2-Chloro-(3-methoxy­salicyl­idene)­aniline

An almost planar conformation exhibited by the title mol­ecule, C₁₄H₁₂ClNO₂, is stabilized by an intramolecular O—H...N hydrogen bond, which forms a ring of graph-set motif S(6). In the crystal structure, π–π and C—H...π interactions involving both the aromatic rings form two-dimensional networks.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.050
• wR factor = 0.144
• Data-to-parameter ratio = 7.5

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level A:



ABSTM_02  Alert A The ratio of Tmax/Tmin expected RT(exp) is > 1.30
          An absorption correction should be applied.
          Tmin and Tmax expected:      0.267     0.586
          RT(exp) =      2.200

General Notes



REFLT_03
         From the CIF: _diffrn_reflns_theta_max           69.91
         From the CIF: _reflns_number_total               1220
         Count of symmetry unique reflns         1231
         Completeness (_total/calc)             99.11%
         TEST3: Check Friedels for noncentro structure
         Estimate of Friedel pairs measured         0
         Fraction of Friedel pairs measured     0.000
         Are heavy atom types Z>Si present          yes
          WARNING: Large fraction of Friedel related reflns may
                   be needed to determine absolute structure


 1 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 0 Alert Level C = Please check

---

S1. Comment

The title compound, (I), was obtained by condensing o-vanillin with o-chloroaniline. Vanillin occurs naturally in vanilla, in potato parings, in siam benzoin, etc. Vanillin is used as a flavoring agent in confectionary, beverages,foods, etc. and as a reagent in analytical chemistry. Vanillin is of current interest due to its non-linear optical properties (Singh et al., 1991). The crystal structures of vanillin-I (Velavan et al., 1995), the polymorphic forms of isovanillin (Iwasaki, 1973), o-vanillin (Iwasaki et al., 1976) and the vanillin derivatives (Usman et al., 2002; Li et al., 1999) have been reported. A study on the condensation of aniline and its derivatives with salicylaldehyde has been reported (Khera et al., 1983). The Schiff base ligands of o-vanillin derivatives with aniline and o-, m- and p-toluidine have also been reported (Viswanathamuthy et al., 2000). In order to gain more structural information on these systems, compound (I) was investigated.

The title molecule (Fig. 1) is slightly distorted from a planar arrangement. The dihedral angle between the two aromatic rings is 7.8 (2)° and the torsion angle C6—N1—C7—C8 is −179.1 (3)°. The almost planar conformation exhibited by the molecule is stabilized by an intramolecular O2—H2···N1 hydrogen bond, which forms a ring of graph-set motif S(6). The methoxy group is coplanar with the attached benzene ring. The bond distances observed in the molecule (Table 1) are comparable with those reported for related structures (Usman et al., 2002; Sethuraman & Muthiah, 2002). In the crystal, the molecules translated by one unit along the a axis are arranged such that the two phenyl rings are stacked with a centroid-to-centroid distance of 3.724 (3) Å, indicating weak π–π interactions. The adjacent symmetry-related stackings are linked by C—H···π interactions (Desiraju, 2002), involving the two phenyl rings (Table 2), to form two-dimensional networks (Fig. 2).

S2. Experimental

Methanol solutions of o-vanillin (152 mg, Merck) and o-chloroaniline (127 mg, Merck) were mixed in 1:1 molar ratio and refluxed for 1 h, yielding the title compound. Recrystallization from methanol gave orange plate-like crystals suitable for X-ray study.

S3. Refinement

H atoms were treated as riding atoms, with C—H distances in the range 0.93–0.96 Å and O—H distance of 0.82 Å. As the intensities of Friedel opposites were not measured, the absolute configuration could not be established. Since the crystal belongs to a non-centrosymmetric space group and intensities for Friedel opposites were not measured, the r/p ratio (7.48) is poor. The ratio of T_max/T_min expected is 2.2. But we were unable to apply absorption correction, as the ψ scan data were not collected.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: MolEN (Fair, 1990); data reduction: MolEN; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 1997); software used to prepare material for publication: PLATON.

Figures

	Fig. 1. The structure of the title compound, showing 50% probability displacement ellipsoids and the intramolecular hydrogen bond.
	Fig. 2. The molecular packing in the unit cell, viewed down the b axis.

3-methoxysalicylidene-2-chloroaniline

Crystal data

C14H12ClNO2	Dx = 1.399 Mg m^−3
Mr = 261.70	Melting point: 108 K
Orthorhombic, Pn21a	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: P -2ac -2n	Cell parameters from 25 reflections
a = 6.409 (1) Å	θ = 4.5–69.9°
b = 13.062 (1) Å	µ = 2.67 mm^−1
c = 14.842 (1) Å	T = 293 K
V = 1242.5 (2) Å^3	Plate, orange
Z = 4	0.6 × 0.6 × 0.2 mm
F(000) = 544

Data collection

Enraf-Nonius CAD-4 four-circle diffractometer	Rint = 0.000
Radiation source: fine-focus sealed tube	θmax = 69.9°, θmin = 4.5°
Graphite monochromator	h = 0→7
ω–2θ scans	k = 0→15
1220 measured reflections	l = 0→18
1220 independent reflections	1 standard reflections every 100 reflections
1136 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.144	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.1185P)^2 + 0.0697P] where P = (Fo^2 + 2Fc^2)/3
1220 reflections	(Δ/σ)max < 0.001
163 parameters	Δρmax = 0.64 e Å^−3
1 restraint	Δρmin = −0.32 e Å^−3
0 constraints

Special details

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All e.s.d.'s are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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

	x	y	z	Uiso*/Ueq
Cl1	1.0284 (2)	0.01223 (10)	−0.11971 (7)	0.0696 (4)
O1	0.2849 (5)	0.0199 (3)	0.1305 (2)	0.0642 (10)
O2	0.6194 (4)	0.0583 (2)	0.0390 (2)	0.0598 (9)
N1	0.8944 (4)	0.1886 (3)	−0.01662 (19)	0.0464 (8)
C1	1.1601 (6)	0.1279 (3)	−0.1171 (3)	0.0507 (11)
C2	1.3403 (7)	0.1381 (4)	−0.1665 (3)	0.0613 (12)
C3	1.4420 (7)	0.2319 (4)	−0.1664 (3)	0.0643 (14)
C4	1.3658 (7)	0.3113 (4)	−0.1168 (3)	0.0563 (11)
C5	1.1858 (6)	0.3002 (3)	−0.0670 (3)	0.0539 (11)
C6	1.0773 (5)	0.2076 (3)	−0.0667 (2)	0.0443 (9)
C7	0.7918 (6)	0.2599 (3)	0.0219 (3)	0.0508 (11)
C8	0.6053 (6)	0.2372 (3)	0.0741 (2)	0.0502 (11)
C9	0.5288 (6)	0.1382 (3)	0.0795 (3)	0.0473 (10)
C10	0.3454 (6)	0.1186 (3)	0.1296 (3)	0.0512 (10)
C11	0.2485 (6)	0.1996 (4)	0.1735 (3)	0.0566 (11)
C12	0.3271 (7)	0.2987 (4)	0.1680 (3)	0.0640 (14)
C13	0.5035 (6)	0.3190 (4)	0.1185 (3)	0.0583 (14)
C14	0.1065 (7)	−0.0049 (5)	0.1839 (3)	0.0747 (18)
H2	0.72337	0.07768	0.01172	0.0897*
H3	1.56280	0.24056	−0.20024	0.0770*
H4	1.43589	0.37368	−0.11666	0.0677*
H5	1.13616	0.35506	−0.03320	0.0648*
H7	0.83683	0.32728	0.01651	0.0610*
H11	0.12884	0.18728	0.20724	0.0682*
H12	0.25960	0.35170	0.19801	0.0769*
H13	0.55507	0.38542	0.11425	0.0698*
H14A	0.07878	−0.07697	0.17971	0.1120*
H14B	−0.01219	0.03264	0.16235	0.1120*
H14C	0.13288	0.01303	0.24564	0.1120*
H20	1.39290	0.08324	−0.19935	0.0736*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0814 (7)	0.0484 (5)	0.0790 (7)	−0.0009 (6)	0.0116 (5)	−0.0022 (5)
O1	0.0519 (15)	0.0662 (19)	0.0745 (16)	−0.0049 (16)	0.0134 (12)	0.0017 (14)
O2	0.0510 (15)	0.0507 (15)	0.0777 (16)	0.0006 (13)	0.0191 (14)	−0.0009 (14)
N1	0.0373 (12)	0.0506 (15)	0.0514 (14)	0.0041 (13)	0.0013 (11)	0.0023 (13)
C1	0.0490 (19)	0.049 (2)	0.054 (2)	0.0037 (17)	−0.0002 (14)	0.0020 (15)
C2	0.060 (2)	0.064 (2)	0.060 (2)	0.012 (2)	0.0118 (18)	−0.0014 (19)
C3	0.047 (2)	0.082 (3)	0.064 (2)	0.001 (2)	0.0078 (17)	0.005 (2)
C4	0.0460 (19)	0.060 (2)	0.063 (2)	−0.0080 (18)	0.0012 (15)	0.0073 (17)
C5	0.0476 (19)	0.056 (2)	0.058 (2)	0.0028 (16)	0.0008 (15)	−0.0001 (17)
C6	0.0370 (14)	0.0514 (19)	0.0445 (15)	0.0060 (15)	−0.0033 (13)	0.0070 (14)
C7	0.0485 (18)	0.0465 (19)	0.0574 (19)	0.0006 (16)	0.0011 (15)	0.0014 (16)
C8	0.0433 (18)	0.055 (2)	0.0522 (18)	0.0084 (15)	−0.0012 (15)	−0.0020 (16)
C9	0.0419 (16)	0.053 (2)	0.0471 (17)	0.0077 (16)	−0.0047 (14)	0.0051 (15)
C10	0.0387 (16)	0.062 (2)	0.0528 (18)	0.0033 (17)	−0.0019 (13)	0.0039 (15)
C11	0.0447 (18)	0.072 (2)	0.053 (2)	0.0089 (19)	0.0074 (15)	0.001 (2)
C12	0.057 (2)	0.070 (3)	0.065 (2)	0.022 (2)	0.0065 (17)	−0.005 (2)
C13	0.053 (2)	0.055 (2)	0.067 (3)	0.0053 (18)	0.0019 (16)	−0.0039 (18)
C14	0.045 (2)	0.095 (4)	0.084 (3)	−0.018 (2)	0.014 (2)	0.004 (3)

Geometric parameters (Å, º)

Cl1—C1	1.731 (4)	C9—C10	1.414 (6)
O1—C10	1.346 (6)	C10—C11	1.389 (6)
O1—C14	1.428 (6)	C11—C12	1.391 (7)
O2—C9	1.337 (5)	C12—C13	1.374 (6)
O2—H2	0.82	C2—H20	0.93
N1—C7	1.275 (5)	C3—H3	0.93
N1—C6	1.410 (4)	C4—H4	0.93
C1—C6	1.387 (5)	C5—H5	0.93
C1—C2	1.374 (6)	C7—H7	0.93
C2—C3	1.388 (7)	C11—H11	0.93
C3—C4	1.362 (7)	C12—H12	0.93
C4—C5	1.378 (6)	C13—H13	0.93
C5—C6	1.395 (5)	C14—H14A	0.96
C7—C8	1.455 (5)	C14—H14B	0.96
C8—C13	1.415 (6)	C14—H14C	0.96
C8—C9	1.385 (6)
Cl1···N1	2.896 (4)	C11···H11^iv	3.0168
Cl1···H2	2.8910	C11···H14C	2.7630
Cl1···H7^i	2.9880	C12···H11^iv	3.0474
Cl1···H12^ii	3.0256	C14···H11	2.5381
Cl1···H13^i	3.1427	H2···Cl1	2.8910
Cl1···H20^iii	2.9709	H2···N1	1.8648
O1···O2	2.587 (4)	H2···C6	3.0627
O2···N1	2.585 (4)	H2···C7	2.4249
O2···O1	2.587 (4)	H3···C2^viii	2.9776
O1···H14C^iv	2.8916	H4···O1^ix	2.6253
O1···H4^i	2.6253	H4···O2^ix	2.6962
O2···H4^i	2.6962	H5···C7	2.6617
N1···Cl1	2.896 (4)	H5···H7	2.0872
N1···O2	2.585 (4)	H7···C5	2.5814
N1···H2	1.8648	H7···H5	2.0872
C4···C7^v	3.485 (6)	H7···H13	2.4376
C4···C8^v	3.365 (6)	H7···Cl1^ix	2.9880
C5···C8^v	3.506 (5)	H11···C14	2.5381
C5···C13^v	3.433 (6)	H11···H14B	2.3110
C6···C10^v	3.577 (5)	H11···H14C	2.3465
C7···C4^vi	3.485 (6)	H11···C11^x	3.0168
C8···C4^vi	3.365 (6)	H11···C12^x	3.0474
C8···C5^vi	3.506 (5)	H12···Cl1^vii	3.0256
C10···C6^vi	3.577 (5)	H13···H7	2.4376
C13···C5^vi	3.433 (6)	H13···Cl1^ix	3.1427
C2···H3^iii	2.9776	H14A···C5^ii	2.8719
C5···H14A^vii	2.8719	H14B···C11	2.7522
C5···H7	2.5814	H14B···H11	2.3110
C6···H2	3.0627	H14C···C11	2.7630
C7···H2	2.4249	H14C···H11	2.3465
C7···H5	2.6617	H14C···O1^x	2.8916
C10···H14C^iv	2.9538	H14C···C10^x	2.9538
C11···H14B	2.7522	H20···Cl1^viii	2.9709
C10—O1—C14	116.9 (4)	C11—C12—C13	120.6 (4)
C9—O2—H2	109.51	C8—C13—C12	118.9 (4)
C6—N1—C7	122.4 (4)	C1—C2—H20	120.64
Cl1—C1—C2	118.8 (3)	C3—C2—H20	120.70
C2—C1—C6	122.4 (4)	C2—C3—H3	119.86
Cl1—C1—C6	118.7 (3)	C4—C3—H3	119.85
C1—C2—C3	118.7 (4)	C3—C4—H4	119.66
C2—C3—C4	120.3 (4)	C5—C4—H4	119.68
C3—C4—C5	120.7 (4)	C4—C5—H5	119.63
C4—C5—C6	120.7 (4)	C6—C5—H5	119.69
N1—C6—C1	118.0 (3)	N1—C7—H7	119.52
C1—C6—C5	117.3 (3)	C8—C7—H7	119.59
N1—C6—C5	124.7 (3)	C10—C11—H11	119.31
N1—C7—C8	120.9 (4)	C12—C11—H11	119.42
C7—C8—C9	120.8 (3)	C11—C12—H12	119.74
C7—C8—C13	118.2 (4)	C13—C12—H12	119.68
C9—C8—C13	121.0 (4)	C8—C13—H13	120.58
O2—C9—C8	123.3 (4)	C12—C13—H13	120.56
O2—C9—C10	117.1 (3)	O1—C14—H14A	109.55
C8—C9—C10	119.6 (4)	O1—C14—H14B	109.49
O1—C10—C11	126.6 (4)	O1—C14—H14C	109.45
C9—C10—C11	118.7 (4)	H14A—C14—H14B	109.43
O1—C10—C9	114.7 (4)	H14A—C14—H14C	109.47
C10—C11—C12	121.3 (4)	H14B—C14—H14C	109.43
C14—O1—C10—C9	176.9 (4)	N1—C7—C8—C9	−3.2 (6)
C14—O1—C10—C11	−1.9 (6)	N1—C7—C8—C13	177.3 (4)
C7—N1—C6—C1	−170.5 (4)	C9—C8—C13—C12	0.5 (6)
C6—N1—C7—C8	−179.1 (3)	C7—C8—C13—C12	180.0 (4)
C7—N1—C6—C5	11.8 (5)	C7—C8—C9—O2	0.7 (6)
Cl1—C1—C2—C3	178.1 (3)	C7—C8—C9—C10	−179.0 (4)
Cl1—C1—C6—C5	−179.2 (3)	C13—C8—C9—O2	−179.8 (4)
C2—C1—C6—N1	−178.5 (4)	C13—C8—C9—C10	0.4 (6)
C2—C1—C6—C5	−0.6 (6)	O2—C9—C10—O1	0.3 (6)
C6—C1—C2—C3	−0.5 (7)	C8—C9—C10—C11	−1.1 (6)
Cl1—C1—C6—N1	2.9 (5)	O2—C9—C10—C11	179.2 (4)
C1—C2—C3—C4	1.2 (7)	C8—C9—C10—O1	−179.9 (4)
C2—C3—C4—C5	−0.8 (7)	C9—C10—C11—C12	0.8 (6)
C3—C4—C5—C6	−0.3 (7)	O1—C10—C11—C12	179.5 (4)
C4—C5—C6—C1	1.0 (6)	C10—C11—C12—C13	0.1 (7)
C4—C5—C6—N1	178.8 (4)	C11—C12—C13—C8	−0.8 (6)

Symmetry codes: (i) −x+2, y−1/2, −z; (ii) −x+1, y−1/2, −z; (iii) x−1/2, y, −z−1/2; (iv) x+1/2, y, −z+1/2; (v) x+1, y, z; (vi) x−1, y, z; (vii) −x+1, y+1/2, −z; (viii) x+1/2, y, −z−1/2; (ix) −x+2, y+1/2, −z; (x) x−1/2, y, −z+1/2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N1	0.82	1.86	2.585 (4)	146
C3—H3···Cg1^viii	0.93	3.01	3.819 (5)	146
C11—H11···Cg2^x	0.93	2.85	3.656 (5)	145

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