The luminescence response of diamine-liganded europium complexes upon resonant and pre-resonant excitation.

The luminescence of four europium thenoyltrifluoroacetonate complexes containing diamine ligands is studied in solutions. The compounds are resonantly excited in the ligand absorption band by means of high-power nanosecond UV laser pulses. Additionally, a continuous light source is also used for resonant, as well as pre-resonant excitation of the complexes. The luminescence response characterizes the synthesized europium coordination complexes as emissive compounds suitable for fluorometric applications. Related to the possible usefulness of the diamine-liganded Eu complexes as luminescent labels for sensing and imaging of biological molecules, the luminescence response of these compounds upon UV excitation was probed also in aqueous media.