RésuméThe aim of the thesis is the exploration of the properties of carbon and a silica nanoform derivatives.
In particular, C60 fullerene and polyhedral oligomeric silsesquioxane (POSS) were selected, as representative of each class, for their peculiar geometry. These nanostructures were thought as suitable starting materials for the synthesis of innovative molecular building blocks to be employed, once complexed with metals, in the creation of self-assembled three dimensional organizations. The target applications were in the fields of catalysis and photoluminescence.
The first part of the PhD thesis was dedicated to the development of heterogeneous catalysts active in asymmetric Henry and Diels-Alder reaction. C60 fullerene was functionalised with bisoxazoline (BOX) ligands to obtain 12 different systems with three different solubility profiles. All the C60-adducts complexed with copper salts were successfully applied as catalysts in asymmetric Henry and Diels-Alder reaction. The best C60-derivatives were also reused in multiple cycles.
In the second part both C60-BOX adducts and POSS (functionalized with terpyridine moieties) were tested as possible light-emitting materials. For this investigation Eu(III) and Tb(III) were selected as metal cations. The most priomising results were achieved in presence of POSS nanostructures. In particular mono and octa terpyridine POSS showed exceptional tuneable blue-red-green emission in presence of Europium ions under UV irradiation.
Moreover, an in-depth investigation of these metal@POSS materials revealed that a controlled and tuneable emission (covering the entire visible spectrum, from blue to red) can be obtained only via slightly chemical modification of the metal environment not requiring an ex-novo synthesis pathway of the ligands.
|la date de réponse||21 févr. 2020|
|Sponsors||Université de Namur & Università di Palermo|
|Superviseur||Carmela APRILE (Promoteur), Francesco Giacalone (Copromoteur), Johan Wouters (Jury), Michelangelo Gruttadauria (Jury) & Anna Barattucci (Jury)|