10 | 120 | C17—N22—H22 | 118.1 (17) |
C5—N1—N2—N3 | −0.7 (3) | C16—N12—N13—N14 | −0.6 (3) |
N1—N2—N3—N4 | 0.6 (3) | N12—N13—N14—N15 | 0.8 (3) |
N2—N3—N4—C5 | −0.2 (3) | N13—N14—N15—C16 | −0.6 (3) |
N2—N1—C5—N4 | 0.6 (3) | N13—N12—C16—N15 | 0.2 (3) |
N2—N1—C5—C6 | −179.6 (2) | N13—N12—C16—C17 | −179.4 (2) |
N3—N4—C5—N1 | −0.2 (3) | N14—N15—C16—N12 | 0.3 (3) |
N3—N4—C5—C6 | 179.9 (2) | N14—N15—C16—C17 | 179.9 (2) |
N1—C5—C6—N11 | 171.7 (2) | N12—C16—C17—N22 | 176.4 (2) |
N4—C5—C6—N11 | −8.4 (3) | N15—C16—C17—N22 | −3.2 (3) |
N1—C5—C6—C7 | −9.1 (4) | N12—C16—C17—C18 | −5.1 (4) |
N4—C5—C6—C7 | 170.8 (2) | N15—C16—C17—C18 | 175.3 (2) |
N11—C6—C7—C8 | −0.3 (3) | N22—C17—C18—C19 | −0.1 (3) |
C5—C6—C7—C8 | −179.5 (2) | C16—C17—C18—C19 | −178.6 (2) |
C6—C7—C8—C9 | 0.9 (4) | C17—C18—C19—C20 | −0.8 (4) |
C7—C8—C9—C10 | −1.1 (4) | C18—C19—C20—C21 | 1.2 (4) |
C8—C9—C10—N11 | 0.8 (4) | C19—C20—C21—N22 | −0.7 (4) |
C9—C10—N11—C6 | −0.2 (4) | C20—C21—N22—C17 | −0.1 (4) |
C7—C6—N11—C10 | 0.0 (3) | C18—C17—N22—C21 | 0.5 (3) |
C5—C6—N11—C10 | 179.2 (2) | C16—C17—N22—C21 | 179.2 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···Cl2i | 0.92 (3) | 2.22 (3) | 3.105 (3) | 162 (3) |
N11—H11···Cl1 | 0.82 (2) | 2.44 (2) | 3.171 (3) | 150 (2) |
N13—H13···Cl4ii | 0.83 (2) | 2.30 (2) | 3.112 (2) | 167 (2) |
N22—H22···Cl1iii | 0.81 (2) | 2.50 (3) | 3.210 (2) | 147 (2) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) x, y, z+1; (iii) −x+1, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | (C6H6N5)2[ZnCl4] |
Mr | 503.49 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 9.196 (5), 10.491 (5), 11.186 (5) |
α, β, γ (°) | 102.407 (5), 98.185 (5), 105.697 (5) |
V (Å3) | 991.3 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 1.80 |
Crystal size (mm) | 0.55 × 0.49 × 0.21 |
Data collection | |
Diffractometer | Oxford SuperNova diffractometer |
Absorption correction | Multi-scan (CrysAlis PRO; Oxford Diffraction, 2011) |
Tmin, Tmax | 0.438, 0.704 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 12476, 4101, 3266 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.628 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.029, 0.070, 1.03 |
No. of reflections | 4101 |
No. of parameters | 260 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.30, −0.27 |
Computer programs: CrysAlis RED (Oxford Diffraction, 2011), CrysAlis PRO (Oxford Diffraction, 2011), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2008), WinGX (Farrugia, 2012).
Zn1—Cl1 | 2.3236 (11) | C6—N11 | 1.342 (3) |
Zn1—Cl2 | 2.2648 (9) | N11—H11 | 0.82 (2) |
Zn1—Cl3 | 2.2297 (10) | N12—N13 | 1.318 (3) |
Zn1—Cl4 | 2.2873 (11) | N12—C16 | 1.323 (3) |
N1—C5 | 1.318 (3) | N13—N14 | 1.308 (3) |
N1—N2 | 1.317 (3) | N13—H13 | 0.83 (2) |
N2—N3 | 1.317 (3) | N14—N15 | 1.317 (2) |
N2—H2 | 0.92 (3) | N15—C16 | 1.343 (3) |
N3—N4 | 1.318 (3) | N22—H22 | 0.81 (2) |
N4—C5 | 1.337 (3) | ||
Cl3—Zn1—Cl2 | 112.68 (3) | N3—N4—C5 | 106.1 (2) |
Cl3—Zn1—Cl4 | 116.09 (3) | N11—C6—C5 | 116.25 (19) |
Cl2—Zn1—Cl4 | 105.13 (4) | C6—N11—H11 | 117.3 (18) |
Cl3—Zn1—Cl1 | 108.78 (4) | N13—N12—C16 | 100.4 (2) |
Cl2—Zn1—Cl1 | 107.68 (4) | N14—N13—N12 | 115.7 (2) |
Cl4—Zn1—Cl1 | 106.00 (3) | N13—N14—N15 | 104.8 (2) |
C5—N1—N2 | 100.9 (2) | N14—N15—C16 | 106.38 (19) |
N3—N2—N1 | 114.8 (2) | N22—C17—C16 | 115.8 (2) |
N2—N3—N4 | 105.2 (2) | C17—N22—H22 | 118.1 (17) |
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2···Cl2i | 0.92 (3) | 2.22 (3) | 3.105 (3) | 162 (3) |
N11—H11···Cl1 | 0.82 (2) | 2.44 (2) | 3.171 (3) | 150 (2) |
N13—H13···Cl4ii | 0.83 (2) | 2.30 (2) | 3.112 (2) | 167 (2) |
N22—H22···Cl1iii | 0.81 (2) | 2.50 (3) | 3.210 (2) | 147 (2) |
Symmetry codes: (i) −x, −y+1, −z+1; (ii) x, y, z+1; (iii) −x+1, −y+1, −z+1. |
During the last decade, the number of reports describing the synthesis and properties of tetrazoles and their complexes has increased dramatically. Tetrazoles are very attractive due to their wide application, for example, in medicinal chemistry (Dhayanithi et al., 2011), coordination chemistry (Bhandari et al., 1998, 2000; Janiak, 1994; Janiak et al., 1995, 1996; Zhou et al., 1998), materials chemistry (Hill et al., 1996; Zhang et al., 2010) and, last but not least, as highly energetic compounds possessing military applications (Carlucci et al., 1999; Ostrovskii et al., 1999; Piekiel & Zachariah, 2012). Tetrazoles may coordinate transition metal ions, forming complexes which can be used as phase transition dielectric materials for applications in micro-electronics and memory storage (Fu et al., 2007, 2008; Fu & Xiong, 2008; Zhao et al., 2008).
The general method of synthesis reported previously is based on the reaction of azides with organic nitriles in the presence of metal catalysts (Demko & Sharpless, 2001a,b, 2002a,b). This method requires solvothermal conditions or at least heating in solvents of high boiling point, such as dimethylformamide (Demko & Sharpless, 2001a,b). This type of procedure is not safe because of the metal azides or HN3 which can be formed. Because of this problem, zinc was used at the very beginning of tetrazole synthesis, as zinc azides are not very sensitive towards detonation; moreover, the earliest reactions were performed in neutral or slightly alkaline media to avoid HN3 evolution. Recently, new methods of tetrazole synthesis, including LiCl instead of Zn or W (He et al., 2009), have been proposed. Nevertheless, a high temperature is still necessary to perform these reactions.
In this paper, we report a simple and safe method for the preparation of a tetrazole complex by the reaction of sodium azide, nitrile and zinc chloride in water at room temperature (see scheme). We characterized the title compound, (I), by elemental analysis and IR and UV–Vis spectroscopy. A crystal of (I) suitable for X-ray analysis was selected from the materials prepared as decribed in the Experimental section. Single-crystal X-ray analysis reveals that (I) crystallizes in the triclinic space group P1. The asymmetric unit is composed of two organic cations and one [ZnCl4]2- anion (Fig. 1), and the crystal packing along b is presented in Fig. 2. In each cation, the pyridine N atom (N11 and N22) is protonated. In the anion, atom Zn1 is coordinated by four chloride ligands in a distorted tetrahedral geometry. Selected bond distances and angles are listed in Table 1. The Cl—Zn—Cl angles are in the range 105.13 (4)–116.09 (3)°. All Zn—Cl bond lengths are different as a result of hydrogen-bond formation (Fig. 3 and Table 2). Atom Cl1 forms a medium-strength hydrogen bond to atom N11 and a weak hydrogen bond to atom N22, while atoms Cl2 and Cl4 each form only weak hydrogen bonds to atoms N2 and N13, respectively (Desiraju & Steiner, 1999; Jeffrey, 1997). Atom Cl3 is not involved in hydrogen bonding, so the Zn—Cl3 distance is the shortest, while Zn—Cl1 is the longest. These interactions create a three-dimensional network (Fig. 4). It can be seen that the hydrogen-bonding network forms layers between which there are no specific interactions.
The IR spectrum of (I) is shown in Fig. 5. The absence of bands in the characteristic range for νCN in pyridine-2-carbonitrile, and the formation of new bands at 1636 and 1282 cm-1 [which can be attributed to the ν(C═ N) and ν(N—N═N–) vibrations in the tetrazole ring, respectively], confirm the formation of tetrazole in (I) (Wang et al., 2011). Bands at 3250 and 3081 cm-1 and at 3053 and 2988 cm-1 confirm the presence of N—H vibrations for the pyridine and tetrazole rings, respectively. In the UV part of the reflectance spectrum of (I) (Fig. 6), two bands are observed at 277 and 237 nm, which may be assigned to an intraligand (IL) π–π* transition (Tong & Xin, 2011).