Heterodinuclear Complexes Comprising a d-Transition Metal Ion and a Lanthanide Ion

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Some new heteronuclear complexes comprising a d-transition metal ion and a lanthanide ion (d-f heteronuclear complexes) were synthesized and characterized. The compartmental ligands used in this work are N,N'-bis (3-hydroxysalicylidene) ethylenediamine, N,N'-bis (3-hydroxysalicylidene) -1,3-propanediamine, and N,N'-bis (3-carboxysalicylidene) ethylenediamine. Based on the absorption spectra and the circular dichroism, it was suggested that amino alcohols are specifically bound at the d-f heterometal center, through the nitrogen to the d-transition metal site and through the oxygen to the lanthanide site. Here, it should be noted that the Nim (II) -Ln (III) complexes coordinate the amino al-cohols, whereas the Ni (II) complex of N,N'-bis (salicylidene) ethylenediamine is square planar without solvating even in polar solvent like pyridine. Cryomagnetic measurements from 4.2K to room temperature revealed that the spin coupling between Cu (II) and Gd (III) ions is always ferromagnetic, whereas the magnetic interaction between V (IV) O and Gd (III) ions is not operated. These results indicate that the spin-polarization mechanism, which has been considered as a general mechanism of magnetic interaction between d-transition metal and lanthanide ions, should be reinvestigated. The strong fluorescence of Eu (III) and Tb (III) was markedly quenched on forming the heteronuclear complexes. Further studies are in progress, in order to get an useful information for the development of complexes with various new functions.