title: 4-Amino-N-(4,6-dimethyl-pyrimidin-2-yl)benzene-sulfonamide-2-nitro-benzoic acid (1/1).
abstract: In the asymmetric unit of the title co-crystal, C(12)H(14)N(4)O(2)S·C(7)H(5)NO(4), the sulfamethazine and 2-nitro-benzoic acid mol-ecules form a heterodimer through inter-molecular amide-carb-oxy-lic acid N-H⋯O and carb-oxy-lic acid-pyrimidine O-H⋯N hydrogen-bond pairs, giving a cyclic motif [graph set R(2) (2)(8)]. The dihedral angle between the two aromatic ring systems in the sulfamethazine mol-ecule is 88.96 (18)° and the nitro group of the acid is 50% rotationally disordered. Secondary aniline N-H⋯O(sulfone) hydrogen-bonding associations give a two-dimensional structure lying parallel to the ab plane.
authors: Science and Engineering Faculty, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4001,  Australia.
authors: Graham
authors: G
authors: Smith
authors: Urs D
authors: UD
authors: Wermuth