5-Fluoro­isophthalic acid

In the crystal structure of the title compound, C₈H₅FO₄, the complete molecule is generated by crystallographic twofold symmetry with two C atoms and the F atom lying on the axis. The mol­ecule is almost planar with the carboxyl group twisted with respect to the mean plane of the benzene ring by a dihedral angle of 2.01 (1)°. In the crystal, inter­molecular O—H⋯O hydrogen bonds and C—H⋯F inter­actions connect the mol­ecules into a two-dimensional supra­molecular array.

Related literature

For isophthalic acid, see: Bhogala et al. (2005); Derissen (1974). For the use of the title compound in crystal engin­eering, see: Zhang et al. (2010).

Experimental

Crystal data

• C₈H₅FO₄

• M_r = 184.12

• Monoclinic, P 2₁ /m

• a = 3.7736 (8) Å

• b = 16.292 (4) Å

• c = 6.2753 (14) Å

• β = 91.871 (5)°

• V = 385.60 (14) ų

• Z = 2

• Mo Kα radiation

• μ = 0.14 mm⁻¹

• T = 297 K

• 0.22 × 0.20 × 0.15 mm

Data collection

• Bruker APEXII CCD diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2003) T_min = 0.969, T_max = 0.979

• 2201 measured reflections

• 743 independent reflections

• 603 reflections with I > 2σ(I)

• R_int = 0.018

Refinement

• R[F² > 2σ(F²)] = 0.041

• wR(F²) = 0.161

• S = 1.04

• 743 reflections

• 64 parameters

• H-atom parameters constrained

• Δρ_max = 0.16 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2^i	0.82	1.81	2.625 (2)	174
C5—H5⋯F1^ii	0.93	2.52	3.404 (2)	160
Symmetry codes: (i) -x+1, -y+1, -z+2; (ii) x-1, y, z+1.

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL.

Supporting information

S1. Comment

As an analogue of isophthalic acid (Bhogala et al. 2005; Derissen, 1974), 5-fluoroisophthalic acid has been seldom used in the crystal engineering of organic or inorganic-organic systems (Zhang et al. 2010). The fluorinated group may participate in hydrogen-bonding and may also induce luminescence properties. Herein we report the crystal structure of the title compound, C₈H₅FO₄, to further investigate the supramolecular interactions involving the fluorine atom. The structure of the title compound, is shown below. The molecule presents C₂ symmetry with the fundamental unit lying on a C₂-axis at [x, 3/4, z]. Intermolecular O—H···O interactions between adjoining centrosymmetry-related carboxylic groups form a hydrogen-bonded ribbon running along the [010] direction. C—H···F interactions connect the ribbons into a two-dimensional supramolecular array.

Related literature

For isophthalic acid, see: Bhogala et al. (2005); Derissen (1974). For the use of the title compound in crystal engineering, see: Zhang et al. (2010).

S2. Experimental

5-Fluoroisophthalic acid and solvents for synthesis and analysis were commercially available and used as received. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of the methanol solution of the title compound.

S3. Refinement

Benzene H atoms were assigned to calculated positions with C—H = 0.93 Å, and refined using a riding model, with Uiso(H) = 1.2Ueq(C). H atoms bound to carboxylic O atoms were located in difference maps and refined as riding with U_iso(H) = 1.5 U_eq(O).

Computing details

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 2005); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of the title compound drawn with 30% probability ellipsoids.
	Fig. 2. Two-dimensional hydrogen-bonded layer of the title compound. Hydrogen bonds are indicated as dashed lines.

5-fluorobenzene-1,3-dicarboxylic acid

Crystal data

C8H5FO4	F(000) = 188
Mr = 184.12	Dx = 1.586 Mg m^−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yb	Cell parameters from 1020 reflections
a = 3.7736 (8) Å	θ = 2.5–28.0°
b = 16.292 (4) Å	µ = 0.14 mm^−1
c = 6.2753 (14) Å	T = 297 K
β = 91.871 (5)°	Block, colourless
V = 385.60 (14) Å^3	0.22 × 0.20 × 0.15 mm
Z = 2

Data collection

Bruker APEXII CCD diffractometer	743 independent reflections
Radiation source: fine-focus sealed tube	603 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.018
ϕ and ω scans	θmax = 25.5°, θmin = 2.5°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −4→4
Tmin = 0.969, Tmax = 0.979	k = −17→19
2201 measured reflections	l = −7→5

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.161	H-atom parameters constrained
S = 1.04	w = 1/[σ^2(Fo^2) + (0.1244P)^2] where P = (Fo^2 + 2Fc^2)/3
743 reflections	(Δ/σ)max < 0.001
64 parameters	Δρmax = 0.16 e Å^−3
0 restraints	Δρmin = −0.15 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.6268 (4)	0.59855 (9)	0.8588 (3)	0.0524 (5)
C2	0.7105 (4)	0.67633 (9)	0.7484 (2)	0.0487 (5)
C3	0.8602 (4)	0.67563 (10)	0.5486 (3)	0.0529 (5)
H3	0.9107	0.6265	0.4806	0.063*
C4	0.9312 (5)	0.7500	0.4549 (3)	0.0540 (6)
C5	0.6370 (5)	0.7500	0.8476 (3)	0.0477 (6)
H5	0.5379	0.7500	0.9813	0.057*
F1	1.0787 (4)	0.7500	0.2629 (2)	0.0744 (6)
O1	0.7073 (4)	0.53205 (8)	0.7622 (2)	0.0775 (6)
H1	0.6348	0.4905	0.8205	0.116*
O2	0.4837 (4)	0.60037 (7)	1.0328 (2)	0.0722 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0490 (9)	0.0612 (10)	0.0474 (10)	−0.0023 (6)	0.0088 (7)	−0.0080 (7)
C2	0.0385 (8)	0.0652 (11)	0.0424 (9)	−0.0012 (6)	0.0022 (6)	−0.0051 (6)
C3	0.0420 (9)	0.0726 (12)	0.0441 (10)	−0.0006 (6)	0.0027 (7)	−0.0087 (7)
C4	0.0426 (11)	0.0852 (16)	0.0346 (11)	0.000	0.0069 (9)	0.000
C5	0.0400 (10)	0.0642 (14)	0.0395 (11)	0.000	0.0072 (8)	0.000
F1	0.0745 (10)	0.1105 (12)	0.0393 (8)	0.000	0.0190 (7)	0.000
O1	0.1022 (11)	0.0610 (8)	0.0715 (10)	−0.0050 (6)	0.0359 (8)	−0.0121 (6)
O2	0.0938 (10)	0.0622 (9)	0.0628 (9)	−0.0038 (6)	0.0355 (7)	−0.0032 (5)

Geometric parameters (Å, º)

C1—O2	1.235 (2)	C3—H3	0.9300
C1—O1	1.2826 (19)	C4—F1	1.343 (2)
C1—C2	1.483 (2)	C4—C3^i	1.377 (2)
C2—C5	1.3841 (18)	C5—C2^i	1.3841 (19)
C2—C3	1.392 (2)	C5—H5	0.9300
C3—C4	1.377 (2)	O1—H1	0.8201
O2—C1—O1	123.73 (15)	C2—C3—H3	121.1
O2—C1—C2	119.91 (13)	F1—C4—C3	118.37 (11)
O1—C1—C2	116.35 (15)	F1—C4—C3^i	118.36 (11)
C5—C2—C3	120.34 (15)	C3—C4—C3^i	123.3 (2)
C5—C2—C1	118.83 (15)	C2—C5—C2^i	120.3 (2)
C3—C2—C1	120.83 (14)	C2—C5—H5	119.9
C4—C3—C2	117.89 (16)	C2^i—C5—H5	119.9
C4—C3—H3	121.1	C1—O1—H1	113.5
O2—C1—C2—C5	2.3 (3)	C1—C2—C3—C4	179.97 (14)
O1—C1—C2—C5	−178.51 (16)	C2—C3—C4—F1	179.40 (14)
O2—C1—C2—C3	−177.68 (14)	C2—C3—C4—C3^i	−0.3 (3)
O1—C1—C2—C3	1.5 (3)	C3—C2—C5—C2^i	0.3 (3)
C5—C2—C3—C4	0.0 (3)	C1—C2—C5—C2^i	−179.72 (12)

Symmetry code: (i) x, −y+3/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O2^ii	0.82	1.81	2.625 (2)	174
C5—H5···F1^iii	0.93	2.52	3.404 (2)	160

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