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In the title compound, C
18H
14Cl
2N
4O
2, the triazole ring and benzylidenamino moiety are each planar, and approximately coplanar with respect to each other. The crystal structure is stabilized by C—H
O and C—H
N intra- and intermolecular hydrogen bonds.
Supporting information
CCDC reference: 214807
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.005 Å
- R factor = 0.060
- wR factor = 0.133
- Data-to-parameter ratio = 11.6
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
Alert Level C:
REFLT_03
From the CIF: _diffrn_reflns_theta_max 24.79
From the CIF: _reflns_number_total 2730
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 3010
Completeness (_total/calc) 90.70%
Alert C: < 95% complete
THETM_01 Alert C The value of sine(theta_max)/wavelength is less than 0.590
Calculated sin(theta_max)/wavelength = 0.5899
0 Alert Level A = Potentially serious problem
0 Alert Level B = Potential problem
2 Alert Level C = Please check
3-(p-Chlorobenzyl)-4-(p-chlorobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol- 5-one (0.01 mol) was treated with 10 ml of acetic anhydride and the mixture was refluxed for 1 h. The resulting product was filtered off and dried in vacuo. Several recrystallizations from ethyl acetate gave the pure title compound. Yield: 84%, m.p.: 461–462 K.
The H atoms were located geometrically and refined using a riding model, fixing the aromatic C—H distance at 0.93 Å, the methylene C—H distance 0.97 Å and methyl group C—H distance 0.96 Å.
Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPIII (Burnett & Johnson, 1996); software used to prepare material for publication: WinGX (Farrugia, 1997) and PARST (Nardelli, 1995).
1-Acetyl-3-(
p-chlorobenzyl)-4-benzylidenamino-4,5-dihydro- 1
H-1,2,4-triazole-5-one
top
Crystal data top
C18H14Cl2N4O2 | Z = 2 |
Mr = 389.23 | F(000) = 400 |
Triclinic, P1 | Dx = 1.478 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.7109 (10) Å | Cell parameters from 870 reflections |
b = 8.6329 (12) Å | θ = 2.4–22.2° |
c = 15.833 (2) Å | µ = 0.39 mm−1 |
α = 84.144 (3)° | T = 293 K |
β = 79.466 (3)° | Prism, colourless |
γ = 76.252 (3)° | 0.42 × 0.10 × 0.10 mm |
V = 874.3 (2) Å3 | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1873 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.027 |
Graphite monochromator | θmax = 24.8°, θmin = 2.4° |
ϕ and ω scans | h = −7→7 |
4127 measured reflections | k = −8→10 |
2730 independent reflections | l = −18→17 |
Refinement top
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)] = 0.060 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.133 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0538P)2 + 0.3745P] where P = (Fo2 + 2Fc2)/3 |
2730 reflections | (Δ/σ)max < 0.001 |
235 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.35 e Å−3 |
Crystal data top
C18H14Cl2N4O2 | γ = 76.252 (3)° |
Mr = 389.23 | V = 874.3 (2) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.7109 (10) Å | Mo Kα radiation |
b = 8.6329 (12) Å | µ = 0.39 mm−1 |
c = 15.833 (2) Å | T = 293 K |
α = 84.144 (3)° | 0.42 × 0.10 × 0.10 mm |
β = 79.466 (3)° | |
Data collection top
Bruker SMART CCD area-detector diffractometer | 1873 reflections with I > 2σ(I) |
4127 measured reflections | Rint = 0.027 |
2730 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.060 | 0 restraints |
wR(F2) = 0.133 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.33 e Å−3 |
2730 reflections | Δρmin = −0.35 e Å−3 |
235 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 | x | y | z | Uiso*/Ueq | |
O2 | −1.1800 (4) | 1.7986 (3) | 1.00736 (17) | 0.0572 (8) | |
C15 | −1.1525 (7) | 1.7652 (5) | 0.5174 (3) | 0.0533 (11) | |
H15 | −1.1149 | 1.8476 | 0.4800 | 0.064* | |
C17 | −1.2249 (6) | 1.7657 (4) | 0.9423 (2) | 0.0402 (9) | |
C18 | −1.4333 (6) | 1.8221 (5) | 0.9154 (3) | 0.0538 (11) | |
H18A | −1.4302 | 1.7809 | 0.8610 | 0.081* | |
H18B | −1.4677 | 1.9367 | 0.9101 | 0.081* | |
H18C | −1.5360 | 1.7848 | 0.9579 | 0.081* | |
Cl1 | −1.5014 (2) | 1.82542 (15) | 0.44684 (8) | 0.0794 (5) | |
C16 | −1.0211 (6) | 1.6824 (5) | 0.5728 (2) | 0.0482 (10) | |
H16 | −0.8947 | 1.7094 | 0.5723 | 0.058* | |
O1 | −0.7919 (4) | 1.5751 (3) | 0.96023 (16) | 0.0450 (7) | |
N3 | −1.0756 (4) | 1.6646 (3) | 0.88547 (18) | 0.0362 (7) | |
C14 | −1.3371 (6) | 1.7252 (5) | 0.5182 (2) | 0.0447 (10) | |
C8 | −0.8808 (6) | 1.5775 (4) | 0.9002 (2) | 0.0368 (9) | |
N4 | −1.1222 (5) | 1.6352 (4) | 0.80651 (18) | 0.0396 (8) | |
N2 | −0.8117 (4) | 1.4923 (3) | 0.82625 (18) | 0.0370 (7) | |
C9 | −0.9615 (5) | 1.5344 (4) | 0.7732 (2) | 0.0351 (9) | |
C11 | −1.0747 (5) | 1.5607 (4) | 0.6287 (2) | 0.0361 (9) | |
C7 | −0.4901 (6) | 1.3436 (4) | 0.8489 (2) | 0.0400 (9) | |
H7 | −0.5061 | 1.3935 | 0.8998 | 0.048* | |
C5 | −0.1342 (6) | 1.1938 (4) | 0.8636 (2) | 0.0430 (10) | |
H5 | −0.1426 | 1.2496 | 0.9119 | 0.052* | |
N1 | −0.6310 (4) | 1.3795 (3) | 0.80140 (18) | 0.0382 (7) | |
C13 | −1.3938 (6) | 1.6057 (5) | 0.5726 (3) | 0.0547 (11) | |
H13 | −1.5202 | 1.5790 | 0.5727 | 0.066* | |
C10 | −0.9282 (6) | 1.4656 (5) | 0.6873 (2) | 0.0463 (10) | |
H10A | −0.9473 | 1.3569 | 0.6958 | 0.056* | |
H10B | −0.7860 | 1.4618 | 0.6594 | 0.056* | |
C6 | −0.3024 (5) | 1.2219 (4) | 0.8210 (2) | 0.0354 (8) | |
C4 | 0.0470 (6) | 1.0837 (4) | 0.8356 (2) | 0.0462 (10) | |
H4 | 0.1605 | 1.0664 | 0.8641 | 0.055* | |
C12 | −1.2630 (6) | 1.5247 (5) | 0.6276 (3) | 0.0513 (11) | |
H12 | −1.3027 | 1.4431 | 0.6651 | 0.062* | |
C3 | 0.0562 (6) | 1.0005 (4) | 0.7648 (2) | 0.0413 (9) | |
C1 | −0.2889 (6) | 1.1329 (4) | 0.7510 (2) | 0.0458 (10) | |
H1 | −0.4030 | 1.1484 | 0.7229 | 0.055* | |
Cl2 | 0.28328 (17) | 0.86281 (13) | 0.72774 (7) | 0.0627 (4) | |
C2 | −0.1114 (6) | 1.0229 (4) | 0.7224 (2) | 0.0481 (10) | |
H2 | −0.1041 | 0.9646 | 0.6753 | 0.058* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O2 | 0.0571 (18) | 0.0689 (19) | 0.0462 (17) | −0.0008 (15) | −0.0156 (14) | −0.0252 (14) |
C15 | 0.067 (3) | 0.043 (2) | 0.049 (3) | −0.009 (2) | −0.015 (2) | 0.0058 (19) |
C17 | 0.043 (2) | 0.038 (2) | 0.037 (2) | −0.0055 (18) | −0.0054 (18) | −0.0040 (17) |
C18 | 0.044 (2) | 0.063 (3) | 0.051 (3) | 0.000 (2) | −0.011 (2) | −0.014 (2) |
Cl1 | 0.0939 (10) | 0.0774 (9) | 0.0656 (8) | 0.0140 (7) | −0.0530 (7) | −0.0047 (6) |
C16 | 0.044 (2) | 0.055 (3) | 0.048 (3) | −0.012 (2) | −0.014 (2) | −0.004 (2) |
O1 | 0.0454 (16) | 0.0528 (17) | 0.0387 (15) | −0.0028 (13) | −0.0188 (13) | −0.0096 (12) |
N3 | 0.0350 (18) | 0.0422 (18) | 0.0308 (17) | −0.0006 (14) | −0.0125 (13) | −0.0053 (14) |
C14 | 0.049 (2) | 0.049 (2) | 0.033 (2) | 0.007 (2) | −0.0178 (18) | −0.0089 (19) |
C8 | 0.039 (2) | 0.039 (2) | 0.033 (2) | −0.0045 (17) | −0.0100 (18) | −0.0033 (17) |
N4 | 0.0405 (18) | 0.0461 (19) | 0.0318 (17) | −0.0023 (16) | −0.0125 (14) | −0.0055 (14) |
N2 | 0.0349 (17) | 0.0423 (18) | 0.0323 (17) | −0.0004 (15) | −0.0102 (14) | −0.0064 (14) |
C9 | 0.037 (2) | 0.036 (2) | 0.031 (2) | −0.0023 (18) | −0.0108 (17) | 0.0006 (16) |
C11 | 0.036 (2) | 0.040 (2) | 0.029 (2) | 0.0031 (18) | −0.0082 (16) | −0.0130 (17) |
C7 | 0.044 (2) | 0.046 (2) | 0.031 (2) | −0.0077 (19) | −0.0086 (18) | −0.0047 (17) |
C5 | 0.044 (2) | 0.051 (2) | 0.036 (2) | −0.0035 (19) | −0.0164 (18) | −0.0085 (18) |
N1 | 0.0347 (17) | 0.0418 (18) | 0.0348 (17) | 0.0006 (14) | −0.0093 (14) | −0.0029 (14) |
C13 | 0.042 (2) | 0.063 (3) | 0.062 (3) | −0.011 (2) | −0.017 (2) | 0.000 (2) |
C10 | 0.045 (2) | 0.055 (3) | 0.035 (2) | 0.0034 (19) | −0.0128 (18) | −0.0088 (18) |
C6 | 0.039 (2) | 0.033 (2) | 0.034 (2) | −0.0033 (17) | −0.0138 (17) | −0.0007 (16) |
C4 | 0.040 (2) | 0.049 (2) | 0.049 (2) | −0.0020 (19) | −0.0153 (19) | −0.007 (2) |
C12 | 0.051 (3) | 0.056 (3) | 0.045 (2) | −0.010 (2) | −0.011 (2) | 0.010 (2) |
C3 | 0.038 (2) | 0.038 (2) | 0.044 (2) | −0.0010 (18) | −0.0084 (18) | −0.0043 (18) |
C1 | 0.047 (2) | 0.050 (2) | 0.044 (2) | 0.000 (2) | −0.0271 (19) | −0.0072 (19) |
Cl2 | 0.0496 (6) | 0.0592 (7) | 0.0724 (8) | 0.0082 (5) | −0.0099 (5) | −0.0204 (6) |
C2 | 0.058 (3) | 0.045 (2) | 0.042 (2) | −0.003 (2) | −0.016 (2) | −0.0114 (19) |
Geometric parameters (Å, º) top
O2—C17 | 1.202 (4) | C11—C12 | 1.375 (5) |
C15—C14 | 1.361 (6) | C11—C10 | 1.515 (5) |
C15—C16 | 1.383 (5) | C7—N1 | 1.276 (4) |
C15—H15 | 0.9300 | C7—C6 | 1.465 (5) |
C17—N3 | 1.411 (4) | C7—H7 | 0.9300 |
C17—C18 | 1.492 (5) | C5—C6 | 1.379 (5) |
C18—H18A | 0.9600 | C5—C4 | 1.385 (5) |
C18—H18B | 0.9600 | C5—H5 | 0.9300 |
C18—H18C | 0.9600 | C13—C12 | 1.372 (5) |
Cl1—C14 | 1.744 (4) | C13—H13 | 0.9300 |
C16—C11 | 1.374 (5) | C10—H10A | 0.9700 |
C16—H16 | 0.9300 | C10—H10B | 0.9700 |
O1—C8 | 1.208 (4) | C6—C1 | 1.390 (5) |
N3—C8 | 1.391 (4) | C4—C3 | 1.376 (5) |
N3—N4 | 1.404 (4) | C4—H4 | 0.9300 |
C14—C13 | 1.355 (6) | C12—H12 | 0.9300 |
C8—N2 | 1.393 (4) | C3—C2 | 1.378 (5) |
N4—C9 | 1.280 (4) | C3—Cl2 | 1.742 (4) |
N2—N1 | 1.384 (4) | C1—C2 | 1.371 (5) |
N2—C9 | 1.386 (4) | C1—H1 | 0.9300 |
C9—C10 | 1.498 (5) | C2—H2 | 0.9300 |
| | | |
C14—C15—C16 | 119.4 (4) | N1—C7—C6 | 118.3 (3) |
C14—C15—H15 | 120.3 | N1—C7—H7 | 120.8 |
C16—C15—H15 | 120.3 | C6—C7—H7 | 120.8 |
O2—C17—N3 | 119.9 (3) | C6—C5—C4 | 121.0 (3) |
O2—C17—C18 | 125.0 (4) | C6—C5—H5 | 119.5 |
N3—C17—C18 | 115.0 (3) | C4—C5—H5 | 119.5 |
C17—C18—H18A | 109.5 | C7—N1—N2 | 119.9 (3) |
C17—C18—H18B | 109.5 | C14—C13—C12 | 119.3 (4) |
H18A—C18—H18B | 109.5 | C14—C13—H13 | 120.3 |
C17—C18—H18C | 109.5 | C12—C13—H13 | 120.3 |
H18A—C18—H18C | 109.5 | C9—C10—C11 | 113.0 (3) |
H18B—C18—H18C | 109.5 | C9—C10—H10A | 109.0 |
C11—C16—C15 | 120.9 (4) | C11—C10—H10A | 109.0 |
C11—C16—H16 | 119.5 | C9—C10—H10B | 109.0 |
C15—C16—H16 | 119.5 | C11—C10—H10B | 109.0 |
C8—N3—N4 | 112.7 (3) | H10A—C10—H10B | 107.8 |
C8—N3—C17 | 127.0 (3) | C5—C6—C1 | 118.4 (3) |
N4—N3—C17 | 120.2 (3) | C5—C6—C7 | 120.6 (3) |
C13—C14—C15 | 120.9 (4) | C1—C6—C7 | 121.0 (3) |
C13—C14—Cl1 | 119.2 (3) | C3—C4—C5 | 118.9 (3) |
C15—C14—Cl1 | 119.9 (3) | C3—C4—H4 | 120.5 |
O1—C8—N3 | 130.2 (3) | C5—C4—H4 | 120.5 |
O1—C8—N2 | 128.3 (3) | C13—C12—C11 | 121.7 (4) |
N3—C8—N2 | 101.5 (3) | C13—C12—H12 | 119.1 |
C9—N4—N3 | 104.5 (3) | C11—C12—H12 | 119.1 |
N1—N2—C9 | 119.7 (3) | C4—C3—C2 | 121.4 (3) |
N1—N2—C8 | 131.3 (3) | C4—C3—Cl2 | 119.8 (3) |
C9—N2—C8 | 109.0 (3) | C2—C3—Cl2 | 118.9 (3) |
N4—C9—N2 | 112.2 (3) | C2—C1—C6 | 121.5 (3) |
N4—C9—C10 | 126.5 (3) | C2—C1—H1 | 119.3 |
N2—C9—C10 | 121.3 (3) | C6—C1—H1 | 119.3 |
C16—C11—C12 | 117.7 (3) | C1—C2—C3 | 118.8 (3) |
C16—C11—C10 | 121.2 (3) | C1—C2—H2 | 120.6 |
C12—C11—C10 | 121.1 (4) | C3—C2—H2 | 120.6 |
| | | |
C14—C15—C16—C11 | −0.2 (6) | C6—C7—N1—N2 | 179.1 (3) |
O2—C17—N3—C8 | 8.9 (6) | C9—N2—N1—C7 | 178.0 (3) |
C18—C17—N3—C8 | −170.2 (3) | C8—N2—N1—C7 | −3.1 (5) |
O2—C17—N3—N4 | −175.3 (3) | C15—C14—C13—C12 | 0.1 (6) |
C18—C17—N3—N4 | 5.6 (5) | Cl1—C14—C13—C12 | 178.7 (3) |
C16—C15—C14—C13 | 0.2 (6) | N4—C9—C10—C11 | 17.2 (6) |
C16—C15—C14—Cl1 | −178.5 (3) | N2—C9—C10—C11 | −162.5 (3) |
N4—N3—C8—O1 | 179.2 (4) | C16—C11—C10—C9 | 91.1 (4) |
C17—N3—C8—O1 | −4.8 (6) | C12—C11—C10—C9 | −91.1 (4) |
N4—N3—C8—N2 | −0.5 (4) | C4—C5—C6—C1 | 2.3 (6) |
C17—N3—C8—N2 | 175.6 (3) | C4—C5—C6—C7 | −177.3 (3) |
C8—N3—N4—C9 | −0.4 (4) | N1—C7—C6—C5 | 171.4 (3) |
C17—N3—N4—C9 | −176.8 (3) | N1—C7—C6—C1 | −8.2 (5) |
O1—C8—N2—N1 | 2.5 (6) | C6—C5—C4—C3 | −0.9 (6) |
N3—C8—N2—N1 | −177.8 (3) | C14—C13—C12—C11 | −0.4 (6) |
O1—C8—N2—C9 | −178.5 (4) | C16—C11—C12—C13 | 0.4 (6) |
N3—C8—N2—C9 | 1.2 (4) | C10—C11—C12—C13 | −177.5 (4) |
N3—N4—C9—N2 | 1.2 (4) | C5—C4—C3—C2 | −0.9 (6) |
N3—N4—C9—C10 | −178.5 (3) | C5—C4—C3—Cl2 | 179.4 (3) |
N1—N2—C9—N4 | 177.5 (3) | C5—C6—C1—C2 | −2.1 (6) |
C8—N2—C9—N4 | −1.6 (4) | C7—C6—C1—C2 | 177.5 (4) |
N1—N2—C9—C10 | −2.8 (5) | C6—C1—C2—C3 | 0.3 (6) |
C8—N2—C9—C10 | 178.1 (3) | C4—C3—C2—C1 | 1.2 (6) |
C15—C16—C11—C12 | −0.1 (5) | Cl2—C3—C2—C1 | −179.1 (3) |
C15—C16—C11—C10 | 177.8 (3) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C10—H10B···N1 | 0.97 | 2.61 | 2.853 (5) | 94 |
C1—H1···N1 | 0.93 | 2.50 | 2.792 (4) | 99 |
C18—H18A···N4 | 0.96 | 2.22 | 2.754 (4) | 114 |
C7—H7···O1 | 0.93 | 2.29 | 2.949 (4) | 127 |
C12—H12···N1i | 0.93 | 2.90 | 3.678 (5) | 142 |
C18—H18C···O1i | 0.96 | 2.77 | 3.513 (5) | 135 |
Symmetry code: (i) x−1, y, z. |
Experimental details
Crystal data |
Chemical formula | C18H14Cl2N4O2 |
Mr | 389.23 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 6.7109 (10), 8.6329 (12), 15.833 (2) |
α, β, γ (°) | 84.144 (3), 79.466 (3), 76.252 (3) |
V (Å3) | 874.3 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.39 |
Crystal size (mm) | 0.42 × 0.10 × 0.10 |
|
Data collection |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4127, 2730, 1873 |
Rint | 0.027 |
(sin θ/λ)max (Å−1) | 0.590 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.060, 0.133, 1.04 |
No. of reflections | 2730 |
No. of parameters | 235 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.35 |
Selected bond lengths (Å) topCl1—C14 | 1.744 (4) | C7—N1 | 1.276 (4) |
N3—N4 | 1.404 (4) | C3—Cl2 | 1.742 (4) |
N4—C9 | 1.280 (4) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C10—H10B···N1 | 0.97 | 2.61 | 2.853 (5) | 94 |
C1—H1···N1 | 0.93 | 2.50 | 2.792 (4) | 99 |
C18—H18A···N4 | 0.96 | 2.22 | 2.754 (4) | 114 |
C7—H7···O1 | 0.93 | 2.29 | 2.949 (4) | 127 |
C12—H12···N1i | 0.93 | 2.90 | 3.678 (5) | 142 |
C18—H18C···O1i | 0.96 | 2.77 | 3.513 (5) | 135 |
Symmetry code: (i) x−1, y, z. |
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The 1,2,4-triazole ring systems are very interesting because of their similarity to the 1,3-imidazole bridging found in the copper–zinc protein superoxide dismutase (Feiters, 1990) and for their ability to act as a doubly bidentate chelating ligand (Wang et al., 1998). Compounds containing these systems have been structurally characterized as part of a study of Schiff bases of amine- and thione-substituted triazoles (McCarrick et al., 1999; Sen et al., 1998) and their metal complexes (Sen et al., 1996, 1997; Clark et al., 1999). Most Schiff bases possess antibacterial, anticancer, antiinflamunantory and antitoxic activities (Williams, 1972), and sulfur-containing Schiff bases are particularly effective. The 4-amino-3-methyl-1,2,4-triazole-5-thione derivative of p-nitrophenyl aldehyde has been structurally characterized and it has been shown to be highly effective as an inhibitor of Staphylococcus aureus (Liu et al., 1999). Therefore, the crystal structure analysis of the title compound, (I), has been carried out.
The title compound consists of one 1,2,4-triazole ring (ring A: N3/C8/N2/C9/N4) with an acetly group substituted at N3, a benzylidenamino group, a p-chlorobenzyl group and an O atom substituted at C9, N2, and C8, respectively.
The N═C bond lengths [N1═C7 = 1.276 (4) Å and N4═C9 = 1.280 (4) Å] are close to the values quoted in the literature (Puviarasan et al., 1999; Liu et al., 1999; Zhu et al., 2000), while the presence of the acetyl group at N3 and the benzylidenamino group at C9 causes a small even if significant stretching of the N—N bond [N3—N4 = 1.404 (4) Å].
The Cl1—C14 and Cl2—C3 bond lengths [1.744 (4) and 1.742 (4) Å, respectively] conform with those previously found (Wang et al., 1998; Puviarasan et al., 1999).
The title compound consists of three planar rings. One is the triazole ring, ring A, others are ring B (C1—C6) and ring C (C11—C16). In the triazole ring, the observed maximum deviation is 0.008 (3) Å for C9 atom. The O1 atom is 0.024 (3) Å from the plane. The dihedral angle between rings A/B, A/C and B/C are 11.1 (1), 84.0 (1) and 89.1 (1)°, respectively.
The crystal structure of (I) is stabilized by four intramolecular and two intermolecular hydrogen bonds. Indeed all intramolecular hydrogen bonds seem to drive the orientation of the substituents with respect to the triazole rings as indicated by the near coplanarity of the groups involved. In the molecule, the p-chlorobenzyl and the acetyl group are able to form hydrogen bonds with the benzylidenamino and atom O1 of a symmetry-related molecule. All details of the C—H···N and C—H···O inter- and intramolecular hydrogen bonds found in the crystal are quoted in Table 2. These contacts generate infinite chains in the crystal and seem to force the molecule to adapt a twisted conformation.