4-Hydro­xy-3,5-di­methoxy­benz­aldehyde (syring­aldehyde)

Molecules of syring­aldehyde, C₉H₁₀O₄, are connected by intermolecular O—H...O [H...O = 2.05 Å and O...O = 2.713 (2) Å] hydrogen bonds between the 4-hydroxy and 1-aldehyde functions into infinite linear chains. The 4-hydroxy H atoms also participate in an intramolecular O—H...O [H...O = 2.22 Å and O...O = 2.662 (2) Å] interaction with a neighbouring methoxy O atom.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.040
• wR factor = 0.111
• Data-to-parameter ratio = 12.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT432_ALERT_2_C Short Inter X...Y Contact  O4     ..  C11     ..       2.98 Ang.

   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: R3m/V User's Guide (Siemens, 1989); cell refinement: R3m/V User's Guide; data reduction: XDISK in R3m/V User's Guide; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1995); software used to prepare material for publication: SHELXL97.

4-hydroxy-3,5-dimethoxybenzaldehyde

Crystal data

C9H10O4	F(000) = 384
Mr = 182.17	Dx = 1.420 Mg m^−3
Monoclinic, P21/n	Melting point: not measured K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 6.9076 (10) Å	Cell parameters from 19 reflections
b = 4.895 (3) Å	θ = 8.2–12.4°
c = 25.213 (4) Å	µ = 0.11 mm^−1
β = 91.349 (7)°	T = 293 K
V = 852.2 (6) Å^3	Prism, colourless
Z = 4	0.42 × 0.36 × 0.34 mm

Data collection

Siemens P4 4-circle diffractometer	Rint = 0.054
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 3.1°
Graphite monochromator	h = −1→8
Profile fitted scans	k = −1→5
2332 measured reflections	l = −29→29
1483 independent reflections	3 standard reflections every 100 reflections
1252 reflections with I > 2σ(I)	intensity decay: 2%

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)] = 0.040	H-atom parameters constrained
wR(F^2) = 0.111	w = 1/[σ^2(Fo^2) + (0.064P)^2 + 0.1548P] where P = (Fo^2 + 2Fc^2)/3
S = 1.04	(Δ/σ)max < 0.001
1483 reflections	Δρmax = 0.21 e Å^−3
121 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.122 (16)

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 > σ(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
C1	0.8740 (2)	0.3635 (3)	0.12698 (6)	0.0417 (4)
O1	1.16438 (16)	0.5265 (3)	0.08884 (5)	0.0605 (4)
C11	1.0510 (2)	0.5232 (4)	0.12479 (7)	0.0500 (4)
H11	1.0802	0.6337	0.1539	0.060*
C2	0.7477 (2)	0.4147 (3)	0.16799 (6)	0.0425 (4)
H2	0.7793	0.5453	0.1935	0.051*
C3	0.5754 (2)	0.2723 (3)	0.17096 (5)	0.0403 (4)
O3	0.43999 (16)	0.3047 (3)	0.20920 (4)	0.0561 (4)
C31	0.4707 (3)	0.5162 (4)	0.24657 (6)	0.0537 (5)
H31	0.5896	0.4837	0.2661	0.081*
H33	0.3651	0.5205	0.2706	0.081*
H32	0.4784	0.6881	0.2284	0.081*
C4	0.5315 (2)	0.0750 (3)	0.13278 (6)	0.0392 (4)
O4	0.36429 (15)	−0.0622 (3)	0.13713 (4)	0.0523 (4)
H4	0.3533	−0.1726	0.1128	0.078*
C5	0.6600 (2)	0.0258 (3)	0.09159 (5)	0.0392 (4)
O5	0.59730 (16)	−0.1720 (2)	0.05728 (4)	0.0511 (4)
C51	0.7138 (3)	−0.2265 (4)	0.01217 (6)	0.0549 (5)
H51	0.6511	−0.3613	−0.0099	0.082*
H52	0.8382	−0.2934	0.0239	0.082*
H53	0.7302	−0.0612	−0.0077	0.082*
C6	0.8310 (2)	0.1680 (3)	0.08848 (6)	0.0418 (4)
H6	0.9160	0.1342	0.0612	0.050*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0367 (8)	0.0438 (8)	0.0447 (8)	−0.0069 (6)	0.0053 (6)	−0.0007 (7)
O1	0.0485 (7)	0.0695 (9)	0.0644 (7)	−0.0228 (6)	0.0212 (6)	−0.0169 (6)
C11	0.0427 (8)	0.0557 (10)	0.0519 (9)	−0.0133 (7)	0.0099 (7)	−0.0109 (8)
C2	0.0426 (8)	0.0429 (8)	0.0422 (8)	−0.0072 (7)	0.0058 (6)	−0.0053 (7)
C3	0.0377 (7)	0.0443 (8)	0.0393 (7)	−0.0046 (6)	0.0082 (6)	−0.0003 (6)
O3	0.0515 (7)	0.0628 (8)	0.0549 (7)	−0.0171 (6)	0.0235 (5)	−0.0161 (6)
C31	0.0596 (10)	0.0543 (10)	0.0478 (9)	−0.0006 (8)	0.0151 (7)	−0.0075 (8)
C4	0.0341 (7)	0.0417 (8)	0.0421 (7)	−0.0072 (6)	0.0043 (6)	0.0024 (6)
O4	0.0442 (6)	0.0573 (7)	0.0561 (7)	−0.0216 (5)	0.0144 (5)	−0.0107 (5)
C5	0.0396 (8)	0.0391 (8)	0.0390 (7)	−0.0054 (6)	0.0028 (6)	−0.0018 (6)
O5	0.0494 (6)	0.0544 (7)	0.0499 (6)	−0.0160 (5)	0.0113 (5)	−0.0149 (5)
C51	0.0558 (9)	0.0629 (11)	0.0465 (8)	−0.0088 (8)	0.0097 (7)	−0.0153 (8)
C6	0.0372 (7)	0.0461 (9)	0.0426 (8)	−0.0047 (6)	0.0095 (6)	−0.0023 (7)

Geometric parameters (Å, º)

C1—C6	1.390 (2)	C31—H32	0.9600
C1—C2	1.391 (2)	C4—O4	1.3430 (18)
C1—C11	1.453 (2)	C4—C5	1.403 (2)
O1—C11	1.2118 (19)	O4—H4	0.8200
C11—H11	0.9300	C5—O5	1.3625 (18)
C2—C3	1.383 (2)	C5—C6	1.374 (2)
C2—H2	0.9300	O5—C51	1.4339 (18)
C3—O3	1.3684 (16)	C51—H51	0.9600
C3—C4	1.392 (2)	C51—H52	0.9600
O3—C31	1.412 (2)	C51—H53	0.9600
C31—H31	0.9600	C6—H6	0.9300
C31—H33	0.9600
C6—C1—C2	121.03 (13)	H33—C31—H32	109.5
C6—C1—C11	120.64 (13)	O4—C4—C3	117.65 (13)
C2—C1—C11	118.32 (14)	O4—C4—C5	122.36 (13)
O1—C11—C1	126.50 (15)	C3—C4—C5	119.98 (13)
O1—C11—H11	116.8	C4—O4—H4	109.5
C1—C11—H11	116.8	O5—C5—C6	125.78 (13)
C3—C2—C1	120.33 (14)	O5—C5—C4	113.23 (12)
C3—C2—H2	119.8	C6—C5—C4	120.99 (13)
C1—C2—H2	119.8	C5—O5—C51	117.35 (11)
O3—C3—C2	125.66 (13)	O5—C51—H51	109.5
O3—C3—C4	115.25 (12)	O5—C51—H52	109.5
C2—C3—C4	119.08 (13)	H51—C51—H52	109.5
C3—O3—C31	117.43 (12)	O5—C51—H53	109.5
O3—C31—H31	109.5	H51—C51—H53	109.5
O3—C31—H33	109.5	H52—C51—H53	109.5
H31—C31—H33	109.5	C5—C6—C1	118.59 (13)
O3—C31—H32	109.5	C5—C6—H6	120.7
H31—C31—H32	109.5	C1—C6—H6	120.7

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O1^i	0.82	2.05	2.7133 (19)	138
C11—H11···O4^ii	0.93	2.51	2.978 (2)	112
O4—H4···O5	0.82	2.22	2.6618 (15)	114

Symmetry codes: (i) x−1, y−1, z; (ii) x+1, y+1, z.