5-Bromo-N 3-[(E)-(6-bromo­pyridin-2-yl)methyl­idene]pyridine-3,4-diamine

Mingjian Cai

doi:10.1107/S1600536811047702

. 2011 Nov 23;67(Pt 12):o3402. doi: 10.1107/S1600536811047702

5-Bromo-N ³-[(E)-(6-bromopyridin-2-yl)methylidene]pyridine-3,4-diamine

Mingjian Cai ^a,^*

PMCID: PMC3239041 PMID: 22199889

Abstract

The title compound, C₁₁H₈Br₂N₄, is a Schiff base obtained from 6-bromopicolinaldehyde and 5-bromopyridine-3,4-diamine. The molecule has an E configuration about the C=N bond and the dihedral angle between the two pyridine rings is 14.02 (1)°. The observed conformation is stabilised by an intramolecular N—H⋯N hydrogen bond. In the crystal, molecules are stacked along the b axis and are linked through N—H⋯N hydrogen bonds into chains along the c axis.

Related literature

For the use of Schiff bases in coordination, see: Burkhardt & Plass (2008 ▶); Keypour et al. (2011 ▶); Tarafder et al. (2002 ▶). For their properties, see: Kocyigit et al. (2010 ▶).

Experimental

Crystal data

C₁₁H₈Br₂N₄
M _r = 356.03
Monoclinic,
a = 24.941 (2) Å
b = 3.8306 (6) Å
c = 15.0868 (14) Å
β = 126.116 (14)°
V = 1164.4 (2) Å³
Z = 4
Mo Kα radiation
μ = 6.94 mm⁻¹
T = 113 K
0.20 × 0.18 × 0.12 mm

Data collection

Rigaku Saturn 724CCD diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002 ▶) T _min = 0.337, T _max = 0.490
5047 measured reflections
2282 independent reflections
2070 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.029
wR(F ²) = 0.055
S = 0.89
2282 reflections
118 parameters
38 restraints
H-atom parameters constrained
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.63 e Å⁻³
Absolute structure: Flack (1983 ▶), 1093 Friedel pairs
Flack parameter: 0.002 (12)

Data collection: CrystalClear (Rigaku/MSC, 2002 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Crystal Impact, 2009 ▶); software used to prepare material for publication: CrystalStructure (Rigaku/MSC, 2006 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811047702/ld2030sup1.cif

e-67-o3402-sup1.cif^{(15.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811047702/ld2030Isup2.hkl

e-67-o3402-Isup2.hkl^{(112.2KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811047702/ld2030Isup3.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
N4—H4B⋯N2	0.88	2.33	2.686 (6)	104
N4—H4A⋯N1ⁱ	0.88	2.44	3.043 (5)	126

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank Professor Wang, Department of Chemistry, Nankai University, for providing experimental facilities.

supplementary crystallographic information

Comment

Schiff bases have played an important role in the development of coordination chemistry as they readily form stable complexes with most of the transition metals (Burkhardt & Plass, 2008; Keypour, et al., 2011; Tarafder, et al., 2002). They possess important properties, such as an ability to reversibly bind oxygen, catalytic activity in hydrogenation of olefins, transfer of an amino group, photochromic properties and complexing ability towards toxic metals (Kocyigit et al., 2010). In this paper, a new Schiff base compound derived from condensation of 6-bromopicolinaldehyde with 5-bromopyridine-3,4-diamine is reported. The molecule of the title compound has an E configuration about the C6=N2 bond (Fig.1). The dihedral angle between the two pyridyl rings is 14.02 (1)°. An intramolecular N—H···N hydrogen bond forms five-membered ring. The five-membered ring and two pyridyl ring form dihedral angles of 3.60 (1)° and 4.02 (1)°. In the crystal, molecules are stacked along y axis and are linked through intermolecular N—H···N hydrogen bonds into chains propagating along z axis (Fig.2).

Experimental

A solution of 6-bromopicolinaldehyde and 5-bromopyridine-3,4-diamine in methanol was refluxed for 30 min, and then the crude product was filtered and recrystallized from methanol to yield yellowish title compound. A small amount of the product was dissolved in methanol and the solution was kept for 5 days at ambient temperature to produce yellowish acicular crystals on slow evaporation of the solvent.