A 1 : 1.5 complex of 5,7-dioxo-1,4,8,11-tetraazacyclotetradecane and 2,6-dihydoxyanthraquinone

A complex of 5,7-dioxo-1,4,8,11-tetraazacyclotetradec (dioxocyclam) and 2,6 -dihydoxyanthraquinone (anthraflavic acid) has been obtained. The complex ( crystals grown from water-ethanol solution) has a stoichiometry dioxocyclam -anthraflavic acid 1:1:5. C31H32N4O8, chemical formula weight 588.61, tricl inic, P - 1, a = 10.542(3) Angstrom, b = 11.936(2) Angstrom c = 12.206(2) A ngstrom, alpha = 104.00(1)degrees, beta = 92.68(2)degrees, gamma = 103.64(2 )degrees, V = 1439.4 (5) Angstrom (3), 2 = 2, D-x = 1.358 g cm(-3). Only on e of the two amine N-atoms of the macrocycle is protonated due to very weak acidic properties of 2,6-dihydoxyanthraquinone. Due to the rather poor qua lity of the crystals and structure refinement, reliable determination of H- bonds is complicated. Nevertheless, several types of H-bonding responsible for the formation of a developed supramolecular network can be suggested: b etween the protonated amino groups and macrocycle's C=O moieties; between n on-protonated amino groups and macrocycle's C=O moieties; between protonate d and non-protonated amino groups; between the amide NH and C=O groups of a nthraflavic acid; and between protonated and deprotonated hydroxy groups of the acid. Two types of anthraflavic components can be distinguished in the lattice: those having a parallel orientation with respect to the macrocycl ic fragments and forming hydrogen bonds with the latter, and those lying in an approximately perpendicular plane and not involved in H-bonding with th e macrocycles.