4-(4-Chloro­benz­yloxy)-3-methoxy­benzaldehyde

In the title compound, C₁₅H₁₃ClO₃, the vanillin group makes a dihedral angle of 72.79 (9)° with the chloro­benzene ring. The crystal structure is stabilized by weak non-classical inter­molecular C—H...O hydrogen bonds that form centrosymmetric dimers.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.054
• wR factor = 0.157
• Data-to-parameter ratio = 13.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT026_ALERT_3_C Ratio Observed / Unique Reflections too Low ....         47 Perc.
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         C9
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C10
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C13
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.17
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          5

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

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

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S1. Comment

There has been a steady growth of interest in the synthesis, structure, and reactivity of Schiff bases due to their potential applications in areas such as biological modelling, catalysis, and molecular magnets (Jones et al., 1979; Larson & Pecoraro, 1991). Consequently, a significant effort has been devoted to the synthesis of new Schiff base derivatives (Santos et al., 2001).

As a part of our interest in the coordination properties of Schiff bases functioning as ligands, we investigated the title compound, (I), used as a precursor in the preparation of Schiff bases.

In the title molecule (Fig. 1), bond lengths and angles are within normal ranges (Allen et al., 1987). The vanillin group (C1—C6/C8/O1/O2) is essentially planar, with an r.m.s. deviation for fitted atoms of 0.0090 Å. This group makes a dihedral angle of 72.79 (9)° with the benzene ring (C10—C15).

The crystal structure is stabilized by weak non-classical intermolecular C14—H14···O2 hydrogen bonds that forms centrosymmetric dimers (Table 1, Fig. 2).

Related literature

For general background, see: Allen et al. (1987); Jones et al. (1979); Larson & Pecoraro (1991); Santos et al. (2001).

S2. Experimental

An anhydrous acetonitrile solution (50 ml) of 4-hydroxy-3-methoxybenzaldehyde (1.52 g, 10 mmol) was added dropwise to a solution (100 ml) of 1-(bromomethyl)-4-chlorobenzene (2.05 g, 10 mmol) and potassium carbonate (1.38 g, 10 mmol) in acetonitrile, in 30 min., and the mixture refluxed for 48 h under nitrogen atmosphere. The solvent was removed and the resultant mixture poured into ice-water (100 ml). The white precipitate was then isolated and recrystallized from acetonitrile, and then dried in a vacuum to give the pure compound in 65% yield. Colorless single crystals of (I) suitable for X-ray analysis were obtained by slow evaporation of an acetonitrile solution.

S3. Refinement

The H atoms were included in calculated positions and refined using a riding model approximation. Constrained C—H and N—H bond lengths and isotropic U parameters: 0.93 Å and U_iso(H) = 1.2U_eq(C) for Csp²—H; 0.97 Å and U_iso(H) = 1.2U_eq(C) for methylene C—H; 0.96 Å and U_iso(H) = 1.5U_eq(C) for methyl C—H.

Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997a); molecular graphics: SHELXTL (Sheldrick, 1997b); software used to prepare material for publication: SHELXTL (Sheldrick, 1997b).

Figures

	Fig. 1. The structure of (I) with displacement ellipsoids for non-H atoms drawn at the 30% probability level.
	Fig. 2. Intermolecular hydrogen bonding interactions (dashed lines).

4-(4-Chlorobenzyloxy)-3-methoxybenzaldehyde

Crystal data

C15H13ClO3	F(000) = 576
Mr = 276.70	Dx = 1.334 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1181 reflections
a = 9.054 (3) Å	θ = 2.3–21.1°
b = 8.535 (2) Å	µ = 0.28 mm^−1
c = 17.828 (5) Å	T = 294 K
β = 90.10 (2)°	Block, colorless
V = 1377.7 (7) Å^3	0.28 × 0.22 × 0.20 mm
Z = 4

Data collection

Bruker SMART APEX CCD area-detector diffractometer	2383 independent reflections
Radiation source: fine-focus sealed tube	1124 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
φ and ω scans	θmax = 25.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→10
Tmin = 0.912, Tmax = 0.946	k = −10→10
6675 measured reflections	l = −20→21

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) = 0.157	H-atom parameters constrained
S = 1.08	w = 1/[σ^2(Fo^2) + (0.064P)^2 + 0.0805P] where P = (Fo^2 + 2Fc^2)/3
2383 reflections	(Δ/σ)max = 0.001
173 parameters	Δρmax = 0.38 e Å^−3
0 restraints	Δρmin = −0.39 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 > 2σ(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
Cl1	0.59471 (15)	−0.34118 (12)	0.00262 (10)	0.1423 (8)
O1	0.9350 (2)	0.3047 (2)	0.11555 (14)	0.0664 (8)
O2	1.1901 (2)	0.2923 (2)	0.17769 (15)	0.0688 (8)
O3	1.3242 (3)	0.8721 (3)	0.23371 (18)	0.0879 (10)
C1	0.9921 (3)	0.4453 (4)	0.13587 (19)	0.0542 (9)
C2	1.1324 (4)	0.4386 (4)	0.17014 (19)	0.0539 (9)
C3	1.1999 (4)	0.5747 (4)	0.1921 (2)	0.0593 (10)
H3	1.2936	0.5707	0.2135	0.071*
C4	1.1305 (4)	0.7187 (4)	0.1830 (2)	0.0560 (10)
C5	0.9929 (4)	0.7241 (4)	0.1508 (2)	0.0648 (11)
H5	0.9454	0.8200	0.1454	0.078*
C6	0.9239 (4)	0.5888 (4)	0.1265 (2)	0.0672 (11)
H6	0.8315	0.5943	0.1038	0.081*
C7	1.3303 (4)	0.2813 (4)	0.2140 (3)	0.0829 (13)
H7A	1.4013	0.3429	0.1870	0.124*
H7B	1.3616	0.1739	0.2149	0.124*
H7C	1.3223	0.3198	0.2644	0.124*
C8	1.2026 (5)	0.8637 (4)	0.2065 (2)	0.0670 (11)
H8	1.1506	0.9567	0.2001	0.080*
C9	0.7940 (4)	0.3070 (4)	0.0790 (2)	0.0767 (12)
H9A	0.8002	0.3664	0.0328	0.092*
H9B	0.7215	0.3566	0.1112	0.092*
C10	0.7489 (4)	0.1425 (4)	0.0626 (2)	0.0554 (10)
C11	0.6410 (4)	0.0703 (5)	0.1033 (2)	0.0744 (11)
H11	0.5989	0.1227	0.1437	0.089*
C12	0.5926 (4)	−0.0802 (6)	0.0857 (3)	0.0843 (14)
H12	0.5184	−0.1286	0.1133	0.101*
C13	0.6582 (6)	−0.1550 (4)	0.0260 (3)	0.0778 (14)
C14	0.7666 (5)	−0.0873 (5)	−0.0142 (3)	0.0786 (12)
H14	0.8106	−0.1407	−0.0537	0.094*
C15	0.8108 (4)	0.0606 (4)	0.0039 (2)	0.0665 (10)
H15	0.8850	0.1077	−0.0242	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.1369 (12)	0.0565 (7)	0.2331 (18)	−0.0265 (6)	−0.1169 (11)	0.0205 (8)
O1	0.0558 (15)	0.0491 (13)	0.094 (2)	−0.0021 (11)	−0.0285 (13)	−0.0118 (13)
O2	0.0572 (16)	0.0501 (13)	0.099 (2)	0.0064 (11)	−0.0255 (14)	−0.0154 (13)
O3	0.0724 (19)	0.0621 (17)	0.129 (3)	−0.0115 (13)	−0.0257 (18)	−0.0126 (15)
C1	0.050 (2)	0.054 (2)	0.059 (3)	−0.0026 (16)	−0.0079 (17)	−0.0058 (18)
C2	0.051 (2)	0.049 (2)	0.062 (3)	−0.0003 (16)	−0.0071 (17)	−0.0057 (18)
C3	0.044 (2)	0.056 (2)	0.077 (3)	−0.0016 (17)	−0.0096 (17)	−0.008 (2)
C4	0.054 (2)	0.050 (2)	0.064 (3)	−0.0048 (17)	−0.0062 (19)	−0.0051 (18)
C5	0.070 (3)	0.045 (2)	0.080 (3)	0.0047 (18)	−0.012 (2)	−0.0033 (19)
C6	0.063 (2)	0.055 (2)	0.083 (3)	0.0038 (18)	−0.025 (2)	−0.003 (2)
C7	0.064 (3)	0.061 (2)	0.123 (4)	0.0113 (19)	−0.036 (2)	−0.013 (2)
C8	0.073 (3)	0.050 (2)	0.078 (3)	−0.0015 (19)	−0.002 (2)	−0.0049 (18)
C9	0.070 (3)	0.062 (2)	0.097 (3)	−0.0031 (18)	−0.038 (2)	−0.002 (2)
C10	0.050 (2)	0.055 (2)	0.061 (3)	−0.0015 (17)	−0.0189 (19)	−0.0009 (19)
C11	0.064 (3)	0.093 (3)	0.066 (3)	0.009 (2)	−0.009 (2)	0.001 (2)
C12	0.057 (3)	0.096 (4)	0.100 (4)	−0.024 (2)	−0.021 (2)	0.046 (3)
C13	0.076 (3)	0.050 (2)	0.107 (4)	−0.010 (2)	−0.052 (3)	0.011 (2)
C14	0.083 (3)	0.068 (3)	0.085 (3)	−0.004 (2)	−0.023 (2)	−0.017 (2)
C15	0.061 (2)	0.074 (3)	0.064 (3)	−0.017 (2)	−0.0031 (19)	0.000 (2)

Geometric parameters (Å, º)

Cl1—C13	1.741 (4)	C7—H7B	0.9600
O1—C1	1.355 (4)	C7—H7C	0.9600
O1—C9	1.432 (4)	C8—H8	0.9300
O2—C2	1.360 (4)	C9—C10	1.491 (4)
O2—C7	1.427 (4)	C9—H9A	0.9700
O3—C8	1.204 (4)	C9—H9B	0.9700
C1—C6	1.381 (4)	C10—C11	1.365 (5)
C1—C2	1.410 (4)	C10—C15	1.378 (5)
C2—C3	1.369 (4)	C11—C12	1.393 (5)
C3—C4	1.390 (4)	C11—H11	0.9300
C3—H3	0.9300	C12—C13	1.376 (6)
C4—C5	1.371 (5)	C12—H12	0.9300
C4—C8	1.461 (4)	C13—C14	1.347 (6)
C5—C6	1.383 (4)	C14—C15	1.363 (5)
C5—H5	0.9300	C14—H14	0.9300
C6—H6	0.9300	C15—H15	0.9300
C7—H7A	0.9600
C1—O1—C9	116.7 (2)	O3—C8—H8	117.5
C2—O2—C7	116.5 (2)	C4—C8—H8	117.5
O1—C1—C6	125.6 (3)	O1—C9—C10	108.7 (3)
O1—C1—C2	115.0 (3)	O1—C9—H9A	110.0
C6—C1—C2	119.4 (3)	C10—C9—H9A	110.0
O2—C2—C3	125.4 (3)	O1—C9—H9B	110.0
O2—C2—C1	115.2 (3)	C10—C9—H9B	110.0
C3—C2—C1	119.4 (3)	H9A—C9—H9B	108.3
C2—C3—C4	121.0 (3)	C11—C10—C15	117.9 (3)
C2—C3—H3	119.5	C11—C10—C9	121.1 (4)
C4—C3—H3	119.5	C15—C10—C9	121.0 (4)
C5—C4—C3	119.3 (3)	C10—C11—C12	121.4 (4)
C5—C4—C8	119.8 (3)	C10—C11—H11	119.3
C3—C4—C8	120.9 (3)	C12—C11—H11	119.3
C4—C5—C6	120.8 (3)	C13—C12—C11	117.8 (4)
C4—C5—H5	119.6	C13—C12—H12	121.1
C6—C5—H5	119.6	C11—C12—H12	121.1
C1—C6—C5	120.1 (3)	C14—C13—C12	121.9 (4)
C1—C6—H6	120.0	C14—C13—Cl1	120.3 (4)
C5—C6—H6	120.0	C12—C13—Cl1	117.8 (4)
O2—C7—H7A	109.5	C13—C14—C15	119.0 (4)
O2—C7—H7B	109.5	C13—C14—H14	120.5
H7A—C7—H7B	109.5	C15—C14—H14	120.5
O2—C7—H7C	109.5	C14—C15—C10	122.0 (4)
H7A—C7—H7C	109.5	C14—C15—H15	119.0
H7B—C7—H7C	109.5	C10—C15—H15	119.0
O3—C8—C4	125.0 (3)
C9—O1—C1—C6	2.2 (5)	C4—C5—C6—C1	1.4 (6)
C9—O1—C1—C2	−178.7 (3)	C5—C4—C8—O3	−178.3 (4)
C7—O2—C2—C3	2.3 (5)	C3—C4—C8—O3	1.2 (6)
C7—O2—C2—C1	−178.4 (3)	C1—O1—C9—C10	−178.9 (3)
O1—C1—C2—O2	0.1 (5)	O1—C9—C10—C11	106.1 (4)
C6—C1—C2—O2	179.3 (3)	O1—C9—C10—C15	−76.4 (4)
O1—C1—C2—C3	179.5 (3)	C15—C10—C11—C12	−1.1 (5)
C6—C1—C2—C3	−1.3 (5)	C9—C10—C11—C12	176.4 (3)
O2—C2—C3—C4	−179.0 (3)	C10—C11—C12—C13	0.6 (6)
C1—C2—C3—C4	1.7 (5)	C11—C12—C13—C14	0.6 (6)
C2—C3—C4—C5	−0.6 (5)	C11—C12—C13—Cl1	−178.5 (3)
C2—C3—C4—C8	179.9 (4)	C12—C13—C14—C15	−1.2 (6)
C3—C4—C5—C6	−1.0 (6)	Cl1—C13—C14—C15	177.9 (3)
C8—C4—C5—C6	178.5 (3)	C13—C14—C15—C10	0.6 (6)
O1—C1—C6—C5	178.9 (3)	C11—C10—C15—C14	0.5 (5)
C2—C1—C6—C5	−0.3 (6)	C9—C10—C15—C14	−177.0 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C14—H14···O2^i	0.93	2.56	3.423 (5)	154

Symmetry code: (i) −x+2, −y, −z.