SYNTHESIS AND NEAR INFRARED LUMINESCENT PROPERTIES OF LANTHANIDE COMPLEXES

In vivo near-infrared (NIR) fluorescence microscopy and imagery is an emerging research area in biology. Organic dyes currently tested for NIR imagery have very severe limitations such as rapid photobleaching. This drastically limits the sample exposure time and/or prevents the experiment to be repeated. Lanthanide complexes have NIR luminescence properties which have strong resistance to photo-bleaching, long luminescence lifetimes and sharp emission bands. In addition, the emission band energies are independent from the experimental condition. All these properties make them the most promising agents for NIR imagery. In this thesis, it was demonstrated that tropolonate ligands can be used as an efficient sensitizer for several luminescent lanthanide cations (Nd, Ho, Er, Tm, Yb) emitting in the NIR. One octadentate ligand was developed to fulfill the complete coordination requirements of lanthanide cations in order to achieve increased stability of the complex to sustain physiological conditions to maximize the protection of the coordinated lanthanide cation against non-radiative deactivation. To study and rationalize the mechanism of ligand to lanthanide of energy transfer, derivatives of tropolone and their corresponding complexes are synthesized. The mechanism of the energy transfer can be used to design lanthanide complexes with controlled properties