MOLECULAR CO-CRYSTALS OF CARBOXYLIC-ACIDS .23. THE 1 1 ADDUCTS OF 3-AMINO-1H-1,2,4-TRIAZOLE WITH 5-NITROSALICYLIC ACID AND 3,5-DINITROSALICYLIC ACID/

The structures of the 1:1 molecular adducts of the herbicide 3-amino-1 H-1,2,4-triazole (amitrole, 3-AT) with 5-nitrosalicylic acid (5-NSA), 3-amino-2H,4H(+)-1,2,4-triazolium 5-nitrosalicylate, C2H5N4+.C7H4NO5-, (1), and 3,5-dinitrosalicylic acid (DNSA), 3-amino-2H,4H(+)-1,2,4-tri azolium 3,5-dinitrosalicylate, C2H5N4+.C7H3N2O7-, (2), have been deter mined by X-ray diffraction and refined to residuals R = 0.035 and 0.03 7 for 1355 and 826 observed reflections, respectively. In both adducts , the acid protonates the hetero N atom of the amitrole ring. For (1), both molecules are involved in a network structure in which all avail able proton-donor and acceptor atoms, including the nitro O atoms, par ticipate in hydrogen bonding. For (2), the two-dimensional sheet struc ture involves those atoms comprising the proximal sites of the interac ting molecules, with limited interaction through the nitro O atoms.