Analysis of the fluorescence spectra of europium(III)-bis-phenanthroline-tris-carboxylate complexes

The fluorescence spectra of microcrystalline complexes of the composition Eu(phen)2(benz)3, Eu(phen)2(sal)3, and Eu(phen)2(p-OH-benz)3 have been investigated under high resolution at room temperature and 77°k. The effective Eu(III) site symmetries for Eu(phen)2(benz)3(C 2v ) and Eu(phen)2(sal)3(D 2) complexes have been established with the help of group theoretical reasoning. The Eu(III) fluorescence lines for Eu(phen)2(p-OH-benz)3 complex are very broad and weak even at 77°k; reasons for this weakness are given. A comparison of fluorescence intensities of Eu(phen)2(benz)3 and Eu(phen)2(sal)3 with other bis-phenanthroline complexes has been presented.