2-(m-Tol­yloxy)benzoic acid

In the crystal structure of the title compound, C₁₄H₁₂O₃, the mol­ecules form classical O—H...O hydrogen-bonded carb­oxy­lic acid dimers. The dihedral angle between the two rings is 80.9 (3)°.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.052
• wR factor = 0.116
• Data-to-parameter ratio = 13.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C3     --  C4      ..        6.0 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C6     --  C7      ..        6.0 su
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C13    --  C14     ..        5.5 su
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         O1
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         C2
PLAT334_ALERT_2_C Small Average Benzene  C-C Dist. C2     -C7            1.37 Ang.

Alert level G
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal ..........    0.03000 Deg.
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......          !

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   6 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 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
   2 ALERT type 5 Informative message, check

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S1. Comment

Diphenylethers areuseful as herbicides, ignifuges, antiinflammatories and also as intermediatesin the synthesis of xanthones, p-dibenzo-furans, and p-dibenzo-dioxines (Pellon, et al., 1995). Knowledge of the crystal structure of such benzoic acid derivatives gives us not only information about nuclearity of the complex molecule, but is important in understanding the behaviour of these compounds with respect to the mechanisms of pharmacological activities and physiological activities. Therefore, we have synthesized the title compound, (I), and report its crystal structure here.

The molecular structure of (I) is shown in Fig. 1, and the intermolecular O—H···O hydrogen bond (Table 1) results in the formation of carboxylic acid dimers (Fig. 2). The bond lengths are within normal ranges (Allen et al., 1987). Similar crystal structure of some compounds have been reported (Shi et al., 2011; Raghunathan et al., 1982; Zhang et al.., 2011).

In the molecule of (I), the dihedral angle of the rings( C3—C6) and (C8—C13) is 80.9 (3)°, the molecules were connected together via O—H···O intermolecular hydrogen bonds to form dimers, which seems to be very effective in the stabilization of the crystal structure.

Related literature

For related structures, see: Shi et al. (2011); Raghunathan et al. (1982); Zhang (2011). For the synthesis of the title compound, see: Pellon et al. (1995). For bond-length data, see: Allen et al. (1987).

S2. Experimental

The title compound, (I), was prepared by the method of Ullmann condensation reaction reported in literature (Pellon et al., 1995). A mixture of 2-chlorobenzoic acid (6.26 g; 0.04 mol), m-cresol (8.65 g; 0.08 mol), anhydrous K₂CO₃ (11.04 g; 0.08 mol), pyridine (1.58 g; 0.02 mol), Cu powder (0.2 g) and cuprous iodide (0.2 g) in 25 ml water was kept at reflux for two hours. The mixture was then basified with Na₂CO₃ solution and extracted with diethyl ether. The aqueous solution was acidified with HCl, the precipitated solid was filtered off and disolved in NaOH; the basic solution was filtered (charcoal) and acidified with acetic acid. The 2-(3-tolyloxy)benzoic acid was crystalized from the mixture.

S3. Refinement

H atoms were positioned geometrically and refined as riding groups, with O—H = 0.82 and C—H = 0.93 Å for aromatic H, and constrained to ride on their parent atoms, with Uiso(H) = xUeq(C), where x = 1.2 for aromatic H, and x = 1.5 for other H.

Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software (Enraf–Nonius, 1985); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I) (thermal ellipsoids are shown at 30% probability levels).
	Fig. 2. The structure of a dimer of (I).

2-(m-Tolyloxy)benzoic acid

Crystal data

C14H12O3	Z = 2
Mr = 228.24	F(000) = 240
Triclinic, P1	Dx = 1.308 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.193 (1) Å	Cell parameters from 25 reflections
b = 7.8000 (16) Å	θ = 9–12°
c = 14.868 (3) Å	µ = 0.09 mm^−1
α = 94.28 (3)°	T = 293 K
β = 97.50 (3)°	Block, colourless
γ = 102.54 (3)°	0.20 × 0.20 × 0.10 mm
V = 579.5 (2) Å^3

Data collection

Enraf–Nonius CAD-4 diffractometer	1132 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.030
Graphite monochromator	θmax = 25.4°, θmin = 1.4°
ω/2θ scans	h = 0→6
Absorption correction: ψ scan (North et al., 1968)	k = −9→9
Tmin = 0.982, Tmax = 0.991	l = −17→17
2387 measured reflections	3 standard reflections every 200 reflections
2132 independent reflections	intensity decay: 1%

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)] = 0.052	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.040P)^2] where P = (Fo^2 + 2Fc^2)/3
2132 reflections	(Δ/σ)max < 0.001
155 parameters	Δρmax = 0.12 e Å^−3
0 restraints	Δρmin = −0.12 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
O1	0.3075 (4)	0.93730 (19)	0.80140 (11)	0.0780 (6)
C1	0.1740 (8)	0.8008 (4)	0.4694 (2)	0.1111 (12)
H1A	0.3613	0.8039	0.4758	0.167*
H1B	0.1429	0.9087	0.4479	0.167*
H1C	0.0778	0.7027	0.4264	0.167*
O2	0.7293 (3)	0.95411 (19)	0.92424 (11)	0.0683 (6)
C2	0.0798 (7)	0.7808 (3)	0.56045 (19)	0.0694 (8)
O3	0.9363 (3)	1.21756 (19)	0.99325 (11)	0.0706 (6)
H3B	1.0355	1.1598	1.0172	0.106*
C3	0.2341 (6)	0.8720 (3)	0.63921 (19)	0.0660 (8)
H3A	0.3994	0.9455	0.6366	0.079*
C4	0.1428 (6)	0.8542 (3)	0.72192 (19)	0.0617 (8)
C5	−0.0968 (6)	0.7484 (3)	0.7283 (2)	0.0720 (8)
H5A	−0.1568	0.7396	0.7844	0.086*
C6	−0.2495 (6)	0.6544 (4)	0.6507 (2)	0.0856 (10)
H6A	−0.4126	0.5789	0.6539	0.103*
C7	−0.1597 (7)	0.6725 (4)	0.5675 (2)	0.0826 (10)
H7A	−0.2652	0.6092	0.5151	0.099*
C8	0.3485 (5)	1.1181 (3)	0.81945 (15)	0.0519 (7)
C9	0.1781 (5)	1.2089 (3)	0.77587 (16)	0.0640 (8)
H9A	0.0352	1.1490	0.7324	0.077*
C10	0.2199 (6)	1.3888 (3)	0.79684 (17)	0.0673 (8)
H10A	0.1049	1.4500	0.7672	0.081*
C11	0.4270 (6)	1.4776 (3)	0.86027 (17)	0.0671 (8)
H11A	0.4544	1.5992	0.8737	0.081*
C12	0.5958 (5)	1.3877 (3)	0.90456 (16)	0.0580 (7)
H12A	0.7366	1.4495	0.9482	0.070*
C13	0.5610 (5)	1.2048 (3)	0.88546 (14)	0.0459 (6)
C14	0.7462 (5)	1.1132 (3)	0.93547 (15)	0.0488 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.1006 (15)	0.0443 (9)	0.0743 (12)	0.0174 (10)	−0.0369 (12)	−0.0027 (9)
C1	0.168 (4)	0.092 (2)	0.081 (2)	0.049 (2)	0.014 (2)	0.0103 (19)
O2	0.0736 (13)	0.0455 (9)	0.0766 (12)	0.0160 (9)	−0.0205 (10)	−0.0042 (8)
C2	0.089 (2)	0.0538 (16)	0.0635 (19)	0.0329 (17)	−0.0149 (18)	−0.0047 (14)
O3	0.0756 (13)	0.0522 (10)	0.0735 (12)	0.0157 (10)	−0.0223 (11)	−0.0048 (9)
C3	0.070 (2)	0.0504 (15)	0.0723 (19)	0.0160 (14)	−0.0116 (17)	0.0070 (14)
C4	0.0639 (19)	0.0383 (13)	0.0723 (19)	0.0136 (13)	−0.0245 (16)	−0.0067 (13)
C5	0.070 (2)	0.0588 (16)	0.084 (2)	0.0207 (16)	0.0002 (18)	−0.0067 (15)
C6	0.066 (2)	0.0715 (19)	0.108 (3)	0.0098 (17)	−0.007 (2)	−0.014 (2)
C7	0.081 (2)	0.0577 (17)	0.095 (3)	0.0232 (18)	−0.036 (2)	−0.0216 (17)
C8	0.0642 (17)	0.0412 (12)	0.0474 (14)	0.0131 (13)	−0.0009 (13)	−0.0003 (11)
C9	0.0706 (19)	0.0557 (15)	0.0618 (17)	0.0210 (14)	−0.0129 (15)	0.0011 (13)
C10	0.081 (2)	0.0549 (16)	0.0689 (18)	0.0288 (15)	0.0007 (17)	0.0041 (14)
C11	0.083 (2)	0.0448 (14)	0.0751 (19)	0.0217 (15)	0.0086 (17)	0.0025 (14)
C12	0.0656 (18)	0.0453 (13)	0.0589 (16)	0.0100 (13)	0.0028 (14)	−0.0012 (12)
C13	0.0534 (15)	0.0438 (13)	0.0387 (13)	0.0108 (12)	0.0019 (12)	0.0040 (10)
C14	0.0523 (16)	0.0449 (13)	0.0446 (14)	0.0053 (13)	0.0035 (12)	−0.0012 (11)

Geometric parameters (Å, º)

O1—C8	1.380 (2)	C5—H5A	0.9300
O1—C4	1.389 (3)	C6—C7	1.384 (4)
C1—C2	1.506 (4)	C6—H6A	0.9300
C1—H1A	0.9600	C7—H7A	0.9300
C1—H1B	0.9600	C8—C9	1.377 (3)
C1—H1C	0.9600	C8—C13	1.390 (3)
O2—C14	1.222 (2)	C9—C10	1.378 (3)
C2—C7	1.365 (4)	C9—H9A	0.9300
C2—C3	1.380 (3)	C10—C11	1.357 (3)
O3—C14	1.304 (2)	C10—H10A	0.9300
O3—H3B	0.8200	C11—C12	1.371 (3)
C3—C4	1.380 (3)	C11—H11A	0.9300
C3—H3A	0.9300	C12—C13	1.401 (3)
C4—C5	1.355 (4)	C12—H12A	0.9300
C5—C6	1.371 (3)	C13—C14	1.476 (3)
C8—O1—C4	118.75 (17)	C2—C7—H7A	119.2
C2—C1—H1A	109.5	C6—C7—H7A	119.2
C2—C1—H1B	109.5	C9—C8—O1	121.0 (2)
H1A—C1—H1B	109.5	C9—C8—C13	121.0 (2)
C2—C1—H1C	109.5	O1—C8—C13	118.0 (2)
H1A—C1—H1C	109.5	C8—C9—C10	119.8 (2)
H1B—C1—H1C	109.5	C8—C9—H9A	120.1
C7—C2—C3	118.2 (3)	C10—C9—H9A	120.1
C7—C2—C1	121.2 (3)	C11—C10—C9	120.7 (2)
C3—C2—C1	120.7 (3)	C11—C10—H10A	119.7
C14—O3—H3B	109.5	C9—C10—H10A	119.7
C2—C3—C4	119.9 (3)	C10—C11—C12	119.9 (2)
C2—C3—H3A	120.1	C10—C11—H11A	120.1
C4—C3—H3A	120.1	C12—C11—H11A	120.1
C5—C4—C3	121.6 (3)	C11—C12—C13	121.4 (2)
C5—C4—O1	118.9 (3)	C11—C12—H12A	119.3
C3—C4—O1	119.3 (3)	C13—C12—H12A	119.3
C4—C5—C6	118.9 (3)	C8—C13—C12	117.2 (2)
C4—C5—H5A	120.5	C8—C13—C14	123.17 (19)
C6—C5—H5A	120.5	C12—C13—C14	119.6 (2)
C5—C6—C7	119.7 (3)	O2—C14—O3	121.7 (2)
C5—C6—H6A	120.2	O2—C14—C13	124.1 (2)
C7—C6—H6A	120.2	O3—C14—C13	114.12 (19)
C2—C7—C6	121.7 (3)
C7—C2—C3—C4	−0.9 (4)	C13—C8—C9—C10	0.9 (4)
C1—C2—C3—C4	179.0 (2)	C8—C9—C10—C11	−0.2 (4)
C2—C3—C4—C5	0.0 (4)	C9—C10—C11—C12	−0.4 (4)
C2—C3—C4—O1	175.7 (2)	C10—C11—C12—C13	0.4 (4)
C8—O1—C4—C5	−110.5 (3)	C9—C8—C13—C12	−0.9 (3)
C8—O1—C4—C3	73.7 (3)	O1—C8—C13—C12	−178.5 (2)
C3—C4—C5—C6	1.3 (4)	C9—C8—C13—C14	178.8 (2)
O1—C4—C5—C6	−174.5 (2)	O1—C8—C13—C14	1.2 (3)
C4—C5—C6—C7	−1.6 (4)	C11—C12—C13—C8	0.2 (4)
C3—C2—C7—C6	0.6 (4)	C11—C12—C13—C14	−179.4 (2)
C1—C2—C7—C6	−179.3 (3)	C8—C13—C14—O2	−0.6 (4)
C5—C6—C7—C2	0.7 (4)	C12—C13—C14—O2	179.0 (2)
C4—O1—C8—C9	18.2 (4)	C8—C13—C14—O3	178.6 (2)
C4—O1—C8—C13	−164.2 (2)	C12—C13—C14—O3	−1.8 (3)
O1—C8—C9—C10	178.4 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3B···O2^i	0.82	1.83	2.648 (2)	176

Symmetry code: (i) −x+2, −y+2, −z+2.