A 1:1:2 complex between 1,4,8,11-tetraazacyclotetradecane (cyclam), anthraflavic acid, and water

A 1:1:2 complex of 1,4,8,11-tetraazacyclotetradecane (cyclam), anthraflavic acid, and water has been obtained and characterized by X-ray diffraction. C24H36N4O6, monoclinic, P21/c, a = 11.966(1) A, b = 11.570(1) A, c = 9.604(1) A, β = 107.16(1)°,V = 1270.5(2) A3, Z = 2. Two of the four N atoms of the macrocyclic ring are protonated, and the corresponding anthraflavic acid exists as a dianion. The following types of H-bonding have been found in this complex: (1) between protonated NH groups of the macrocycle and O atoms of the ionized anthraflavic hydroxyls; (2) between protonated and nonprotonated NH groups of the macrocycle; (3) between the water molecules and O atoms of the ionized anthraflavic hydroxyls. The above interactions give rise to the formation of a 2D-supramolecular network in the cyclam complex; however, the major difference from the azamacrocyclic anthraflavates studied previously is that there is no direct interaction between the anthraflavic anions.