(E)-2-(Benzyl­imino­meth­yl)-4,6-dibromo­phenol

Jiang, W.

doi:10.1107/S1600536808019247

organic compounds

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Volume 64| Part 8| August 2008| Page o1398

doi:10.1107/S1600536808019247

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(E)-2-(Benzyliminomethyl)-4,6-dibromophenol

Wei Jiang ^a ^*

^aCollege of Chemistry and Life Sciences, Maoming University, Guandu Second Road 139, Maoming 525000, People's Republic of China
^*Correspondence e-mail: gdmmjw@yahoo.cn

(Received 22 June 2008; accepted 25 June 2008; online 5 July 2008)

The title compound, C₁₄H₁₁Br₂NO, was prepared by the condensation of benzylamine and 3,5-dibromo-2-hydroxybenzaldehyde. The crystal structure is stabilized by aromatic π–π stacking interactions between the phenol rings of neighbouring molecules [centroid–centroid distance = 3.530 (5) Å]. In addition, the stacked molecules exhibit intermolecular C—H⋯π and intramolecular O—H⋯N interactions.

Related literature

For details of the photochromism and thermochromism of Schiff base compounds, see: Cohen et al. (1964 ).

Experimental

Crystal data

C₁₄H₁₁Br₂NO
M_r = 369.07
Monoclinic, P 2₁ /c
a = 12.086 (2) Å
b = 8.326 (1) Å
c = 13.576 (2) Å
β = 93.126 (2)°
V = 1364.1 (3) Å³
Z = 4
Mo Kα radiation
μ = 5.93 mm⁻¹
T = 296 (2) K
0.34 × 0.30 × 0.25 mm

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2000 ) T_min = 0.156, T_max = 0.231
11566 measured reflections
3156 independent reflections
2339 reflections with I > 2σ(I)
R_int = 0.030

Refinement

R[F² > 2σ(F²)] = 0.030
wR(F²) = 0.073
S = 1.01
3156 reflections
164 parameters
H-atom parameters constrained
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.55 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7A⋯Cgⁱ	0.97	2.88	3.526 (3)	125
O—H1O⋯N	0.82	1.88	2.601 (3)	147
Symmetry code: (i) -x+1, -y+2, -z+1. Cg is the centroid of the C9–C14 ring.

Data collection: APEX2 (Bruker, 2004 ); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808019247/lx2061sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808019247/lx2061Isup2.hkl

checkCIF report

Comment top

Compounds presenting photochromism, a reversible color change brought about in at least one direction, by the action of electromagnetic radiation, attract considerable attention from various fields of chemistry, physics and material science as potential candidates for practical applications. Since long time,the Schiff bases of salicylaldehyde with aromatic amines (anils or N-salicylideneaniline derivatives) are recognized as such compounds, which undergo enol-keto tautomerism and present common features in their structures and reaction mechanisms.The schiff base compounds show photochromism and thermochromism in the solid state by proton transfer from the hydroxyl O atom to the imine N atom (Cohen et al., 1964). The tautomerism involves proton transfer from the hydroxylic oxygen to the imino nitrogen atom that occurs intramolecularly via a six-membered ring, with the keto species showing bathochromically shifted spectra. As our continuing studies on the relation between the Schiff base geometry in the crystalline state and photochromism and/or thermochromism, here we report the crystal structure of the title compound, (E)-benzyliminomethyl-4,6-dibromophenol (Fig. 1).

The molecular structure is a typical salicylaldehyde schiff derivative with normal geometric parameters. The molecular packing (Fig. 2) is stabilized by π—π interactions between the phenol rings of neighbouring molecules. The Cg···Cgⁱⁱ distance is 3.530 (5) Å (Cg1 is the centroid of the C9-C14 ring, symmetry code as in Fig. 2). The crystal packing (Fig. 2) is further stabilized by the C—H···π interactions between a methylene H atom of the benzyl group and the phenol ring, i.e. with a C7–H7A···Cgⁱ separation of 2.88 Å (Fig. 2 and Table 1; symmetry code as in Fig. 2). Additionally, intramolecular O—H···N interactions in the structure were observed (Fig. 2 and Table 1; symmetry code as in Fig. 2).

Related literature top

For details of the photochromism and thermochromism of Schiff base compounds, see: Cohen et al. (1964). Cg is the centroid of the C9–C14 ring.

Experimental top

Benzylamine (0.02 mol, 2.14 g) and 3,5-dibromo-2-hydroxybenzaldehyde(0.02 mol, 5.498 g) were dissolved in ethanol and the solution was refluxed for 3 h. After evaporation, a crude product was recrystallized twice from ethanol to give a pure yellow product. Yield: 82.5%. Calcd. for C₁₄H₁₁Br₂NO: C, 45.56; H, 3.00; N, 3.80; Found: C, 45.21; H, 2.858; N, 3.67%.

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The structure of (I), showing displacement ellipsoids drawn at the 30% probability level.
	Fig. 2. π···π, C—H···π and N—H···O interactions (dotted lines) in the title compound. Cg denotes the ring centroids. [Symmetry code: (i) -x+1, -y+2, -z+1; (ii) -x+1, -y+1, -z+1.]

(E)-2-(Benzyliminomethyl)-4,6-dibromophenol top

Crystal data top

C₁₄H₁₁Br₂NO	F(000) = 720
M_r = 369.07	D_x = 1.797 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1859 reflections
a = 12.086 (2) Å	θ = 1.0–27.6°
b = 8.326 (1) Å	µ = 5.93 mm⁻¹
c = 13.576 (2) Å	T = 296 K
β = 93.126 (2)°	Block, yellow
V = 1364.1 (3) Å³	0.34 × 0.30 × 0.25 mm
Z = 4

Data collection top

Bruker APEXII area-detector diffractometer	3156 independent reflections
Radiation source: fine-focus sealed tube	2339 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.030
Detector resolution: 10.00 pixels mm^-1	θ_max = 27.6°, θ_min = 1.7°
ϕ and ω scans	h = −15→15
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	k = −10→10
T_min = 0.156, T_max = 0.231	l = −17→17
11566 measured reflections

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.030	H-atom parameters constrained
wR(F²) = 0.073	w = 1/[σ²(F_o²) + (0.0301P)² + 0.6854P] where P = (F_o² + 2F_c²)/3
S = 1.01	(Δ/σ)_max = 0.001
3156 reflections	Δρ_max = 0.45 e Å⁻³
164 parameters	Δρ_min = −0.55 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0030 (4)

Crystal data top

C₁₄H₁₁Br₂NO	V = 1364.1 (3) Å³
M_r = 369.07	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.086 (2) Å	µ = 5.93 mm⁻¹
b = 8.326 (1) Å	T = 296 K
c = 13.576 (2) Å	0.34 × 0.30 × 0.25 mm
β = 93.126 (2)°

Data collection top

Bruker APEXII area-detector diffractometer	3156 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	2339 reflections with I > 2σ(I)
T_min = 0.156, T_max = 0.231	R_int = 0.030
11566 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.030	0 restraints
wR(F²) = 0.073	H-atom parameters constrained
S = 1.01	Δρ_max = 0.45 e Å⁻³
3156 reflections	Δρ_min = −0.55 e Å⁻³
164 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.75214 (3)	0.53350 (5)	0.72206 (2)	0.07826 (14)
Br2	0.67394 (2)	0.50575 (4)	0.31003 (2)	0.05547 (11)
O	0.48779 (13)	0.7332 (2)	0.35440 (11)	0.0493 (4)
H1O	0.4316	0.7816	0.3682	0.074*
N	0.35471 (16)	0.8850 (2)	0.46645 (16)	0.0460 (5)
C1	0.0119 (3)	0.7850 (6)	0.3456 (3)	0.0974 (13)
H1	−0.0168	0.7738	0.2810	0.117*
C2	−0.0382 (3)	0.7132 (5)	0.4196 (4)	0.0908 (12)
H2	−0.1027	0.6544	0.4063	0.109*
C3	0.0041 (3)	0.7256 (5)	0.5129 (3)	0.0836 (11)
H3	−0.0311	0.6754	0.5638	0.100*
C4	0.0993 (2)	0.8125 (4)	0.5333 (2)	0.0612 (7)
H4	0.1286	0.8189	0.5979	0.073*
C5	0.15180 (19)	0.8895 (3)	0.46034 (19)	0.0450 (6)
C6	0.1066 (2)	0.8759 (5)	0.3656 (2)	0.0778 (10)
H6	0.1398	0.9281	0.3144	0.093*
C7	0.2567 (2)	0.9840 (3)	0.4827 (3)	0.0575 (7)
H7A	0.2572	1.0781	0.4407	0.069*
H7B	0.2591	1.0200	0.5508	0.069*
C8	0.41771 (19)	0.8452 (3)	0.54029 (19)	0.0426 (6)
H8	0.4014	0.8824	0.6025	0.051*
C9	0.51473 (17)	0.7434 (3)	0.53116 (16)	0.0353 (5)
C10	0.54482 (17)	0.6901 (3)	0.43760 (16)	0.0361 (5)
C11	0.63563 (18)	0.5885 (3)	0.43328 (16)	0.0359 (5)
C12	0.69736 (18)	0.5414 (3)	0.51723 (17)	0.0401 (5)
H12	0.7580	0.4736	0.5127	0.048*
C13	0.66716 (19)	0.5970 (3)	0.60777 (17)	0.0418 (5)
C14	0.57710 (19)	0.6958 (3)	0.61547 (17)	0.0422 (5)
H14	0.5577	0.7311	0.6772	0.051*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0719 (2)	0.1044 (3)	0.05549 (19)	0.01255 (19)	−0.02322 (15)	0.00917 (17)
Br2	0.05471 (18)	0.0672 (2)	0.04574 (16)	0.00181 (13)	0.01445 (12)	−0.00697 (12)
O	0.0414 (9)	0.0656 (12)	0.0408 (9)	0.0077 (8)	0.0003 (7)	0.0096 (8)
N	0.0298 (10)	0.0410 (12)	0.0675 (14)	−0.0021 (8)	0.0053 (9)	0.0040 (10)
C1	0.053 (2)	0.156 (4)	0.082 (3)	0.000 (2)	−0.0136 (18)	−0.022 (3)
C2	0.0439 (18)	0.100 (3)	0.129 (4)	−0.0135 (19)	0.009 (2)	−0.029 (3)
C3	0.064 (2)	0.079 (3)	0.109 (3)	−0.0202 (18)	0.026 (2)	0.010 (2)
C4	0.0560 (17)	0.0622 (19)	0.0658 (18)	−0.0063 (14)	0.0082 (14)	0.0068 (14)
C5	0.0305 (12)	0.0431 (14)	0.0618 (15)	0.0078 (10)	0.0070 (11)	0.0023 (12)
C6	0.0477 (17)	0.121 (3)	0.065 (2)	0.0031 (18)	0.0077 (15)	0.0122 (19)
C7	0.0386 (13)	0.0434 (16)	0.091 (2)	0.0027 (11)	0.0084 (14)	−0.0010 (14)
C8	0.0348 (12)	0.0384 (13)	0.0555 (15)	−0.0075 (10)	0.0107 (11)	−0.0058 (11)
C9	0.0293 (11)	0.0349 (12)	0.0420 (12)	−0.0083 (9)	0.0040 (9)	−0.0002 (10)
C10	0.0310 (11)	0.0368 (12)	0.0406 (12)	−0.0077 (9)	0.0036 (9)	0.0040 (10)
C11	0.0321 (11)	0.0367 (13)	0.0394 (12)	−0.0079 (9)	0.0075 (9)	−0.0003 (10)
C12	0.0316 (12)	0.0364 (13)	0.0522 (14)	−0.0026 (9)	0.0016 (10)	0.0033 (10)
C13	0.0356 (12)	0.0479 (15)	0.0407 (12)	−0.0065 (11)	−0.0070 (9)	0.0050 (11)
C14	0.0391 (13)	0.0480 (14)	0.0394 (12)	−0.0102 (11)	0.0025 (10)	−0.0060 (10)

Geometric parameters (Å, º) top

Br1—C13	1.889 (2)	C5—C6	1.375 (4)
Br2—C11	1.890 (2)	C5—C7	1.509 (4)
O—C10	1.340 (3)	C6—H6	0.9300
O—H1O	0.8200	C7—H7A	0.9700
N—C8	1.269 (3)	C7—H7B	0.9700
N—C7	1.469 (3)	C8—C9	1.458 (3)
C1—C2	1.343 (5)	C8—H8	0.9300
C1—C6	1.386 (5)	C9—C14	1.393 (3)
C1—H1	0.9300	C9—C10	1.412 (3)
C2—C3	1.343 (5)	C10—C11	1.390 (3)
C2—H2	0.9300	C11—C12	1.384 (3)
C3—C4	1.375 (4)	C12—C13	1.381 (3)
C3—H3	0.9300	C12—H12	0.9300
C4—C5	1.364 (4)	C13—C14	1.373 (3)
C4—H4	0.9300	C14—H14	0.9300

C10—O—H1O	109.5	C5—C7—H7B	109.5
C8—N—C7	118.8 (2)	H7A—C7—H7B	108.1
C2—C1—C6	119.9 (3)	N—C8—C9	122.4 (2)
C2—C1—H1	120.1	N—C8—H8	118.8
C6—C1—H1	120.1	C9—C8—H8	118.8
C1—C2—C3	120.5 (3)	C14—C9—C10	119.7 (2)
C1—C2—H2	119.8	C14—C9—C8	119.8 (2)
C3—C2—H2	119.8	C10—C9—C8	120.5 (2)
C2—C3—C4	120.1 (3)	O—C10—C11	119.9 (2)
C2—C3—H3	119.9	O—C10—C9	121.9 (2)
C4—C3—H3	119.9	C11—C10—C9	118.2 (2)
C5—C4—C3	121.2 (3)	C12—C11—C10	121.9 (2)
C5—C4—H4	119.4	C12—C11—Br2	118.59 (17)
C3—C4—H4	119.4	C10—C11—Br2	119.44 (16)
C4—C5—C6	117.6 (3)	C13—C12—C11	118.8 (2)
C4—C5—C7	121.2 (3)	C13—C12—H12	120.6
C6—C5—C7	121.2 (3)	C11—C12—H12	120.6
C5—C6—C1	120.7 (3)	C14—C13—C12	121.2 (2)
C5—C6—H6	119.7	C14—C13—Br1	120.20 (18)
C1—C6—H6	119.7	C12—C13—Br1	118.63 (18)
N—C7—C5	110.7 (2)	C13—C14—C9	120.2 (2)
N—C7—H7A	109.5	C13—C14—H14	119.9
C5—C7—H7A	109.5	C9—C14—H14	119.9
N—C7—H7B	109.5

C6—C1—C2—C3	−1.5 (7)	C8—C9—C10—O	1.5 (3)
C1—C2—C3—C4	0.1 (6)	C14—C9—C10—C11	1.1 (3)
C2—C3—C4—C5	1.0 (5)	C8—C9—C10—C11	−177.7 (2)
C3—C4—C5—C6	−0.6 (5)	O—C10—C11—C12	179.7 (2)
C3—C4—C5—C7	−179.6 (3)	C9—C10—C11—C12	−1.1 (3)
C4—C5—C6—C1	−0.9 (5)	O—C10—C11—Br2	−2.4 (3)
C7—C5—C6—C1	178.1 (3)	C9—C10—C11—Br2	176.78 (15)
C2—C1—C6—C5	2.0 (6)	C10—C11—C12—C13	0.3 (3)
C8—N—C7—C5	−112.6 (3)	Br2—C11—C12—C13	−177.68 (17)
C4—C5—C7—N	95.3 (3)	C11—C12—C13—C14	0.7 (3)
C6—C5—C7—N	−83.7 (3)	C11—C12—C13—Br1	−179.63 (17)
C7—N—C8—C9	178.1 (2)	C12—C13—C14—C9	−0.6 (4)
N—C8—C9—C14	−176.2 (2)	Br1—C13—C14—C9	179.65 (17)
N—C8—C9—C10	2.6 (3)	C10—C9—C14—C13	−0.3 (3)
C14—C9—C10—O	−179.7 (2)	C8—C9—C14—C13	178.5 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···Cgⁱ	0.97	2.88	3.526 (3)	125
O—H1O···N	0.82	1.88	2.601 (3)	147

Symmetry code: (i) −x+1, −y+2, −z+1.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₁Br₂NO
M_r	369.07
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	12.086 (2), 8.326 (1), 13.576 (2)
β (°)	93.126 (2)
V (Å³)	1364.1 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	5.93
Crystal size (mm)	0.34 × 0.30 × 0.25

Data collection
Diffractometer	Bruker APEXII area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2000)
T_min, T_max	0.156, 0.231
No. of measured, independent and observed [I > 2σ(I)] reflections	11566, 3156, 2339
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.653

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.030, 0.073, 1.01
No. of reflections	3156
No. of parameters	164
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.55

Computer programs: APEX2 (Bruker, 2004), SAINT (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···Cgⁱ	0.97	2.88	3.526 (3)	125.2
O—H1O···N	0.82	1.88	2.601 (3)	146.8

Symmetry code: (i) −x+1, −y+2, −z+1.

References

Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cohen, M. D., Schmidt, G. M. J. & Flavian, S. (1964). J. Chem. Soc. pp. 2041–2043. CrossRef Web of Science Google Scholar
Sheldrick, G. M. (2000). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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doi:10.1107/S1600536808019247

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