Gd-complexes of macrocyclic DTPA conjugates of 1,1′-bis(amino)ferrocenes as high relaxivity MRI blood-pool contrast agents (BPCAs)All animal experiments were performed in accordance with the rules of the animal research committee of Kyungpook National University.Electronic supplementary information (ESI) available: Experimental section including synthetic procedures and characterization; potentiometric measurements and computational method; the method of transmetallation kinetics; relaxivity; in vitrocell toxicity; serum stability assay; in vivoMR imaging; stability constants; kinetic constants; osmolality and viscosity data. See DOI: 10.1039/c0cc03145c

We report the synthesis of macrocyclic DTPA conjugates of 1,1′-bis(amino)ferrocenes (1a–b) and their Gd-complexes [Gd(L)(H2O)] (2a–b, L = 1a–b) for use as new MRI blood-pool contrast agents. High R1relaxivity in HSA as well as high thermodynamic and kinetic stabilities is observed for 2a. [ABSTRACT FROM AUTHOR]