2,4-Dimeth­oxy-6-methyl­benzoic acid

In the crystal structure of the title compound, C₁₀H₁₂O₄, mol­ecules are linked into dimers through O—H...O hydrogen bonds. The dimers are further linked through C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C)= 0.001 Å
• R factor = 0.037
• wR factor = 0.111
• Data-to-parameter ratio = 19.2

checkCIF/PLATON results

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Computing details

Data collection: PROCESS-AUTO (Rigaku/MSC, 2004); cell refinement: PROCESS-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2004); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: CrystalStructure and PLATON (Spek, 2003).

(I)

Crystal data

C10H12O4	Z = 2
Mr = 196.20	F(000) = 208.00
Triclinic, P1	Dx = 1.366 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71075 Å
a = 7.3211 (3) Å	Cell parameters from 6151 reflections
b = 8.3536 (4) Å	θ = 3.1–30.0°
c = 8.5798 (4) Å	µ = 0.11 mm^−1
α = 88.847 (2)°	T = 150 K
β = 75.7410 (19)°	Block, colorless
γ = 70.0857 (19)°	0.55 × 0.50 × 0.25 mm
V = 476.97 (4) Å^3

Data collection

Rigaku RAXIS-RAPID II diffractometer	2301 reflections with I > 2σ(I)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.031
ω scans	θmax = 30.0°, θmin = 3.1°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −10→10
Tmin = 0.850, Tmax = 0.974	k = −11→11
7011 measured reflections	l = −11→12
2687 independent reflections

Refinement

Refinement on F^2	140 parameters
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.037	w = 1/[σ^2(Fo^2) + (0.0634P)^2 + 0.086P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.111	(Δ/σ)max < 0.001
S = 1.08	Δρmax = 0.29 e Å^−3
2687 reflections	Δρmin = −0.32 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 > 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	Occ. (<1)
O1	0.50299 (12)	0.20765 (9)	0.50292 (10)	0.03001 (18)
O2	0.33729 (11)	0.08888 (8)	0.38392 (9)	0.02661 (17)
O3	0.39058 (12)	0.22523 (8)	0.09065 (8)	0.02831 (18)
O4	0.07362 (12)	0.82553 (8)	0.12510 (9)	0.02782 (18)
C1	0.30530 (13)	0.37886 (10)	0.34056 (10)	0.01800 (17)
C2	0.30590 (13)	0.37919 (10)	0.17533 (10)	0.01980 (18)
C3	0.22875 (13)	0.53113 (11)	0.10681 (10)	0.02102 (18)
H3	0.2306	0.5312	−0.0020	0.025*
C4	0.14833 (13)	0.68379 (11)	0.20279 (11)	0.02028 (18)
C5	0.14658 (13)	0.68605 (10)	0.36508 (10)	0.01975 (18)
H5	0.0922	0.7890	0.4274	0.024*
C6	0.22656 (12)	0.53363 (10)	0.43470 (10)	0.01795 (17)
C7	0.38594 (13)	0.21432 (10)	0.41187 (10)	0.01870 (17)
C8	0.38676 (17)	0.21950 (13)	−0.07482 (12)	0.0298 (2)
H8A	0.2501	0.2636	−0.0826	0.045*
H8B	0.4480	0.1036	−0.1198	0.045*
H8C	0.4596	0.2875	−0.1333	0.045*
C9	−0.0101 (2)	0.98688 (12)	0.21640 (14)	0.0354 (3)
H9A	−0.1192	0.9857	0.3049	0.053*
H9B	−0.0586	1.0757	0.1484	0.053*
H9C	0.0915	1.0075	0.2571	0.053*
C10	0.21727 (14)	0.54317 (11)	0.61205 (10)	0.02157 (18)
H10A	0.3491	0.5250	0.6255	0.032*
H10B	0.1690	0.4570	0.6634	0.032*
H10C	0.1278	0.6537	0.6601	0.032*
H1	0.544 (4)	0.115 (4)	0.535 (3)	0.025 (8)*	0.56 (4)
H2	0.392 (6)	−0.004 (5)	0.418 (5)	0.041 (13)*	0.44 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0372 (4)	0.0232 (3)	0.0361 (4)	−0.0091 (3)	−0.0233 (3)	0.0089 (3)
O2	0.0359 (4)	0.0165 (3)	0.0303 (4)	−0.0093 (3)	−0.0135 (3)	0.0040 (3)
O3	0.0426 (4)	0.0174 (3)	0.0181 (3)	−0.0006 (3)	−0.0093 (3)	−0.0026 (2)
O4	0.0424 (4)	0.0155 (3)	0.0233 (3)	−0.0036 (3)	−0.0138 (3)	0.0044 (2)
C1	0.0208 (4)	0.0148 (3)	0.0180 (4)	−0.0044 (3)	−0.0068 (3)	0.0018 (3)
C2	0.0235 (4)	0.0159 (4)	0.0179 (4)	−0.0039 (3)	−0.0055 (3)	−0.0006 (3)
C3	0.0264 (4)	0.0185 (4)	0.0165 (4)	−0.0049 (3)	−0.0064 (3)	0.0018 (3)
C4	0.0236 (4)	0.0158 (3)	0.0212 (4)	−0.0052 (3)	−0.0079 (3)	0.0040 (3)
C5	0.0234 (4)	0.0147 (3)	0.0204 (4)	−0.0050 (3)	−0.0065 (3)	0.0002 (3)
C6	0.0200 (4)	0.0165 (3)	0.0179 (4)	−0.0061 (3)	−0.0062 (3)	0.0014 (3)
C7	0.0213 (4)	0.0154 (3)	0.0178 (4)	−0.0039 (3)	−0.0056 (3)	0.0004 (3)
C8	0.0423 (6)	0.0249 (4)	0.0187 (4)	−0.0062 (4)	−0.0086 (4)	−0.0034 (3)
C9	0.0545 (7)	0.0161 (4)	0.0300 (5)	−0.0020 (4)	−0.0158 (5)	0.0031 (4)
C10	0.0275 (4)	0.0205 (4)	0.0173 (4)	−0.0079 (3)	−0.0072 (3)	0.0009 (3)

Geometric parameters (Å, º)

O1—C7	1.2819 (11)	C4—C5	1.3898 (12)
O1—H1	0.80 (3)	C5—C6	1.3980 (11)
O2—C7	1.2605 (11)	C5—H5	0.9300
O2—H2	0.83 (4)	C6—C10	1.5088 (12)
O3—C2	1.3560 (10)	C8—H8A	0.9599
O3—C8	1.4289 (11)	C8—H8B	0.9599
O4—C4	1.3609 (10)	C8—H8C	0.9599
O4—C9	1.4314 (12)	C9—H9A	0.9599
C1—C6	1.4004 (11)	C9—H9B	0.9599
C1—C2	1.4165 (12)	C9—H9C	0.9599
C1—C7	1.4844 (11)	C10—H10A	0.9599
C2—C3	1.3859 (11)	C10—H10B	0.9599
C3—C4	1.3940 (12)	C10—H10C	0.9599
C3—H3	0.9300
C7—O1—H1	111.8 (17)	O2—C7—O1	122.52 (8)
C7—O2—H2	119 (2)	O2—C7—C1	120.32 (8)
C2—O3—C8	117.80 (7)	O1—C7—C1	117.15 (7)
C4—O4—C9	117.73 (7)	O3—C8—H8A	109.5
C6—C1—C2	119.52 (7)	O3—C8—H8B	109.5
C6—C1—C7	120.95 (7)	H8A—C8—H8B	109.5
C2—C1—C7	119.52 (7)	O3—C8—H8C	109.5
O3—C2—C3	123.31 (8)	H8A—C8—H8C	109.5
O3—C2—C1	116.18 (7)	H8B—C8—H8C	109.5
C3—C2—C1	120.49 (8)	O4—C9—H9A	109.5
C2—C3—C4	119.25 (8)	O4—C9—H9B	109.5
C2—C3—H3	120.4	H9A—C9—H9B	109.5
C4—C3—H3	120.4	O4—C9—H9C	109.5
O4—C4—C5	124.09 (8)	H9A—C9—H9C	109.5
O4—C4—C3	114.82 (8)	H9B—C9—H9C	109.5
C5—C4—C3	121.09 (8)	C6—C10—H10A	109.5
C4—C5—C6	120.05 (8)	C6—C10—H10B	109.5
C4—C5—H5	120.0	H10A—C10—H10B	109.5
C6—C5—H5	120.0	C6—C10—H10C	109.5
C5—C6—C1	119.59 (8)	H10A—C10—H10C	109.5
C5—C6—C10	117.82 (7)	H10B—C10—H10C	109.5
C1—C6—C10	122.55 (7)
C8—O3—C2—C3	−4.46 (14)	O4—C4—C5—C6	179.87 (8)
C8—O3—C2—C1	177.53 (8)	C3—C4—C5—C6	0.09 (14)
C6—C1—C2—O3	177.87 (8)	C4—C5—C6—C1	−1.01 (13)
C7—C1—C2—O3	−2.85 (13)	C4—C5—C6—C10	−178.89 (8)
C6—C1—C2—C3	−0.20 (13)	C2—C1—C6—C5	1.07 (13)
C7—C1—C2—C3	179.08 (8)	C7—C1—C6—C5	−178.21 (8)
O3—C2—C3—C4	−178.64 (8)	C2—C1—C6—C10	178.84 (8)
C1—C2—C3—C4	−0.72 (14)	C7—C1—C6—C10	−0.43 (13)
C9—O4—C4—C5	0.63 (14)	C6—C1—C7—O2	133.29 (9)
C9—O4—C4—C3	−179.58 (9)	C2—C1—C7—O2	−45.99 (12)
C2—C3—C4—O4	−179.02 (8)	C6—C1—C7—O1	−45.88 (12)
C2—C3—C4—C5	0.78 (14)	C2—C1—C7—O1	134.85 (9)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^i	0.80 (2)	1.84 (2)	2.6335 (9)	172 (3)
O2—H2···O1^i	0.83 (4)	1.81 (4)	2.6335 (9)	177 (4)
C9—H9C···O2^ii	0.96	2.59	3.5477 (17)	174
C9—H9B···O4^iii	0.96	2.49	3.3536 (14)	150

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