(E)-4-[(4-Bromo­phen­yl)imino­meth­yl]-2-meth­oxy­phenol

In the crystal structure of the title compound, C₁₄H₁₂BrNO₂, the dihedral angle between the rings is 37.87 (10)° and the mol­ecule has an E conformation about the central C=N bond. In the crystal, mol­ecules are connected by inter­molecular O—H...N hydrogen bonds into zigzag chains running parallel to the b axis. The packing also features C—H...O inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.028
• wR factor = 0.067
• Data-to-parameter ratio = 14.0

checkCIF/PLATON results

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Alert level C
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.597          3

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          1
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) still          83 Perc.
PLAT960_ALERT_3_G Number of Intensities with I .LT. - 2*sig(I) ...          2

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   1 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Schiff base compounds exhibit a broad range of biological activities, including antifungal and antibacterial properties (da Silva et al., 2011). They are used as anion sensors (Dalapati et al., 2011) and as non-linear optics compounds (Sun et al., 2012).

The present work is part of a ongoing structural study of Schiff bases (Khalaji et al., 2009; Fejfarová et al., 2010a,b) and we report here the structure of (E)-(4-hydroxy-3-methoxybenzylidene)-4-bromoaniline, (1). In the crystal, the dihedral angle between the two phenyl rings is 37.87 (10)° and the molecule has an E conformation about the central C=N bond. The methoxy group is slightly twisted from the attached benzene ring [C2—C3—O1—C7 = 13.8 (3)°]. The C=N and C—N bond lengths of 1.283 (3) Å and 1.419 (3) Å agree well with the corresponding distances in other Schiff bases (Akkurt et al., 2008; Özek et al., 2009, 2010; Khalaji et al., 2007, 2009; Fejfarová et al., 2010a,b).

The molecules are connected by intermolecular O—H···N hydrogen bonds, forming zigzag chains parallel to the b axis (Fig. 2). The crystal structure is further stabilized by intermolecular C—H···O hydrogen bonds.

Related literature

For Schiff base derivatives and related structures, see: Fejfarová et al. (2010a,b); Özek et al. (2009, 2010); Akkurt et al. (2008); Khalaji et al. (2007, 2009). For applications and properties of Schiff base compounds, see: da Silva et al. (2011); Dalapati et al. (2011); Sun et al. (2012).

S2. Experimental

To a stirring solution of the 4-hydroxy-3-methoxybenzaldehyde (0.2 mmol, in 5 ml of methanol) was added 4-bromoaniline (0.2 mmol) in 10 ml of methanol, and the mixture was stirred for 1 h in air at 323 K and was then left at room temperature for several days without disturbance yielding suitable crystals of (1) that subsequently were filtered off and washed with Et₂O. Yield: 91%.

S3. Refinement

All H atoms bonded to carbon atoms were positioned geometrically and treated as riding on their parent atoms. The methyl H atoms were allowed to rotate freely about the adjacent C—O bonds. The hydroxyl H atoms were found in difference Fourier maps and their coordinates were refined with a restraint on the O—H bond length 0.85 Å with σ of 0.01. All hydrogen atoms were refined with thermal displacement coefficients U_iso(H) set to 1.5U_eq(C, O) for methyl and hydroxyl groups and to 1.2Ueq(C) for the CH and CH₂ groups.

Computing details

Data collection: CrysAlis PRO (Agilent, 2011); cell refinement: CrysAlis PRO (Agilent, 2011); data reduction: CrysAlis PRO (Agilent, 2011); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006 (Petříček et al., 2006).

Figures

	Fig. 1. Molecular structure of (1). Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Packing of molecules in direction of a axis. Hydrogen bonds are drawn as dashed lines.

(E)-4-[(4-Bromophenyl)iminomethyl]-2-methoxyphenol

Crystal data

C14H12BrNO2	F(000) = 616
Mr = 306.2	Dx = 1.556 Mg m^−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.5418 Å
Hall symbol: -P 2ybc	Cell parameters from 6414 reflections
a = 6.5692 (3) Å	θ = 3.9–66.9°
b = 11.4323 (4) Å	µ = 4.24 mm^−1
c = 17.5552 (9) Å	T = 120 K
β = 97.798 (4)°	Plate, colourless
V = 1306.22 (10) Å^3	0.33 × 0.13 × 0.04 mm
Z = 4

Data collection

Agilent Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector	2320 independent reflections
Radiation source: Enhance Ultra (Cu) X-ray Source	1991 reflections with I > 3σ(I)
Mirror monochromator	Rint = 0.044
Detector resolution: 10.3784 pixels mm^-1	θmax = 67.0°, θmin = 4.6°
Rotation method data acquisition using ω scans	h = −7→7
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011)	k = −13→13
Tmin = 0.432, Tmax = 1	l = −19→20
12474 measured reflections

Refinement

Refinement on F^2	45 constraints
R[F > 3σ(F)] = 0.028	H atoms treated by a mixture of independent and constrained refinement
wR(F) = 0.067	Weighting scheme based on measured s.u.'s w = 1/(σ^2(I) + 0.0004I^2)
S = 1.65	(Δ/σ)max = 0.0003
2320 reflections	Δρmax = 0.27 e Å^−3
166 parameters	Δρmin = −0.37 e Å^−3
1 restraint

Special details

Experimental. Absorption correction: CrysAlis PRO (Agilent, 2011) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F² for refinement carried out on F and F², respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.

The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.68807 (4)	0.03813 (2)	0.611307 (17)	0.04255 (10)
O1	1.0904 (2)	0.70826 (13)	0.18744 (10)	0.0341 (5)
O2	0.8114 (2)	0.88161 (13)	0.17128 (9)	0.0283 (5)
N1	0.8397 (3)	0.43584 (16)	0.39607 (10)	0.0260 (6)
C1	0.7469 (3)	0.61449 (19)	0.32641 (12)	0.0268 (6)
C2	0.9135 (3)	0.61379 (19)	0.28390 (13)	0.0278 (7)
C3	0.9362 (3)	0.70156 (18)	0.23240 (13)	0.0260 (6)
C4	0.7941 (3)	0.79425 (18)	0.22238 (13)	0.0252 (6)
C5	0.6294 (3)	0.79520 (19)	0.26391 (13)	0.0292 (7)
C6	0.6055 (3)	0.70607 (19)	0.31557 (13)	0.0296 (7)
C7	1.2114 (4)	0.6054 (2)	0.18148 (15)	0.0342 (8)
C8	0.7179 (3)	0.52315 (19)	0.38158 (12)	0.0278 (7)
C9	0.7943 (3)	0.34873 (18)	0.44886 (12)	0.0263 (6)
C10	0.9598 (3)	0.29543 (19)	0.49366 (13)	0.0304 (7)
C11	0.9292 (4)	0.2049 (2)	0.54324 (13)	0.0326 (7)
C12	0.7312 (4)	0.16602 (19)	0.54612 (13)	0.0308 (7)
C13	0.5637 (3)	0.21731 (19)	0.50239 (13)	0.0312 (7)
C14	0.5954 (3)	0.30931 (19)	0.45378 (13)	0.0281 (7)
H2	1.012127	0.551422	0.290947	0.0333*
H5	0.531306	0.857837	0.256922	0.035*
H6	0.490709	0.70739	0.344094	0.0355*
H7a	1.305933	0.618817	0.14521	0.0513*
H7b	1.286592	0.587401	0.230856	0.0513*
H7c	1.12292	0.541111	0.164378	0.0513*
H8	0.600817	0.52848	0.408718	0.0334*
H10	1.096928	0.321827	0.490106	0.0365*
H11	1.043401	0.169756	0.575023	0.0391*
H13	0.42723	0.189582	0.505637	0.0374*
H14	0.480191	0.345928	0.423465	0.0337*
H2o	0.930 (2)	0.882 (2)	0.1576 (16)	0.0424*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.04436 (17)	0.03681 (16)	0.05028 (18)	0.00744 (11)	0.02019 (12)	0.01743 (12)
O1	0.0363 (9)	0.0270 (8)	0.0426 (9)	0.0074 (6)	0.0190 (7)	0.0074 (7)
O2	0.0264 (8)	0.0245 (8)	0.0347 (9)	0.0004 (6)	0.0066 (6)	0.0055 (6)
N1	0.0294 (9)	0.0254 (9)	0.0235 (9)	−0.0014 (7)	0.0044 (8)	0.0003 (7)
C1	0.0314 (11)	0.0256 (11)	0.0237 (11)	0.0006 (9)	0.0050 (9)	−0.0045 (9)
C2	0.0310 (11)	0.0240 (11)	0.0287 (11)	0.0035 (9)	0.0054 (9)	−0.0003 (9)
C3	0.0275 (10)	0.0251 (11)	0.0261 (11)	−0.0003 (8)	0.0063 (9)	−0.0029 (9)
C4	0.0264 (10)	0.0216 (10)	0.0271 (11)	−0.0035 (8)	0.0014 (9)	−0.0031 (9)
C5	0.0294 (11)	0.0259 (11)	0.0327 (12)	0.0030 (9)	0.0062 (9)	−0.0012 (9)
C6	0.0306 (11)	0.0297 (11)	0.0299 (12)	0.0018 (9)	0.0093 (9)	−0.0022 (9)
C7	0.0317 (12)	0.0276 (12)	0.0459 (14)	0.0044 (9)	0.0146 (11)	0.0005 (10)
C8	0.0315 (11)	0.0288 (12)	0.0243 (11)	−0.0001 (9)	0.0075 (9)	−0.0043 (9)
C9	0.0321 (11)	0.0237 (11)	0.0237 (11)	0.0004 (8)	0.0066 (9)	−0.0037 (9)
C10	0.0255 (11)	0.0327 (12)	0.0331 (12)	−0.0009 (9)	0.0043 (9)	0.0011 (10)
C11	0.0317 (12)	0.0339 (13)	0.0317 (12)	0.0057 (9)	0.0025 (10)	0.0053 (10)
C12	0.0349 (12)	0.0271 (11)	0.0318 (12)	0.0024 (9)	0.0101 (10)	0.0035 (9)
C13	0.0276 (11)	0.0321 (12)	0.0356 (13)	−0.0005 (9)	0.0108 (10)	−0.0005 (10)
C14	0.0275 (11)	0.0302 (12)	0.0273 (11)	0.0032 (9)	0.0060 (9)	0.0010 (9)

Geometric parameters (Å, º)

Br1—C12	1.901 (2)	C6—H6	0.96
O1—C3	1.368 (3)	C7—H7a	0.96
O1—C7	1.431 (3)	C7—H7b	0.96
O2—C4	1.358 (3)	C7—H7c	0.96
O2—H2o	0.846 (19)	C8—H8	0.96
N1—C8	1.283 (3)	C9—C10	1.393 (3)
N1—C9	1.419 (3)	C9—C14	1.396 (3)
C1—C2	1.406 (3)	C10—C11	1.385 (3)
C1—C6	1.396 (3)	C10—H10	0.96
C1—C8	1.454 (3)	C11—C12	1.382 (3)
C2—C3	1.372 (3)	C11—H11	0.96
C2—H2	0.96	C12—C13	1.384 (3)
C3—C4	1.407 (3)	C13—C14	1.388 (3)
C4—C5	1.384 (3)	C13—H13	0.96
C5—C6	1.387 (3)	C14—H14	0.96
C5—H5	0.96
C3—O1—C7	117.28 (17)	H7a—C7—H7b	109.4709
C4—O2—H2o	111.1 (19)	H7a—C7—H7c	109.4715
C8—N1—C9	119.6 (2)	H7b—C7—H7c	109.4709
C2—C1—C6	118.9 (2)	N1—C8—C1	123.8 (2)
C2—C1—C8	122.1 (2)	N1—C8—H8	118.1105
C6—C1—C8	119.0 (2)	C1—C8—H8	118.1102
C1—C2—C3	120.5 (2)	N1—C9—C10	117.3 (2)
C1—C2—H2	119.7453	N1—C9—C14	123.25 (18)
C3—C2—H2	119.747	C10—C9—C14	119.3 (2)
O1—C3—C2	125.18 (19)	C9—C10—C11	120.9 (2)
O1—C3—C4	114.60 (19)	C9—C10—H10	119.5592
C2—C3—C4	120.2 (2)	C11—C10—H10	119.5589
O2—C4—C3	121.5 (2)	C10—C11—C12	118.7 (2)
O2—C4—C5	118.94 (19)	C10—C11—H11	120.6272
C3—C4—C5	119.5 (2)	C12—C11—H11	120.6256
C4—C5—C6	120.3 (2)	Br1—C12—C11	119.14 (17)
C4—C5—H5	119.8487	Br1—C12—C13	119.19 (18)
C6—C5—H5	119.849	C11—C12—C13	121.7 (2)
C1—C6—C5	120.5 (2)	C12—C13—C14	119.2 (2)
C1—C6—H6	119.7435	C12—C13—H13	120.3851
C5—C6—H6	119.7433	C14—C13—H13	120.3861
O1—C7—H7a	109.4713	C9—C14—C13	120.15 (19)
O1—C7—H7b	109.4714	C9—C14—H14	119.9259
O1—C7—H7c	109.4714	C13—C14—H14	119.925
C2—C3—O1—C7	13.8 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O2^i	0.96	2.31	3.247 (3)	165
C14—H14···O2^ii	0.96	2.40	3.325 (3)	163
O2—H2o···N1^iii	0.85 (2)	1.98 (2)	2.787 (2)	158 (3)

Symmetry codes: (i) −x+2, y−1/2, −z+1/2; (ii) −x+1, y−1/2, −z+1/2; (iii) −x+2, y+1/2, −z+1/2.