Two different three-dimensional hydrogen-bonded framework structures in two hydrated adducts meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-terephthalic acid-water (1/1/4) and (1/1/6)

Co-crystallization of meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, C16H36N4, with terephthalic acid (1,4-benzenedicarboxylic acid), C8H6O4, from ethanol yields the tetrahydrate (C16H36N4).(C8H6O4).(H2O)(4) (1), meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-terephthalic acid-water (1/1/4), while similar co-crystallization from methanol yields the hexahydrate (C16H36N4).-(C8H6O4).(H2O), (2), meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-terephthalic acid-water (1/1/6). Both compounds are salts, [C16H38N4](2+).[C8H4O4](2-).-4H(2)O (1) and [C16H38N4](2+).[C8H4O4](2-).6H(2)O (2): in (2) both ionic components lie across centres of inversion and in both salts there are two protons held within the N-4 cavity of the cation. In the structure of (1), the cations and anions are linked into chains by means of paired N-H ... O hydrogen bonds, and the water molecules are linked into continuous chains by means of O-H ... O hydrogen bonds, in which each of the H atoms is independently disordered over two equally populated sites. The water chains link the ionic chains into a continuous three-dimensional framework by means of further O-H ... O hydrogen bonds. In (2) the cations and anions are linked by single N--H ... O hydrogen bonds, again into chains: at the same time the anions and the water molecules are linked by multiple O-H ... O hydrogen bonds into continuous two-dimensional nets, which are linked by the cations, by means of N-H ... O hydrogen bonds into a three-dimensional framework, entirely different from that in (1).