Luminescent lanthanide complexes for advanced photonic applications

The lanthanide compounds containing unsymmetrical beta-diketone with [2.2]paracyclophane moiety in particular the europium complex with three [1-(4-[2.2]paracyclophanyl)]-3-phenylpropane-1,3-dione and 1,10-phenanthroline has been synthesized for the first time. The optical properties of [2.2]paracyclophane-derived ligands ( symmetrical beta-diketones and their respective N-phenylimines) as well as those of the europium complex were studied by UV-visible and luminescence spectroscopy. The diastereomers (racemic chiral, (R*,R*)- and achiral meso, ( R, S)-) of the beta-diketones and their respective N-phenylimines exhibit quite identical absorption spectra with intense broad band centered at 360 and 380 nm, respectively. The designed blue-emitting unsymmetrical beta-diketone acts as a very efficient sensitizer of the Eu-III emission and does so in the near-UV region. The introduction of [2.2] paracyclophane moiety in the beta-diketonates allows to expand the excitation wavelength of the lanthanide complex up to 500 nm and to obtain the relatively high overall quantum yield for the europium ion.