N′-(3-Thienylmethyl­ene)pyridine-2-carbohydrazide

Haojin Cheng; Brandon Djukic; Laura E Harrington; James F Britten; Martin T Lemaire

doi:10.1107/S1600536808004960

. 2008 Mar 14;64(Pt 4):o719. doi: 10.1107/S1600536808004960

N′-(3-Thienylmethylene)pyridine-2-carbohydrazide

Haojin Cheng ^a, Brandon Djukic ^a, Laura E Harrington ^b, James F Britten ^b, Martin T Lemaire ^a,^*

PMCID: PMC2961063 PMID: 21202109

Abstract

The title compound, C₁₁H₉N₃OS, was prepared to investigate the coordination chemistry of thiophene-containing ligands as precursors to interesting metallopolymers. The molecule is nearly planar. The angle between the thiophene and pyridine rings is 8.63 (4)° and features the expected trans configuration about the imine bond. The structure is stabilized by a weak intermolecular N—H⋯O hydrogen bond. The distance between centroids of adjacent thiophene rings [3.67 (8) Å] suggests the presence of π–π interactions.

Related literature

The preparation and coordination chemistry of a similar compound containing a 2-substituted thiophene were reported previously by El-Motaleb et al. (2005 ▶); however, no structural details were provided. For related literature and structures of other molecules containing the pyridine-2-carbonohydrazide system, see: Klingele & Brooker (2004 ▶); Xie et al. (2006 ▶); Zhang et al. (2006 ▶).

Experimental

Crystal data

C₁₁H₉N₃OS
M _r = 231.27
Monoclinic,
a = 11.6817 (3) Å
b = 9.1454 (3) Å
c = 10.0890 (3) Å
β = 103.230 (1)°
V = 1049.24 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 173 (2) K
0.40 × 0.30 × 0.20 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.908, T _max = 0.959
32428 measured reflections
6449 independent reflections
5355 reflections with I > 2σ(I)
R _int = 0.024

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.109
S = 1.05
6449 reflections
181 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ▶); cell refinement: APEX2; data reduction: APEX2; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808004960/fl2185sup1.cif

e-64-0o719-sup1.cif^{(16.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808004960/fl2185Isup2.hkl

e-64-0o719-Isup2.hkl^{(315.7KB, 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—H2⋯O1ⁱ	0.83 (1)	2.38 (1)	3.0717 (8)	140 (1)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the Natural Sciences and Engineering Research Council for financial support. Martin Lemaire thanks Brock University and Research Corporation for a Cottrell College grant (No. CC6686) in support of this research. The X-ray crystallographic analyses were performed at the McMaster Analytical X-ray (MAX) Diffraction Facility.

supplementary crystallographic information

Comment

We are interested in the coordination chemistry of thiophene containing ligands as precursors to interesting metallopolymers. The title compound (I, Fig. 1) features a pyridine-2-carbonohydrazide moiety grafted onto the 3 position of the thiophene ring and offers a number of possible coordination modes to metal ions, which we are currently exploring.

Bond lengths and angles are in the normal range reported for other molecules containing the pyridine-2-carbonohydrazide moiety (Xie et al., 2006; Zhang et al., 2006). Bond parameters within the thiophene and pyridine rings are also within normal ranges. The C5 - N1 bond is 1.284 (8) Å, typical for a double bond and features the expected trans configuration. The C6 - N2 bond of 1.356 (8) Å is in the range between the expected values for purely single or double bonds as a result of the π-conjugation. The molecule is nearly planar; the angle between the thiophene and pyridine ring is 8.63° (4). The structure is stabilized by an intermolecular hydrogen-bond (H2···O1 = 2.38 (1) Å) between the amide hydrogen and carbonyl oxygen atoms. Other weak intermolecular interactions are suggested by close contacts between H4···N1 (2.591 (14) Å) and H5···O1 (2.609 (12) Å), Fig. 2. The structure is further stabilized by π-π interactions between adjacent thiophene rings (ring centroids are 3.6720(0.0818 Å apart).

Experimental

Pyridine-2-carbonohydrazide (Klingele & Brooker, 2004) (2.28 g, 16.6 mmol)was dissolved in 50 ml of absolute ethanol and cooled in an ice-water bath. A solution of 3-formylthiophene (2.91 g, 17.0 mmol) in 25 ml of absolute ethanol was added slowly dropwise to the cold hydrazide solution. Following the addition the ice-water bath was removed and the reaction was let stir at room temperature for 4 hr. While warming to room temperature, the appearance of a white microcrystalline precipitate was observed. The reaction flask was cooled in ice and the product was isolated by vacuum filtration, washed with cold ethanol and dried (yield 2.5 g, 65%). The compound was recrystallized by slow evaporation of a methanol solution to give large transparent blocks. MS (EI) = m/z 231 (M⁺, 20%), 79 (py⁺, 100%). FT—IR (KBr pellet) = 3295 (w, νN-H), 3072 (w), 1677 (s, νC=O), 1607 (m), 1533 (s), 1344 (m), 799 (m), 741 (m), 603 cm^-1 (m). ¹H NMR (CDCl₃) = δ 10.91 (s, 1H, N—H), 8.60 (d, 1H, Ar—H), 8.42 (s, 1H, H—C=N), 8.33 (d, 1H, Ar—H), 7.92 (dd, 1H, Ar—H), 7.70 (d, 1H, Ar—H), 7.66 (d, 1H, Ar—H), 7.5 (dd, 1H, Ar—H), 7.38 (dd, 1H, Ar—H).