organic compounds
5-(1-Benzyl-1H-1,2,3-triazol-4-yl)-2,1,3-benzoxadiazole
aAlberta Glycomics Centre, Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada, and bX-ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada
*Correspondence e-mail: Bob.McDonald@ualberta.ca
In the title compound, C15H11N5O, which was prepared as part of a study to identify fluorogenic substrates for the Cu-catalysed azide–alkyne cycloaddition (CuAAC) reaction, the benzoxadiazole unit and the triazole ring are much more closely coplanar [dihedral angle = 10.92 (7)°] than either is to the benzyl group [dihedral angles = 69.13 (3)° and 78.20 (4)°, respectively]. The features two different sets of weak intermolecular C—H⋯N interactions between adjacent benzoxadiazole and triazole rings, forming a chain that propagates in the [-110] direction parallel to the ab plane.
Related literature
For the synthesis of the title compound, see: Key & Cairo (2011). For computational studies of the absorption and fluorescence of the title compound, see: Brown et al. (2012). For structures with 4-aryl substituted 1-benzyl-1,2,3-triazole rings, see: Key et al. (2008); Li et al. (2011); Raghavendra & Lam (2004); Sarmiento-Sánchez et al. (2011). For two related benzoxadiazole structures, see: Key, Cairo & Ferguson (2012); Key, Cairo & McDonald (2012). For the synthesis of analogous triazole-substituted coumarin structures, see: Key et al. (2009). For information on reactive chromophores, see: Cairo et al. (2010). For recent work on small molecule fluorophores, see: Lavis & Raines (2008).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXD (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).
Supporting information
10.1107/S1600536812041827/mw2083sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536812041827/mw2083Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536812041827/mw2083Isup3.cml
4-Ethynylbenzoxadiazole (II) (26 mg, 0.18 mmol, 1 equiv) was dissolved in 1:1 water/methanol (5 mL), followed by addition of benzyl azide (0.095 mL, 0.90 mmol, 5 equiv). Copper sulphate (6 mg, 0.036 mmol, 0.2 equiv) and ascorbic acid (10 mg, 0.025 mmol, 0.3 equiv) were then added to the solution. The reaction mixture was allowed to stir at room temperature for 1.5 h turning an opaque white colour. The solvent was removed in vacuo and the crude product was dissolved into chloroform, washed with water, dried over MgSO4, and concentrated in vacuo. The compound was purified by δ 8.19 (s, 1H), 8.02 (dd, 1H, 4J = 1.2 Hz, 3J = 9.6 Hz), 8.01 (dd, 1H, 4J = 1.2 Hz, 3J = 9.6 Hz), 7.88 (s, 1H), 7.40-7.48 (m, 3H), 7.34-7.40 (m, 2H), 5.64 (s, 2H); 13C NMR (100 MHz, CDCl3): δ 149.6, 149.0, 146.2, 133.8, 131.2, 129.6, 129.4, 128.5, 121.4, 117.3, 111.3, 54.8; IR (microscope): ν = 3138, 3122, 3071, 3040, 2924, 2853, 1630, 1564 cm-1; ES-HRMS calculated for C15H11N5O [M+H]+: 278.1036; observed: 278.1032. Rf = 0.18 (1:3 EtOAc/hexanes).
(EtOAc/hexanes), and obtained as a white powder (30 mg, 60% yield). m.p. 148.7-149.5 °C; 1H NMR (400 MHz, CDCl3):All H atoms were generated in idealized positions and refined using a riding model with fixed C-H distances (C-Haromatic = 0.95 Å, C-Hmethylene = 0.99 Å) and with Uiso(H) = 1.2Ueq(C).
Data collection: APEX2 (Bruker, 2008); cell
SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXD (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: publCIF (Westrip, 2010).C15H11N5O | Z = 2 |
Mr = 277.29 | F(000) = 288 |
Triclinic, P1 | Dx = 1.436 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 5.7526 (4) Å | Cell parameters from 4623 reflections |
b = 9.9261 (6) Å | θ = 2.7–27.3° |
c = 11.7012 (8) Å | µ = 0.10 mm−1 |
α = 90.3799 (7)° | T = 173 K |
β = 99.2517 (7)° | Fragment, colourless |
γ = 103.2900 (7)° | 0.50 × 0.29 × 0.23 mm |
V = 641.14 (7) Å3 |
Bruker APEXII CCD diffractometer | 2879 independent reflections |
Radiation source: fine-focus sealed tube | 2489 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.012 |
Detector resolution: 8.26 pixels mm-1 | θmax = 27.3°, θmin = 1.8° |
ω scans | h = −7→7 |
Absorption correction: numerical (SADABS; Sheldrick, 2008) | k = −12→12 |
Tmin = 0.953, Tmax = 0.978 | l = −15→15 |
5667 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.035 | H-atom parameters constrained |
wR(F2) = 0.096 | w = 1/[σ2(Fo2) + (0.0444P)2 + 0.1305P] where P = (Fo2 + 2Fc2)/3 |
S = 1.06 | (Δ/σ)max < 0.001 |
2879 reflections | Δρmax = 0.23 e Å−3 |
191 parameters | Δρmin = −0.17 e Å−3 |
0 restraints | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 constraints | Extinction coefficient: 0.027 (4) |
Primary atom site location: structure-invariant direct methods |
C15H11N5O | γ = 103.2900 (7)° |
Mr = 277.29 | V = 641.14 (7) Å3 |
Triclinic, P1 | Z = 2 |
a = 5.7526 (4) Å | Mo Kα radiation |
b = 9.9261 (6) Å | µ = 0.10 mm−1 |
c = 11.7012 (8) Å | T = 173 K |
α = 90.3799 (7)° | 0.50 × 0.29 × 0.23 mm |
β = 99.2517 (7)° |
Bruker APEXII CCD diffractometer | 2879 independent reflections |
Absorption correction: numerical (SADABS; Sheldrick, 2008) | 2489 reflections with I > 2σ(I) |
Tmin = 0.953, Tmax = 0.978 | Rint = 0.012 |
5667 measured reflections |
R[F2 > 2σ(F2)] = 0.035 | 0 restraints |
wR(F2) = 0.096 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.23 e Å−3 |
2879 reflections | Δρmin = −0.17 e Å−3 |
191 parameters |
Geometry. All standard uncertainties (s.u.'s) (except the s.u. in the dihedral angle between two least-squares 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 least-squares 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 | ||
O | 0.37047 (18) | 0.60313 (9) | −0.24598 (8) | 0.0488 (3) | |
N1 | 0.5182 (2) | 0.51386 (12) | −0.25718 (9) | 0.0454 (3) | |
N2 | 0.2225 (2) | 0.56215 (11) | −0.16419 (9) | 0.0426 (3) | |
N3 | 0.3192 (2) | 0.05933 (11) | 0.11897 (9) | 0.0397 (3) | |
N4 | 0.2143 (2) | −0.00352 (11) | 0.20195 (9) | 0.0405 (3) | |
N5 | 0.02778 (17) | 0.05338 (10) | 0.21296 (8) | 0.0326 (2) | |
C1 | 0.4623 (2) | 0.41788 (12) | −0.18298 (10) | 0.0351 (3) | |
C2 | 0.2785 (2) | 0.44754 (12) | −0.12510 (10) | 0.0337 (3) | |
C3 | 0.1868 (2) | 0.36165 (12) | −0.03855 (10) | 0.0324 (2) | |
H3 | 0.0650 | 0.3818 | 0.0002 | 0.039* | |
C4 | 0.28041 (19) | 0.24890 (11) | −0.01314 (9) | 0.0298 (2) | |
C5 | 0.4649 (2) | 0.21869 (12) | −0.07346 (10) | 0.0340 (3) | |
H5 | 0.5248 | 0.1388 | −0.0539 | 0.041* | |
C6 | 0.5554 (2) | 0.29873 (13) | −0.15607 (10) | 0.0370 (3) | |
H6 | 0.6760 | 0.2766 | −0.1946 | 0.044* | |
C7 | 0.2003 (2) | 0.15745 (11) | 0.07735 (9) | 0.0303 (2) | |
C8 | 0.0138 (2) | 0.15328 (12) | 0.13786 (10) | 0.0332 (3) | |
H8 | −0.1008 | 0.2093 | 0.1285 | 0.040* | |
C9 | −0.1176 (2) | 0.01211 (12) | 0.30362 (10) | 0.0354 (3) | |
H9A | −0.0691 | −0.0676 | 0.3429 | 0.042* | |
H9B | −0.2903 | −0.0184 | 0.2678 | 0.042* | |
C10 | −0.0894 (2) | 0.12825 (11) | 0.39256 (9) | 0.0305 (2) | |
C11 | 0.1235 (2) | 0.22895 (13) | 0.42168 (11) | 0.0382 (3) | |
H11 | 0.2570 | 0.2280 | 0.3835 | 0.046* | |
C12 | 0.1428 (2) | 0.33104 (13) | 0.50619 (11) | 0.0432 (3) | |
H12 | 0.2891 | 0.4004 | 0.5251 | 0.052* | |
C13 | −0.0481 (2) | 0.33292 (13) | 0.56299 (10) | 0.0416 (3) | |
H13 | −0.0332 | 0.4023 | 0.6218 | 0.050* | |
C14 | −0.2610 (2) | 0.23349 (15) | 0.53388 (11) | 0.0442 (3) | |
H14 | −0.3934 | 0.2341 | 0.5729 | 0.053* | |
C15 | −0.2825 (2) | 0.13267 (13) | 0.44798 (10) | 0.0381 (3) | |
H15 | −0.4314 | 0.0659 | 0.4269 | 0.046* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O | 0.0609 (6) | 0.0388 (5) | 0.0460 (5) | 0.0100 (4) | 0.0090 (4) | 0.0048 (4) |
N1 | 0.0503 (6) | 0.0426 (6) | 0.0405 (6) | 0.0057 (5) | 0.0074 (5) | −0.0029 (5) |
N2 | 0.0504 (6) | 0.0356 (6) | 0.0421 (6) | 0.0119 (5) | 0.0060 (5) | 0.0023 (4) |
N3 | 0.0464 (6) | 0.0395 (6) | 0.0409 (6) | 0.0237 (5) | 0.0101 (4) | 0.0023 (4) |
N4 | 0.0477 (6) | 0.0387 (6) | 0.0426 (6) | 0.0241 (5) | 0.0091 (5) | 0.0027 (4) |
N5 | 0.0361 (5) | 0.0305 (5) | 0.0329 (5) | 0.0136 (4) | 0.0029 (4) | −0.0026 (4) |
C1 | 0.0359 (6) | 0.0367 (6) | 0.0293 (5) | 0.0039 (5) | 0.0025 (4) | −0.0075 (5) |
C2 | 0.0347 (6) | 0.0319 (6) | 0.0328 (6) | 0.0089 (5) | −0.0008 (4) | −0.0063 (4) |
C3 | 0.0314 (5) | 0.0339 (6) | 0.0333 (6) | 0.0118 (5) | 0.0034 (4) | −0.0050 (4) |
C4 | 0.0289 (5) | 0.0309 (5) | 0.0288 (5) | 0.0089 (4) | −0.0004 (4) | −0.0076 (4) |
C5 | 0.0348 (6) | 0.0356 (6) | 0.0336 (6) | 0.0149 (5) | 0.0018 (4) | −0.0085 (5) |
C6 | 0.0343 (6) | 0.0433 (7) | 0.0345 (6) | 0.0115 (5) | 0.0061 (5) | −0.0089 (5) |
C7 | 0.0317 (5) | 0.0291 (5) | 0.0308 (5) | 0.0125 (4) | −0.0002 (4) | −0.0064 (4) |
C8 | 0.0344 (6) | 0.0332 (6) | 0.0344 (6) | 0.0149 (5) | 0.0028 (4) | −0.0002 (4) |
C9 | 0.0383 (6) | 0.0302 (6) | 0.0370 (6) | 0.0069 (5) | 0.0060 (5) | 0.0000 (5) |
C10 | 0.0337 (6) | 0.0285 (5) | 0.0294 (5) | 0.0085 (4) | 0.0037 (4) | 0.0040 (4) |
C11 | 0.0336 (6) | 0.0388 (6) | 0.0413 (6) | 0.0049 (5) | 0.0090 (5) | −0.0032 (5) |
C12 | 0.0430 (7) | 0.0369 (7) | 0.0440 (7) | −0.0006 (5) | 0.0055 (5) | −0.0050 (5) |
C13 | 0.0538 (8) | 0.0392 (7) | 0.0333 (6) | 0.0160 (6) | 0.0042 (5) | −0.0033 (5) |
C14 | 0.0415 (7) | 0.0581 (8) | 0.0365 (6) | 0.0159 (6) | 0.0111 (5) | −0.0012 (6) |
C15 | 0.0336 (6) | 0.0431 (7) | 0.0353 (6) | 0.0036 (5) | 0.0065 (5) | 0.0012 (5) |
O—N1 | 1.3804 (15) | C6—H6 | 0.9500 |
O—N2 | 1.3833 (14) | C7—C8 | 1.3706 (16) |
N1—C1 | 1.3133 (16) | C8—H8 | 0.9500 |
N2—C2 | 1.3173 (15) | C9—C10 | 1.5107 (15) |
N3—N4 | 1.3112 (14) | C9—H9A | 0.9900 |
N3—C7 | 1.3633 (14) | C9—H9B | 0.9900 |
N4—N5 | 1.3452 (13) | C10—C15 | 1.3821 (16) |
N5—C8 | 1.3370 (14) | C10—C11 | 1.3833 (16) |
N5—C9 | 1.4582 (15) | C11—C12 | 1.3845 (17) |
C1—C6 | 1.4237 (17) | C11—H11 | 0.9500 |
C1—C2 | 1.4260 (16) | C12—C13 | 1.3756 (18) |
C2—C3 | 1.4168 (16) | C12—H12 | 0.9500 |
C3—C4 | 1.3642 (16) | C13—C14 | 1.3766 (19) |
C3—H3 | 0.9500 | C13—H13 | 0.9500 |
C4—C5 | 1.4486 (15) | C14—C15 | 1.3844 (18) |
C4—C7 | 1.4609 (16) | C14—H14 | 0.9500 |
C5—C6 | 1.3485 (17) | C15—H15 | 0.9500 |
C5—H5 | 0.9500 | ||
N1—O—N2 | 112.34 (9) | C8—C7—C4 | 130.21 (10) |
C1—N1—O | 104.58 (10) | N5—C8—C7 | 105.21 (10) |
C2—N2—O | 104.48 (10) | N5—C8—H8 | 127.4 |
N4—N3—C7 | 108.93 (9) | C7—C8—H8 | 127.4 |
N3—N4—N5 | 107.19 (9) | N5—C9—C10 | 112.41 (9) |
C8—N5—N4 | 110.86 (10) | N5—C9—H9A | 109.1 |
C8—N5—C9 | 128.06 (10) | C10—C9—H9A | 109.1 |
N4—N5—C9 | 120.90 (9) | N5—C9—H9B | 109.1 |
N1—C1—C6 | 130.24 (11) | C10—C9—H9B | 109.1 |
N1—C1—C2 | 109.44 (11) | H9A—C9—H9B | 107.9 |
C6—C1—C2 | 120.32 (11) | C15—C10—C11 | 118.90 (11) |
N2—C2—C3 | 129.42 (11) | C15—C10—C9 | 118.67 (10) |
N2—C2—C1 | 109.17 (11) | C11—C10—C9 | 122.42 (10) |
C3—C2—C1 | 121.40 (10) | C10—C11—C12 | 120.27 (11) |
C4—C3—C2 | 117.34 (10) | C10—C11—H11 | 119.9 |
C4—C3—H3 | 121.3 | C12—C11—H11 | 119.9 |
C2—C3—H3 | 121.3 | C13—C12—C11 | 120.54 (12) |
C3—C4—C5 | 120.84 (11) | C13—C12—H12 | 119.7 |
C3—C4—C7 | 120.67 (10) | C11—C12—H12 | 119.7 |
C5—C4—C7 | 118.48 (10) | C12—C13—C14 | 119.45 (11) |
C6—C5—C4 | 123.01 (11) | C12—C13—H13 | 120.3 |
C6—C5—H5 | 118.5 | C14—C13—H13 | 120.3 |
C4—C5—H5 | 118.5 | C13—C14—C15 | 120.20 (12) |
C5—C6—C1 | 117.08 (10) | C13—C14—H14 | 119.9 |
C5—C6—H6 | 121.5 | C15—C14—H14 | 119.9 |
C1—C6—H6 | 121.5 | C10—C15—C14 | 120.61 (11) |
N3—C7—C8 | 107.80 (10) | C10—C15—H15 | 119.7 |
N3—C7—C4 | 121.94 (10) | C14—C15—H15 | 119.7 |
N2—O—N1—C1 | 0.09 (13) | N4—N3—C7—C8 | −0.26 (13) |
N1—O—N2—C2 | −0.13 (13) | N4—N3—C7—C4 | 177.60 (10) |
C7—N3—N4—N5 | 0.44 (13) | C3—C4—C7—N3 | −168.10 (11) |
N3—N4—N5—C8 | −0.47 (13) | C5—C4—C7—N3 | 10.64 (16) |
N3—N4—N5—C9 | −176.07 (10) | C3—C4—C7—C8 | 9.23 (18) |
O—N1—C1—C6 | −179.98 (11) | C5—C4—C7—C8 | −172.03 (11) |
O—N1—C1—C2 | −0.02 (12) | N4—N5—C8—C7 | 0.31 (13) |
O—N2—C2—C3 | 178.79 (11) | C9—N5—C8—C7 | 175.51 (10) |
O—N2—C2—C1 | 0.11 (12) | N3—C7—C8—N5 | −0.03 (12) |
N1—C1—C2—N2 | −0.06 (13) | C4—C7—C8—N5 | −177.65 (11) |
C6—C1—C2—N2 | 179.90 (10) | C8—N5—C9—C10 | −61.08 (15) |
N1—C1—C2—C3 | −178.86 (10) | N4—N5—C9—C10 | 113.69 (11) |
C6—C1—C2—C3 | 1.10 (16) | N5—C9—C10—C15 | 149.78 (10) |
N2—C2—C3—C4 | −178.88 (11) | N5—C9—C10—C11 | −31.20 (15) |
C1—C2—C3—C4 | −0.34 (16) | C15—C10—C11—C12 | 0.90 (18) |
C2—C3—C4—C5 | −0.45 (16) | C9—C10—C11—C12 | −178.12 (11) |
C2—C3—C4—C7 | 178.26 (9) | C10—C11—C12—C13 | 0.7 (2) |
C3—C4—C5—C6 | 0.53 (17) | C11—C12—C13—C14 | −1.0 (2) |
C7—C4—C5—C6 | −178.21 (10) | C12—C13—C14—C15 | −0.1 (2) |
C4—C5—C6—C1 | 0.22 (16) | C11—C10—C15—C14 | −2.06 (18) |
N1—C1—C6—C5 | 178.95 (12) | C9—C10—C15—C14 | 177.00 (11) |
C2—C1—C6—C5 | −1.00 (16) | C13—C14—C15—C10 | 1.69 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N3i | 0.95 | 2.50 | 3.3483 (15) | 148 |
C8—H8···N2ii | 0.95 | 2.57 | 3.4367 (15) | 151 |
Symmetry codes: (i) −x+1, −y, −z; (ii) −x, −y+1, −z. |
Experimental details
Crystal data | |
Chemical formula | C15H11N5O |
Mr | 277.29 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 173 |
a, b, c (Å) | 5.7526 (4), 9.9261 (6), 11.7012 (8) |
α, β, γ (°) | 90.3799 (7), 99.2517 (7), 103.2900 (7) |
V (Å3) | 641.14 (7) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.50 × 0.29 × 0.23 |
Data collection | |
Diffractometer | Bruker APEXII CCD diffractometer |
Absorption correction | Numerical (SADABS; Sheldrick, 2008) |
Tmin, Tmax | 0.953, 0.978 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5667, 2879, 2489 |
Rint | 0.012 |
(sin θ/λ)max (Å−1) | 0.646 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.035, 0.096, 1.06 |
No. of reflections | 2879 |
No. of parameters | 191 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.17 |
Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXD (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), publCIF (Westrip, 2010).
D—H···A | D—H | H···A | D···A | D—H···A |
C5—H5···N3i | 0.95 | 2.50 | 3.3483 (15) | 148 |
C8—H8···N2ii | 0.95 | 2.57 | 3.4367 (15) | 151 |
Symmetry codes: (i) −x+1, −y, −z; (ii) −x, −y+1, −z. |
Acknowledgements
We acknowledge the University of Alberta, the Natural Sciences and Engineering Research Council of Canada and the Alberta Glycomics Centre for funding of this work.
References
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Small molecule fluorophores have significant applications in both chemistry and biology, and new probes are an area of continued research (Lavis & Raines, 2008). Reactive chromophores, or dyes which change their spectral properties upon chemical reaction, have the potential to act as indicators of specific functional groups or enzymatic activity in complex mixtures (Cairo et al., 2010). We examined benzoxadiazole chromophores as substrates for the Cu-catalyzed azide-alkyne cycloaddition (CuAAC) by generating a series of analogs that contained either an alkyne or azide group appended to the ring. The title compound, I, was generated from 4-ethynylbenzoxadiazole (II), and showed a large increase in fluorescence relative to the precursor (Key & Cairo, 2011). As a result, we designated compound II as a fluorogenic substrate for CuAAC.
In the crystal, the dihedral angle between the mean planes of the benzoxadiazole group and the triazole ring is 10.92 (7)°, while the benzyl ring is twisted significantly out of the plane of the other two rings, with dihedral angles of 69.13 (3)° and 78.20 (4)° to the benzoxadiazole and triazole rings, respectively. Two different sets of weak intermolecular C-H···N interactions are observed between adjacent triazole and benzoxadiazole rings related by the inversion centers (1/2, 0, 0) (2.50 Å for H5···N3[1-x, -y, -z]) and (0, 1/2, 0) (2.57 Å for H8···N2[-x, 1-y, -z]). A parallel-stacking interaction is observed between benzoxadiazole rings related by the inversion center (1/2, 1/2, 0) (interplanar spacing = 3.366 Å).