3,3′-Dihydr­oxy-4,4′-(propane-1,3-diyldi­oxy)dibenzaldehyde

The title compound, C₁₉H₂₀O₆, is composed of two individual vanillin subunits bonded to a central chain of C atoms. The mol­ecule lies on a twofold rotation axis. The two aromatic rings are approximately perpendicular to each other and both make a dihedral angle of 53.36 (4)° with the backbone chain. A weak C—H...π inter­action consolidates the crystal packing.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.031
• wR factor = 0.074
• Data-to-parameter ratio = 8.2

checkCIF/PLATON results

No syntax errors found



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           26.18
           From the CIF: _reflns_number_total                950
           Count of symmetry unique reflns          950
           Completeness (_total/calc)            100.00%
           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         no

   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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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.

3,3'-Dihydroxy-4,4'-(propane-1,3-diyldioxy)dibenzaldehyde

Crystal data

C19H20O6	F(000) = 1456
Mr = 344.35	Dx = 1.358 Mg m^−3
Orthorhombic, Fdd2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: F 2 -2d	Cell parameters from 1884 reflections
a = 22.247 (5) Å	θ = 2.3–26.1°
b = 31.175 (6) Å	µ = 0.10 mm^−1
c = 4.8562 (10) Å	T = 294 K
V = 3368.1 (12) Å^3	Block, colorless
Z = 8	0.26 × 0.20 × 0.18 mm

Data collection

Bruker SMART CCD area-detector diffractometer	950 independent reflections
Radiation source: fine-focus sealed tube	781 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.029
φ and ω scans	θmax = 26.2°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −20→27
Tmin = 0.964, Tmax = 0.982	k = −38→37
4635 measured reflections	l = −6→4

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.031	H-atom parameters constrained
wR(F^2) = 0.074	w = 1/[σ^2(Fo^2) + (0.0299P)^2 + 1.8179P] where P = (Fo^2 + 2Fc^2)/3
S = 1.10	(Δ/σ)max = 0.001
950 reflections	Δρmax = 0.13 e Å^−3
116 parameters	Δρmin = −0.12 e Å^−3
1 restraint	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0028 (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	Occ. (<1)
O1	0.42750 (6)	0.02013 (4)	0.8424 (3)	0.0445 (4)
O2	0.34941 (7)	−0.01229 (4)	0.5072 (4)	0.0551 (5)
O3	0.26282 (8)	0.11871 (6)	−0.0181 (5)	0.0743 (6)
C1	0.39797 (9)	0.04880 (6)	0.6823 (4)	0.0393 (5)
C2	0.35536 (9)	0.03145 (6)	0.4996 (5)	0.0416 (5)
C3	0.32341 (9)	0.05797 (7)	0.3285 (5)	0.0465 (6)
H3	0.2950	0.0465	0.2087	0.056*
C4	0.33354 (10)	0.10218 (7)	0.3342 (5)	0.0479 (6)
C5	0.37533 (10)	0.11902 (7)	0.5116 (5)	0.0512 (6)
H5	0.3820	0.1485	0.5142	0.061*
C6	0.40776 (9)	0.09265 (6)	0.6868 (5)	0.0455 (6)
H6	0.4359	0.1043	0.8067	0.055*
C7	0.31500 (12)	−0.03134 (8)	0.2927 (6)	0.0642 (8)
H7A	0.2743	−0.0212	0.3028	0.096*
H7B	0.3156	−0.0620	0.3129	0.096*
H7C	0.3319	−0.0237	0.1176	0.096*
C8	0.30021 (11)	0.13015 (8)	0.1456 (6)	0.0607 (7)
H8	0.3087	0.1593	0.1529	0.073*
C9	0.47513 (9)	0.03657 (6)	1.0128 (5)	0.0441 (5)
H9A	0.4598	0.0588	1.1339	0.053*
H9B	0.5065	0.0489	0.8989	0.053*
C10	0.5000	0.0000	1.1796 (7)	0.0449 (7)
H10A	0.4684	−0.0110	1.2977	0.054*	0.50
H10B	0.5316	0.0110	1.2977	0.054*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0496 (8)	0.0415 (8)	0.0424 (9)	−0.0021 (6)	−0.0054 (8)	0.0009 (7)
O2	0.0673 (10)	0.0414 (8)	0.0565 (10)	−0.0076 (7)	−0.0153 (10)	0.0046 (8)
O3	0.0685 (12)	0.0748 (12)	0.0797 (15)	0.0166 (9)	−0.0061 (13)	0.0175 (12)
C1	0.0419 (11)	0.0417 (11)	0.0342 (12)	0.0025 (9)	0.0080 (10)	0.0016 (11)
C2	0.0451 (11)	0.0401 (10)	0.0395 (12)	0.0003 (9)	0.0060 (11)	0.0031 (11)
C3	0.0446 (12)	0.0508 (12)	0.0442 (14)	0.0014 (10)	0.0014 (12)	0.0029 (12)
C4	0.0501 (12)	0.0454 (12)	0.0482 (15)	0.0085 (10)	0.0126 (12)	0.0079 (12)
C5	0.0610 (14)	0.0385 (11)	0.0541 (14)	0.0037 (10)	0.0143 (13)	0.0023 (12)
C6	0.0514 (13)	0.0426 (12)	0.0426 (13)	−0.0020 (10)	0.0062 (12)	−0.0031 (12)
C7	0.0764 (17)	0.0498 (13)	0.0666 (18)	−0.0127 (12)	−0.0139 (15)	0.0001 (14)
C8	0.0607 (16)	0.0539 (14)	0.0673 (19)	0.0117 (12)	0.0117 (15)	0.0121 (14)
C9	0.0463 (11)	0.0459 (11)	0.0401 (12)	−0.0039 (10)	0.0002 (11)	−0.0058 (11)
C10	0.0468 (17)	0.0535 (18)	0.0344 (16)	−0.0036 (14)	0.000	0.000

Geometric parameters (Å, º)

O1—C1	1.355 (2)	C5—H5	0.9300
O1—C9	1.439 (2)	C6—H6	0.9300
O2—C2	1.371 (2)	C7—H7A	0.9600
O2—C7	1.423 (3)	C7—H7B	0.9600
O3—C8	1.204 (3)	C7—H7C	0.9600
C1—C6	1.385 (3)	C8—H8	0.9300
C1—C2	1.407 (3)	C9—C10	1.504 (3)
C2—C3	1.371 (3)	C9—H9A	0.9700
C3—C4	1.397 (3)	C9—H9B	0.9700
C3—H3	0.9300	C10—C9^i	1.504 (3)
C4—C5	1.372 (3)	C10—H10A	0.9700
C4—C8	1.466 (3)	C10—H10B	0.9700
C5—C6	1.386 (3)
C1—O1—C9	116.87 (15)	O2—C7—H7B	109.5
C2—O2—C7	116.59 (18)	H7A—C7—H7B	109.5
O1—C1—C6	124.5 (2)	O2—C7—H7C	109.5
O1—C1—C2	115.80 (17)	H7A—C7—H7C	109.5
C6—C1—C2	119.71 (19)	H7B—C7—H7C	109.5
O2—C2—C3	124.5 (2)	O3—C8—C4	125.8 (2)
O2—C2—C1	115.52 (18)	O3—C8—H8	117.1
C3—C2—C1	120.00 (18)	C4—C8—H8	117.1
C2—C3—C4	120.0 (2)	O1—C9—C10	108.09 (15)
C2—C3—H3	120.0	O1—C9—H9A	110.1
C4—C3—H3	120.0	C10—C9—H9A	110.1
C5—C4—C3	120.0 (2)	O1—C9—H9B	110.1
C5—C4—C8	120.5 (2)	C10—C9—H9B	110.1
C3—C4—C8	119.5 (2)	H9A—C9—H9B	108.4
C4—C5—C6	120.7 (2)	C9—C10—C9^i	114.8 (3)
C4—C5—H5	119.6	C9—C10—H10A	108.6
C6—C5—H5	119.6	C9^i—C10—H10A	108.6
C1—C6—C5	119.6 (2)	C9—C10—H10B	108.6
C1—C6—H6	120.2	C9^i—C10—H10B	108.6
C5—C6—H6	120.2	H10A—C10—H10B	107.5
O2—C7—H7A	109.5
C9—O1—C1—C6	−4.8 (2)	C2—C3—C4—C8	178.50 (16)
C9—O1—C1—C2	174.52 (14)	C3—C4—C5—C6	−0.3 (3)
C7—O2—C2—C3	10.6 (3)	C8—C4—C5—C6	−178.86 (17)
C7—O2—C2—C1	−168.95 (16)	O1—C1—C6—C5	179.34 (16)
O1—C1—C2—O2	−0.2 (2)	C2—C1—C6—C5	0.0 (2)
C6—C1—C2—O2	179.13 (15)	C4—C5—C6—C1	0.3 (3)
O1—C1—C2—C3	−179.77 (16)	C5—C4—C8—O3	179.7 (2)
C6—C1—C2—C3	−0.4 (2)	C3—C4—C8—O3	1.1 (3)
O2—C2—C3—C4	−179.06 (16)	C1—O1—C9—C10	177.95 (14)
C1—C2—C3—C4	0.4 (3)	O1—C9—C10—C9^i	59.39 (10)
C2—C3—C4—C5	−0.1 (3)

Symmetry code: (i) −x+1, −y, z.