Significant impact of lanthanide contraction on the structure of the phenanthroline complexes

The structure of La, Nd, Eu and Lu complexes with N,N,N',N'-tetrabutyl-1,10-phenanthroline-2,9-dicarbox- amide ligand was examined using X-ray diffraction analysis. Due to the effect of lanthanide contraction, lutetium forms unique type of complex having the coordination number 9 in contrast to other 10-coordinated lanthanides.