3-[2-(3-Formyl­phen­oxy)eth­oxy]benzaldehyde

The molecule of the title compound, C₁₆H₁₄O₄, is nearly planar. A crystallographic centre of symmetry is located at the mid-point of the central C—C bond. The two aromatic rings are parallel to each other. The crystal structure is stabilized by weak inter­molecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.043
• wR factor = 0.130
• Data-to-parameter ratio = 15.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.02

   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


checkCIF publication errors

Alert level A
PUBL023_ALERT_1_A There is a mismatched ^ on line 304
               Refinement of F2^ against ALL reflections.  The weighted R-factor wR and
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C
PUBL023_ALERT_1_A There is a mismatched ^ on line 305
               goodness of fit S are based on F2^, conventional R-factors R are based
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C
PUBL023_ALERT_1_A There is a mismatched ^ on line 306
               on F, with F set to zero for negative F2^. The threshold expression of
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C
PUBL023_ALERT_1_A There is a mismatched ^ on line 309
               on F2^ are statistically about twice as large as those based on F, and R-
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C
PUBL023_ALERT_1_A There is a mismatched ^ on line 317
               'calc w = 1/[\s2^(Fo2^)+(0.0734P)2^+0.0615P] where P=(Fo2^+2Fc2^)/3'
              If you require a ^ then it should be escaped
              with a \, i.e. \^
              Otherwise there must be a matching closing ~, e.g. ^12^C

   5 ALERT level A = Data missing that is essential or data in wrong format
   0 ALERT level G = General alerts. Data that may be required is missing

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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.

3-[2-(3-Formylphenoxy)ethoxy]benzaldehyde

Crystal data

C16H14O4	F(000) = 284
Mr = 270.27	Dx = 1.342 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1346 reflections
a = 5.6966 (14) Å	θ = 3.1–24.5°
b = 16.098 (4) Å	µ = 0.10 mm^−1
c = 7.4113 (18) Å	T = 294 K
β = 100.309 (4)°	Block, colourless
V = 668.7 (3) Å^3	0.36 × 0.22 × 0.14 mm
Z = 2

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1366 independent reflections
Radiation source: fine-focus sealed tube	899 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.032
φ and ω scans	θmax = 26.4°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −7→6
Tmin = 0.952, Tmax = 0.987	k = −13→20
3701 measured reflections	l = −8→9

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.130	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.0734P)^2 + 0.0615P] where P = (Fo^2 + 2Fc^2)/3
1366 reflections	(Δ/σ)max < 0.001
91 parameters	Δρmax = 0.20 e Å^−3
0 restraints	Δρmin = −0.18 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	0.1928 (3)	0.83773 (8)	0.8136 (2)	0.0731 (5)
O2	0.2299 (2)	0.51668 (7)	0.84160 (18)	0.0594 (4)
C1	0.0769 (3)	0.57881 (10)	0.7689 (2)	0.0456 (5)
C2	0.1214 (3)	0.66224 (10)	0.7957 (2)	0.0455 (5)
H2	0.2640	0.6800	0.8665	0.055*
C3	−0.0478 (3)	0.71993 (10)	0.7165 (2)	0.0454 (4)
C4	−0.2600 (3)	0.69346 (11)	0.6119 (3)	0.0539 (5)
H4	−0.3743	0.7321	0.5610	0.065*
C5	−0.3023 (3)	0.60955 (12)	0.5831 (3)	0.0569 (5)
H5	−0.4442	0.5918	0.5113	0.068*
C6	−0.1346 (3)	0.55210 (11)	0.6605 (3)	0.0508 (5)
H6	−0.1627	0.4957	0.6403	0.061*
C7	0.0042 (4)	0.80932 (11)	0.7398 (3)	0.0575 (5)
H7	−0.1170	0.8465	0.6944	0.069*
C8	0.4346 (3)	0.53985 (10)	0.9722 (2)	0.0497 (5)
H8A	0.3876	0.5665	1.0776	0.060*
H8B	0.5345	0.5778	0.9180	0.060*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0737 (10)	0.0420 (8)	0.0952 (12)	−0.0063 (7)	−0.0079 (9)	0.0038 (7)
O2	0.0588 (8)	0.0343 (7)	0.0753 (9)	0.0112 (6)	−0.0144 (7)	−0.0015 (6)
C1	0.0469 (10)	0.0366 (9)	0.0509 (10)	0.0081 (7)	0.0022 (8)	0.0036 (8)
C2	0.0429 (10)	0.0372 (9)	0.0522 (10)	0.0023 (7)	−0.0033 (8)	0.0000 (7)
C3	0.0476 (10)	0.0370 (9)	0.0497 (10)	0.0051 (7)	0.0034 (8)	0.0044 (7)
C4	0.0461 (10)	0.0465 (11)	0.0648 (12)	0.0092 (8)	−0.0019 (9)	0.0092 (9)
C5	0.0453 (10)	0.0520 (12)	0.0671 (12)	−0.0028 (8)	−0.0071 (9)	0.0035 (9)
C6	0.0507 (11)	0.0368 (9)	0.0610 (11)	−0.0036 (8)	−0.0003 (9)	−0.0013 (8)
C7	0.0642 (12)	0.0389 (10)	0.0654 (12)	0.0089 (9)	0.0011 (10)	0.0073 (9)
C8	0.0509 (10)	0.0393 (9)	0.0544 (10)	0.0099 (8)	−0.0027 (8)	−0.0008 (8)

Geometric parameters (Å, º)

O1—C7	1.205 (2)	C4—C5	1.382 (3)
O2—C1	1.372 (2)	C4—H4	0.9300
O2—C8	1.425 (2)	C5—C6	1.379 (2)
C1—C2	1.375 (2)	C5—H5	0.9300
C1—C6	1.391 (2)	C6—H6	0.9300
C2—C3	1.391 (2)	C7—H7	0.9300
C2—H2	0.9300	C8—C8^i	1.504 (3)
C3—C4	1.381 (2)	C8—H8A	0.9700
C3—C7	1.473 (2)	C8—H8B	0.9700
C1—O2—C8	117.45 (14)	C6—C5—H5	119.9
O2—C1—C2	124.60 (16)	C4—C5—H5	119.9
O2—C1—C6	115.16 (16)	C5—C6—C1	119.79 (17)
C2—C1—C6	120.24 (15)	C5—C6—H6	120.1
C1—C2—C3	119.71 (16)	C1—C6—H6	120.1
C1—C2—H2	120.1	O1—C7—C3	124.65 (18)
C3—C2—H2	120.1	O1—C7—H7	117.7
C4—C3—C2	120.11 (16)	C3—C7—H7	117.7
C4—C3—C7	120.32 (16)	O2—C8—C8^i	105.52 (17)
C2—C3—C7	119.53 (16)	O2—C8—H8A	110.6
C3—C4—C5	119.94 (16)	C8^i—C8—H8A	110.6
C3—C4—H4	120.0	O2—C8—H8B	110.6
C5—C4—H4	120.0	C8^i—C8—H8B	110.6
C6—C5—C4	120.18 (16)	H8A—C8—H8B	108.8
C8—O2—C1—C2	8.4 (3)	C3—C4—C5—C6	0.9 (3)
C8—O2—C1—C6	−172.15 (15)	C4—C5—C6—C1	0.4 (3)
O2—C1—C2—C3	−179.42 (16)	O2—C1—C6—C5	179.03 (16)
C6—C1—C2—C3	1.1 (3)	C2—C1—C6—C5	−1.4 (3)
C1—C2—C3—C4	0.2 (3)	C4—C3—C7—O1	−172.63 (19)
C1—C2—C3—C7	−177.75 (17)	C2—C3—C7—O1	5.4 (3)
C2—C3—C4—C5	−1.2 (3)	C1—O2—C8—C8^i	179.57 (18)
C7—C3—C4—C5	176.73 (18)

Symmetry code: (i) −x+1, −y+1, −z+2.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···O1^ii	0.93	2.57	3.475 (2)	163
C5—H5···O1^iii	0.93	2.57	3.306 (2)	136

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