Synthesis Neutral Rare Earth Complexes of Diethylenetriamine-N, N″-bis(acetyl-o-hydroxybenzoyl hydrazide) -N, N′, N-triacetic Acid as Potential Contrast Enhancement Agents for Magnetic Resonance Imaging

A novel ligand (H3L), diethylenetriamine-N,N″-bis(acetyl-o-hydroxybenzoyl hydrazide)-N, N′, N″-triacetic acid and its four rare earth (La, Eu, Gd, Tb) complexes have been synthesized and characterized on the basis of elemental analyses, molar conductivities, 1H NMR spectra, FAB-MS, TG-DTA analysis, and IR spectra. In addition, relaxivity (R1) of complexes are determined. The relaxivity of LaL, EuL, GdL, TbL, and Gd(DTPA)2– used as a control are 0.94, 2.79, 6.39, 1.59, and 4.34 L·mmol−1·s−1, respectively. The spin-lattice relaxivity of GdL is larger than that of Gd(DTPA)2−. The results showed that complex of GdL may be a potential magnetic resonance imaging contrast agent.