2-[4-(2-Formyl-6-methoxy­phen­oxy)but­oxy]-3-methoxy­benzaldehyde

The title compound, C₂₀H₂₂O₆, comprises two o-vanillin subunits covalently linked to a central butyl chain; the molecule lies on an inversion center. The dihedral angle between the bridging butyl group and the plane through the aromatic ring is 7.13 (14)°, indicating the overall planarity of the mol­ecule. The mol­ecules are linked by weak C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.041
• wR factor = 0.114
• Data-to-parameter ratio = 14.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.11

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 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
   1 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
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 1999); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; 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.

2-[4-(2-Formyl-6-methoxyphenoxy)butoxy]-3-methoxybenzaldehyde

Crystal data

C20H22O6	F(000) = 380
Mr = 358.38	Dx = 1.355 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1571 reflections
a = 7.068 (4) Å	θ = 2.5–24.7°
b = 16.068 (9) Å	µ = 0.10 mm^−1
c = 7.745 (4) Å	T = 294 K
β = 93.171 (10)°	Block, colorless
V = 878.1 (8) Å^3	0.22 × 0.16 × 0.12 mm
Z = 2

Data collection

Bruker SMART CCD area-detector diffractometer	1774 independent reflections
Radiation source: fine-focus sealed tube	1179 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.033
φ and ω scans	θmax = 26.3°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −8→8
Tmin = 0.967, Tmax = 0.988	k = −20→19
4812 measured reflections	l = −9→6

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.114	H-atom parameters constrained
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0497P)^2 + 0.2229P] where P = (Fo^2 + 2Fc^2)/3
1774 reflections	(Δ/σ)max = 0.001
119 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.17 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
O1	0.58221 (17)	0.95118 (7)	0.32891 (17)	0.0483 (4)
O2	0.22559 (15)	0.90857 (7)	0.19655 (15)	0.0373 (3)
O3	0.0705 (2)	0.67350 (9)	0.1027 (3)	0.0770 (5)
C1	0.3646 (2)	0.84893 (10)	0.2231 (2)	0.0329 (4)
C2	0.5467 (2)	0.86905 (11)	0.2942 (2)	0.0362 (4)
C3	0.6767 (2)	0.80577 (11)	0.3275 (2)	0.0443 (5)
H3	0.7977	0.8186	0.3730	0.053*
C4	0.6283 (3)	0.72369 (12)	0.2937 (3)	0.0487 (5)
H4	0.7172	0.6819	0.3163	0.058*
C5	0.4508 (3)	0.70354 (11)	0.2273 (2)	0.0440 (5)
H5	0.4190	0.6481	0.2064	0.053*
C6	0.3174 (2)	0.76609 (10)	0.1911 (2)	0.0359 (4)
C7	0.1287 (3)	0.74368 (13)	0.1176 (3)	0.0501 (5)
H7	0.0484	0.7866	0.0800	0.060*
C8	0.7523 (3)	0.97046 (12)	0.4299 (3)	0.0512 (5)
H8A	0.7550	0.9397	0.5363	0.077*
H8B	0.7559	1.0290	0.4547	0.077*
H8C	0.8602	0.9556	0.3664	0.077*
C9	0.2605 (2)	0.97026 (11)	0.0667 (3)	0.0432 (5)
H9A	0.2899	0.9432	−0.0405	0.052*
H9B	0.3676	1.0047	0.1047	0.052*
C10	0.0860 (2)	1.02328 (10)	0.0381 (2)	0.0381 (4)
H10A	0.1144	1.0687	−0.0387	0.046*
H10B	0.0547	1.0473	0.1479	0.046*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0365 (7)	0.0402 (7)	0.0655 (9)	0.0012 (5)	−0.0212 (6)	−0.0046 (6)
O2	0.0250 (6)	0.0388 (7)	0.0476 (7)	0.0052 (5)	−0.0031 (5)	0.0078 (5)
O3	0.0487 (9)	0.0494 (9)	0.1299 (15)	−0.0105 (7)	−0.0206 (9)	−0.0076 (9)
C1	0.0271 (8)	0.0374 (9)	0.0338 (9)	0.0056 (7)	−0.0029 (7)	0.0027 (7)
C2	0.0313 (9)	0.0382 (10)	0.0381 (10)	0.0027 (8)	−0.0061 (7)	−0.0002 (8)
C3	0.0279 (9)	0.0480 (11)	0.0555 (12)	0.0051 (8)	−0.0126 (8)	−0.0007 (9)
C4	0.0412 (11)	0.0436 (11)	0.0599 (13)	0.0131 (9)	−0.0103 (9)	0.0012 (9)
C5	0.0440 (11)	0.0354 (10)	0.0518 (12)	0.0022 (8)	−0.0036 (9)	0.0000 (8)
C6	0.0300 (9)	0.0388 (10)	0.0385 (10)	−0.0005 (7)	−0.0009 (7)	0.0021 (8)
C7	0.0374 (10)	0.0436 (11)	0.0682 (14)	−0.0014 (9)	−0.0088 (9)	−0.0016 (10)
C8	0.0407 (11)	0.0508 (12)	0.0600 (13)	−0.0061 (9)	−0.0171 (9)	−0.0040 (10)
C9	0.0286 (9)	0.0481 (11)	0.0522 (11)	0.0013 (8)	−0.0046 (8)	0.0136 (9)
C10	0.0303 (9)	0.0354 (9)	0.0474 (11)	0.0000 (7)	−0.0084 (8)	0.0052 (8)

Geometric parameters (Å, º)

O1—C2	1.367 (2)	C5—H5	0.9300
O1—C8	1.432 (2)	C6—C7	1.466 (3)
O2—C1	1.3793 (19)	C7—H7	0.9300
O2—C9	1.443 (2)	C8—H8A	0.9600
O3—C7	1.204 (2)	C8—H8B	0.9600
C1—C6	1.391 (2)	C8—H8C	0.9600
C1—C2	1.409 (2)	C9—C10	1.505 (2)
C2—C3	1.385 (2)	C9—H9A	0.9700
C3—C4	1.384 (3)	C9—H9B	0.9700
C3—H3	0.9300	C10—C10^i	1.518 (3)
C4—C5	1.368 (3)	C10—H10A	0.9700
C4—H4	0.9300	C10—H10B	0.9700
C5—C6	1.396 (2)
C2—O1—C8	117.13 (13)	O3—C7—H7	117.8
C1—O2—C9	115.68 (13)	C6—C7—H7	117.8
O2—C1—C2	121.75 (15)	O1—C8—H8A	109.5
O2—C1—C6	118.46 (15)	O1—C8—H8B	109.5
C6—C1—C2	119.59 (15)	H8A—C8—H8B	109.5
O1—C2—C1	116.88 (14)	O1—C8—H8C	109.5
O1—C2—C3	123.99 (15)	H8A—C8—H8C	109.5
C3—C2—C1	119.11 (16)	H8B—C8—H8C	109.5
C4—C3—C2	120.67 (16)	O2—C9—C10	108.73 (14)
C4—C3—H3	119.7	O2—C9—H9A	109.9
C2—C3—H3	119.7	C10—C9—H9A	109.9
C5—C4—C3	120.56 (17)	O2—C9—H9B	109.9
C5—C4—H4	119.7	C10—C9—H9B	109.9
C3—C4—H4	119.7	H9A—C9—H9B	108.3
C4—C5—C6	120.01 (17)	C9—C10—C10^i	114.20 (18)
C4—C5—H5	120.0	C9—C10—H10A	108.7
C6—C5—H5	120.0	C10^i—C10—H10A	108.7
C1—C6—C5	120.05 (16)	C9—C10—H10B	108.7
C1—C6—C7	120.54 (16)	C10^i—C10—H10B	108.7
C5—C6—C7	119.41 (16)	H10A—C10—H10B	107.6
O3—C7—C6	124.50 (18)
C9—O2—C1—C6	−118.26 (17)	C3—C4—C5—C6	0.8 (3)
C9—O2—C1—C2	66.9 (2)	O2—C1—C6—C5	−175.76 (15)
C8—O1—C2—C3	−10.1 (3)	C2—C1—C6—C5	−0.8 (3)
C8—O1—C2—C1	168.66 (16)	O2—C1—C6—C7	4.9 (2)
O2—C1—C2—O1	−2.7 (2)	C2—C1—C6—C7	179.83 (16)
C6—C1—C2—O1	−177.54 (15)	C4—C5—C6—C1	−0.3 (3)
O2—C1—C2—C3	176.13 (15)	C4—C5—C6—C7	179.11 (18)
C6—C1—C2—C3	1.3 (3)	C1—C6—C7—O3	−172.0 (2)
O1—C2—C3—C4	177.96 (17)	C5—C6—C7—O3	8.6 (3)
C1—C2—C3—C4	−0.8 (3)	C1—O2—C9—C10	172.81 (14)
C2—C3—C4—C5	−0.2 (3)	O2—C9—C10—C10^i	−65.1 (2)

Symmetry code: (i) −x, −y+2, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3···O3^ii	0.93	2.55	3.427 (3)	157

Symmetry code: (ii) x+1, −y+3/2, z+1/2.