(E)-5-Phenyl-N′-(1-phenyl­ethyl­idene)-1H-pyrazole-3-carbohydrazide

Yongqi Qin; Fangfang Jian; Hailian Xiao; Jing Zhang

doi:10.1107/S160053680706223X

. 2007 Dec 21;64(Pt 1):o320. doi: 10.1107/S160053680706223X

(E)-5-Phenyl-N′-(1-phenylethylidene)-1H-pyrazole-3-carbohydrazide

Yongqi Qin ^a, Fangfang Jian ^a,^*, Hailian Xiao ^a, Jing Zhang ^a

PMCID: PMC2915364 PMID: 21200882

Abstract

In the molecule of the title compound, C₁₈H₁₆N₄O, the intramolecular N—H⋯N hydrogen bond results in the formation of a planar five-membered ring, which is also co-planar with the adjacent five-membered ring, being oriented at a dihedral angle of 1.23 (3)°. The dihedral angles formed by the planar pyrazole ring with the adjacent phenyl ring and the other phenyl ring are 7.29 and 11.21°, respectively. The dihedral angle between the two phenyl rings is 18.07°. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules.

Related literature

For general background, see: Ogretir et al. (2006 ▶); Tarafder et al. (2000 ▶); Deschamps et al. (2003 ▶); Wu et al. (2006 ▶). For related literature, see: Yang & Raptis (2003 ▶); Ali et al. (2005 ▶). For bond-length data, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₁₈H₁₆N₄O
M _r = 304.35
Tetragonal,
a = 8.0190 (11) Å
c = 24.147 (5) Å
V = 1552.8 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 294 (2) K
0.25 × 0.20 × 0.18 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: none
3737 measured reflections
1686 independent reflections
1017 reflections with I > 2σ(I)
R _int = 0.081
3 standard reflections every 100 reflections intensity decay: 4.1%

Refinement

R[F ² > 2σ(F ²)] = 0.054
wR(F ²) = 0.143
S = 1.04
1686 reflections
209 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.32 e Å⁻³

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ▶); cell refinement: CAD-4 Software; data reduction: NRCVAX (Gabe et al., 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: SHELXTL/PC (Siemens, 1990 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680706223X/hk2398sup1.cif

e-64-0o320-sup1.cif^{(16.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680706223X/hk2398Isup2.hkl

e-64-0o320-Isup2.hkl^{(83.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2A⋯N3	0.86	2.34	2.714 (2)	107
N4—H4A⋯O1ⁱ	0.86	1.98	2.788 (2)	157

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Natural Science Foundation of Shandong Province (grant No. Y2005B04).

supplementary crystallographic information

Comment

Schiff bases have been used extensively as ligands in the field of coordination chemistry (Ogretir et al., 2006). As dinegatively charged ligands, Schiff bases show potential as antimicrobial and anticancer agents (Tarafder et al., 2000; Deschamps et al., 2003) and so have biochemical and pharmacological applications. In addition, the chemical behavior of metal complexes with Schiff base ligands has attracted much attention because of their catalytic activity in some industrial and biochemical processes (Wu et al., 2006). The title compound, (I), was synthesized as part of our study of these ligands and we report herein its crystal structure.

In the molecule of (I), (Fig. 1) the bond lengths and angles are within normal ranges (Allen et al., 1987). They are in good agreement with the corresponding values reported (Yang & Raptis, 2003). The C7—N1 [1.285 (6) Å] bond has a double-bond character (Ali et al., 2005). The intramolecular N—H···N hydrogen bond (Table 1) results in the formation of a planar five-membered ring B (N2/H2A/N3/C9/C1). Rings A (C1—C6), C (N3/N4/C10—C11) and D (C13—C18) are, of course, planar and the dihedral angles between them are A/B = 11.06 (3)°, A/C = 11.10 (3)°, A/D = 17.82 (2)°, B/C = 1.23 (3)°, B/D = 7.85 (3)° and C/D = 7.15 (3)°. So, rings B and C are also co-planar.

In the crystal structure, intermolecular N—H···O hydrogen bonds (Table 1) link the molecules, in which they may be effective in the stabilization of the structure.

Experimental

A mixture of 5-phenyl-1H-pyrazole-3-carbohydrazide (10 mmol) with acetophenone (10 mmol) was stirred in refluxing ethanol (30 ml) for 5 h to afford the title compound, (I), (yield; 81%). Single crystals suitable for X-ray analysis were obtained by recrystallization from dimethylformamide (DMF) at 309 K.