The title compound, C
8H
8O
4, has an intramolecular O—H
O hydrogen bond. Intermolecular O—H
O hydrogen bonding gives rise to a dimeric structure, which is further extended into infinite stacks parallel to the
a axis
via π–π interactions between the aromatic rings of neigboring molecules.
Supporting information
CCDC reference: 647725
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.002 Å
- R factor = 0.038
- wR factor = 0.116
- Data-to-parameter ratio = 12.0
checkCIF/PLATON results
No syntax errors found
Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature 293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature . 293 K
0 ALERT level A = In general: serious problem
0 ALERT level B = Potentially serious problem
0 ALERT level C = Check and explain
2 ALERT level G = General alerts; check
2 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
0 ALERT type 4 Improvement, methodology, query or suggestion
0 ALERT type 5 Informative message, check
Data collection: APEXII (Bruker, 2004); cell refinement: SAINT (Bruker, 2004); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2004); software used to prepare material for publication: SHELXTL.
2-Hydroxy-3-methoxybenzoic acid
top
Crystal data top
C8H8O4 | F(000) = 352 |
Mr = 168.14 | Dx = 1.464 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2yn | Cell parameters from 2100 reflections |
a = 3.8668 (2) Å | θ = 2.2–26.0° |
b = 27.9090 (11) Å | µ = 0.12 mm−1 |
c = 7.0885 (3) Å | T = 293 K |
β = 94.319 (2)° | Lamellar, yellow |
V = 762.81 (6) Å3 | 0.20 × 0.18 × 0.15 mm |
Z = 4 | |
Data collection top
Bruker APEXII area-detector diffractometer | 1051 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.024 |
Graphite monochromator | θmax = 25.2°, θmin = 1.5° |
φ and ω scans | h = −4→4 |
4322 measured reflections | k = −30→33 |
1346 independent reflections | l = −8→6 |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.038 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.116 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.069P)2 + 0.0476P] where P = (Fo2 + 2Fc2)/3 |
1346 reflections | (Δ/σ)max = 0.001 |
112 parameters | Δρmax = 0.12 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.4035 (4) | 0.17003 (5) | 0.1476 (2) | 0.0460 (4) | |
C2 | 0.2917 (4) | 0.13424 (5) | 0.2686 (2) | 0.0447 (4) | |
C3 | 0.2827 (4) | 0.08649 (5) | 0.20800 (19) | 0.0448 (4) | |
C4 | 0.3878 (4) | 0.07488 (6) | 0.0281 (2) | 0.0550 (4) | |
H4 | 0.3834 | 0.0432 | −0.0123 | 0.066* | |
C5 | 0.4962 (4) | 0.11006 (6) | −0.0875 (2) | 0.0590 (5) | |
H5 | 0.5648 | 0.1023 | −0.2066 | 0.071* | |
C6 | 0.5044 (4) | 0.15738 (6) | −0.0276 (2) | 0.0530 (4) | |
H6 | 0.5795 | 0.1810 | −0.1075 | 0.064* | |
C7 | 0.1627 (4) | 0.04937 (5) | 0.3328 (2) | 0.0501 (4) | |
C8 | 0.5193 (5) | 0.25334 (6) | 0.1062 (2) | 0.0618 (5) | |
H8A | 0.7517 | 0.2465 | 0.0753 | 0.093* | |
H8B | 0.5167 | 0.2829 | 0.1755 | 0.093* | |
H8C | 0.3711 | 0.2562 | −0.0082 | 0.093* | |
O1 | 0.0536 (3) | 0.05803 (4) | 0.48888 (16) | 0.0623 (4) | |
O2 | 0.1764 (4) | 0.00539 (4) | 0.26777 (16) | 0.0730 (4) | |
H2 | 0.1122 | −0.0134 | 0.3471 | 0.109* | |
O3 | 0.1979 (3) | 0.14855 (4) | 0.43896 (16) | 0.0610 (4) | |
H3 | 0.1345 | 0.1253 | 0.4980 | 0.092* | |
O4 | 0.3980 (3) | 0.21545 (4) | 0.21884 (15) | 0.0578 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.0465 (9) | 0.0449 (8) | 0.0462 (9) | 0.0002 (6) | 0.0014 (7) | 0.0042 (6) |
C2 | 0.0486 (9) | 0.0473 (8) | 0.0384 (8) | 0.0027 (6) | 0.0051 (6) | 0.0002 (6) |
C3 | 0.0486 (9) | 0.0440 (8) | 0.0417 (8) | 0.0034 (6) | 0.0027 (6) | −0.0001 (6) |
C4 | 0.0660 (10) | 0.0516 (9) | 0.0479 (9) | 0.0054 (7) | 0.0066 (8) | −0.0062 (7) |
C5 | 0.0654 (11) | 0.0698 (11) | 0.0426 (8) | 0.0059 (8) | 0.0106 (8) | −0.0023 (8) |
C6 | 0.0523 (10) | 0.0610 (10) | 0.0464 (9) | 0.0007 (7) | 0.0079 (7) | 0.0102 (8) |
C7 | 0.0620 (10) | 0.0408 (8) | 0.0476 (9) | 0.0025 (7) | 0.0047 (8) | −0.0034 (7) |
C8 | 0.0675 (11) | 0.0549 (10) | 0.0631 (11) | −0.0117 (8) | 0.0062 (9) | 0.0148 (7) |
O1 | 0.0964 (9) | 0.0413 (6) | 0.0516 (7) | −0.0021 (5) | 0.0202 (6) | −0.0002 (5) |
O2 | 0.1180 (11) | 0.0398 (7) | 0.0646 (8) | −0.0023 (6) | 0.0297 (7) | −0.0052 (5) |
O3 | 0.0970 (9) | 0.0423 (6) | 0.0464 (7) | −0.0032 (6) | 0.0230 (6) | −0.0018 (5) |
O4 | 0.0772 (8) | 0.0425 (6) | 0.0551 (7) | −0.0054 (5) | 0.0141 (6) | 0.0064 (5) |
Geometric parameters (Å, º) top
C1—O4 | 1.3651 (17) | C5—H5 | 0.9300 |
C1—C6 | 1.376 (2) | C6—H6 | 0.9300 |
C1—C2 | 1.406 (2) | C7—O1 | 1.2371 (17) |
C2—O3 | 1.3473 (18) | C7—O2 | 1.3138 (17) |
C2—C3 | 1.400 (2) | C8—O4 | 1.4256 (18) |
C3—C4 | 1.405 (2) | C8—H8A | 0.9600 |
C3—C7 | 1.460 (2) | C8—H8B | 0.9600 |
C4—C5 | 1.364 (2) | C8—H8C | 0.9600 |
C4—H4 | 0.9300 | O2—H2 | 0.8200 |
C5—C6 | 1.387 (2) | O3—H3 | 0.8200 |
| | | |
O4—C1—C6 | 125.84 (14) | C1—C6—C5 | 121.26 (15) |
O4—C1—C2 | 114.84 (14) | C1—C6—H6 | 119.4 |
C6—C1—C2 | 119.31 (14) | C5—C6—H6 | 119.4 |
O3—C2—C3 | 123.72 (14) | O1—C7—O2 | 121.45 (13) |
O3—C2—C1 | 116.88 (13) | O1—C7—C3 | 123.26 (13) |
C3—C2—C1 | 119.40 (14) | O2—C7—C3 | 115.28 (13) |
C2—C3—C4 | 119.72 (14) | O4—C8—H8A | 109.5 |
C2—C3—C7 | 119.41 (13) | O4—C8—H8B | 109.5 |
C4—C3—C7 | 120.87 (14) | H8A—C8—H8B | 109.5 |
C5—C4—C3 | 120.12 (15) | O4—C8—H8C | 109.5 |
C5—C4—H4 | 119.9 | H8A—C8—H8C | 109.5 |
C3—C4—H4 | 119.9 | H8B—C8—H8C | 109.5 |
C4—C5—C6 | 120.18 (15) | C7—O2—H2 | 109.5 |
C4—C5—H5 | 119.9 | C2—O3—H3 | 109.5 |
C6—C5—H5 | 119.9 | C1—O4—C8 | 117.81 (13) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O1i | 0.82 | 1.85 | 2.6703 (15) | 176 |
O3—H3···O1 | 0.82 | 1.90 | 2.6169 (14) | 145 |
Symmetry code: (i) −x, −y, −z+1. |