MOLECULAR CO-CRYSTALS OF CARBOXYLIC-ACIDS .3. STRUCTURES OF THE 1-1 ADDUCTS OF 2,4,6-TRINITROBENZOIC ACID WITH 4-AMINOBENZOIC ACID AND 3-HYDROXYPYRIDINE

(1) C7H8NO2+.C7H2N3O8-.H2O, M(r) = 412.3, orthorhombic, Pbcn, a = 29.528 (4), b = 11.306 (2), c = 10.603 (1) angstrom, V = 3539.9 (8) angstrom 3, Z = 8, D(m) = 1.55, D(x) = 1.546 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.15 mm-1, F(000) = 1696, T = 295 K, R = 0.039 for 958 observed reflections. (2) C5H6NO+.C7H2N3O8-, M(r) = 352.2, monoclinic, P2(1)/c, a = 7.276 (3), b = 8.310 (1), c = 24.130 (7) angstrom, beta = 92.48 (2)-degrees, V = 1457.6 (7) angstrom 3, Z = 4, D(m) = 1.60, D(x) = 1.604 Mg m-3, lambda(Mo K-alpha) = 0.71073 angstrom, mu = 0.15 mm-1, F(000) = 720, T = 295 K, R = 0.032 for 1368 observed reflections. Compound (1) may be prepared by both solid-state and solution reactions. Crystals were obtained from water. Extensive hydrogen bonding between amino groups, carboxylic acids and waters exists. The two acids are uniquely hydrogen bonded across one carboxylic acid oxygen pair, with no interactions between the other two oxygens. Compound (2) was prepared in aqueous solution and crystallized from water. In this adduct, hydrogen bonding exists between the deprotonated carboxylic acid groups and the protonated pyridine nitrogens.