The synthesis and characterization of four new dioxotetraazamacrocycles: 1,4,8,11-tetraazacyclotetradecane-3,9-dione; 1,4,7,10-tetraazacyclotridecane-2,9-dione; 1,4,7,10-tetraazacyclotridecane-3,8-dione; and 1,4,7,10-tetraazacyclododecane-2,9-dione are described. Two related, previously prepared macrocycles, are included in this study: 1,4,8,11-tetraazacyclotetradecane-5,7-dione and 1,4,7,10-tetraazacyclotridecane-11,13-dione. The protonation constants, stability constants with Cu2+ ions, as well as electronic spectra of the di-deprotonated copper(II) complexes are also reported. These results are discussed in terms of the suitability of this new class of 62Cu, 64Cu, 67Cu complexes in PET imaging or radiotherapeutic applications. The synthetic schemes outlined provide a study of the relative Cu2+ behavior with a family of positional isomers of unsubstituted dioxotetraazamacrocycles.Key words: multidentate ligand, tetraazamacrocyclic compound, dioxopolyaza macrocycles, cyclic amides, copper(II) complexes.
Synthesis and characterization of the tetranuclear iron(iii) complex of a new asymmetric multidentate ligand. A structural model for purple acid phosphatases
