MOLECULAR COCRYSTALS OF CARBOXYLIC-ACIDS .2. THE CRYSTAL-STRUCTURE OF THE 1-2 ADDUCT OF PHENOXYACETIC ACID WITH 3,5-DINITROBENZOIC ACID

The 1:2 molecular adduct between phenoxyacetic acid and 3,5-dinitrobenzoic acid, with formula [(C6H5OCH2COOH)2{3,5-(NO2)2C6H3COOH}4(H2O)2], has been prepared and its structure determined by X-ray diffraction. Crystals are triclinic, space group P1BAR with two complex units in a cell with dimensions a 7.202(2), b 18.519(5), c 20.924(6) angstrom, alpha-66.33(3), beta-86.04(2), gamma-89.32(2)-degrees. The molecular repeating unit comprises two phenoxyacetic acid molecules [forming hydrogen-bonded cyclic dimers (O...O, 2.71, 2.74 angstrom)], four 3,5-dinitrobenzoic acid molecules [giving two unusual one-bond hydrogen bonds (O...O, 2.59, 2.64 angstrom)] and two water molecules. The water are intimately involved in a hydrogen-bonding network with carboxylic acid oxygens.