(E)-4-Bromo-2-[(2-hydroxy­phen­yl)iminiometh­yl]phenolate

Naser Eltaher Eltayeb; Siang Guan Teoh; Hoong-Kun Fun; Suchada Chantrapromma

doi:10.1107/S1600536810015230

. 2010 May 8;66(Pt 6):o1262–o1263. doi: 10.1107/S1600536810015230

(E)-4-Bromo-2-[(2-hydroxyphenyl)iminiomethyl]phenolate

Naser Eltaher Eltayeb ^a,^‡, Siang Guan Teoh ^a, Hoong-Kun Fun ^b,^*,^§, Suchada Chantrapromma ^c,^¶

PMCID: PMC2979394 PMID: 21579365

Abstract

The title compound, C₁₃H₁₀BrNO₂, crystallizes in a zwitterionic form. The zwitterion exists in a trans configuration about the C=N bond and is almost planar, the dihedral angle between the two benzene rings being 2.29 (9)°. An intramolecular N—H⋯O hydrogen bond formed between the iminium NH⁺ and the phenolate O⁻ atoms generates an S(6) ring motif. In the crystal, the zwitterions are linked through O—H⋯O hydrogen bonds into chains along [101] and these chains are further connected through C—H⋯Br interactions into a two-dimensional network perpendicular to (101). C⋯C [3.572 (3)–3.592 (3) Å] and C⋯Br [3.5633 (19)–3.7339 (18) Å] short contacts are observed. The crystal studied was a twin with twin law Inline graphic 00, 00, 001 with a domain ratio of 0.09919 (2):0.90081 (2).

Related literature

For bond-length data, see: Allen et al. (1987 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For background to Schiff bases and their applications, see: Dao et al. (2000 ▶); Kagkelari et al. (2009 ▶); Karthikeyan et al. (2006 ▶); Sriram et al. (2006 ▶); Wei & Atwood (1998 ▶). For related structures, see: Eltayeb et al. (2009 ▶; 2010 ▶); Tan & Liu (2009 ▶). For the stability of the temperature controller used in the data collection, see Cosier & Glazer, (1986 ▶).

Experimental

Crystal data

C₁₃H₁₀BrNO₂
M _r = 291.12
Monoclinic,
a = 4.6387 (3) Å
b = 18.9379 (13) Å
c = 6.2270 (4) Å
β = 90.144 (3)°
V = 547.02 (6) Å³
Z = 2
Mo Kα radiation
μ = 3.74 mm⁻¹
T = 100 K
0.43 × 0.14 × 0.14 mm

Data collection

Bruker APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.295, T _max = 0.628
8575 measured reflections
3120 independent reflections
3034 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.018
wR(F ²) = 0.041
S = 1.02
3120 reflections
191 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.59 e Å⁻³
Δρ_min = −0.29 e Å⁻³
Absolute structure: Flack (1983 ▶), 1480 Friedel pairs
Flack parameter: 0.027 (7)

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810015230/rz2436sup1.cif

e-66-o1262-sup1.cif^{(17.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810015230/rz2436Isup2.hkl

e-66-o1262-Isup2.hkl^{(153.1KB, 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
O2—H1O2⋯O1ⁱ	0.82	1.76	2.5641 (19)	169
N1—H1N1⋯O1	0.89 (3)	1.84 (3)	2.6129 (18)	143 (3)
C7—H7A⋯O2	0.95 (2)	2.12 (2)	2.794 (2)	127.1 (18)
C11—H11A⋯Br1ⁱⁱ	0.96 (3)	2.89 (3)	3.6982 (19)	143.1 (19)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors thank the Malaysian Government, the Ministry of Science, Technology and Innovation (MOSTI) and Universiti Sains Malaysia for the RU research grants (PKIMIA/815002 and PKIMIA/811120). NEE would like to acknowledge Universiti Sains Malaysia for a post-doctoral fellowship. The International University of Africa (Sudan) is acknowledged for providing study leave to NEE. The authors thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

supplementary crystallographic information

Comment

Much attention has been given to Schiff base ligands due to their applications such as in coordination chemistry (Kagkelari et al., 2009), chelated boron catalyst (Wei & Atwood, 1998), pharmacological activities, anticancer (Dao et al., 2000), anti-HIV (Sriram et al., 2006), antibacterial and antifungal (Karthikeyan et al., 2006) activities. We have reported the crystal structures of Schiff base ligands which existed in a zwitterionic form i.e 2-((E)-{2-[(E)-2,3-dihydroxybenzylideneamino]-5-methylphenyl}- iminiomethyl)-6-hydroxyphenolate (Eltayeb et al., 2009) and (E)-4-allyl-2-{[(2-hydroxyphenyl)iminio]methyl}-6-methoxyphenolate (Eltayeb et al., 2010). Herein we report the crystal structure of the title zwitterionic Schiff base ligand (I).

The molecule of (I) (Fig. 1), C₁₃H₉BrNO₂, crystallizes in a zwitterionic form with cationic iminium and anionic enolate, and exists in a trans configuration about the C═N bond [1.310 (2) Å]; the torsion angle C8–N1–C7–C6 is 179.25 (17)°. The molecule is almost planar with the dihedral angle between the two benzene rings of 2.31 (9)°. The hydroxy group is co-planar with the attached C8–C13 benzene ring with the r.m.s. of 0.0102 (2) Å for the seven non H atoms. Intramolecular N—H···O hydrogen bond between the NH⁺ and the phenolate O^- generates an S(6) ring motif (Fig. 1; Table 1) which help to stabilize the planarity of the molecule (Bernstein et al., 1995). The bond distances are in normal ranges (Allen et al., 1987) and comparable with those found in related structures (Eltayeb et al., 2009, 2010; Tan & Liu, 2009).

In the crystal packing (Fig. 2), the zwitterions are linked through O2–H1O2···O1 hydrogen bonds into chains along the [101] and these chains are further connected through C11—H11A···Br1 interactions into a 2-D network perpendicular to the (101)-plane. The crystal is stabilized by O—H···O and weak C—H···Br interactions (Table 1). C···C [3.572 (3)-3.592 (3) Å] and C···Br [3.5633 (19)-3.7339 (18) Å] short contacts are observed.

Experimental

The title compound was synthesized by adding 5-bromo-2-hydroxybenzaldehyde (0.402 g, 2 mmol) to a solution of 2-aminophenol (0.218 g, 2 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for half an hour. The resultant yellow solution was filtered and the filtrate was evaporated to give a yellow solid product. Yellow needle-shaped single crystals of the title compound suitable for x-ray structure determination were obtained from ethanol by slow evaporation at room temperature after nine days.