The macrocyclic mononuclear lanthanide complexes derived from 2,6-diformyl-4-methylphenol and 1,3-diamino-2-hydroxypropane

The new macrocyclic Schiff base lanthanide(III) complexes of the formula Ln (H4L)Cl-2. nH(2)O have been synthesised in the template condensation of 1,3 -diamino-2-hydroxypropane and 2,6-diformyl-4-methylphenol in the presence o f La(III), Ce(III) and Eu(III) ions. The complexes have been characterised by elemental analyses, spectroscopic methods and X-ray crystallography. The ir H-1 and C-13 NMR spectra have been assigned on the basis of COSY, NOESY and HMQC techniques. The isotropic shifts of the paramagnetic Ce(III) and E u(III) derivatives indicate the unsymmetrical coordination of the lanthanid e(III) ions within the macrocyclic ligand H4L. The crystal structure of Eu( III) complex contains two different complex molecules; in each molecule the Eu(III) ion is eight-coordinate and the ligand adopts a bent conformation. In the first molecule the Eu(III) is bound to two nitrogen atoms and three oxygen atoms derived from the macrocyclic ligand as well as to three water molecules, while in the second molecule one of the coordinated water molec ules is substituted by chloride anion. (C) 1998 Elsevier Science Ltd. All r ights reserved.