3-Benzyl-4-(p-fluoro­benzyl­iden­amino)-4,5-di­hydro-1H-1,2,4-triazol-5-one

In the crystal structure of the title compound, C₁₆H₁₃N₄OF, molecules are linked through intermolecular N—H...O hydrogen bonds to form dimers. The dimers are held together by van der Waals interactions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.047
• wR factor = 0.153
• Data-to-parameter ratio = 16.7

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           29.27
         From the CIF: _reflns_number_total               3550
         TEST2: Reflns within _diffrn_reflns_theta_max
         Count of symmetry unique reflns         3953
         Completeness (_total/calc)             89.81%
          Alert B: < 90% complete (theta max?)


 Alert Level C:



PLAT_031  Alert C Refined Extinction Parameter within Range ....       2.80 Sigma


 0 Alert Level A = Potentially serious problem

 1 Alert Level B = Potential problem

 1 Alert Level C = Please check

---

S1. Comment

Most Schiff bases possess antibacterial, anticancer, anti-inflammatory and antitoxic activities (Williams, 1972), and sulfur-containing Schiff bases are particularly effective. For example, the 4-amino-3-methyl-1,2,4-triazole-5-thione derivative of p-nitrophenylaldehyde is known as a highly effective inhibitor of Staphylococcus aureus (Liu et al., 1999). As part of our continuing study of Schiff bases of amine and 1,2,4-triazole derivatives, we have structurally characterized the title compounds, (I) (Fig. 1) (Kahveci et al., 2000; Çoruh et al., 2003; Işık et al., 2003).

The bonds and angles in (I) (Table 1) are consistent with those in similar substituted triazoles (Kahveci et al., 2000; Çoruh et al., 2003; Işık et al., 2003). Benzyl rings and 1,2,4-triazole ring are almost planar, with a maximum deviation of 0.008 (2) Å for N2. The dihedral angles between the 1,2,4-triazole ring and benzyl rings C1–C6 and C11–C16 are 179.3 (1) and 104.9 (1)°, respectively, and the dihedral angle between the benzyl rings is 104.9 (1)°.

The molecules of (I) form hydrogen-bonded dimers through the N—H···O interactions involving triazole atom O1 and the adjacent protonated N2 atom on the ring, shown as dashed lines in Fig.2. This feature appears to be common in Schiff bases of 4-amino-3-alkyl-1,2,4-triazole-5-thiones (Sen et al., 1998). The molecule has also an intramolecular C7—H7···O1 contact (Table 2).

S2. Experimental

The corresponding amino compound (1.90 g., 0.01 mol) was heated in an oil both with 4-fluorobenzene (1.04 ml, 0.01 mol) at 428–433 K for one hour and then allowed to cool. The solid product was recrystallized from ethanol (yield; 96%) to give the desired compound (I) (m.p. = 466–467 K). Calculated: C 64.86, H 4.42, N 18.91%; found: C 64.83, H 4.26, N 18.35%. IR data (KBr/cm⁻¹): 3250 (N—H), 1720 (C═O), 1620, 1600 (C═N), 700, 680, 840 (aromatic). ¹H NMR (CDCl₃, δ/p.p.m.): 4.18 (CH₂,s, 2H), 9,78 (CH, s, 1H), 10.10 (NH, s, 1H); Ar—H: 7.04–7.40 (m, 7H), 7.70 (d, 2H).

S3. Refinement

H atoms were located geometrically and refined using a riding model, fixing the aromatic C—H distance at 0.93 Å, the C—H₂ distance 0.97 Å and the N—H distance at 0.86 Å.

Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2002); 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).

Figures

	Fig. 1. The structure of (I), showing ellipsoids drawn at the 50% probability level and the atom-numbering scheme.
	Fig. 2. A packing diagram showing the crystal packing in (I). Intermolecular N—H···O hydrogen bonds are shown as dashed lines.

3-Benzyl-4-(p-Fluorobenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one

Crystal data

C16H13FN4O	Z = 2
Mr = 296.30	F(000) = 308
Triclinic, P1	Dx = 1.359 Mg m^−3
a = 7.0290 (15) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.141 (2) Å	Cell parameters from 8077 reflections
c = 11.205 (3) Å	θ = 0.0–29.5°
α = 96.40 (2)°	µ = 0.10 mm^−1
β = 102.944 (17)°	T = 293 K
γ = 108.394 (16)°	Prismatic, colourless
V = 724.2 (3) Å^3	0.75 × 0.46 × 0.22 mm

Data collection

Stoe IPDS 2 diffractometer	2341 reflections with I > 2σ(I)
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	Rint = 0.000
Plane graphite monochromator	θmax = 29.3°, θmin = 1.9°
Detector resolution: 6.67 pixels mm^-1	h = −9→0
rotation method scans	k = −12→12
3550 measured reflections	l = −14→15
3550 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.047	Only H-atom coordinates refined
wR(F^2) = 0.153	w = 1/[σ^2(Fo^2) + (0.1093P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 1.00	(Δ/σ)max < 0.001
3550 reflections	Δρmax = 0.17 e Å^−3
212 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.028 (10)

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
F1	−1.4326 (2)	−0.61860 (15)	0.06208 (10)	0.1022 (4)
O1	−1.11115 (17)	−0.55461 (11)	0.82528 (10)	0.0617 (3)
N1	−1.17520 (16)	−0.36093 (13)	0.64075 (10)	0.0500 (3)
N2	−1.0435 (2)	−0.34595 (13)	0.96421 (12)	0.0593 (3)
H2N	−1.0214	−0.3758	1.0331	0.088 (6)*
N3	−1.0307 (2)	−0.20838 (14)	0.95922 (12)	0.0590 (3)
N4	−1.11808 (16)	−0.33816 (12)	0.77025 (10)	0.0479 (3)
C1	−1.3825 (2)	−0.5857 (2)	0.18884 (15)	0.0668 (5)
C2	−1.3695 (2)	−0.68901 (19)	0.25405 (17)	0.0682 (5)
H2	−1.3964	−0.7808	0.2134	0.084 (6)*
C3	−1.3146 (2)	−0.65300 (17)	0.38293 (15)	0.0607 (4)
H3	−1.3043	−0.7219	0.4297	0.070 (5)*
C4	−1.27424 (19)	−0.51637 (15)	0.44418 (13)	0.0514 (3)
C5	−1.2921 (2)	−0.41500 (18)	0.37347 (14)	0.0608 (4)
H5	−1.2669	−0.3232	0.4131	0.071 (5)*
C6	−1.3469 (3)	−0.4491 (2)	0.24488 (16)	0.0708 (5)
H6	−1.3590	−0.3812	0.1971	0.091 (7)*
C7	−1.2139 (2)	−0.48508 (16)	0.58112 (14)	0.0538 (3)
H7	−1.2039	−0.5565	0.6248	0.068 (5)*
C8	−1.0934 (2)	−0.42931 (15)	0.85141 (13)	0.0512 (3)
C9	−1.0778 (2)	−0.20621 (15)	0.84086 (13)	0.0503 (3)
C10	−1.0716 (2)	−0.07868 (16)	0.78746 (14)	0.0547 (3)
H10A	−1.0914	−0.0099	0.8464	0.068 (5)*
H10B	−1.1848	−0.1042	0.7116	0.049 (4)*
C11	−0.8661 (2)	−0.01279 (14)	0.75829 (13)	0.0500 (3)
C12	−0.8509 (3)	−0.02903 (18)	0.63691 (14)	0.0621 (4)
H12	−0.9684	−0.0814	0.5718	0.065 (5)*
C13	−0.6634 (3)	0.0318 (2)	0.61191 (18)	0.0757 (5)
H13	−0.6551	0.0211	0.5299	0.135 (9)*
C14	−0.4882 (3)	0.1079 (2)	0.7073 (2)	0.0794 (5)
H14	−0.3615	0.1491	0.6902	0.094 (6)*
C15	−0.5010 (3)	0.1231 (2)	0.8279 (2)	0.0845 (6)
H15	−0.3823	0.1737	0.8929	0.087 (6)*
C16	−0.6887 (3)	0.06387 (18)	0.85354 (16)	0.0701 (5)
H16	−0.6960	0.0755	0.9356	0.103 (7)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.1184 (9)	0.1180 (11)	0.0591 (6)	0.0442 (8)	0.0119 (6)	−0.0090 (6)
O1	0.0787 (7)	0.0414 (6)	0.0650 (6)	0.0184 (5)	0.0220 (5)	0.0134 (4)
N1	0.0482 (6)	0.0469 (7)	0.0545 (6)	0.0147 (5)	0.0173 (4)	0.0078 (5)
N2	0.0783 (8)	0.0479 (7)	0.0566 (7)	0.0227 (6)	0.0250 (6)	0.0145 (5)
N3	0.0731 (8)	0.0490 (8)	0.0599 (7)	0.0235 (6)	0.0255 (6)	0.0100 (5)
N4	0.0499 (6)	0.0421 (6)	0.0530 (6)	0.0148 (4)	0.0186 (4)	0.0097 (4)
C1	0.0609 (8)	0.0770 (12)	0.0566 (8)	0.0259 (8)	0.0111 (6)	−0.0049 (8)
C2	0.0588 (8)	0.0575 (10)	0.0782 (11)	0.0211 (7)	0.0107 (7)	−0.0114 (8)
C3	0.0587 (8)	0.0482 (9)	0.0712 (9)	0.0202 (6)	0.0121 (6)	0.0035 (7)
C4	0.0440 (6)	0.0476 (8)	0.0604 (8)	0.0153 (5)	0.0147 (5)	0.0041 (6)
C5	0.0684 (9)	0.0507 (9)	0.0624 (9)	0.0210 (7)	0.0187 (7)	0.0054 (7)
C6	0.0809 (11)	0.0687 (12)	0.0635 (9)	0.0281 (9)	0.0187 (8)	0.0132 (8)
C7	0.0537 (7)	0.0474 (8)	0.0605 (8)	0.0174 (6)	0.0169 (6)	0.0094 (6)
C8	0.0517 (7)	0.0444 (8)	0.0591 (8)	0.0134 (5)	0.0218 (6)	0.0131 (6)
C9	0.0521 (7)	0.0449 (8)	0.0573 (7)	0.0176 (5)	0.0217 (6)	0.0075 (6)
C10	0.0609 (8)	0.0449 (8)	0.0644 (8)	0.0257 (6)	0.0195 (6)	0.0094 (6)
C11	0.0621 (8)	0.0343 (7)	0.0575 (7)	0.0216 (6)	0.0164 (6)	0.0108 (5)
C12	0.0717 (9)	0.0582 (10)	0.0578 (8)	0.0241 (7)	0.0152 (7)	0.0190 (7)
C13	0.0914 (12)	0.0756 (12)	0.0746 (11)	0.0325 (10)	0.0396 (9)	0.0289 (9)
C14	0.0743 (11)	0.0595 (11)	0.1118 (15)	0.0201 (8)	0.0425 (10)	0.0221 (10)
C15	0.0665 (10)	0.0678 (12)	0.0965 (14)	0.0053 (8)	0.0154 (9)	−0.0063 (10)
C16	0.0745 (10)	0.0586 (10)	0.0652 (9)	0.0142 (8)	0.0175 (7)	−0.0047 (7)

Geometric parameters (Å, º)

F1—C1	1.3598 (19)	C5—H5	0.9300
O1—C8	1.2314 (18)	C6—H6	0.9304
N1—C7	1.2730 (19)	C7—H7	0.9299
N1—N4	1.3878 (16)	C9—C10	1.477 (2)
N2—C8	1.3459 (19)	C10—C11	1.514 (2)
N2—N3	1.3777 (19)	C10—H10A	0.9698
N2—H2N	0.8596	C10—H10B	0.9702
N3—C9	1.2975 (19)	C11—C16	1.380 (2)
N4—C9	1.3859 (18)	C11—C12	1.384 (2)
N4—C8	1.3890 (19)	C12—C13	1.374 (2)
C1—C2	1.357 (3)	C12—H12	0.9294
C1—C6	1.376 (3)	C13—C14	1.372 (3)
C2—C3	1.383 (2)	C13—H13	0.9300
C2—H2	0.9302	C14—C15	1.369 (3)
C3—C4	1.387 (2)	C14—H14	0.9294
C3—H3	0.9301	C15—C16	1.375 (3)
C4—C5	1.385 (2)	C15—H15	0.9297
C4—C7	1.466 (2)	C16—H16	0.9294
C5—C6	1.379 (2)
C7—N1—N4	117.68 (13)	O1—C8—N4	128.10 (13)
C8—N2—N3	113.84 (13)	N2—C8—N4	102.63 (12)
C8—N2—H2N	123.1	N3—C9—N4	110.75 (13)
N3—N2—H2N	123.1	N3—C9—C10	125.16 (13)
C9—N3—N2	104.55 (12)	N4—C9—C10	123.88 (13)
C9—N4—N1	120.65 (12)	C9—C10—C11	111.28 (12)
C9—N4—C8	108.21 (11)	C9—C10—H10A	109.3
N1—N4—C8	131.14 (12)	C11—C10—H10A	109.3
C2—C1—F1	118.45 (16)	C9—C10—H10B	109.4
C2—C1—C6	123.13 (16)	C11—C10—H10B	109.4
F1—C1—C6	118.41 (18)	H10A—C10—H10B	108.0
C1—C2—C3	117.67 (15)	C16—C11—C12	118.65 (14)
C1—C2—H2	121.2	C16—C11—C10	120.16 (14)
C3—C2—H2	121.2	C12—C11—C10	121.18 (13)
C2—C3—C4	121.53 (16)	C13—C12—C11	120.49 (16)
C2—C3—H3	119.3	C13—C12—H12	119.7
C4—C3—H3	119.2	C11—C12—H12	119.8
C5—C4—C3	118.65 (14)	C14—C13—C12	120.32 (17)
C5—C4—C7	122.70 (13)	C14—C13—H13	119.9
C3—C4—C7	118.65 (15)	C12—C13—H13	119.8
C6—C5—C4	120.59 (15)	C15—C14—C13	119.63 (17)
C6—C5—H5	119.7	C15—C14—H14	120.2
C4—C5—H5	119.7	C13—C14—H14	120.2
C1—C6—C5	118.42 (18)	C14—C15—C16	120.39 (17)
C1—C6—H6	120.8	C14—C15—H15	119.9
C5—C6—H6	120.8	C16—C15—H15	119.7
N1—C7—C4	120.54 (15)	C15—C16—C11	120.51 (17)
N1—C7—H7	119.7	C15—C16—H16	119.7
C4—C7—H7	119.7	C11—C16—H16	119.8
O1—C8—N2	129.27 (14)
C8—N2—N3—C9	1.31 (16)	C9—N4—C8—N2	0.94 (14)
C7—N1—N4—C9	−178.74 (12)	N1—N4—C8—N2	−178.05 (12)
C7—N1—N4—C8	0.14 (19)	N2—N3—C9—N4	−0.62 (15)
F1—C1—C2—C3	178.80 (13)	N2—N3—C9—C10	−175.56 (13)
C6—C1—C2—C3	−1.0 (3)	N1—N4—C9—N3	178.91 (10)
C1—C2—C3—C4	0.1 (2)	C8—N4—C9—N3	−0.20 (15)
C2—C3—C4—C5	0.7 (2)	N1—N4—C9—C10	−6.07 (19)
C2—C3—C4—C7	−179.16 (13)	C8—N4—C9—C10	174.82 (12)
C3—C4—C5—C6	−0.6 (2)	N3—C9—C10—C11	94.75 (16)
C7—C4—C5—C6	179.21 (14)	N4—C9—C10—C11	−79.54 (16)
C2—C1—C6—C5	1.1 (3)	C9—C10—C11—C16	−75.33 (18)
F1—C1—C6—C5	−178.73 (14)	C9—C10—C11—C12	103.94 (17)
C4—C5—C6—C1	−0.2 (2)	C16—C11—C12—C13	−0.9 (3)
N4—N1—C7—C4	−179.74 (10)	C10—C11—C12—C13	179.82 (16)
C5—C4—C7—N1	0.0 (2)	C11—C12—C13—C14	0.8 (3)
C3—C4—C7—N1	179.86 (12)	C12—C13—C14—C15	0.0 (3)
N3—N2—C8—O1	177.93 (13)	C13—C14—C15—C16	−0.7 (3)
N3—N2—C8—N4	−1.39 (15)	C14—C15—C16—C11	0.6 (3)
C9—N4—C8—O1	−178.40 (13)	C12—C11—C16—C15	0.2 (3)
N1—N4—C8—O1	2.6 (2)	C10—C11—C16—C15	179.48 (17)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2N···O1^i	0.86	1.97	2.799 (2)	161
C7—H7···O1	0.93	2.19	2.893 (2)	132

Symmetry code: (i) −x−2, −y−1, −z+2.