Hybrid materials based on a novel POSS

Hybrid materials will be prepared based on a new polyhedral oligomeric silsesquioxane (POSS), octakis[dimethyl(p-carboxyphenyl)siloxy]silicate (denoted as Q8 M 8 COOH), which is the first example of octacarboxyl functionalized POSS and was previously prepared by the applicant. The reactivity of the carboxy functional groups renders it an attractive synthetic platform on which to build new ligands for inorganic and organic derivatives of POSS molecules, new dendrimers and new monomers for copolymerization. Q 8 M 8 COOH is a unique and novel nanosized building block (NBB) for hybrid materials, because it provides new linkage options for the synthesis of such materials. Thus, the goal of the project is to explore the scope of these new options and to synthesize and characterize hybrid nanostructured materials based on Q8 M 8 COOH. The following hybrid materials will be prepared: 1. Hybrid polymers covalently or ionicly linked by Q8 M 8 COOH derivatives. 2. Coordination polymers using Q8 M 8 COOHfor metal-organic framework (MOF)-type reactions, i.e. reactions with metal ions or metal complexes as linkers. 3. Novel cluster-based materials using Q8 M 8 COOH as carboxylic acid to react with different metal alkoxides. Structure-properties correlations will be studied through a full characterization of the POSS derivatives and through a complete compositional and microstructural characterization of the new materials. In particular, the possibility to modulate also functional performances will be explored, for instance thermal and mechanical stability or optical responses, by a deliberate variation of synthesis conditions and parameters. The planned work is not applications-driven but is instead heading at increasing fundamental knowledge on NBB-based hybrid materials and exploring the possibilities offered by the new NBB - Q8 M 8 COOH.