3-Meth­oxy-N-[2-(methyl­sulfan­yl)phenyl]salicylaldimine

The molecule of the title compound, C₁₅H₁₅NO₂S, is nearly planar, with a dihedral angle of 6.78 (7)° between the benzene rings. The planarity of the mol­ecule is promoted by an intra­molecular O—H...N hydrogen bond.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.030
• wR factor = 0.079
• Data-to-parameter ratio = 22.2

checkCIF/PLATON results

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Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           30.50
           From the CIF: _reflns_number_total               3900
           Count of symmetry unique reflns         2069
           Completeness (_total/calc)            188.50%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1831
           Fraction of Friedel pairs measured     0.885
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   0 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

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

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S1. Comment

Schiff base ligands are common in coordination chemistry (Che & Huang, 2003). Our group is interested in the sythesis and coordination chemistry of novel sulfur-containing mixed-donor ligands (Hamaker & Halbach, 2005). As part of these ongoing studies, we report here the synthesis and molecular structure of the title compound, (I).

The molecule of compound (I) (Fig. 1) is nearly planar, with a dihedral angle between the two aromatic rings of 6.78 (7)° and a C21—C20—N—C16 torsion angle of 179.07 (11)°. The planarity of (I) is stabilized by an intramolecular O2—H2···N hydrogen bond (Table 2). The bond lengths and angles (Table 1) are similar to those of related Schiff base compounds (Singh et al., 2003; Yeap et al., 2003; Francis et al., 2003).

S2. Experimental

To a solution of 2-(methylthio)aniline (2.778 g, 19.95 mmol) in absolute ethanol (50 ml) in a 100 ml round-bottomed flask equipped with a reflux condensor, o-vanillin was added (3.061 g, 20.12 mmol). The mixture was heated to reflux for 1.5 h, cooled to room temperature and placed in a freezer at 233 K for 14 h. The reaction was filtered, washed with cold ethanol and dried in vacuo to yield 4.700 g (86%) of the title compound as an orange solid. Crystals of (I) were grown by slow evaporation of an ethanol solution (m.p. 384–386 K). Spectroscopic analysis: ¹H NMR (CDCl₃, 400 MHz, δ, p.p.m.): 13.35 (s, 1H, OH), 8.65 (s, 1H, N═CH), 7.27 (m, 2H, arom), 7.21 (m, 2H, arom), 7.05 (dd, 1H, arom), 7.01 (dd, 1H, arom), 6.89 (t, 1H, arom), 3.90 (s, 3H, OCH₃), 2.48 (s, 3H, SCH₃); ¹³C NMR (CDCl₃, 400 MHz, δ, p.p.m.): 162.4, 151.9, 149.0, 145.6, 135.5, 128.0, 125.8, 125.6, 124.4, 119.8, 119.0, 117.6, 115.9, 56.7, 15.3; IR (Medium?, ν, cm⁻¹): 1610 (C═ N); UV–vis (CH₂Cl₂): λ_max (ε) 361 nm (8230 M⁻¹ cm⁻¹), 273 nm (19,100 M⁻¹ cm⁻¹). Analysis calculated (found) for C₁₅H₁₅NO₂S: C 65.91 (65.76), H 5.53 (5.46), N 5.12 (5.17)%.

S3. Refinement

The H atom of the hydroxyl group was found in a difference Fourier map and refined isotropically. The other H atoms were treated as riding atoms, with C—H distances of 0.95 Å (aromatic) or 0.98 Å (aliphatic), and with U_iso(H) = 1.2U_eq(C) for the aromatic and CH₂ H atoms or 1.5U_eq(C) for the CH₃ H atoms.

Computing details

Data collection: SMART (Bruker, 2002); cell refinement: SAINT-Plus (Bruker, 2003); data reduction: SAINT-Plus; program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

Fig. 1. A view of (I), showing the atom-numbering scheme and with 50% probability displacement ellipsoids.

3-Methoxy-N-[2-(methylsulfanyl)phenyl]salicylaldimine

Crystal data

C15H15NO2S	F(000) = 576
Mr = 273.34	Dx = 1.391 Mg m^−3
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 7027 reflections
a = 6.5559 (4) Å	θ = 3.0–30.5°
b = 13.7147 (7) Å	µ = 0.25 mm^−1
c = 14.5200 (8) Å	T = 100 K
V = 1305.53 (13) Å^3	Block, orange-yellow
Z = 4	0.59 × 0.33 × 0.32 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer	3900 independent reflections
Radiation source: fine-focus sealed tube	3875 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
ϕ and ω scans	θmax = 30.5°, θmin = 1.5°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −9→9
Tmin = 0.841, Tmax = 0.930	k = −19→19
14274 measured reflections	l = −20→20

Refinement

Refinement on F^2	H atoms treated by a mixture of independent and constrained refinement
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0364P)^2 + 0.4174P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.030	(Δ/σ)max < 0.001
wR(F^2) = 0.079	Δρmax = 0.30 e Å^−3
S = 1.13	Δρmin = −0.22 e Å^−3
3900 reflections	Absolute structure: Flack (1983), with 1831 Friedel pairs
176 parameters	Absolute structure parameter: 0.06 (5)
1 restraint

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.

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

	x	y	z	Uiso*/Ueq
C1	1.0270 (2)	0.90390 (13)	0.58287 (11)	0.0293 (3)
H1A	0.9965	0.9038	0.6489	0.044*
H1B	1.0581	0.9705	0.5629	0.044*
H1C	1.1449	0.8618	0.5709	0.044*
C11	0.8955 (2)	0.86534 (9)	0.40546 (9)	0.0157 (2)
C12	1.06672 (19)	0.91808 (9)	0.37733 (9)	0.0184 (2)
H12	1.1441	0.9537	0.4213	0.022*
C13	1.1243 (2)	0.91865 (10)	0.28521 (10)	0.0204 (2)
H13	1.2398	0.9553	0.2663	0.024*
C14	1.0131 (2)	0.86557 (10)	0.22048 (10)	0.0207 (3)
H14	1.0544	0.8649	0.1578	0.025*
C15	0.8418 (2)	0.81371 (9)	0.24793 (9)	0.0183 (2)
H15	0.7669	0.7772	0.2038	0.022*
C16	0.77864 (18)	0.81464 (9)	0.33978 (8)	0.0154 (2)
C20	0.46858 (19)	0.72829 (9)	0.32072 (9)	0.0163 (2)
H20	0.4825	0.7356	0.256	0.02*
C21	0.29351 (18)	0.67619 (9)	0.35701 (9)	0.0160 (2)
C22	0.2565 (2)	0.67077 (9)	0.45218 (9)	0.0162 (2)
C23	0.0801 (2)	0.62239 (10)	0.48438 (10)	0.0177 (2)
C24	−0.0506 (2)	0.57793 (10)	0.42205 (10)	0.0194 (3)
H24	−0.1682	0.5446	0.4438	0.023*
C25	−0.0107 (2)	0.58169 (10)	0.32718 (10)	0.0208 (2)
H25	−0.1001	0.5501	0.2852	0.025*
C26	0.1581 (2)	0.63112 (9)	0.29469 (10)	0.0184 (2)
H26	0.183	0.6348	0.2303	0.022*
C30	−0.1198 (2)	0.57256 (12)	0.61210 (11)	0.0278 (3)
H30A	−0.1218	0.5764	0.6795	0.042*
H30B	−0.1154	0.504	0.5931	0.042*
H30C	−0.2431	0.6033	0.5872	0.042*
N	0.60549 (16)	0.76485 (8)	0.37401 (8)	0.0164 (2)
O1	0.05566 (16)	0.62189 (8)	0.57788 (7)	0.0217 (2)
O2	0.38302 (14)	0.71055 (7)	0.51535 (8)	0.02124 (18)
S	0.81038 (4)	0.85925 (2)	0.52030 (2)	0.01842 (7)
H2	0.471 (4)	0.7359 (16)	0.4864 (17)	0.040 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0287 (7)	0.0389 (8)	0.0203 (6)	−0.0137 (6)	−0.0024 (6)	−0.0037 (6)
C11	0.0154 (5)	0.0165 (5)	0.0154 (5)	0.0017 (4)	0.0013 (4)	0.0009 (4)
C12	0.0159 (5)	0.0189 (5)	0.0205 (6)	−0.0013 (4)	0.0003 (4)	−0.0001 (4)
C13	0.0165 (5)	0.0213 (6)	0.0233 (6)	−0.0015 (4)	0.0035 (5)	0.0017 (5)
C14	0.0198 (6)	0.0240 (6)	0.0183 (6)	−0.0004 (5)	0.0044 (5)	0.0017 (5)
C15	0.0176 (5)	0.0197 (5)	0.0177 (5)	0.0008 (4)	0.0003 (4)	0.0001 (4)
C16	0.0132 (5)	0.0158 (5)	0.0171 (5)	0.0003 (4)	0.0003 (4)	0.0011 (4)
C20	0.0152 (5)	0.0165 (5)	0.0172 (5)	0.0005 (4)	0.0007 (4)	0.0002 (4)
C21	0.0147 (5)	0.0147 (5)	0.0185 (5)	0.0008 (4)	−0.0008 (4)	0.0000 (4)
C22	0.0143 (5)	0.0161 (5)	0.0183 (6)	−0.0010 (4)	−0.0010 (4)	0.0002 (4)
C23	0.0146 (5)	0.0169 (5)	0.0216 (6)	−0.0002 (4)	0.0013 (5)	0.0005 (5)
C24	0.0158 (5)	0.0169 (6)	0.0257 (7)	−0.0012 (4)	−0.0013 (5)	0.0028 (4)
C25	0.0175 (5)	0.0193 (6)	0.0256 (6)	−0.0023 (4)	−0.0043 (5)	−0.0007 (5)
C26	0.0179 (6)	0.0183 (6)	0.0191 (6)	0.0009 (4)	−0.0023 (5)	−0.0012 (4)
C30	0.0237 (7)	0.0329 (8)	0.0268 (7)	−0.0078 (6)	0.0066 (6)	0.0052 (6)
N	0.0141 (5)	0.0167 (5)	0.0184 (5)	−0.0011 (4)	0.0016 (4)	0.0006 (4)
O1	0.0186 (4)	0.0256 (5)	0.0207 (5)	−0.0050 (4)	0.0014 (4)	0.0036 (4)
O2	0.0181 (4)	0.0282 (4)	0.0175 (4)	−0.0081 (3)	−0.0001 (4)	−0.0002 (4)
S	0.01643 (13)	0.02338 (14)	0.01544 (13)	−0.00177 (10)	0.00058 (12)	−0.00074 (13)

Geometric parameters (Å, º)

C1—S	1.7939 (15)	C20—H20	0.95
C1—H1A	0.98	C21—C22	1.4051 (18)
C1—H1B	0.98	C21—C26	1.4103 (18)
C1—H1C	0.98	C22—O2	1.3517 (16)
C11—C12	1.3963 (18)	C22—C23	1.4128 (18)
C11—C16	1.4072 (17)	C23—O1	1.3670 (18)
C11—S	1.7605 (13)	C23—C24	1.3873 (18)
C12—C13	1.3898 (19)	C24—C25	1.403 (2)
C12—H12	0.95	C24—H24	0.95
C13—C14	1.395 (2)	C25—C26	1.3811 (19)
C13—H13	0.95	C25—H25	0.95
C14—C15	1.3873 (18)	C26—H26	0.95
C14—H14	0.95	C30—O1	1.4243 (17)
C15—C16	1.3965 (18)	C30—H30A	0.98
C15—H15	0.95	C30—H30B	0.98
C16—N	1.4150 (16)	C30—H30C	0.98
C20—N	1.2868 (16)	O2—H2	0.79 (2)
C20—C21	1.4510 (17)
S—C1—H1A	109.5	C22—C21—C20	121.32 (12)
S—C1—H1B	109.5	C26—C21—C20	118.73 (12)
H1A—C1—H1B	109.5	O2—C22—C21	122.68 (12)
S—C1—H1C	109.5	O2—C22—C23	117.87 (11)
H1A—C1—H1C	109.5	C21—C22—C23	119.46 (12)
H1B—C1—H1C	109.5	O1—C23—C24	124.98 (13)
C12—C11—C16	119.70 (12)	O1—C23—C22	115.27 (12)
C12—C11—S	123.81 (10)	C24—C23—C22	119.73 (13)
C16—C11—S	116.48 (10)	C23—C24—C25	120.62 (12)
C13—C12—C11	120.17 (12)	C23—C24—H24	119.7
C13—C12—H12	119.9	C25—C24—H24	119.7
C11—C12—H12	119.9	C26—C25—C24	120.19 (13)
C12—C13—C14	120.25 (12)	C26—C25—H25	119.9
C12—C13—H13	119.9	C24—C25—H25	119.9
C14—C13—H13	119.9	C25—C26—C21	120.02 (13)
C15—C14—C13	119.79 (12)	C25—C26—H26	120
C15—C14—H14	120.1	C21—C26—H26	120
C13—C14—H14	120.1	O1—C30—H30A	109.5
C14—C15—C16	120.65 (12)	O1—C30—H30B	109.5
C14—C15—H15	119.7	H30A—C30—H30B	109.5
C16—C15—H15	119.7	O1—C30—H30C	109.5
C15—C16—C11	119.35 (11)	H30A—C30—H30C	109.5
C15—C16—N	124.69 (11)	H30B—C30—H30C	109.5
C11—C16—N	115.93 (11)	C20—N—C16	122.44 (11)
N—C20—C21	121.69 (11)	C23—O1—C30	116.32 (12)
N—C20—H20	119.2	C22—O2—H2	105.3 (17)
C21—C20—H20	119.2	C11—S—C1	102.27 (7)
C22—C21—C26	119.94 (12)
C16—C11—C12—C13	−1.52 (18)	O2—C22—C23—O1	0.53 (18)
S—C11—C12—C13	179.66 (10)	C21—C22—C23—O1	−179.22 (13)
C11—C12—C13—C14	−0.8 (2)	O2—C22—C23—C24	−178.01 (12)
C12—C13—C14—C15	1.4 (2)	C21—C22—C23—C24	2.23 (19)
C13—C14—C15—C16	0.5 (2)	O1—C23—C24—C25	−179.26 (14)
C14—C15—C16—C11	−2.79 (19)	C22—C23—C24—C25	−0.9 (2)
C14—C15—C16—N	179.43 (12)	C23—C24—C25—C26	−1.0 (2)
C12—C11—C16—C15	3.31 (18)	C24—C25—C26—C21	1.4 (2)
S—C11—C16—C15	−177.79 (9)	C22—C21—C26—C25	−0.01 (19)
C12—C11—C16—N	−178.72 (11)	C20—C21—C26—C25	−179.48 (12)
S—C11—C16—N	0.19 (15)	C21—C20—N—C16	179.07 (11)
N—C20—C21—C22	5.67 (19)	C15—C16—N—C20	−13.02 (19)
N—C20—C21—C26	−174.88 (12)	C11—C16—N—C20	169.13 (11)
C26—C21—C22—O2	178.46 (12)	C24—C23—O1—C30	−0.8 (2)
C20—C21—C22—O2	−2.09 (19)	C22—C23—O1—C30	−179.29 (12)
C26—C21—C22—C23	−1.80 (19)	C12—C11—S—C1	−15.22 (13)
C20—C21—C22—C23	177.65 (11)	C16—C11—S—C1	165.92 (10)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2···N	0.79 (2)	1.90 (3)	2.6255 (15)	152 (2)