• Circularly Polarized Light
• Glycoconjugate-derivative
• Lanthanide (III) complexes

This thesis embarks on an exploration of a potentially new generation of chiral glycoconjugated lanthanide complexes tailored to potentially improve diagnostic imaging and purposes. The imperative role of lanthanide complexes in biomedical imaging has prompted significant interest in their functionalization with biologically relevant ligands, such as glycans - nevertheless proteins and nucleic acids - , to enhance their targeting specificity and biocompatibility.
Lanthanide complexes with chromophoric organic ligands possess remarkable emissive properties in a large span of wavelengths from UV to near IR. In the more specific instance of a chiral enantiopure complex the possibility of emitting circularly polarized radiation (or circularly polarized luminescence, CPL) occurs.
CPL can be considered as the emissive counterpart of the electronic circular dichroism (ECD), allowing to study the excited state of optically active molecular entities. Such luminescence dissymmetry factor can be considered as an enantiomeric excess of the radiation emitted from the enantiopure chiral compound, and it runs in a span of values to -2 from +2. Alluringly, while small chiral non racemic organic molecules possess a glum of 10-5 to 10-3 (calculated in solution), we can easily find examples of chiral lanthanide complexes with glum close to its maximum value.
It is yet important to notice that Lanthanide (III) ions possess weak absorption and emissive intensities because of their spectra consisting of bands resulting from forbidden f – f transitions, due to the Laporte rule. This impeding can be overcame by coordinating organic chromophores to the metal (III) ion, which can absorb photons and transfer them to the lanthanide excited state ion through the alleged “Antenna” effect.
The primary aim of this thesis was to continue to work on a previously synthesized generation of glyconjugated lanthanide complexes based on dipicolinic acid, focusing on improving the chiral perturbation on the lanthanide (III) ion by the sugar moiety in the ligand structure and their CPL emitting capacities alongside their synthetic pathways. The main issues that former complexes encountered were partial hydrolyzations reactions that occurred mainly because of the trait of Ln(III) ions of being strong Lewis acids in aqueous solution; pivot of this work was to pledge enough space, by the insertion of a 2 carbon atoms spacer, between the Oxygen bonded to the anomeric carbon C1 and the ester bond related to the DPA.