Synthesis and characterization of new polyethyleneoxy substituted salicylaldimine Schiff bases and some corresponding reduced tetra- and penta-aza ligands and their gadolinium(III) complexes: new potential contrast agents in magnetic resonance imaging

Abstract

A series of polyether substituted salicylaldehyde derivatives OHCC₆H₃OH-2-OR-3 [R = CH₂(CH₂OCH₂)_nCH₂OR′, n= 1, 4 and R′= Me; n= 5 and R′= H] have been synthesised and used to prepare the polydentate ligands HN[(CH₂CH₂NHCH₂CH₂NCHC₆H₃OH-2-OR-3]₂,HN[CH₂CH₂NHCH₂CH₂NHCH₂C₆H₃-OH-2-OR-3]₂ and HN[CH₂CH₂NCHC₆H₃OH-2-OR-3]₃; a preliminary evaluation has been made of the potential use of their gadolinium complexes as contrast agents for diagnostic Magnetic Resonance Imaging.