6-Benzyl-3-[4-(trifluoro­meth­yl)phen­yl]-1,2,4,5-tetra­zine

In the title compound, C₁₆H₁₁F₃N₄, the trifluoro-substituted benzene ring is almost coplanar with the central tetra­zine ring, but the benzyl ­phenyl ring is twisted by an angle of 76.7 (2)°. There are no hydrogen bonds in the crystal structure. The F atoms are disordered over two sets of positions with refined site occupancy factors of 0.604 (9) and 0.396 (9).

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.007 Å
• Disorder in main residue
• R factor = 0.073
• wR factor = 0.261
• Data-to-parameter ratio = 14.5

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT026_ALERT_3_B Ratio Observed / Unique Reflections too Low ....         38 Perc.
PLAT242_ALERT_2_B Check Low       Ueq as Compared to Neighbors for        C13

Alert level C
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           28.39
           From the CIF: _diffrn_reflns_theta_full          28.39
           From the CIF: _reflns_number_total               3418
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         3742
           Completeness (_total/calc)             91.34%
RFACR01_ALERT_3_C  The value of the weighted R factor is > 0.25
            Weighted R factor given   0.261
PLAT084_ALERT_2_C High R2 Value ..................................       0.26
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.56 Ratio
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for        C18
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C15
PLAT301_ALERT_3_C Main Residue  Disorder .........................      12.00 Perc.
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7
PLAT779_ALERT_2_C Suspect or Irrelevant (Bond) Angle in CIF ......      42.40 Deg.
              F3B  -C13  -F1A     1.555   1.555   1.555

   0 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
   9 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 ALERT type 2 Indicator that the structure model may be wrong or deficient
   5 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

1,2,4,5-Tetrazine derivatives have great potential for biological activity, possessing a wide spectrum of antiviral and antitumour properties. They have been widely used in pesticides and herbicides (Sauer, 1996). In continuation of our work on the structure–activity relationship of 1,2,4,5-tetrazine derivatives (Hu et al., 2004, 2005), we present here the structure of the title compound, (I).

The molecule structure of (I) is illustrated in Fig. 1. The benzene (C7–C12) ring is almost coplanar with the the central tetrazine ring [dihedral angle 5.9 (2)°], but the benzylphenyl ring (C15–C20) is twisted by an angle of 76.7 (2)°. There are no hydrogen bonds in the crystal structure.

Related literature

For related literature, see: Hu et al. (2004, 2005); Sauer (1996).

S2. Experimental

With sulfur (1.0 g) as catalyst, 85% hydrazine hydrate (10 ml, 170 mmol) was added dropwise to an anhydrous ethanol solution (15 ml) of benzyl cyanide (50 mmol) and p-trifluoromethylbenzonitrile (50 mmol) at 295 K. After refluxing

for 3 h, the mixture was cooled to room temperature and the resulting solid product was filtered off. The solid product was then dissolved in diethyl ether

(15 ml), and oxidized by sodium nitrate (14 mmol) and acetic acid (14 mmol) over a period of 2 h to afford the product, which was purified by preparative thin-layer chromatography over silica gel PF254 (2 mm) (cyclohexane–dichloromethane, 1:1 v/v) to give red single crystals of (I). The solid product was dissolved in tetrahydrofuran and the solution evaporated gradually at room temperature to afford single crystals of (I) (m.p. 408–409 K).

S3. Refinement

The trifluoromethyl group is disordered over two positions; their occupancy ratio was refined to 0.604 (9):0.396 (9). The six C—F bond distances were restrained to within 0.01 Å of each other and the displacement parameters of the disordered F atoms were restrained to approximately isotropic behaviour. H atoms were placed in calculated positions, with C—H = 0.93 or 0.97 Å, and refined in riding mode, with U_iso(H) = 1.2U_eq(C). Owing to the large number of weak high-angle reflections, the ratio of observed to unique reflections is low (38%).

Computing details

Data collection: SMART (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2005); software used to prepare material for publication: SHELXTL.

Figures

Fig. 1. The molecular structure of (I), showing 30% probability displacement ellipsoids (arbitrary spheres for H atoms). Only the major component of the disordered CF3 group is shown.

6-Benzyl-3-[4-(trifluoromethyl)phenyl]-1,2,4,5-tetrazine

Crystal data

C16H11F3N4	F(000) = 648
Mr = 316.29	Dx = 1.413 Mg m^−3
Monoclinic, P21/C	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1418 reflections
a = 4.701 (2) Å	θ = 2.4–21.5°
b = 30.810 (15) Å	µ = 0.11 mm^−1
c = 10.889 (5) Å	T = 296 K
β = 109.490 (17)°	Prism, red
V = 1486.8 (12) Å^3	0.30 × 0.25 × 0.20 mm
Z = 4

Data collection

Bruker SMART APEX2 CCD area-detector diffractometer	3418 independent reflections
Radiation source: fine-focus sealed tube	1315 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.043
φ and ω scans	θmax = 28.4°, θmin = 1.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→3
Tmin = 0.967, Tmax = 0.968	k = −40→39
9146 measured reflections	l = −12→14

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)] = 0.073	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.261	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.1289P)^2] where P = (Fo^2 + 2Fc^2)/3
3418 reflections	(Δ/σ)max = 0.005
236 parameters	Δρmax = 0.41 e Å^−3
51 restraints	Δρmin = −0.30 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	Occ. (<1)
F1A	0.5850 (10)	0.14622 (19)	0.6417 (8)	0.117 (3)	0.604 (9)
F2A	0.166 (3)	0.1461 (3)	0.4790 (6)	0.195 (5)	0.604 (9)
F3A	0.2082 (15)	0.17115 (14)	0.6674 (7)	0.121 (3)	0.604 (9)
F1B	0.416 (2)	0.1351 (3)	0.5049 (10)	0.128 (4)	0.396 (9)
F2B	0.0598 (18)	0.1627 (3)	0.5302 (13)	0.120 (4)	0.396 (9)
F3B	0.481 (4)	0.1634 (5)	0.6852 (11)	0.196 (6)	0.396 (9)
N1	0.0160 (7)	−0.07196 (11)	0.9373 (3)	0.0835 (10)
N2	0.1103 (7)	−0.03635 (10)	0.8948 (3)	0.0780 (9)
N4	−0.3120 (7)	−0.03970 (10)	0.7028 (3)	0.0809 (10)
N5	−0.4068 (7)	−0.07520 (11)	0.7460 (3)	0.0843 (10)
C3	−0.0555 (7)	−0.02094 (11)	0.7777 (3)	0.0601 (9)
C6	−0.2405 (8)	−0.09063 (12)	0.8627 (4)	0.0704 (10)
C7	0.0443 (7)	0.01888 (11)	0.7313 (3)	0.0578 (8)
C8	0.2930 (8)	0.04200 (12)	0.8082 (3)	0.0672 (10)
H8	0.4047	0.0314	0.8901	0.081*
C9	0.3766 (8)	0.07991 (14)	0.7658 (4)	0.0758 (11)
H9	0.5438	0.0950	0.8189	0.091*
C10	0.2139 (8)	0.09624 (12)	0.6437 (3)	0.0684 (10)
C11	−0.0269 (9)	0.07270 (13)	0.5642 (4)	0.0790 (11)
H11	−0.1328	0.0828	0.4809	0.095*
C12	−0.1110 (8)	0.03464 (12)	0.6068 (3)	0.0766 (11)
H12	−0.2736	0.0191	0.5522	0.092*
C13	0.2897 (10)	0.13876 (16)	0.6007 (4)	0.0953 (13)
C14	−0.3392 (9)	−0.13095 (13)	0.9099 (4)	0.0843 (12)
H14A	−0.5438	−0.1376	0.8550	0.101*
H14B	−0.3410	−0.1263	0.9977	0.101*
C15	−0.1404 (8)	−0.16889 (11)	0.9100 (4)	0.0679 (10)
C16	−0.1595 (11)	−0.18897 (16)	0.7945 (4)	0.0984 (14)
H16	−0.3000	−0.1794	0.7169	0.118*
C17	0.0242 (17)	−0.2223 (2)	0.7936 (8)	0.137 (2)
H17	0.0094	−0.2354	0.7146	0.165*
C18	0.2330 (18)	−0.23762 (19)	0.9061 (11)	0.147 (3)
H18	0.3573	−0.2609	0.9041	0.177*
C19	0.2543 (12)	−0.2179 (2)	1.0217 (8)	0.125 (2)
H19	0.3949	−0.2277	1.0989	0.150*
C20	0.0700 (10)	−0.18376 (15)	1.0240 (4)	0.0879 (13)
H20	0.0862	−0.1705	1.1028	0.106*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1A	0.091 (4)	0.092 (3)	0.188 (7)	−0.015 (2)	0.075 (4)	0.002 (3)
F2A	0.257 (10)	0.187 (8)	0.110 (5)	−0.076 (7)	0.020 (6)	0.045 (5)
F3A	0.127 (4)	0.068 (3)	0.184 (6)	0.010 (3)	0.075 (4)	0.000 (3)
F1B	0.129 (7)	0.144 (6)	0.139 (8)	0.026 (5)	0.082 (6)	0.053 (5)
F2B	0.109 (6)	0.088 (5)	0.176 (10)	0.016 (4)	0.066 (6)	0.045 (5)
F3B	0.235 (11)	0.161 (9)	0.157 (8)	−0.064 (8)	0.017 (8)	0.015 (7)
N1	0.076 (2)	0.086 (2)	0.073 (2)	−0.0075 (18)	0.0043 (17)	0.0113 (17)
N2	0.068 (2)	0.081 (2)	0.067 (2)	−0.0071 (16)	−0.0018 (16)	0.0083 (16)
N4	0.070 (2)	0.073 (2)	0.075 (2)	−0.0102 (17)	−0.0084 (17)	−0.0023 (16)
N5	0.069 (2)	0.079 (2)	0.086 (2)	−0.0093 (17)	0.0016 (18)	−0.0017 (18)
C3	0.0501 (19)	0.067 (2)	0.051 (2)	0.0063 (16)	0.0009 (16)	−0.0095 (16)
C6	0.052 (2)	0.076 (2)	0.079 (3)	0.0016 (18)	0.016 (2)	−0.0034 (19)
C7	0.0501 (18)	0.061 (2)	0.052 (2)	0.0063 (15)	0.0028 (15)	−0.0084 (15)
C8	0.059 (2)	0.079 (2)	0.050 (2)	−0.0047 (18)	0.0001 (16)	−0.0023 (17)
C9	0.066 (2)	0.088 (3)	0.065 (2)	−0.010 (2)	0.011 (2)	−0.0100 (19)
C10	0.068 (2)	0.069 (2)	0.069 (2)	−0.0018 (18)	0.025 (2)	−0.0046 (18)
C11	0.081 (3)	0.079 (3)	0.063 (2)	0.005 (2)	0.006 (2)	0.0038 (19)
C12	0.071 (2)	0.074 (3)	0.061 (2)	−0.0037 (19)	−0.0088 (18)	−0.0064 (18)
C13	0.088 (3)	0.104 (4)	0.088 (3)	−0.013 (3)	0.021 (3)	0.001 (3)
C14	0.074 (3)	0.088 (3)	0.098 (3)	−0.007 (2)	0.037 (2)	0.001 (2)
C15	0.063 (2)	0.071 (2)	0.075 (2)	−0.0146 (19)	0.0291 (19)	0.000 (2)
C16	0.102 (3)	0.108 (3)	0.093 (3)	−0.021 (3)	0.042 (3)	−0.017 (3)
C17	0.158 (6)	0.104 (5)	0.186 (7)	−0.028 (4)	0.106 (5)	−0.054 (4)
C18	0.143 (6)	0.066 (3)	0.276 (11)	0.009 (3)	0.126 (7)	0.015 (5)
C19	0.097 (4)	0.101 (4)	0.179 (6)	0.017 (3)	0.051 (4)	0.057 (4)
C20	0.082 (3)	0.098 (3)	0.084 (3)	−0.011 (2)	0.028 (2)	0.014 (2)

Geometric parameters (Å, º)

F1A—C13	1.329 (6)	C10—C11	1.380 (5)
F2A—C13	1.278 (6)	C10—C13	1.474 (6)
F3A—C13	1.362 (6)	C11—C12	1.367 (5)
F1B—C13	1.368 (7)	C11—H11	0.93
F2B—C13	1.322 (7)	C12—H12	0.93
F3B—C13	1.295 (7)	C14—C15	1.496 (5)
N1—N2	1.323 (4)	C14—H14A	0.97
N1—C6	1.338 (4)	C14—H14B	0.97
N2—C3	1.340 (4)	C15—C16	1.377 (6)
N4—N5	1.325 (4)	C15—C20	1.383 (5)
N4—C3	1.340 (4)	C16—C17	1.345 (8)
N5—C6	1.337 (5)	C16—H16	0.93
C3—C7	1.462 (5)	C17—C18	1.373 (9)
C6—C14	1.477 (5)	C17—H17	0.93
C7—C8	1.386 (4)	C18—C19	1.371 (9)
C7—C12	1.395 (4)	C18—H18	0.93
C8—C9	1.361 (5)	C19—C20	1.368 (7)
C8—H8	0.93	C19—H19	0.93
C9—C10	1.388 (5)	C20—H20	0.93
C9—H9	0.93
N2—N1—C6	118.9 (3)	F1A—C13—F3A	98.2 (5)
N1—N2—C3	118.0 (3)	F2A—C13—F1B	52.2 (6)
N5—N4—C3	118.7 (3)	F3B—C13—F1B	102.4 (10)
N4—N5—C6	118.1 (3)	F2B—C13—F1B	94.7 (7)
N4—C3—N2	123.1 (3)	F1A—C13—F1B	66.3 (6)
N4—C3—C7	118.6 (3)	F3A—C13—F1B	137.6 (6)
N2—C3—C7	118.3 (3)	F2A—C13—C10	114.4 (5)
N5—C6—N1	123.1 (3)	F3B—C13—C10	118.6 (7)
N5—C6—C14	118.5 (3)	F2B—C13—C10	116.3 (5)
N1—C6—C14	118.3 (4)	F1A—C13—C10	112.5 (4)
C8—C7—C12	118.0 (3)	F3A—C13—C10	109.9 (4)
C8—C7—C3	121.7 (3)	F1B—C13—C10	112.4 (5)
C12—C7—C3	120.2 (3)	C6—C14—C15	112.9 (3)
C9—C8—C7	121.1 (3)	C6—C14—H14A	109.0
C9—C8—H8	119.4	C15—C14—H14A	109.0
C7—C8—H8	119.4	C6—C14—H14B	109.0
C8—C9—C10	120.4 (3)	C15—C14—H14B	109.0
C8—C9—H9	119.8	H14A—C14—H14B	107.8
C10—C9—H9	119.8	C16—C15—C20	118.7 (4)
C11—C10—C9	119.0 (4)	C16—C15—C14	120.0 (4)
C11—C10—C13	120.2 (4)	C20—C15—C14	121.2 (4)
C9—C10—C13	120.8 (3)	C17—C16—C15	120.3 (5)
C12—C11—C10	120.5 (3)	C17—C16—H16	119.9
C12—C11—H11	119.8	C15—C16—H16	119.9
C10—C11—H11	119.8	C16—C17—C18	121.6 (6)
C11—C12—C7	120.8 (3)	C16—C17—H17	119.2
C11—C12—H12	119.6	C18—C17—H17	119.2
C7—C12—H12	119.6	C19—C18—C17	118.6 (6)
F2A—C13—F3B	126.9 (8)	C19—C18—H18	120.7
F2A—C13—F2B	45.3 (6)	C17—C18—H18	120.7
F3B—C13—F2B	109.0 (10)	C20—C19—C18	120.4 (6)
F2A—C13—F1A	112.4 (7)	C20—C19—H19	119.8
F3B—C13—F1A	42.4 (9)	C18—C19—H19	119.8
F2B—C13—F1A	131.2 (6)	C19—C20—C15	120.4 (5)
F2A—C13—F3A	108.1 (8)	C19—C20—H20	119.8
F3B—C13—F3A	56.2 (10)	C15—C20—H20	119.8
F2B—C13—F3A	65.2 (6)
C6—N1—N2—C3	−0.7 (5)	C11—C10—C13—F2A	−15.3 (10)
C3—N4—N5—C6	−0.1 (5)	C9—C10—C13—F2A	166.7 (9)
N5—N4—C3—N2	−0.1 (5)	C11—C10—C13—F3B	168.1 (13)
N5—N4—C3—C7	−178.4 (3)	C9—C10—C13—F3B	−9.9 (14)
N1—N2—C3—N4	0.6 (5)	C11—C10—C13—F2B	35.1 (9)
N1—N2—C3—C7	178.8 (3)	C9—C10—C13—F2B	−142.9 (8)
N4—N5—C6—N1	0.0 (6)	C11—C10—C13—F1A	−145.2 (5)
N4—N5—C6—C14	−178.1 (3)	C9—C10—C13—F1A	36.8 (7)
N2—N1—C6—N5	0.4 (6)	C11—C10—C13—F3A	106.5 (5)
N2—N1—C6—C14	178.5 (3)	C9—C10—C13—F3A	−71.5 (6)
N4—C3—C7—C8	174.5 (3)	C11—C10—C13—F1B	−72.6 (8)
N2—C3—C7—C8	−3.8 (5)	C9—C10—C13—F1B	109.4 (7)
N4—C3—C7—C12	−5.6 (5)	N5—C6—C14—C15	108.7 (4)
N2—C3—C7—C12	176.1 (3)	N1—C6—C14—C15	−69.5 (5)
C12—C7—C8—C9	2.6 (5)	C6—C14—C15—C16	−75.4 (5)
C3—C7—C8—C9	−177.4 (3)	C6—C14—C15—C20	102.9 (4)
C7—C8—C9—C10	−0.2 (6)	C20—C15—C16—C17	−0.1 (6)
C8—C9—C10—C11	−2.3 (5)	C14—C15—C16—C17	178.2 (4)
C8—C9—C10—C13	175.7 (4)	C15—C16—C17—C18	0.5 (8)
C9—C10—C11—C12	2.4 (6)	C16—C17—C18—C19	−0.5 (9)
C13—C10—C11—C12	−175.6 (4)	C17—C18—C19—C20	0.2 (9)
C10—C11—C12—C7	0.1 (6)	C18—C19—C20—C15	0.2 (7)
C8—C7—C12—C11	−2.6 (5)	C16—C15—C20—C19	−0.2 (6)
C3—C7—C12—C11	177.5 (3)	C14—C15—C20—C19	−178.5 (4)