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

In the title compound, C₁₃H₉BrClNO, the dihedral angle between the substituted benzene rings is 44.25 (11)°. There are strong intra­molecular O—H...N hydrogen bonds, which generate S(6) rings, and also inter­molecular Cl...Cl [3.431 (3) Å] and Br... Br [3.846 (1) Å] contacts. The crystal packing a C—H...O and C—H...π inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.054
• wR factor = 0.128
• Data-to-parameter ratio = 19.4

checkCIF/PLATON results

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Datablock: I


Alert level B
PLAT934_ALERT_3_B Number of (Iobs-Icalc)/SigmaW > 10 Outliers ....          2 Check

Alert level C
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds ...............     0.0061 Ang.
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      5.643 Check
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1

Alert level G
PLAT007_ALERT_5_G Number of Unrefined Donor-H Atoms ..............          1 Why ?
PLAT083_ALERT_2_G SHELXL Second Parameter in WGHT Unusually Large.       7.49
PLAT910_ALERT_3_G Missing # of FCF Reflections Below Th(Min) .....          2 Why ?
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         10

   0 ALERT level A = Most likely a serious problem - resolve or explain
   1 ALERT level B = A potentially serious problem, consider carefully
   3 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 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
   5 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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S1. Comment

Schiff bases are condensed by primary amines and carbonyl compounds, containing strong electronegative with atoms O and N, thus it is easy to coordinate with the metal ions to form stable complexes (Akmal et al., 2007; Rehmana et al., 2008). It is reported that metal complexes of Schiff base derivatives have a variety of important biological activities, such as anti-bacterial, anti-cancer, anti-tumor, hypoglycemic and so on (Vanco et al., 2008; Li et al., 2007; Ritter et al., 2009). Our reports indicated that copper and vanadium complexes of Schiff bases are potential inhitors over protein tyrosine phosphatases (Li et al., 2011; Lu et al., 2011; Ma et al., 2011; Yuan et al., 2009, 2010).

We report here the synthesis and characterization a potentially bidentate Schiff base derivative, (I), and prepared from the condensation reaction of an equimolar proportion of 5-chloro-salicylaldehyde and 4-bromo-aniline in absolute ethanol. The molecular structure is depicted in Fig. 1. X-ray structural analysis confirmed that in the title compound, (I), the dihedral angle between the substituted benzene rings is nearly 44.25 (11)°, similar to the compound 4-bromo-2-[(E)-(4-chlorophenyl)iminomethyl]phenol (Ardakani et al., 2011). In the crystal, there are strong intramolecular O—H···N hydrogen bonds with a distance of 2.593 (5) Å between donor and acceptor, which generate S(6) ring and intermolecular Cl1···Cl1ⁱ [3.430 (2) Å, i -x, -y, -z] as well as Br1···Br1ⁱⁱ [3.846 (1) Å, ii 2 - x, -y, -z] contacts. The crystal packing is further stabilized by intermolecular C—H···O and C—H···π interactions (Table 1).

Related literature

For background to the biological activity of Schiff bases, see: Akmal et al. (2007); Li et al. (2007, 2011); Lu et al. (2011); Ma et al. (2011); Rehmana et al. (2008); Ritter et al. (2009); Vanco et al. (2008); Yuan et al. (2009, 2010). For related structures, see: Ardakani et al. (2011). For hydrogen-bond motifs, see: Bernstein et al. (1995).

S2. Experimental

A 0.1566 g (1.0 mmol) 5-chloro-salicylaldehyde in 15 ml of absolute ethanol was heated until thoroughly dissolved and 0.1720 g (1.0 mmol) of 4-bromo-aniline in 5 ml of absolute ethanol was added dropwise with a constant stirring. The reaction mixture was heated under refluxing for 3 h. After cooling slowly, the orange powder was separated out. Orange–red crystal was obtained from filter after two weeks.

S3. Refinement

H atoms attached to C and O of (I) were placed in geometrically idealized positions with Csp²—H = 0.93 Å and O—H = 0.84 Å and constrained to refine with U_iso(H) = 1.2U_eq(C) and U_iso(H) = 1.5U_eq(O).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. A view of the structure of (I), with displacement ellipsoids drawn at the 30% probability level. Dashed line indicates hydrogen-bonding interaction.
	Fig. 2. The packing diagram of the title compound, showing the intermolecular O—H···N and intermolecular Cl···Cl, Br···Br and C—H···O interactions (dotted lines).

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

Crystal data

C13H9BrClNO	F(000) = 1232
Mr = 310.57	Dx = 1.720 Mg m^−3
Orthorhombic, Pccn	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ab 2ac	Cell parameters from 4170 reflections
a = 6.9964 (15) Å	θ = 2.2–22.6°
b = 55.786 (12) Å	µ = 3.63 mm^−1
c = 6.1443 (14) Å	T = 298 K
V = 2398.1 (9) Å^3	Block, colourless
Z = 8	0.30 × 0.25 × 0.20 mm

Data collection

Bruker SMART 1K CCD area-detector diffractometer	3013 independent reflections
Radiation source: fine-focus sealed tube	2056 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.061
ω scans	θmax = 28.4°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2000)	h = −9→9
Tmin = 0.409, Tmax = 0.530	k = −74→74
30095 measured reflections	l = −8→8

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.054	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.128	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.027P)^2 + 7.4937P] where P = (Fo^2 + 2Fc^2)/3
3013 reflections	(Δ/σ)max = 0.001
155 parameters	Δρmax = 0.42 e Å^−3
0 restraints	Δρmin = −0.95 e Å^−3

Special details

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

	x	y	z	Uiso*/Ueq
Br1	−0.03618 (9)	0.228348 (8)	−0.07815 (11)	0.0634 (2)
C1	−0.0360 (6)	0.08714 (7)	0.5859 (7)	0.0339 (8)
C2	−0.0711 (6)	0.06455 (8)	0.6715 (7)	0.0404 (10)
H2	−0.1186	0.0631	0.8123	0.049*
C3	−0.0364 (6)	0.04435 (7)	0.5506 (8)	0.0426 (11)
H3	−0.0609	0.0293	0.6092	0.051*
C4	0.0346 (6)	0.04637 (7)	0.3425 (7)	0.0372 (10)
C5	0.0691 (6)	0.06843 (7)	0.2537 (7)	0.0333 (9)
H5	0.1169	0.0695	0.1129	0.040*
C6	0.0332 (6)	0.08932 (7)	0.3722 (6)	0.0306 (8)
C7	0.0538 (6)	0.11247 (7)	0.2675 (7)	0.0335 (9)
H7	0.0897	0.1132	0.1219	0.040*
C8	0.0157 (5)	0.15412 (7)	0.2599 (7)	0.0304 (8)
C9	−0.0626 (6)	0.15603 (7)	0.0518 (7)	0.0335 (9)
H9	−0.1044	0.1424	−0.0209	0.040*
C10	−0.0780 (6)	0.17821 (7)	−0.0459 (7)	0.0359 (9)
H10	−0.1315	0.1795	−0.1839	0.043*
C11	−0.0140 (6)	0.19838 (7)	0.0610 (8)	0.0392 (10)
C12	0.0610 (6)	0.19682 (7)	0.2681 (8)	0.0401 (10)
H12	0.1013	0.2106	0.3402	0.048*
C13	0.0759 (6)	0.17470 (7)	0.3676 (7)	0.0352 (9)
H13	0.1265	0.1736	0.5072	0.042*
Cl1	0.0736 (2)	0.02081 (2)	0.1879 (2)	0.0614 (4)
N1	0.0235 (5)	0.13186 (6)	0.3721 (5)	0.0322 (7)
O1	−0.0721 (5)	0.10666 (5)	0.7096 (5)	0.0474 (8)
H1	−0.0470	0.1188	0.6401	0.071*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0722 (4)	0.0352 (2)	0.0829 (4)	0.0069 (2)	−0.0019 (3)	0.0149 (3)
C1	0.035 (2)	0.038 (2)	0.029 (2)	−0.0004 (18)	−0.0007 (18)	−0.0038 (17)
C2	0.036 (2)	0.053 (3)	0.032 (2)	−0.004 (2)	0.002 (2)	0.007 (2)
C3	0.046 (2)	0.034 (2)	0.048 (3)	−0.0034 (19)	0.000 (2)	0.0120 (19)
C4	0.039 (2)	0.0318 (19)	0.041 (2)	0.0016 (18)	−0.001 (2)	−0.0023 (17)
C5	0.037 (2)	0.0304 (19)	0.032 (2)	0.0017 (17)	0.0008 (19)	−0.0019 (16)
C6	0.030 (2)	0.0345 (19)	0.028 (2)	0.0024 (17)	−0.0034 (17)	0.0023 (15)
C7	0.034 (2)	0.038 (2)	0.029 (2)	0.0013 (17)	0.0027 (19)	0.0018 (17)
C8	0.029 (2)	0.0299 (18)	0.032 (2)	0.0004 (15)	0.0030 (17)	−0.0019 (16)
C9	0.039 (2)	0.0289 (18)	0.033 (2)	−0.0029 (17)	−0.0012 (19)	−0.0041 (16)
C10	0.033 (2)	0.038 (2)	0.037 (2)	0.0031 (17)	0.0000 (19)	−0.0019 (18)
C11	0.036 (2)	0.0315 (19)	0.050 (3)	0.0041 (17)	0.006 (2)	0.0035 (19)
C12	0.042 (2)	0.0299 (19)	0.048 (3)	−0.0017 (18)	−0.003 (2)	−0.0077 (18)
C13	0.033 (2)	0.037 (2)	0.036 (2)	−0.0005 (17)	−0.0029 (18)	−0.0080 (17)
Cl1	0.0858 (10)	0.0333 (5)	0.0652 (8)	−0.0007 (6)	0.0074 (8)	−0.0081 (6)
N1	0.0343 (18)	0.0305 (15)	0.0318 (18)	−0.0003 (14)	−0.0008 (15)	−0.0009 (14)
O1	0.069 (2)	0.0394 (16)	0.0342 (17)	0.0003 (16)	0.0096 (17)	−0.0042 (13)

Geometric parameters (Å, º)

Br1—C11	1.884 (4)	C7—H7	0.9300
C1—O1	1.352 (5)	C8—C13	1.390 (5)
C1—C2	1.387 (6)	C8—C9	1.395 (6)
C1—C6	1.405 (6)	C8—N1	1.422 (5)
C2—C3	1.371 (6)	C9—C10	1.379 (5)
C2—H2	0.9300	C9—H9	0.9300
C3—C4	1.377 (6)	C10—C11	1.378 (6)
C3—H3	0.9300	C10—H10	0.9300
C4—C5	1.367 (6)	C11—C12	1.379 (7)
C4—Cl1	1.735 (4)	C12—C13	1.381 (6)
C5—C6	1.397 (5)	C12—H12	0.9300
C5—H5	0.9300	C13—H13	0.9300
C6—C7	1.450 (5)	O1—H1	0.8200
C7—N1	1.276 (5)
O1—C1—C2	119.1 (4)	C13—C8—C9	119.5 (4)
O1—C1—C6	121.3 (4)	C13—C8—N1	118.6 (4)
C2—C1—C6	119.6 (4)	C9—C8—N1	121.7 (3)
C3—C2—C1	120.6 (4)	C10—C9—C8	119.8 (4)
C3—C2—H2	119.7	C10—C9—H9	120.1
C1—C2—H2	119.7	C8—C9—H9	120.1
C2—C3—C4	120.0 (4)	C11—C10—C9	120.0 (4)
C2—C3—H3	120.0	C11—C10—H10	120.0
C4—C3—H3	120.0	C9—C10—H10	120.0
C5—C4—C3	120.5 (4)	C10—C11—C12	120.8 (4)
C5—C4—Cl1	119.6 (3)	C10—C11—Br1	118.8 (3)
C3—C4—Cl1	119.9 (3)	C12—C11—Br1	120.4 (3)
C4—C5—C6	120.8 (4)	C11—C12—C13	119.6 (4)
C4—C5—H5	119.6	C11—C12—H12	120.2
C6—C5—H5	119.6	C13—C12—H12	120.2
C5—C6—C1	118.5 (4)	C12—C13—C8	120.3 (4)
C5—C6—C7	119.6 (4)	C12—C13—H13	119.9
C1—C6—C7	121.7 (4)	C8—C13—H13	119.9
N1—C7—C6	121.0 (4)	C7—N1—C8	120.2 (3)
N1—C7—H7	119.5	C1—O1—H1	109.5
C6—C7—H7	119.5
O1—C1—C2—C3	179.9 (4)	C1—C6—C7—N1	5.4 (6)
C6—C1—C2—C3	0.9 (6)	C13—C8—C9—C10	0.6 (6)
C1—C2—C3—C4	0.3 (7)	N1—C8—C9—C10	176.0 (4)
C2—C3—C4—C5	−0.8 (7)	C8—C9—C10—C11	0.7 (6)
C2—C3—C4—Cl1	−178.6 (4)	C9—C10—C11—C12	−1.8 (6)
C3—C4—C5—C6	0.1 (6)	C9—C10—C11—Br1	179.7 (3)
Cl1—C4—C5—C6	178.0 (3)	C10—C11—C12—C13	1.4 (7)
C4—C5—C6—C1	1.1 (6)	Br1—C11—C12—C13	179.9 (3)
C4—C5—C6—C7	−174.2 (4)	C11—C12—C13—C8	0.0 (6)
O1—C1—C6—C5	179.5 (4)	C9—C8—C13—C12	−1.0 (6)
C2—C1—C6—C5	−1.6 (6)	N1—C8—C13—C12	−176.6 (4)
O1—C1—C6—C7	−5.3 (6)	C6—C7—N1—C8	−170.4 (3)
C2—C1—C6—C7	173.6 (4)	C13—C8—N1—C7	−148.7 (4)
C5—C6—C7—N1	−179.4 (4)	C9—C8—N1—C7	35.8 (6)

Hydrogen-bond geometry (Å, º)

Cg1 and Cg2 are the centroids of the C1–C6 and C8–C13 benzene rings, respectively.

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1	0.82	1.87	2.593 (4)	147
C2—H2···Cg1^i	0.93	2.82	3.489 (5)	129
C5—H5···Cg1^ii	0.93	2.85	3.513 (5)	129
C10—H10···Cg2^iii	0.93	2.75	3.460 (5)	133
C13—H13···Cg2^iv	0.93	2.78	3.473 (5)	132

Symmetry codes: (i) −x+1/2, y, z−1/2; (ii) −x+3/2, y, z−3/2; (iii) −x+1/2, y, z−3/2; (iv) −x+3/2, y, z−1/2.