SYNTHESIS AND CRYSTAL-STRUCTURE OF A NOVEL HEXAAZA MACROCYCLIC LIGAND WITH 2-HYDROXY-3,5-DIMETHYLBENZYL PENDANT ARMS AND ITS GADOLINIUM(III) COMPLEX

Two new hexaaza macrocycles H-4L1 and H-4L2 substituted with 2-hydroxy-3,5-dimethylbenzyl groups on the secondary amine nitrogens have been synthesized; the crystal structure of H-4L2 shows that the six nitrogen donor atoms adopt a chair conformation in the solid state, and the gadolinium(III) complex of monodeprotonated H-4L1, [Gd(H-3L1)(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.