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Acta Crystallogr Sect E Struct Rep Online. 2008 August 1; 64(Pt 8): o1398.
Published online 2008 July 5. doi:  10.1107/S1600536808019247
PMCID: PMC2962031

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

Abstract

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 [triangle]).

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Object name is e-64-o1398-scheme1.jpg

Experimental

Crystal data

  • C14H11Br2NO
  • M r = 369.07
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-64-o1398-efi1.jpg
  • 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 [triangle]) 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[F 2 > 2σ(F 2)] = 0.030
  • wR(F 2) = 0.073
  • S = 1.01
  • 3156 reflections
  • 164 parameters
  • H-atom parameters constrained
  • Δρmax = 0.45 e Å−3
  • Δρmin = −0.55 e Å−3

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

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

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

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

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

supplementary crystallographic information

Comment

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).

Experimental

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%.

Refinement

All H atoms were located from difference Fourier syntheses, H atoms from the C—H groups and O—H group were placed in geometrically idealized positions and constrained to ride on their parent atoms (C—H = 0.93 %A, 0.96 %A, 0.97 %A; O—H = 0.82 Å) and Uiso(H) values equal to 1.2 Ueq(C) or 1.5Ueq(O).

Figures

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, ...

Crystal data

C14H11Br2NOF000 = 720
Mr = 369.07Dx = 1.797 Mg m3
Monoclinic, P21/cMo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 1859 reflections
a = 12.086 (2) Åθ = 1.0–27.6º
b = 8.326 (1) ŵ = 5.93 mm1
c = 13.576 (2) ÅT = 296 (2) K
β = 93.126 (2)ºBlock, yellow
V = 1364.1 (3) Å30.34 × 0.30 × 0.25 mm
Z = 4

Data collection

Bruker APEXII area-detector diffractometer3156 independent reflections
Radiation source: fine-focus sealed tube2339 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.030
Detector resolution: 10.00 pixels mm-1θmax = 27.6º
T = 296(2) Kθmin = 1.7º
[var phi] and ω scansh = −15→15
Absorption correction: multi-scan(SADABS; Sheldrick, 2000)k = −10→10
Tmin = 0.156, Tmax = 0.231l = −17→17
11566 measured reflections

Refinement

Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullH-atom parameters constrained
R[F2 > 2σ(F2)] = 0.030  w = 1/[σ2(Fo2) + (0.0301P)2 + 0.6854P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.073(Δ/σ)max = 0.001
S = 1.01Δρmax = 0.45 e Å3
3156 reflectionsΔρmin = −0.55 e Å3
164 parametersExtinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
Primary atom site location: structure-invariant direct methodsExtinction coefficient: 0.0030 (4)
Secondary atom site location: difference Fourier map

Special details

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)

xyzUiso*/Ueq
Br10.75214 (3)0.53350 (5)0.72206 (2)0.07826 (14)
Br20.67394 (2)0.50575 (4)0.31003 (2)0.05547 (11)
O0.48779 (13)0.7332 (2)0.35440 (11)0.0493 (4)
H1O0.43160.78160.36820.074*
N0.35471 (16)0.8850 (2)0.46645 (16)0.0460 (5)
C10.0119 (3)0.7850 (6)0.3456 (3)0.0974 (13)
H1−0.01680.77380.28100.117*
C2−0.0382 (3)0.7132 (5)0.4196 (4)0.0908 (12)
H2−0.10270.65440.40630.109*
C30.0041 (3)0.7256 (5)0.5129 (3)0.0836 (11)
H3−0.03110.67540.56380.100*
C40.0993 (2)0.8125 (4)0.5333 (2)0.0612 (7)
H40.12860.81890.59790.073*
C50.15180 (19)0.8895 (3)0.46034 (19)0.0450 (6)
C60.1066 (2)0.8759 (5)0.3656 (2)0.0778 (10)
H60.13980.92810.31440.093*
C70.2567 (2)0.9840 (3)0.4827 (3)0.0575 (7)
H7A0.25721.07810.44070.069*
H7B0.25911.02000.55080.069*
C80.41771 (19)0.8452 (3)0.54029 (19)0.0426 (6)
H80.40140.88240.60250.051*
C90.51473 (17)0.7434 (3)0.53116 (16)0.0353 (5)
C100.54482 (17)0.6901 (3)0.43760 (16)0.0361 (5)
C110.63563 (18)0.5885 (3)0.43328 (16)0.0359 (5)
C120.69736 (18)0.5414 (3)0.51723 (17)0.0401 (5)
H120.75800.47360.51270.048*
C130.66716 (19)0.5970 (3)0.60777 (17)0.0418 (5)
C140.57710 (19)0.6958 (3)0.61547 (17)0.0422 (5)
H140.55770.73110.67720.051*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Br10.0719 (2)0.1044 (3)0.05549 (19)0.01255 (19)−0.02322 (15)0.00917 (17)
Br20.05471 (18)0.0672 (2)0.04574 (16)0.00181 (13)0.01445 (12)−0.00697 (12)
O0.0414 (9)0.0656 (12)0.0408 (9)0.0077 (8)0.0003 (7)0.0096 (8)
N0.0298 (10)0.0410 (12)0.0675 (14)−0.0021 (8)0.0053 (9)0.0040 (10)
C10.053 (2)0.156 (4)0.082 (3)0.000 (2)−0.0136 (18)−0.022 (3)
C20.0439 (18)0.100 (3)0.129 (4)−0.0135 (19)0.009 (2)−0.029 (3)
C30.064 (2)0.079 (3)0.109 (3)−0.0202 (18)0.026 (2)0.010 (2)
C40.0560 (17)0.0622 (19)0.0658 (18)−0.0063 (14)0.0082 (14)0.0068 (14)
C50.0305 (12)0.0431 (14)0.0618 (15)0.0078 (10)0.0070 (11)0.0023 (12)
C60.0477 (17)0.121 (3)0.065 (2)0.0031 (18)0.0077 (15)0.0122 (19)
C70.0386 (13)0.0434 (16)0.091 (2)0.0027 (11)0.0084 (14)−0.0010 (14)
C80.0348 (12)0.0384 (13)0.0555 (15)−0.0075 (10)0.0107 (11)−0.0058 (11)
C90.0293 (11)0.0349 (12)0.0420 (12)−0.0083 (9)0.0040 (9)−0.0002 (10)
C100.0310 (11)0.0368 (12)0.0406 (12)−0.0077 (9)0.0036 (9)0.0040 (10)
C110.0321 (11)0.0367 (13)0.0394 (12)−0.0079 (9)0.0075 (9)−0.0003 (10)
C120.0316 (12)0.0364 (13)0.0522 (14)−0.0026 (9)0.0016 (10)0.0033 (10)
C130.0356 (12)0.0479 (15)0.0407 (12)−0.0065 (11)−0.0070 (9)0.0050 (11)
C140.0391 (13)0.0480 (14)0.0394 (12)−0.0102 (11)0.0025 (10)−0.0060 (10)

Geometric parameters (Å, °)

Br1—C131.889 (2)C5—C61.375 (4)
Br2—C111.890 (2)C5—C71.509 (4)
O—C101.340 (3)C6—H60.9300
O—H1O0.8200C7—H7A0.9700
N—C81.269 (3)C7—H7B0.9700
N—C71.469 (3)C8—C91.458 (3)
C1—C21.343 (5)C8—H80.9300
C1—C61.386 (5)C9—C141.393 (3)
C1—H10.9300C9—C101.412 (3)
C2—C31.343 (5)C10—C111.390 (3)
C2—H20.9300C11—C121.384 (3)
C3—C41.375 (4)C12—C131.381 (3)
C3—H30.9300C12—H120.9300
C4—C51.364 (4)C13—C141.373 (3)
C4—H40.9300C14—H140.9300
C10—O—H1O109.5C5—C7—H7B109.5
C8—N—C7118.8 (2)H7A—C7—H7B108.1
C2—C1—C6119.9 (3)N—C8—C9122.4 (2)
C2—C1—H1120.1N—C8—H8118.8
C6—C1—H1120.1C9—C8—H8118.8
C1—C2—C3120.5 (3)C14—C9—C10119.7 (2)
C1—C2—H2119.8C14—C9—C8119.8 (2)
C3—C2—H2119.8C10—C9—C8120.5 (2)
C2—C3—C4120.1 (3)O—C10—C11119.9 (2)
C2—C3—H3119.9O—C10—C9121.9 (2)
C4—C3—H3119.9C11—C10—C9118.2 (2)
C5—C4—C3121.2 (3)C12—C11—C10121.9 (2)
C5—C4—H4119.4C12—C11—Br2118.59 (17)
C3—C4—H4119.4C10—C11—Br2119.44 (16)
C4—C5—C6117.6 (3)C13—C12—C11118.8 (2)
C4—C5—C7121.2 (3)C13—C12—H12120.6
C6—C5—C7121.2 (3)C11—C12—H12120.6
C5—C6—C1120.7 (3)C14—C13—C12121.2 (2)
C5—C6—H6119.7C14—C13—Br1120.20 (18)
C1—C6—H6119.7C12—C13—Br1118.63 (18)
N—C7—C5110.7 (2)C13—C14—C9120.2 (2)
N—C7—H7A109.5C13—C14—H14119.9
C5—C7—H7A109.5C9—C14—H14119.9
N—C7—H7B109.5
C6—C1—C2—C3−1.5 (7)C8—C9—C10—O1.5 (3)
C1—C2—C3—C40.1 (6)C14—C9—C10—C111.1 (3)
C2—C3—C4—C51.0 (5)C8—C9—C10—C11−177.7 (2)
C3—C4—C5—C6−0.6 (5)O—C10—C11—C12179.7 (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—C1178.1 (3)C9—C10—C11—Br2176.78 (15)
C2—C1—C6—C52.0 (6)C10—C11—C12—C130.3 (3)
C8—N—C7—C5−112.6 (3)Br2—C11—C12—C13−177.68 (17)
C4—C5—C7—N95.3 (3)C11—C12—C13—C140.7 (3)
C6—C5—C7—N−83.7 (3)C11—C12—C13—Br1−179.63 (17)
C7—N—C8—C9178.1 (2)C12—C13—C14—C9−0.6 (4)
N—C8—C9—C14−176.2 (2)Br1—C13—C14—C9179.65 (17)
N—C8—C9—C102.6 (3)C10—C9—C14—C13−0.3 (3)
C14—C9—C10—O−179.7 (2)C8—C9—C14—C13178.5 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C7—H7A···Cgi0.972.883.526 (3)125
O—H1O···N0.821.882.601 (3)147

Symmetry codes: (i) −x+1, −y+2, −z+1.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: LX2061).

References

  • Bruker (2004). APEX2 and SAINT Bruker AXS Inc., Madison, Wisconsin, USA.
  • Cohen, M. D., Schmidt, G. M. J. & Flavian, S. (1964). J. Chem. Soc. pp. 2041–2043.
  • Sheldrick, G. M. (2000). SADABS University of Göttingen, Germany.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography