Received 15 December 2012
In the asymmetric unit of the title co-crystal, C12H14N4O2S·C7H5NO4, the sulfamethazine and 2-nitrobenzoic acid molecules form a heterodimer through intermolecular amide-carboxylic acid N-HO and carboxylic acid-pyrimidine O-HN hydrogen-bond pairs, giving a cyclic motif [graph set R22(8)]. The dihedral angle between the two aromatic ring systems in the sulfamethazine molecule is 88.96 (18)° and the nitro group of the acid is 50% rotationally disordered. Secondary aniline N-HOsulfone hydrogen-bonding associations give a two-dimensional structure lying parallel to the ab plane.
For background to sulfamethazole as a model for co-crystal formation, see: Caira (2007); Ghosh et al. (2011). For structures of 1:1 adducts of sulfamethazine with nitrobenzoic acid analogues, see: Lynch et al. (2000); Smith & Wermuth (2012). For graph-set analysis, see: Etter et al. (1990).
Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR92 (Altomare et al., 1993); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008) within WinGX (Farrugia, 2012); molecular graphics: PLATON (Spek, 2009); software used to prepare material for publication: PLATON.
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: GG2106 ).
The authors acknowledge financial support from the Australian Reseach Council and the Science and Engineering Faculty and the University Library, Queensland University of Technology.
Agilent (2012). CrysAlis PRO. Agilent Technologies Ltd, Yarnton, England.
Altomare, A., Cascarano, G., Giacovazzo, C. & Guagliardi, A. (1993). J. Appl. Cryst. 26, 343-350.
Caira, M. R. (2007). Mol. Pharm. 4, 310-316.
Etter, M. C., MacDonald, J. C. & Bernstein, J. (1990). Acta Cryst. B46, 256-262.
Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.
Flack, H. D. (1983). Acta Cryst. A39, 876-881.
Ghosh, S., Bag, P. P. & Reddy, C. M. (2011). Cryst. Growth Des. 11, 3489-3503.
Lynch, D. E., Sandhu, P. & Parsons, S. (2000). Aust. J. Chem. 53, 383-387.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Smith, G. & Wermuth, U. D. (2012). Acta Cryst. E68, o1649-o1650.
Spek, A. L. (2009). Acta Cryst. D65, 148-155.