N′-[(2Z)-4-Oxo-4-phenyl­but-2-en-2-yl]pyridine-4-carbohydrazide

Rahman Bikas; Parisa Mahboubi Anarjan; Sanam Aslekhademi; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812000529

. 2012 Jan 14;68(Pt 2):o412. doi: 10.1107/S1600536812000529

N′-[(2Z)-4-Oxo-4-phenylbut-2-en-2-yl]pyridine-4-carbohydrazide

Rahman Bikas ^a,^‡, Parisa Mahboubi Anarjan ^b, Sanam Aslekhademi ^c, Seik Weng Ng ^d,^e, Edward R T Tiekink ^d,^*

PMCID: PMC3275172 PMID: 22347028

Abstract

There are significant twists in the title compound, C₁₆H₁₅N₃O₂, as seen in the dihedral angle between the benzene and adjacent but-2-enal group [29.26 (4)°] and between the pyridine ring and amide group [24.79 (6)°]. A twist is also evident around the hydrazine bond [the C—N—N—C torsion angle is −138.25 (13)°]. The conformation about the ethene bond is Z. An intramolecular N—H⋯O hydrogen bond involving the benzoyl O atom and leading to an S(6) motif is formed. Significant delocalization of π-electron density is found in this part of the molecule. In the crystal, helical supramolecular chains aligned along the b axis and mediated by N—H⋯O hydrogen bonds are formed.

Related literature

For the structures of related carbohydrazides, see: Bikas et al. (2010 ▶, 2012 ▶).

Experimental

Crystal data

C₁₆H₁₅N₃O₂
M _r = 281.31
Monoclinic,
a = 15.7640 (4) Å
b = 6.5194 (1) Å
c = 13.3093 (3) Å
β = 93.579 (2)°
V = 1365.15 (5) Å³
Z = 4
Cu Kα radiation
μ = 0.76 mm⁻¹
T = 100 K
0.20 × 0.10 × 0.05 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010 ▶) T _min = 0.864, T _max = 0.963
5321 measured reflections
2808 independent reflections
2397 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.109
S = 1.02
2808 reflections
199 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: X-SEED (Barbour, 2001 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812000529/hg5158sup1.cif

e-68-0o412-sup1.cif^{(17KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812000529/hg5158Isup2.hkl

e-68-0o412-Isup2.hkl^{(137.9KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812000529/hg5158Isup3.cml

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—H2⋯O2ⁱ	0.88 (2)	1.90 (2)	2.750 (2)	163 (2)
N3—H3⋯O2	0.90 (2)	1.91 (2)	2.607 (1)	133 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are grateful to the Islamic Azad University (Tabriz Branch), the University of Zanjan and the Ministry of Higher Education of Malaysia (grant No. UM.C/HIR/MOHE/SC/12) for support of this study.

supplementary crystallographic information

Comment

The reaction of acid hydrazides (R—C(═ O)–NH–NH₂) with β-diketones forms a class of molecules that can function as tridentate Schiff base ligands and which can have diverse tautomeric states. As part of continuing studies on the synthesis and characterization of aroylhydrazone compounds (Bikas et al., 2010; Bikas et al., 2012), we describe herein the crystal structure of (Z)-N'-(4-oxo-4-phenylbut-2-en-2-yl)isonicotinohydrazide, (I).

The structure determination of (I), Fig. 1, shows that the molecule exists in the di-enone form and that the conformation about the ethene bond is Z. However, it is noted that the ketone C═O bond length of 1.2705 (15) Å is significantly longer than the amide C═O bond length of 1.2213 (16) Å. Further, the formally ethene double bond length of 1.3905 (18) Å is only marginally longer than the C(═O)—C-ethene bond of 1.4097 (18) Å. These observations coupled with the shorter than expected N3—C7 bond length of 1.3369 (16) Å and the planarity of this residue (the r.m.s. = 0.0141 Å, including the N—H atom) indicates significant delocalization of π-electron density over the non-H atoms. It is noted that in this residue a six-membered ring is formed through the agency of an intramolecular N—H···O hydrogen bond, Table 1.

There are significant twists in the molecule with the benzene group twisted out of the plane through the adjacent but-2-enal group (dihedral angle = 29.26 (4)°) and the pyridyl ring twisted out of the plane through the amide group (dihedral angle = 24.79 (6)°). There is also a twist around the hydrazine bond as seen in the value of the C6—N2—N3—C7 torsion angle of -138.25 (13)°.

The most prominent feature of the crystal packing is the formation of helical supramolecular chains along [010] mediated by N—H···O hydrogen bonds, Fig. 2 and Table 1.

Experimental

All reagents were commercially available and used as received. A methanol (10 ml) solution of benzoylacetone (1.5 mmol) was added drop-wise to a methanol solution (10 ml) of 4-pyridinecarboxylic acid hydrazide (1.5 mmol), and the mixture was refluxed for 3 h. Then the solution was evaporated on a steam bath to 5 ml and cooled to room temperature. Light-yellow precipitates of the title compound were separated and filtered off, washed with 3 ml of cooled methanol and then dried in air. Crystals of the title compound were obtained from its methanol solution by slow solvent evaporation. Yield 92%. Selected IR (cm^-1): 3155 (s, broad), 1690 (versus), 1596 (s), 1520 (m), 1309 (s), 1224 (s), 931 (versus), 772 (s).