2-Chloro-6-fluoro­benzoic acid

Betz, R.; Gerber, T.

doi:10.1107/S1600536811016734

Volume 67
Part 6
Page o1329
June 2011

Received 27 January 2011
Accepted 3 May 2011
Online 7 May 2011

Key indicators
Single-crystal X-ray study
T = 200 K
Mean (C-C) = 0.002 Å
R = 0.032
wR = 0.081
Data-to-parameter ratio = 16.5
Details

2-Chloro-6-fluorobenzoic acid

Richard Betz ^a ^* and Thomas Gerber ^a

^aNelson Mandela Metropolitan University, Summerstrand Campus, Department of Chemistry, University Way, Summerstrand, PO Box 77000, Port Elizabeth 6031, South Africa
Correspondence e-mail: richard.betz@webmail.co.za

The title compound, C₇H₄ClFO₂, is a twofold halogenated derivative of benzoic acid. The C-C-C angles within the aromatic moiety cover a range 116.11 (14)-123.96 (15)°, with the maximum and the minimum value next to each other. In the crystal, O-HO hydrogen bonds form carboxylic acid dimers, which are further connected by C-HF contacts into undulating sheets perpendicular to the a axis.

Related literature

For the crystal structure of benzoic acid (applying neutron radiation), see: Wilson et al. (1996). For the crystal structure of ortho-fluorobenzoic acid, see: Krausse & Dunken (1966) and of ortho-chlorobenzoic acid, see: Ferguson & Sim (1961); Polito et al. (2008). For graph-set analysis of hydrogen bonds, see: Etter et al. (1990); Bernstein et al. (1995).

Experimental

Crystal data

C₇H₄ClFO₂
M_r = 174.55
Monoclinic, P 2₁ /c
a = 3.7655 (2) Å
b = 13.9660 (7) Å
c = 13.2300 (7) Å
= 98.034 (3)°
V = 688.92 (6) Å³
Z = 4
Mo K radiation
= 0.51 mm^-1
T = 200 K
0.51 × 0.19 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer
11312 measured reflections
1671 independent reflections
1267 reflections with I > 2(I)
R_int = 0.081

Refinement

R[F² > 2(F²)] = 0.032
wR(F²) = 0.081
S = 1.02
1671 reflections
101 parameters
H-atom parameters constrained
_max = 0.23 e Å^-3
_min = -0.21 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
O1-H1O2ⁱ	0.84	1.81	2.6436 (17)	172
C5-H5F1ⁱⁱ	0.95	2.46	3.175 (2)	132
Symmetry codes: (i) -x+1, -y+1, -z; (ii) $[x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); 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 (Farrugia, 1997) and Mercury (Macrae et al., 2006); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GW2099 ).

Acknowledgements

The authors thank Mrs Wilma Nelson for helpful discussions.

References

Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.
Bruker (2010). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
Ferguson, G. & Sim, G. A. (1961). Acta Cryst. 14, 1262-1270.
Krausse, J. & Dunken, H. (1966). Acta Cryst. 20, 67-73.
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.
Polito, M., D'Oria, E., Maini, L., Karamertzanis, P. G., Grepioni, F., Braga, D. & Price, S. L. (2008). CrystEngComm, 10, 1848-1854.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Spek, A. L. (2009). Acta Cryst. D65, 148-155.
Wilson, C. C., Shankland, N. & Florence, A. J. (1996). J. Chem. Soc. Faraday Trans. pp. 5051-5057.

organic compounds