Characterization of Lanthanide Complexes with a Series of Amide-Based Macrocycles, Potential MRI Contrast Agents, Using Eu3+ Luminescence Spectroscopy and Molecular Mechanics

Eu 3+ luminescence spectroscopy was used to characterize the solution complexes of the following ligands: 4,10,13-tris(carboxymethyl)-8,15-dioxo-1,4,7,10,13-pentaazacyclopentadecane (edta-dam); 1,4,7-tris(carboxymethyl)9,14-dioxo-1,4,7,10,13-pentaazacyclopentadecane (edta-dam); 1,4,7-tris(carboxymethyl)-9,14-dioxo-1,4,7,10,13-pentaazacyclopentadecane (dtpa-eam); 1,4,7-tris(carboxymethyl)-9,20-dioxo-13, 16-dioxa-1,4,7,10,19-pentaazacycloheneicosane (dtpa-oam); 1,4,7 16, 19,22-hexa(carboxymethyl)-9,14,24,29-dioxo-1,4,7,10,13,16,19,22,25,28-decaazacyclotriacontane (bis(dtpa-eam)), 1,4-bis((4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododecan-1-yl)acetyl)piperazine (piperazine do3a-dimer)