Crystal structure of 3,6-bis­(2-chloro­phen­yl)-1,2,4,5-tetra­zine: the acaricide clofentezine

The whole molecule of the title compound, C₁₄H₈Cl₂N₄, is generated by inversion symmetry. The dihedral angle between the 2-chloro­phenyl ring and the tetra­zine ring is 47.65 (5)°. In the crystal, mol­ecules are linked by slipped parallel π–π inter­actions [centroid–centroid distance = 3.8199 (5), normal distance = 3.3127 (8), slippage 1.902 Å] forming columns along the a-axis direction.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.038
• wR factor = 0.096
• Data-to-parameter ratio = 16.0

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S1. Comment

Clofentezine, C₁₄H₈Cl₂N₄, is an acaricide that is used in plant protection for the control of spider mites on a wide range of crops (Zhao et al., 1996; Ay & Ebru Kara, 2011), and its crystal structure is reported herein. This molecule is located on a centre of symmetry, and a half molecule constitutes the asymmetric unit (Scheme 1, Fig. 1). The dihedral angle between a mean plane of the 2-chlorophenyl ring (r.m.s. deviation 0.0109 Å) and a mean plane of the tetrazine ring (r.m.s. deviation 0.0002 Å) is 47.65 (5)°. All bond lengths and bond angles are normal and comparable to those observed in the crystal structure of m- and p-isomers (Infantes et al., 2003).

In the crystal structure, weak intermolecular face-to-face π···π interactions between the tetrazine ring systems [Cg1···Cg1ⁱⁱ, 3.8199 (5) Å] and the phenyl ring systems [Cg2···Cg2ⁱⁱ, 3.8199 (5) Å] link molecules in one-dimensional packing structure along [100] (Cg1 and Cg2 are the centroids of the N1···C1 and C2···C7 rings, respectively) [for symmetry codes: (ii), -x + 1, -y + 1, -z + 1].

Related literature

For information on the toxicity and acaricidal properties of the title compound, which is used in plant protection for the control of spider mites on a wide range of crops, see: Zhao et al. (1996); Ay & Ebru Kara (2011). For the structures of the m- and p-isomers, see: Infantes et al. (2003).

S2. Experimental

The title compound was purchased from the Dr Ehrenstorfer GmbH Company. Slow evaporation of a solution in CHCl₃ gave single crystals suitable for X-ray analysis.

S3. Refinement

All H-atoms were positioned geometrically and refined using a riding model with d(C—H) = 0.95 Å, U_iso = 1.2U_eq(C) for aromatic C—H groups.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2010); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

Fig. 1. The asymmetric unit of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radius.

3,6-bis(2-Chlorophenyl)-1,2,4,5-tetrazine

Crystal data

C14H8Cl2N4	F(000) = 308
Mr = 303.14	Dx = 1.561 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 1312 reflections
a = 3.8199 (4) Å	θ = 2.2–27.0°
b = 14.0706 (16) Å	µ = 0.50 mm^−1
c = 12.1066 (15) Å	T = 173 K
β = 97.715 (3)°	Plate, red
V = 644.82 (13) Å^3	0.45 × 0.09 × 0.06 mm
Z = 2

Data collection

Bruker APEXII CCD diffractometer	1456 independent reflections
Radiation source: fine-focus sealed tube	1222 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ϕ and ω scans	θmax = 27.4°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −4→4
Tmin = 0.808, Tmax = 0.971	k = −14→18
4197 measured reflections	l = −15→15

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.038	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.096	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0377P)^2 + 0.299P] where P = (Fo^2 + 2Fc^2)/3
1456 reflections	(Δ/σ)max < 0.001
91 parameters	Δρmax = 0.44 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.72153 (14)	0.44093 (3)	0.68048 (4)	0.03196 (18)
N1	1.1350 (5)	0.45432 (11)	0.91567 (14)	0.0288 (4)
N2	0.8626 (5)	0.58937 (11)	0.98682 (13)	0.0281 (4)
C1	0.9976 (5)	0.54235 (12)	0.90522 (16)	0.0221 (4)
C2	1.0066 (5)	0.59412 (12)	0.79914 (15)	0.0219 (4)
C3	0.9028 (5)	0.55442 (12)	0.69426 (16)	0.0229 (4)
C4	0.9276 (5)	0.60556 (14)	0.59725 (17)	0.0310 (5)
H4	0.8507	0.5782	0.5264	0.037*
C5	1.0657 (6)	0.69676 (15)	0.60499 (19)	0.0355 (5)
H5	1.0929	0.7310	0.5390	0.043*
C6	1.1638 (6)	0.73814 (14)	0.7076 (2)	0.0349 (5)
H6	1.2533	0.8012	0.7122	0.042*
C7	1.1319 (5)	0.68778 (14)	0.80399 (18)	0.0296 (4)
H7	1.1959	0.7172	0.8744	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0376 (3)	0.0258 (3)	0.0319 (3)	−0.0065 (2)	0.0026 (2)	−0.00350 (19)
N1	0.0405 (10)	0.0240 (8)	0.0224 (8)	0.0090 (7)	0.0064 (7)	0.0001 (6)
N2	0.0410 (10)	0.0225 (7)	0.0214 (8)	0.0082 (7)	0.0060 (7)	0.0006 (6)
C1	0.0238 (9)	0.0204 (8)	0.0220 (9)	0.0013 (7)	0.0022 (7)	−0.0021 (7)
C2	0.0219 (9)	0.0218 (8)	0.0228 (9)	0.0040 (7)	0.0053 (7)	0.0013 (7)
C3	0.0227 (9)	0.0212 (9)	0.0251 (10)	0.0013 (7)	0.0044 (8)	0.0007 (7)
C4	0.0340 (11)	0.0353 (11)	0.0238 (10)	0.0043 (9)	0.0046 (8)	0.0035 (8)
C5	0.0380 (12)	0.0340 (11)	0.0362 (12)	0.0042 (9)	0.0109 (10)	0.0170 (9)
C6	0.0326 (11)	0.0222 (9)	0.0506 (14)	−0.0005 (8)	0.0078 (10)	0.0084 (9)
C7	0.0297 (11)	0.0249 (9)	0.0338 (11)	0.0009 (8)	0.0029 (9)	−0.0006 (8)

Geometric parameters (Å, º)

Cl1—C3	1.7397 (18)	C3—C4	1.391 (3)
N1—N2^i	1.330 (2)	C4—C5	1.386 (3)
N1—C1	1.345 (2)	C4—H4	0.9500
N2—N1^i	1.330 (2)	C5—C6	1.378 (3)
N2—C1	1.348 (2)	C5—H5	0.9500
C1—C2	1.481 (3)	C6—C7	1.385 (3)
C2—C3	1.395 (3)	C6—H6	0.9500
C2—C7	1.401 (3)	C7—H7	0.9500
N2^i—N1—C1	117.74 (16)	C5—C4—H4	120.3
N1^i—N2—C1	117.78 (16)	C3—C4—H4	120.3
N1—C1—N2	124.49 (17)	C6—C5—C4	120.48 (19)
N1—C1—C2	118.72 (16)	C6—C5—H5	119.8
N2—C1—C2	116.74 (16)	C4—C5—H5	119.8
C3—C2—C7	117.95 (17)	C5—C6—C7	119.98 (19)
C3—C2—C1	123.74 (16)	C5—C6—H6	120.0
C7—C2—C1	118.30 (17)	C7—C6—H6	120.0
C4—C3—C2	121.19 (17)	C6—C7—C2	120.95 (19)
C4—C3—Cl1	117.72 (15)	C6—C7—H7	119.5
C2—C3—Cl1	121.05 (14)	C2—C7—H7	119.5
C5—C4—C3	119.4 (2)
N2^i—N1—C1—N2	0.1 (3)	C7—C2—C3—Cl1	−176.46 (14)
N2^i—N1—C1—C2	177.28 (17)	C1—C2—C3—Cl1	4.6 (3)
N1^i—N2—C1—N1	−0.1 (3)	C2—C3—C4—C5	1.5 (3)
N1^i—N2—C1—C2	−177.33 (17)	Cl1—C3—C4—C5	179.03 (15)
N1—C1—C2—C3	47.7 (3)	C3—C4—C5—C6	−2.7 (3)
N2—C1—C2—C3	−134.8 (2)	C4—C5—C6—C7	1.4 (3)
N1—C1—C2—C7	−131.16 (19)	C5—C6—C7—C2	1.2 (3)
N2—C1—C2—C7	46.3 (3)	C3—C2—C7—C6	−2.3 (3)
C7—C2—C3—C4	1.0 (3)	C1—C2—C7—C6	176.64 (18)
C1—C2—C3—C4	−177.93 (18)

Symmetry code: (i) −x+2, −y+1, −z+2.