SYNTHESIS, PROTONATION CONSTANTS, AND COPPER(II) AND COBALT(II) BINDING CONSTANTS OF A NEW OCTAAZA MACROBICYCLIC CRYPTAND - (MX)3(TREN)2 - HYDROXIDE AND CARBONATE BINDING OF THE DICOPPER(II) CRYPTATE AND CRYSTAL-STRUCTURES OF THE CRYPTAND AND OF THE CARBONATO-BRIDGED DINUCLEAR COPPER(II) CRYPTATE

A two-step synthesis in good yield of a new octaaza macrobicyclic (cryptand) ligand (MX)3(TREN)2 containing two TREN, tris(2-aminoethyl)amine, moieties bridged by three m-xylyl groups is reported. Protonation constants and metal ion stability constants of the mononuclear and binuclear copper(II) and cobalt(II) cryptate complexes have been measured potentiometrically and are compared with those of analogous cryptand ligands. The crystal structure of the cryptand is reported. The crystal structure of the dinuclear copper(II) cryptate is also reported and is found to be unique in the presence of a bridging carbonate ion, taken up from atmospheric CO2, in which the Cu(II) centers are coordinated to two different carbonate oxygens, thus forming a three-atom bridge.