2,6-Bis(trifluoro­meth­yl)benzoic acid

Tobin, J.M.; Masuda, J.D.

doi:10.1107/S1600536809016468

organic compounds

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page o1217

doi:10.1107/S1600536809016468

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2,6-Bis(trifluoromethyl)benzoic acid

John M. Tobin ^a and Jason D. Masuda ^a ^*

^aDepartment of Chemistry, Saint Mary's University, 923 Robie Street, Halifax, NS, Canada B3H 3C3
^*Correspondence e-mail: jason.masuda@smu.ca

(Received 24 April 2009; accepted 1 May 2009; online 7 May 2009)

The title compound, C₉H₄F₆O₂, contains two molecules in the asymmetric unit, one of which exhibits disorder in both of its trifluoromethyl groups. The dihedral angles between the benzene ring and the carboxyl group are 71.5 (2) and 99.3 (2)° in the two independent molecules. The compound exhibits a catemeric structure resulting from intermolecular O—H⋯O hydrogen bonding between the carboxyl groups.

Related literature

There is only one example in the literature of a crystallographically characterized benzoic acid with trifluoromethyl groups in the ortho position, namely 2-trifluoromethyl-3-pyrrole benzoic acid (see Faigl et al., 1999 ). For a recent example of crystal engineering to promote the formation of dimeric or catemeric structures in benzoic acids, see: Moorthy et al. (2002 ). For synthesis details, see: Dmowski & Piasecka-Macieiewska (1998 ).

Experimental

Crystal data

C₉H₄F₆O₂
M_r = 258.12
Monoclinic, P 2₁ /c
a = 10.873 (2) Å
b = 15.755 (3) Å
c = 11.561 (2) Å
β = 94.961 (2)°
V = 1973.0 (6) Å³
Z = 8
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 296 K
0.39 × 0.31 × 0.26 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ) T_min = 0.834, T_max = 0.951
12904 measured reflections
3438 independent reflections
2889 reflections with I > 2σ(I)
R_int = 0.021

Refinement

R[F² > 2σ(F²)] = 0.039
wR(F²) = 0.112
S = 1.02
3438 reflections
331 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2A⋯O4ⁱ	0.82	1.82	2.6340 (19)	169
O3—H3A⋯O1	0.82	1.88	2.6951 (18)	176
Symmetry code: (i) $[x, -y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and Mercury (Macrae et al., 2006 ); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809016468/bi2369sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809016468/bi2369Isup2.hkl

checkCIF report

Comment top

The title molecule crystallizes in a catemer motif, a relatively rare form compared to the typical dimeric motif exhibited by benzoic acids resulting from intermolecular hydrogen bonding between the carboxylic acid groups (Moorthy et al., 2002). The sterically bulky o-CF₃ groups result in the carboxylic acid fragments being twisted with respect to the aryl ring. This results in dihedral angles between the aryl ring and carboxylic acid fragments of C7—C2—C1—O1 = 71.5 (2)° and C12—C11—C10—O4 = 99.3 (2)°.

Related literature top

There is only one example in the literature of a crystallographically characterized benzoic acid with trifluoromethyl groups in the ortho position, namely 2-trifluoromethyl-3-pyrrole benzoic acid (see Faigl et al., 1999). For a recent example of crystal engineering to promote the formation of dimeric or catemeric structures in benzoic acids, see: Moorthy et al. (2002). For synthesis details, see: Dmowski & Piasecka-Macieiewska (1998).

Experimental top

The title compound was prepared following the literature methods (Dmowski & Piasecka-Macieiewska, 1998) with a slight modification. The compound crystallized from the oily reaction mixture that remained after acidification of the potassium benzoate salt with concentrated HCl, extraction of the organic components with toluene, drying of the organic fraction with magnesium sulfate and concentration by rotary evaporation.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. The two molecules in the asymmetric unit with displacement ellipsoids shown at 50% probability for non-H atoms. For the disordered CF₃ groups, both disorder components are shown.
	Fig. 2. Ball and stick representation featuring the catemeric structure formed through O—H···O hydrogen bonding. H atoms not involved in H-bonding and the CF₃ groups have been omitted for clarity.

2,6-Bis(trifluoromethyl)benzoic acid top

Crystal data top

C₉H₄F₆O₂	F(000) = 1024
M_r = 258.12	D_x = 1.738 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 6970 reflections
a = 10.873 (2) Å	θ = 2.3–28.0°
b = 15.755 (3) Å	µ = 0.20 mm⁻¹
c = 11.561 (2) Å	T = 296 K
β = 94.961 (2)°	Block, colorless
V = 1973.0 (6) Å³	0.39 × 0.31 × 0.26 mm
Z = 8

Data collection top

Bruker APEXII CCD diffractometer	3438 independent reflections
Radiation source: fine-focus sealed tube	2889 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.021
ϕ and ω scans	θ_max = 25.0°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −12→12
T_min = 0.834, T_max = 0.951	k = −18→18
12904 measured reflections	l = −13→11

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.112	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.058P)² + 0.5224P] where P = (F_o² + 2F_c²)/3
3438 reflections	(Δ/σ)_max < 0.001
331 parameters	Δρ_max = 0.21 e Å⁻³
0 restraints	Δρ_min = −0.23 e Å⁻³

Crystal data top

C₉H₄F₆O₂	V = 1973.0 (6) Å³
M_r = 258.12	Z = 8
Monoclinic, P2₁/c	Mo Kα radiation
a = 10.873 (2) Å	µ = 0.20 mm⁻¹
b = 15.755 (3) Å	T = 296 K
c = 11.561 (2) Å	0.39 × 0.31 × 0.26 mm
β = 94.961 (2)°

Data collection top

Bruker APEXII CCD diffractometer	3438 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2008)	2889 reflections with I > 2σ(I)
T_min = 0.834, T_max = 0.951	R_int = 0.021
12904 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	0 restraints
wR(F²) = 0.112	H-atom parameters constrained
S = 1.02	Δρ_max = 0.21 e Å⁻³
3438 reflections	Δρ_min = −0.23 e Å⁻³
331 parameters

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	U_iso*/U_eq	Occ. (<1)
C1	0.25273 (16)	0.14562 (11)	0.00186 (14)	0.0532 (4)
C2	0.34011 (15)	0.08652 (10)	0.07069 (14)	0.0490 (4)
C3	0.43893 (16)	0.11687 (12)	0.14433 (16)	0.0564 (4)
C4	0.51596 (17)	0.06028 (14)	0.20807 (17)	0.0666 (5)
H4A	0.5807	0.0808	0.2581	0.080*
C5	0.49740 (19)	−0.02557 (14)	0.19783 (18)	0.0689 (5)
H5A	0.5498	−0.0629	0.2405	0.083*
C6	0.40178 (18)	−0.05640 (12)	0.12489 (16)	0.0614 (5)
H6A	0.3900	−0.1147	0.1175	0.074*
C7	0.32257 (15)	−0.00131 (10)	0.06209 (14)	0.0508 (4)
C8	0.46743 (19)	0.20978 (14)	0.1562 (2)	0.0756 (6)
F1	0.5244 (2)	0.22865 (11)	0.25885 (18)	0.1361 (7)
F2	0.53907 (15)	0.23619 (9)	0.07602 (19)	0.1232 (7)
F3	0.36850 (12)	0.25931 (8)	0.14440 (14)	0.0893 (4)
C9	0.21830 (18)	−0.03876 (12)	−0.01534 (17)	0.0632 (5)
F4	0.11518 (12)	−0.04286 (10)	0.03733 (13)	0.0975 (4)
F5	0.19338 (14)	0.00483 (8)	−0.11254 (11)	0.0911 (4)
F6	0.24344 (13)	−0.11707 (8)	−0.04877 (12)	0.0906 (4)
C10	0.10257 (17)	0.15284 (11)	0.30263 (15)	0.0545 (4)
C11	0.07034 (16)	0.13002 (10)	0.42282 (14)	0.0514 (4)
C12	−0.04150 (17)	0.15569 (11)	0.46310 (15)	0.0561 (4)
C13	−0.0643 (2)	0.14110 (13)	0.57757 (18)	0.0711 (5)
H13A	−0.1380	0.1593	0.6045	0.085*
C14	0.0220 (2)	0.09977 (15)	0.65140 (18)	0.0801 (6)
H14A	0.0066	0.0906	0.7283	0.096*
C15	0.1301 (2)	0.07212 (14)	0.61252 (17)	0.0730 (6)
H15A	0.1869	0.0430	0.6626	0.088*
C16	0.15558 (18)	0.08709 (12)	0.49899 (16)	0.0603 (5)
O1	0.14736 (11)	0.15753 (8)	0.02411 (10)	0.0606 (3)
O2	0.30404 (14)	0.18036 (9)	−0.08444 (12)	0.0751 (4)
H2A	0.2549	0.2129	−0.1192	0.113*
O3	0.05615 (13)	0.10397 (9)	0.22093 (11)	0.0684 (4)
H3A	0.0818	0.1182	0.1592	0.103*
O4	0.16936 (19)	0.21110 (11)	0.28586 (13)	0.0999 (6)
C17	−0.13950 (10)	0.19782 (8)	0.38373 (10)	0.0726 (5)
F7A	−0.09321 (12)	0.25255 (8)	0.31618 (10)	0.1010 (13)	0.569 (5)
F8A	−0.19164 (10)	0.13805 (10)	0.31178 (10)	0.0901 (11)	0.569 (5)
F9A	−0.22489 (10)	0.23045 (8)	0.43893 (12)	0.139 (2)	0.569 (5)
F7B	−0.17175 (10)	0.16347 (9)	0.28614 (11)	0.144 (3)	0.431 (5)
F9B	−0.10986 (11)	0.28028 (10)	0.35381 (9)	0.1164 (19)	0.431 (5)
F8B	−0.24254 (11)	0.21614 (8)	0.43317 (12)	0.0970 (19)	0.431 (5)
C18	0.27540 (10)	0.05569 (8)	0.46034 (11)	0.0751 (6)
F10A	0.26369 (10)	0.01894 (8)	0.35789 (13)	0.0877 (11)	0.689 (5)
F11A	0.36230 (10)	0.11205 (10)	0.46284 (11)	0.1163 (14)	0.689 (5)
F12A	0.32020 (9)	−0.01015 (9)	0.52898 (13)	0.1142 (11)	0.689 (5)
F10B	0.33236 (9)	0.12165 (10)	0.40107 (11)	0.108 (2)	0.311 (5)
F12B	0.35672 (10)	0.03614 (8)	0.54011 (13)	0.125 (3)	0.311 (5)
F11B	0.26173 (10)	0.00490 (9)	0.37781 (12)	0.154 (5)	0.311 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0618 (10)	0.0542 (9)	0.0442 (9)	0.0104 (7)	0.0085 (7)	0.0040 (7)
C2	0.0497 (8)	0.0552 (9)	0.0428 (8)	0.0073 (7)	0.0077 (7)	0.0041 (7)
C3	0.0508 (9)	0.0623 (10)	0.0566 (10)	0.0011 (8)	0.0089 (8)	−0.0018 (8)
C4	0.0507 (10)	0.0864 (14)	0.0607 (11)	0.0064 (9)	−0.0062 (8)	−0.0020 (10)
C5	0.0631 (11)	0.0776 (13)	0.0641 (12)	0.0199 (10)	−0.0061 (9)	0.0105 (10)
C6	0.0689 (11)	0.0567 (10)	0.0582 (11)	0.0113 (8)	0.0025 (9)	0.0077 (8)
C7	0.0535 (9)	0.0551 (9)	0.0436 (9)	0.0056 (7)	0.0044 (7)	0.0031 (7)
C8	0.0608 (11)	0.0702 (12)	0.0965 (16)	−0.0044 (10)	0.0112 (11)	−0.0113 (11)
F1	0.1536 (16)	0.0987 (11)	0.1447 (15)	−0.0163 (10)	−0.0518 (13)	−0.0361 (10)
F2	0.1085 (11)	0.0773 (9)	0.1956 (19)	−0.0172 (8)	0.0813 (12)	−0.0035 (10)
F3	0.0828 (8)	0.0627 (7)	0.1245 (12)	0.0037 (6)	0.0221 (8)	−0.0124 (7)
C9	0.0672 (11)	0.0597 (11)	0.0615 (11)	0.0030 (9)	−0.0013 (9)	0.0003 (9)
F4	0.0628 (7)	0.1270 (12)	0.1024 (10)	−0.0164 (7)	0.0050 (7)	−0.0162 (9)
F5	0.1201 (11)	0.0832 (8)	0.0628 (7)	−0.0013 (7)	−0.0338 (7)	0.0035 (6)
F6	0.1079 (10)	0.0632 (7)	0.0972 (10)	0.0013 (6)	−0.0118 (8)	−0.0186 (6)
C10	0.0609 (10)	0.0574 (10)	0.0454 (9)	−0.0107 (8)	0.0059 (7)	−0.0075 (7)
C11	0.0640 (10)	0.0495 (9)	0.0408 (8)	−0.0136 (7)	0.0046 (7)	−0.0079 (7)
C12	0.0679 (11)	0.0526 (9)	0.0486 (9)	−0.0112 (8)	0.0089 (8)	−0.0117 (7)
C13	0.0839 (13)	0.0731 (12)	0.0591 (12)	−0.0128 (10)	0.0231 (10)	−0.0126 (10)
C14	0.1122 (18)	0.0860 (15)	0.0440 (10)	−0.0135 (13)	0.0171 (11)	0.0010 (10)
C15	0.0927 (15)	0.0781 (13)	0.0473 (10)	−0.0043 (11)	0.0009 (10)	0.0031 (9)
C16	0.0698 (11)	0.0606 (10)	0.0499 (10)	−0.0094 (9)	0.0017 (8)	−0.0042 (8)
O1	0.0575 (7)	0.0753 (8)	0.0490 (7)	0.0156 (6)	0.0041 (5)	0.0077 (6)
O2	0.0858 (9)	0.0756 (9)	0.0677 (8)	0.0301 (7)	0.0294 (7)	0.0303 (7)
O3	0.0850 (9)	0.0783 (9)	0.0420 (6)	−0.0259 (7)	0.0064 (6)	−0.0103 (6)
O4	0.1505 (15)	0.0963 (11)	0.0575 (9)	−0.0706 (11)	0.0357 (9)	−0.0223 (8)
C17	0.0723 (13)	0.0783 (14)	0.0675 (13)	0.0023 (11)	0.0087 (10)	−0.0092 (11)
F7A	0.115 (2)	0.088 (2)	0.099 (2)	0.0095 (16)	0.0008 (17)	0.0347 (18)
F8A	0.0718 (17)	0.0977 (19)	0.095 (2)	−0.0026 (14)	−0.0251 (14)	−0.0169 (16)
F9A	0.153 (4)	0.144 (3)	0.121 (4)	0.087 (3)	0.022 (3)	−0.030 (3)
F7B	0.156 (5)	0.187 (5)	0.079 (3)	0.090 (4)	−0.040 (3)	−0.064 (3)
F9B	0.100 (3)	0.097 (3)	0.151 (4)	0.009 (2)	0.005 (3)	0.039 (3)
F8B	0.055 (2)	0.146 (4)	0.092 (4)	0.006 (3)	0.018 (2)	0.007 (3)
C18	0.0736 (13)	0.0807 (15)	0.0699 (14)	−0.0014 (11)	0.0001 (11)	−0.0030 (11)
F10A	0.082 (2)	0.116 (2)	0.0655 (15)	0.0210 (16)	0.0119 (13)	−0.0152 (16)
F11A	0.0730 (14)	0.115 (2)	0.161 (3)	−0.0229 (14)	0.0114 (17)	−0.033 (2)
F12A	0.1041 (18)	0.130 (2)	0.107 (2)	0.0381 (17)	−0.0002 (15)	0.0232 (16)
F10B	0.076 (3)	0.109 (4)	0.146 (6)	0.006 (3)	0.039 (3)	0.029 (4)
F12B	0.084 (3)	0.204 (9)	0.081 (4)	0.039 (5)	−0.020 (3)	0.023 (4)
F11B	0.099 (7)	0.145 (7)	0.222 (11)	−0.022 (5)	0.038 (6)	−0.109 (7)

Geometric parameters (Å, º) top

C1—O1	1.210 (2)	C11—C12	1.399 (3)
C1—O2	1.305 (2)	C12—C13	1.387 (3)
C1—C2	1.507 (2)	C12—C17	1.500 (2)
C2—C3	1.396 (2)	C13—C14	1.376 (3)
C2—C7	1.399 (2)	C13—H13A	0.930
C3—C4	1.390 (3)	C14—C15	1.365 (3)
C3—C8	1.500 (3)	C14—H14A	0.930
C4—C5	1.371 (3)	C15—C16	1.385 (3)
C4—H4A	0.930	C15—H15A	0.930
C5—C6	1.370 (3)	C16—C18	1.498 (2)
C5—H5A	0.930	O2—H2A	0.820
C6—C7	1.383 (2)	O3—H3A	0.820
C6—H6A	0.930	C17—F7B	1.2729 (11)
C7—C9	1.503 (3)	C17—F9A	1.2791 (11)
C8—F1	1.324 (3)	C17—F7A	1.2941 (11)
C8—F3	1.326 (3)	C17—F8B	1.3326 (12)
C8—F2	1.328 (3)	C17—F8A	1.3485 (12)
C9—F4	1.323 (2)	C17—F9B	1.3895 (12)
C9—F5	1.325 (2)	C18—F11B	1.2443 (10)
C9—F6	1.328 (2)	C18—F12B	1.2593 (11)
C10—O4	1.197 (2)	C18—F11A	1.2952 (11)
C10—O3	1.287 (2)	C18—F10A	1.3146 (11)
C10—C11	1.506 (2)	C18—F12A	1.3697 (11)
C11—C16	1.397 (3)	C18—F10B	1.4165 (12)

O1—C1—O2	124.93 (16)	C13—C12—C17	118.76 (16)
O1—C1—C2	123.28 (15)	C11—C12—C17	121.09 (14)
O2—C1—C2	111.78 (14)	C14—C13—C12	120.1 (2)
C3—C2—C7	118.36 (15)	C14—C13—H13A	119.9
C3—C2—C1	121.80 (15)	C12—C13—H13A	119.9
C7—C2—C1	119.84 (15)	C15—C14—C13	120.45 (19)
C4—C3—C2	120.00 (17)	C15—C14—H14A	119.8
C4—C3—C8	117.85 (18)	C13—C14—H14A	119.8
C2—C3—C8	122.14 (17)	C14—C15—C16	120.4 (2)
C5—C4—C3	120.63 (18)	C14—C15—H15A	119.8
C5—C4—H4A	119.7	C16—C15—H15A	119.8
C3—C4—H4A	119.7	C15—C16—C11	120.24 (19)
C6—C5—C4	120.08 (17)	C15—C16—C18	118.50 (17)
C6—C5—H5A	120.0	C11—C16—C18	121.25 (15)
C4—C5—H5A	120.0	C1—O2—H2A	109.5
C5—C6—C7	120.36 (18)	C10—O3—H3A	109.5
C5—C6—H6A	119.8	F9A—C17—F7A	111.7
C7—C6—H6A	119.8	F7B—C17—F8B	107.2
C6—C7—C2	120.55 (16)	F9A—C17—F8A	107.7
C6—C7—C9	118.00 (16)	F7A—C17—F8A	104.9
C2—C7—C9	121.45 (15)	F7B—C17—F9B	103.2
F1—C8—F3	105.80 (19)	F8B—C17—F9B	97.2
F1—C8—F2	107.3 (2)	F7B—C17—C12	118.73 (8)
F3—C8—F2	105.3 (2)	F9A—C17—C12	112.38 (8)
F1—C8—C3	112.2 (2)	F7A—C17—C12	111.79 (8)
F3—C8—C3	113.92 (17)	F8B—C17—C12	114.37 (8)
F2—C8—C3	111.77 (18)	F8A—C17—C12	107.87 (8)
F4—C9—F5	107.23 (17)	F9B—C17—C12	113.47 (8)
F4—C9—F6	107.01 (17)	F11B—C18—F12B	115.7
F5—C9—F6	105.48 (16)	F11A—C18—F10A	109.6
F4—C9—C7	111.76 (16)	F11A—C18—F12A	106.5
F5—C9—C7	112.95 (16)	F10A—C18—F12A	101.0
F6—C9—C7	111.98 (16)	F11B—C18—F10B	97.4
O4—C10—O3	123.01 (17)	F12B—C18—F10B	103.0
O4—C10—C11	121.71 (15)	F11B—C18—C16	113.07 (8)
O3—C10—C11	115.25 (15)	F12B—C18—C16	115.85 (8)
C16—C11—C12	118.60 (16)	F11A—C18—C16	114.75 (8)
C16—C11—C10	120.19 (16)	F10A—C18—C16	113.29 (8)
C12—C11—C10	121.10 (16)	F12A—C18—C16	110.63 (9)
C13—C12—C11	120.14 (18)	F10B—C18—C16	109.27 (9)

C7—C2—C1—O1	71.5 (2)	C12—C11—C10—O4	99.3 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O4ⁱ	0.82	1.82	2.6340 (19)	169
O3—H3A···O1	0.82	1.88	2.6951 (18)	176

Symmetry code: (i) x, −y+1/2, z−1/2.

Experimental details

Crystal data
Chemical formula	C₉H₄F₆O₂
M_r	258.12
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	296
a, b, c (Å)	10.873 (2), 15.755 (3), 11.561 (2)
β (°)	94.961 (2)
V (Å³)	1973.0 (6)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.20
Crystal size (mm)	0.39 × 0.31 × 0.26

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2008)
T_min, T_max	0.834, 0.951
No. of measured, independent and observed [I > 2σ(I)] reflections	12904, 3438, 2889
R_int	0.021
(sin θ/λ)_max (Å⁻¹)	0.595

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.039, 0.112, 1.02
No. of reflections	3438
No. of parameters	331
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.23

Computer programs: APEX2 (Bruker, 2008), SAINT (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and Mercury (Macrae et al., 2006), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2A···O4ⁱ	0.82	1.82	2.6340 (19)	169.1
O3—H3A···O1	0.82	1.88	2.6951 (18)	175.6

Symmetry code: (i) x, −y+1/2, z−1/2.

Acknowledgements

The authors thank Saint Mary's University for providing funding in the form of initial operating funds (JDM) and student funding through the Summer Employment Experience Program (JMT).

References

Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dmowski, W. & Piasecka-Macieiewska, K. (1998). Tetrahedron, 54, 6781–6792. Web of Science CrossRef CAS Google Scholar
Faigl, F., Fogassy, K., Szűcs, E., Kovács, K., Keserű, G. M., Harmat, V., Böcski, Z. & Tőke, L. (1999). Tetrahedron, 55, 7881–7892. Web of Science CSD CrossRef CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453–457. Web of Science CrossRef CAS IUCr Journals Google Scholar
Moorthy, J. N., Natarajan, R., Mal, P. & Venugopalan, P. (2002). J. Am. Chem. Soc. 124, 6530–6531. Web of Science CSD CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar