Synthesis and crystal structure of a novel hexaaza macrocyclic ligand with 2-hydroxy-3,5-dimethylbenzyl pendant arms and its gadolinium(III) complex

Abstract

Two new hexaaza macrocycles H₄L¹ and H₄L² substituted with 2-hydroxy-3,5-dimethylbenzyl groups on the secondary amine nitrogens have been synthesized; the crystal structure of H₄L² shows that the six nitrogen donor atoms adopt a chair conformation in the solid state, and the gadolinium(III) complex of monodeprotonated H₄L¹, [Gd(H₃L¹)(NO₃)]NO₃.3H₂O, has a nine-co-ordinate gadolinium bound to one phenolic oxygen atom, two oxygen atoms from one nitrate and six nitrogen donors from the macrocyclic ligand.