Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805018519/dn6225sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536805018519/dn6225Isup2.hkl |
CCDC reference: 287547
Key indicators
- Single-crystal X-ray study
- T = 298 K
- Mean (C-C) = 0.009 Å
- R factor = 0.040
- wR factor = 0.122
- Data-to-parameter ratio = 8.8
checkCIF/PLATON results
No syntax errors found
Alert level B PLAT031_ALERT_4_B Refined Extinction Parameter within Range ...... 1.89 Sigma PLAT242_ALERT_2_B Check Low Ueq as Compared to Neighbors for C16
Alert level C PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low .... 42 Perc. PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical . ? PLAT220_ALERT_2_C Large Non-Solvent C Ueq(max)/Ueq(min) ... 2.56 Ratio PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C8 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C11 PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for C14 PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ... 9 PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd. # 1 C18 H16 Cl2 N4 O
Alert level G REFLT03_ALERT_4_G WARNING: Large fraction of Friedel related reflns may be needed to determine absolute structure From the CIF: _diffrn_reflns_theta_max 25.17 From the CIF: _reflns_number_total 1997 Count of symmetry unique reflns 1910 Completeness (_total/calc) 104.55% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 87 Fraction of Friedel pairs measured 0.046 Are heavy atom types Z>Si present yes
0 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 8 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 5 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 3 ALERT type 4 Improvement, methodology, query or suggestion
The title compound was prepared according to the procedure of Rao & Hu (2004). A solution of the compound in ethanol was concentrated gradually at room temperature to afford yellow prisms (m.p. 472–474 K).
H atoms were included in calculated positions and refined using a riding model. H atoms were given isotropic displacement parameters equal to 1.2 (or 1.5 for methyl H atoms) times the equivalent isotropic displacement parameters of their parent atoms and C—H distances were restrained to 0.93 Å for aromatic H atoms, 0.96 Å for methyl H atoms, and 0.97 Å for the remainder. N—H distances were restrained to 0.86 Å.
Although there are not sufficient Friedel pairs to determine reliably the absolute structure, the values of the Flack's parameter, 0.3 (2) for one model and 0.7 (2) for the inverted one, seems to be in favour of the initial model.
Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Version 1.05; Farrugia, 1997) and PLATON (Spek, 2003); software used to prepare material for publication: WinGX (Farrugia, 1999).
C18H16Cl2N4O | Dx = 1.364 Mg m−3 |
Mr = 375.25 | Melting point = 472–474 K |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 25 reflections |
a = 7.268 (4) Å | θ = 10.1–10.8° |
b = 11.813 (1) Å | µ = 0.37 mm−1 |
c = 21.282 (3) Å | T = 298 K |
V = 1827.2 (10) Å3 | Prismatic, yellow |
Z = 4 | 0.25 × 0.25 × 0.20 mm |
F(000) = 776 |
Enraf–Nonius CAD-4 diffractometer | 840 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.025 |
Graphite monochromator | θmax = 25.2°, θmin = 1.9° |
ω/2θ scans | h = 0→8 |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | k = 0→14 |
Tmin = 0.912, Tmax = 0.930 | l = −1→25 |
2019 measured reflections | 3 standard reflections every 60 min |
1997 independent reflections | intensity decay: 0.3% |
Refinement on F2 | Hydrogen site location: inferred from neighbouring sites |
Least-squares matrix: full | H-atom parameters constrained |
R[F2 > 2σ(F2)] = 0.040 | w = 1/[σ2(Fo2) + (0.0447P)2 + 0.4296P] where P = (Fo2 + 2Fc2)/3 |
wR(F2) = 0.122 | (Δ/σ)max < 0.001 |
S = 0.99 | Δρmax = 0.21 e Å−3 |
1997 reflections | Δρmin = −0.21 e Å−3 |
227 parameters | Extinction correction: SHELXL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
0 restraints | Extinction coefficient: 0.0017 (9) |
Primary atom site location: structure-invariant direct methods | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
Secondary atom site location: difference Fourier map | Absolute structure parameter: 0.27 (17) |
C18H16Cl2N4O | V = 1827.2 (10) Å3 |
Mr = 375.25 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.268 (4) Å | µ = 0.37 mm−1 |
b = 11.813 (1) Å | T = 298 K |
c = 21.282 (3) Å | 0.25 × 0.25 × 0.20 mm |
Enraf–Nonius CAD-4 diffractometer | 840 reflections with I > 2σ(I) |
Absorption correction: multi-scan (ABSCOR; Higashi, 1995) | Rint = 0.025 |
Tmin = 0.912, Tmax = 0.930 | 3 standard reflections every 60 min |
2019 measured reflections | intensity decay: 0.3% |
1997 independent reflections |
R[F2 > 2σ(F2)] = 0.040 | H-atom parameters constrained |
wR(F2) = 0.122 | Δρmax = 0.21 e Å−3 |
S = 0.99 | Δρmin = −0.21 e Å−3 |
1997 reflections | Absolute structure: Flack H D (1983), Acta Cryst. A39, 876-881 |
227 parameters | Absolute structure parameter: 0.27 (17) |
0 restraints |
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 | ||
C16 | 1.4950 (9) | −0.0440 (5) | 0.4576 (3) | 0.0628 (17) | |
H16 | 1.4681 | −0.0104 | 0.4165 | 0.075* | |
C18 | 1.6985 (10) | −0.0351 (7) | 0.4693 (4) | 0.116 (3) | |
H18A | 1.7638 | −0.0762 | 0.4374 | 0.174* | |
H18B | 1.7268 | −0.0664 | 0.5098 | 0.174* | |
H18C | 1.7347 | 0.0430 | 0.4682 | 0.174* | |
C17 | 1.4311 (12) | −0.1640 (5) | 0.4570 (3) | 0.115 (3) | |
H17A | 1.3024 | −0.1664 | 0.4471 | 0.173* | |
H17B | 1.4511 | −0.1971 | 0.4976 | 0.173* | |
H17C | 1.4989 | −0.2056 | 0.4260 | 0.173* | |
Cl1 | 0.9862 (4) | 0.23932 (17) | 0.13453 (7) | 0.1189 (9) | |
Cl2 | 0.8599 (3) | −0.0054 (2) | 0.78382 (9) | 0.1269 (10) | |
N2 | 1.1658 (7) | 0.0636 (4) | 0.42558 (19) | 0.0528 (13) | |
N4 | 1.1253 (7) | 0.2547 (4) | 0.44721 (19) | 0.0535 (13) | |
H4 | 1.1544 | 0.3214 | 0.4345 | 0.064* | |
O1 | 1.4435 (5) | 0.0319 (3) | 0.56104 (16) | 0.0576 (11) | |
N5 | 1.0751 (7) | 0.2352 (4) | 0.5094 (2) | 0.0580 (14) | |
C14 | 1.0869 (8) | 0.1838 (5) | 0.3401 (3) | 0.0455 (15) | |
N1 | 1.2212 (7) | 0.0637 (4) | 0.49067 (19) | 0.0497 (13) | |
C3 | 1.1268 (8) | 0.1641 (5) | 0.4067 (2) | 0.0472 (15) | |
C11 | 1.0220 (10) | 0.2165 (6) | 0.2134 (3) | 0.0657 (19) | |
C9 | 0.9997 (10) | 0.2792 (5) | 0.3189 (3) | 0.0678 (19) | |
H9 | 0.9618 | 0.3338 | 0.3476 | 0.081* | |
C15 | 1.3881 (10) | 0.0197 (5) | 0.5069 (3) | 0.0512 (16) | |
C6 | 1.1253 (8) | 0.1387 (5) | 0.5305 (3) | 0.0511 (16) | |
C5 | 1.0356 (9) | 0.1805 (6) | 0.6398 (3) | 0.0697 (19) | |
H5 | 1.0572 | 0.2567 | 0.6316 | 0.084* | |
C12 | 1.1059 (10) | 0.1198 (6) | 0.2333 (3) | 0.070 (2) | |
H12 | 1.1399 | 0.0648 | 0.2043 | 0.084* | |
C7 | 0.9748 (10) | 0.1477 (7) | 0.6989 (3) | 0.081 (2) | |
H7 | 0.9581 | 0.2011 | 0.7305 | 0.097* | |
C8 | 0.9404 (10) | 0.0372 (8) | 0.7097 (3) | 0.081 (2) | |
C13 | 1.1407 (10) | 0.1033 (5) | 0.2967 (3) | 0.071 (2) | |
H13 | 1.2005 | 0.0380 | 0.3101 | 0.086* | |
C2 | 1.0312 (10) | −0.0096 (6) | 0.6061 (3) | 0.075 (2) | |
H2 | 1.0536 | −0.0638 | 0.5753 | 0.090* | |
C4 | 1.0640 (9) | 0.1021 (5) | 0.5934 (3) | 0.0557 (16) | |
C1 | 0.9648 (10) | −0.0434 (6) | 0.6647 (3) | 0.086 (2) | |
H1 | 0.9377 | −0.1189 | 0.6727 | 0.103* | |
C10 | 0.9675 (11) | 0.2954 (5) | 0.2559 (3) | 0.080 (2) | |
H10 | 0.9081 | 0.3607 | 0.2424 | 0.095* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C16 | 0.065 (5) | 0.060 (4) | 0.063 (4) | 0.015 (4) | −0.007 (4) | −0.007 (3) |
C18 | 0.065 (6) | 0.136 (7) | 0.148 (7) | 0.024 (5) | 0.007 (5) | −0.053 (7) |
C17 | 0.144 (9) | 0.077 (5) | 0.126 (6) | 0.007 (6) | −0.008 (6) | −0.049 (5) |
Cl1 | 0.180 (2) | 0.1185 (17) | 0.0581 (9) | 0.012 (2) | −0.0217 (15) | 0.0090 (11) |
Cl2 | 0.1070 (17) | 0.202 (3) | 0.0716 (12) | 0.0083 (19) | 0.0134 (13) | 0.0428 (15) |
N2 | 0.063 (3) | 0.052 (3) | 0.044 (3) | 0.007 (3) | −0.010 (3) | −0.007 (2) |
N4 | 0.068 (3) | 0.042 (3) | 0.050 (3) | −0.006 (3) | 0.006 (3) | −0.006 (3) |
O1 | 0.065 (3) | 0.049 (2) | 0.059 (2) | −0.001 (2) | −0.013 (2) | −0.001 (2) |
N5 | 0.064 (4) | 0.057 (3) | 0.052 (3) | 0.008 (3) | 0.000 (3) | −0.003 (3) |
C14 | 0.041 (4) | 0.043 (3) | 0.052 (3) | −0.001 (3) | 0.001 (3) | 0.001 (3) |
N1 | 0.052 (3) | 0.053 (3) | 0.044 (3) | 0.005 (3) | −0.004 (3) | −0.002 (3) |
C3 | 0.030 (3) | 0.055 (4) | 0.056 (4) | 0.002 (4) | −0.004 (3) | −0.006 (3) |
C11 | 0.072 (5) | 0.075 (5) | 0.050 (3) | 0.002 (5) | −0.006 (4) | 0.002 (4) |
C9 | 0.090 (5) | 0.057 (4) | 0.057 (4) | 0.024 (5) | −0.005 (4) | −0.006 (3) |
C15 | 0.065 (5) | 0.038 (3) | 0.051 (4) | 0.000 (4) | −0.001 (4) | 0.001 (3) |
C6 | 0.044 (4) | 0.059 (4) | 0.050 (3) | 0.003 (4) | −0.006 (4) | −0.003 (3) |
C5 | 0.068 (5) | 0.083 (5) | 0.058 (4) | 0.017 (4) | 0.003 (4) | −0.001 (4) |
C12 | 0.090 (5) | 0.068 (5) | 0.053 (4) | 0.008 (5) | −0.007 (4) | −0.009 (3) |
C7 | 0.075 (5) | 0.109 (6) | 0.060 (4) | 0.021 (5) | 0.006 (4) | −0.004 (4) |
C8 | 0.059 (5) | 0.122 (6) | 0.062 (4) | 0.000 (5) | 0.002 (4) | 0.026 (5) |
C13 | 0.089 (5) | 0.063 (4) | 0.062 (4) | 0.017 (5) | −0.012 (4) | −0.009 (4) |
C2 | 0.088 (5) | 0.082 (5) | 0.054 (4) | 0.000 (5) | −0.001 (4) | 0.007 (4) |
C4 | 0.055 (4) | 0.060 (4) | 0.052 (4) | 0.009 (4) | −0.006 (3) | 0.001 (4) |
C1 | 0.095 (6) | 0.089 (5) | 0.074 (5) | −0.014 (5) | −0.010 (5) | 0.012 (5) |
C10 | 0.107 (6) | 0.060 (4) | 0.072 (4) | 0.029 (5) | −0.017 (5) | 0.004 (4) |
C16—C17 | 1.491 (8) | N1—C15 | 1.364 (7) |
C16—C18 | 1.503 (9) | N1—C6 | 1.411 (7) |
C16—C15 | 1.508 (7) | C11—C10 | 1.358 (8) |
C16—H16 | 0.9800 | C11—C12 | 1.362 (8) |
C18—H18A | 0.9600 | C9—C10 | 1.374 (7) |
C18—H18B | 0.9600 | C9—H9 | 0.9300 |
C18—H18C | 0.9600 | C6—C4 | 1.475 (8) |
C17—H17A | 0.9600 | C5—C4 | 1.369 (7) |
C17—H17B | 0.9600 | C5—C7 | 1.388 (8) |
C17—H17C | 0.9600 | C5—H5 | 0.9300 |
Cl1—C11 | 1.721 (6) | C12—C13 | 1.388 (7) |
Cl2—C8 | 1.755 (6) | C12—H12 | 0.9300 |
N2—C3 | 1.284 (6) | C7—C8 | 1.349 (9) |
N2—N1 | 1.443 (5) | C7—H7 | 0.9300 |
N4—C3 | 1.375 (6) | C8—C1 | 1.363 (9) |
N4—N5 | 1.392 (5) | C13—H13 | 0.9300 |
N4—H4 | 0.8600 | C2—C4 | 1.368 (8) |
O1—C15 | 1.228 (6) | C2—C1 | 1.394 (8) |
N5—C6 | 1.278 (7) | C2—H2 | 0.9300 |
C14—C9 | 1.369 (7) | C1—H1 | 0.9300 |
C14—C13 | 1.381 (7) | C10—H10 | 0.9300 |
C14—C3 | 1.466 (7) | ||
C17—C16—C18 | 112.0 (7) | C14—C9—H9 | 119.5 |
C17—C16—C15 | 108.6 (5) | C10—C9—H9 | 119.5 |
C18—C16—C15 | 110.9 (6) | O1—C15—N1 | 119.0 (5) |
C17—C16—H16 | 108.4 | O1—C15—C16 | 122.9 (6) |
C18—C16—H16 | 108.4 | N1—C15—C16 | 118.1 (5) |
C15—C16—H16 | 108.4 | N5—C6—N1 | 119.4 (5) |
C16—C18—H18A | 109.5 | N5—C6—C4 | 119.6 (6) |
C16—C18—H18B | 109.5 | N1—C6—C4 | 120.6 (5) |
H18A—C18—H18B | 109.5 | C4—C5—C7 | 120.8 (6) |
C16—C18—H18C | 109.5 | C4—C5—H5 | 119.6 |
H18A—C18—H18C | 109.5 | C7—C5—H5 | 119.6 |
H18B—C18—H18C | 109.5 | C11—C12—C13 | 120.1 (6) |
C16—C17—H17A | 109.5 | C11—C12—H12 | 120.0 |
C16—C17—H17B | 109.5 | C13—C12—H12 | 120.0 |
H17A—C17—H17B | 109.5 | C8—C7—C5 | 119.0 (6) |
C16—C17—H17C | 109.5 | C8—C7—H7 | 120.5 |
H17A—C17—H17C | 109.5 | C5—C7—H7 | 120.5 |
H17B—C17—H17C | 109.5 | C7—C8—C1 | 122.1 (6) |
C3—N2—N1 | 111.2 (4) | C7—C8—Cl2 | 119.5 (7) |
C3—N4—N5 | 118.0 (4) | C1—C8—Cl2 | 118.4 (7) |
C3—N4—H4 | 121.0 | C14—C13—C12 | 120.1 (6) |
N5—N4—H4 | 121.0 | C14—C13—H13 | 119.9 |
C6—N5—N4 | 114.0 (5) | C12—C13—H13 | 119.9 |
C9—C14—C13 | 118.6 (5) | C4—C2—C1 | 120.9 (6) |
C9—C14—C3 | 122.7 (5) | C4—C2—H2 | 119.6 |
C13—C14—C3 | 118.7 (5) | C1—C2—H2 | 119.6 |
C15—N1—C6 | 121.8 (5) | C2—C4—C5 | 118.9 (6) |
C15—N1—N2 | 119.5 (5) | C2—C4—C6 | 121.0 (6) |
C6—N1—N2 | 116.0 (5) | C5—C4—C6 | 120.0 (6) |
N2—C3—N4 | 121.7 (5) | C8—C1—C2 | 118.3 (7) |
N2—C3—C14 | 119.5 (5) | C8—C1—H1 | 120.8 |
N4—C3—C14 | 118.8 (5) | C2—C1—H1 | 120.8 |
C10—C11—C12 | 120.0 (6) | C11—C10—C9 | 120.3 (6) |
C10—C11—Cl1 | 119.9 (6) | C11—C10—H10 | 119.9 |
C12—C11—Cl1 | 120.1 (5) | C9—C10—H10 | 119.9 |
C14—C9—C10 | 121.0 (6) | ||
C3—N4—N5—C6 | 34.2 (8) | C15—N1—C6—C4 | −62.2 (7) |
C3—N2—N1—C15 | −123.6 (6) | N2—N1—C6—C4 | 136.7 (5) |
C3—N2—N1—C6 | 38.0 (7) | C10—C11—C12—C13 | −1.9 (11) |
N1—N2—C3—N4 | −5.3 (8) | Cl1—C11—C12—C13 | 177.7 (6) |
N1—N2—C3—C14 | 173.4 (5) | C4—C5—C7—C8 | −1.3 (11) |
N5—N4—C3—N2 | −31.7 (8) | C5—C7—C8—C1 | 0.5 (12) |
N5—N4—C3—C14 | 149.7 (5) | C5—C7—C8—Cl2 | −179.0 (5) |
C9—C14—C3—N2 | 162.7 (6) | C9—C14—C13—C12 | −0.2 (9) |
C13—C14—C3—N2 | −17.9 (8) | C3—C14—C13—C12 | −179.6 (6) |
C9—C14—C3—N4 | −18.6 (9) | C11—C12—C13—C14 | 1.4 (10) |
C13—C14—C3—N4 | 160.8 (6) | C1—C2—C4—C5 | 1.9 (10) |
C13—C14—C9—C10 | −0.5 (10) | C1—C2—C4—C6 | −176.9 (6) |
C3—C14—C9—C10 | 178.9 (7) | C7—C5—C4—C2 | 0.1 (10) |
C6—N1—C15—O1 | 11.0 (8) | C7—C5—C4—C6 | 178.9 (6) |
N2—N1—C15—O1 | 171.5 (5) | N5—C6—C4—C2 | 147.1 (7) |
C6—N1—C15—C16 | −170.1 (5) | N1—C6—C4—C2 | −25.8 (9) |
N2—N1—C15—C16 | −9.6 (7) | N5—C6—C4—C5 | −31.7 (9) |
C17—C16—C15—O1 | 93.5 (7) | N1—C6—C4—C5 | 155.5 (6) |
C18—C16—C15—O1 | −30.0 (8) | C7—C8—C1—C2 | 1.4 (12) |
C17—C16—C15—N1 | −85.4 (7) | Cl2—C8—C1—C2 | −179.1 (5) |
C18—C16—C15—N1 | 151.2 (6) | C4—C2—C1—C8 | −2.7 (11) |
N4—N5—C6—N1 | −0.5 (8) | C12—C11—C10—C9 | 1.2 (12) |
N4—N5—C6—C4 | −173.5 (5) | Cl1—C11—C10—C9 | −178.3 (6) |
C15—N1—C6—N5 | 125.0 (6) | C14—C9—C10—C11 | 0.0 (13) |
N2—N1—C6—N5 | −36.2 (8) |
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4···O1i | 0.86 | 2.32 | 2.851 (6) | 121 |
Symmetry code: (i) x−1/2, −y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C18H16Cl2N4O |
Mr | 375.25 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 298 |
a, b, c (Å) | 7.268 (4), 11.813 (1), 21.282 (3) |
V (Å3) | 1827.2 (10) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.37 |
Crystal size (mm) | 0.25 × 0.25 × 0.20 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | Multi-scan (ABSCOR; Higashi, 1995) |
Tmin, Tmax | 0.912, 0.930 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 2019, 1997, 840 |
Rint | 0.025 |
(sin θ/λ)max (Å−1) | 0.598 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.040, 0.122, 0.99 |
No. of reflections | 1997 |
No. of parameters | 227 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.21, −0.21 |
Absolute structure | Flack H D (1983), Acta Cryst. A39, 876-881 |
Absolute structure parameter | 0.27 (17) |
Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), CAD-4 EXPRESS, XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), ORTEP-3 for Windows (Version 1.05; Farrugia, 1997) and PLATON (Spek, 2003), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
N4—H4···O1i | 0.86 | 2.32 | 2.851 (6) | 120.7 |
Symmetry code: (i) x−1/2, −y+1/2, −z+1. |
1,2,4,5-Tetrazine derivatives have a high potential for biological activity and possess a wide range of antiviral and antitumor properties. These derivatives have been widely used in making pesticides and herbicides (Sauer, 1996). As part of our continuing interest in the structure-activity relationship of 1,2,4,5-tetrazine derivatives (Hu et al., 2002, 2004), we have isolated the product, (I), of the reaction of isobutyric anhydride and 3,6-bis(4-chlorophenyl)-1,2-dihydro-1,2,4,5-tetrazine as yellow crystals suitable for X-ray analysis.
The molecular structure of (I) is illustrated in Fig. 1. Atoms N2, C3, N5 and C6 are coplanar, with the largest deviation from the plane being −0.024 (3) Å for atom N5. Atoms N1 and N4 deviate from this plane by 0.413 (8) and 0.344 (8) Å, respectively, indicating a boat conformation. There is an N—H···O hydrogen interactions building a zigzag chain parallel to the a axis (Table 1 and Fig. 2).