OXYDIACETIC ACID AND COPPER(II) COMPLEXES OF A NEW HEXAAZA MACROCYCLIC DINUCLEATING LIGAND

The synthesis of a new hexaaza macrocyclic ligand tratriaconta-1(32),1 3,15,17(34),29(33),30-hexaene, Me, by hydrogenation of the correspondi ng Schiff base is described. The crystal structure of its hexabromide salt, determined by means of X-ray analysis, is also reported. The com pound with the empirical formula C28H52N6Br6 was obtained as a colorle ss plate crystallizing in the space group P1 as a triclinic crystal wi th the cell dimensions a = 7.966 Angstrom, b = 16.083 Angstrom, c = 7. 8870 Angstrom, alpha = 93.45 degrees, beta = 97.26 degrees, and gamma = 102.28 degrees, with one molecule per unit cell. Protonation constan ts and metal ion stability constants of the mononuclear and dinuclear copper(II) macrocyclic complexes have been measured potentiometrically and are compared with those of analogous ligands. The different proto nated forms of the basic ligand Mc recognize oxydiacetic acid and its anions forming nine strongly bound complexes. The formation constants for those complexes were determined with the use of potentiometric met hods, and the nature of these complexes is discussed and compared with other analogous host-guest interactions.