A 1:1 co-crystal of the herbicide triflusulfuron-methyl and its degradation product triazine amine

• Main Author: Kurt Mereiter
• Format: Article
• Language: English
• Published: International Union of Crystallography 2011-09-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536811031631

The herbicide triflusulfuron-methyl (systematic name: methyl 2-{[4-dimethylamino-6-(2,2,2-trifluoroethoxy)-1,3,5-triazin-2-yl]carbamoylsulfamoyl}-3-methylbenzoate) and its degradation product triazine amine [systematic name: 2-amino-4-dimethylamino-6-(2,2,2-trifluoroethoxy)-1,3,5-triazine] form a triclinic 1:1 co-crystal of the title compound, C7H10F3N5O·C17H19F3N6O6S, in which its two components are connected via a pair of complementary N—H...N hydrogen bonds, similar to the monoclinic crystal structure of the parent compound triflusulfuron-methyl [Mereiter (2011). Acta Cryst. E67, o1778–o1779] in which a pair of molecules related by a twofold axis are linked by two N—H...N bonds. The triflusulfuron-methyl molecules of both crystal structures are similar in geometric parameters and conformation, which is due to stiffening by a short intramolecular N—H...N bond [N...N = 2.620 (4) Å] and an intramolecular dipole–dipole interaction between the sulfamide and the carboxyl moieties, with Os...Cc = 2.802 (5) Å and Oc...Ns = 2.846 (4) Å. Intermolecular N—H...O hydrogen bonds and slipped π–π stacking interactions between the diaminotriazine moieties [perpendicular distances of 3.25 Å within hydrogen-bonded tetramers and 3.27 Å between adjacent tetramers] link the two constituents of the co-crystal into columns parallel to the a axis. An intramolecular C—H...O hydrogen bond occurs in the triflusulfuron-methyl molecule and intermolecular C—H...O interactions between triflusulfuron-methyl molecules occur in the crystal structure. In the triflusulfuron-methyl molecule the dihedral angle between the least-squares planes of the two rings is 75.8 (1)°. In the triazine molecule, the CF3 group is partly orientationally disordered.