Adducts of meso and racemic 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane with trigonally trisubstituted benzene carboxylic acids:: supramolecular structures in one and two dimensions

The meso and racemic forms of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, C16H36N4 (tet-a and tet-b, respectively), form adducts with trigonally trisubstituted benzene carboxylic acids; tet-a-3,5-dinitrobenzoic acid (1/2) (1), tet-a-5-hydroxyisophthalic acid-water (1/1/1) (3) and tet-b-5-hydroxyisophthalic acid-water (1/1/1) (4) are all salts, [C16H38N4](2+).2[C7H3N2O6](-) (1) and [C16H38N4](2+).-[C8H4O5](2-).H2O (3) and (4). The conformations of the [(tet-a)H-2](2+) and [(tet-b)H-2](2+) cations are entirely different: [(tet-a)H2](2+) is precisely centrosymmetric in (1) and approximately so in (3), while [(tet-b)H2] 2+ has approximate C-2 symmetry in (4). In each salt the cation forms two intramolecular N-H . . .N and four intermolecular N-H . . .O hydrogen bonds. In (1) the supramolecular structure is one-dimensional, a C-2(2)(13)[R-2(4)(16)] chain of rings. Compounds (3) and (4) crystallize in space groups P2(1)2(1)2(1) and P2(1)/c, respectively, but the supramolecular structures are very similar: in each, the anions and the water molecules form a C(7)[R-3(3)(13)] chain of rings, generated in (3) by a 2(1) axis and in (4) by a glide plane. These chains are linked, in both (3) and (4), by cations to form sheets. Adjacent meso cations in (3) are related by a 2(1) axis and adjacent chiral cations in (4) are related by a glide plane.