Défense de thèse de doctorat en sciences chimiques

Synthesis and applications of novel fullerenes and silsesquioxanes based structures

Jury

• Johan WOUTERS (UNamur), President
• Carmela APRILE (UNamur), Secretary
• Anna BARATTUCCI (University of Messina)
• Michelangelo GRUTTADAURIA (University of Palermo)
• Francesco GIACALONE (University of Palermo)
  

Summary

The 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 promising 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.

 

The session is open to the public.

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