Conformation effects on the fluorescence spectra of europium and terbium complexes with a family of ether-amide type multipodal ligands.

Three multipodal ligands: 3,3,7,7-tetra[N-methyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (La), 3,3,7,7-tetra[N-ethyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (Lb), 3,3,7,7-tetra[N-benzyl-N-phenyl(acetamide)-2-oxymethyl]-5-oxanonane (Lc) and their europium and terbium nitrate and perchlorate complexes were synthesized. The 12 complexes were characterized by elemental analysis, IR, fluorescence spectroscopy and conductivity. The novel cup-like crystal structure of the Eu(III) complex with Lb and fluorescence emission properties of the complexes have also been studied. It has been showed that the nature of the anion has a great effect upon the composition of the complexes. The difference in the composition of the complexes results in the difference in the emission properties of them. The [Ln(NO3)5] group is negatively effective to the fluorescence intensity of the nitrate complexes. The luminescence intensity of Ln(III) perchlorate complex is stronger than that of nitrate complex.