Abstract
Fundamental requirements for MRI contrast agents (CAs) are high thermodynamic stability and kinetic inertness to assure low toxicity of the CAs, and at least one coordination site available for coordination of a water molecule which is crucial for the contrast enhancement. The clinically approved gadolinium (Gd)(III)-based CAs utilize octadentate ligands.
This chapter is dedicated to the synthesis and characterization of ligands and their Gd(III) complexes. First, it talks about the CAs employing linear polyamine scaffold, and CAs employing cyclen scaffold.
Next, the chapter presents representative examples of the polyaminopolycarboxylic bifunctional ligands and conjugation strategies utilized in the frame of MRI research. Description of the ligand syntheses is mostly presented in accordance with the ligand motif.
Finally, the chapter describes synthesis and characterization of the lanthanide (Ln)(III) complexes.