Novos materiais funcionais organo-híbridos baseados em óxidos metálicos e diimidas aromáticas

Abstract

As Naftaleno Diimidas interagiram de forma especial com nanopartículas de óxido de cério conferindo ausência de atividade hidrolítica e um comportamento X fotocrômico singular. Propõe-se que o corante orgânico se adsorve nas ranhuras das nanopartículas e, além disso forma dímeros estáveis que têm importância para as novas fotoatividades observadas. Palavras-chave:naftaleno diimidas, óxido de cério, material híbrido, agregados, fluorescência e surfactantes. XI Abstract (Chagas-Silva, F.A.C.) New Hybrid Functional Materials based in Metal Oxides and Aromatic Diimides. 2012. (150p). PhD Thesis -Graduate Program in Chemistry. Instituto de Química, Universidade de São Paulo, São Paulo.The use and study of hybrid materials is a challenge for the chemist to develop materials having new and superior qualities for applications in photonics, sensors and related areas. In this context one has to speculate on the properties of the organic and inorganic partners to achieve better and new properties.In this study the metal oxides (in particular Cerium Oxides), a special class among inorganic nanoparticles were selected to exploit their applications with an also special class of organic compounds the Naphthalene Diimides.Cerium Oxide is a wide bandgap semiconductor well known for its catalytic capabilities and for its simple manipulation to prepare thin films and nanoparticles. Naphthalene Diimides derivatives are known for their superior electrochemical activities comparable to those of Paraquat (Methyl Viologen) but with larger amplitude of photochemical applications.Positively and negatively charged, surfactant like, Naphthalene Diimides, were synthesized. After detailed characterization of the Naphthalene Diimides including selfassociation and interaction with surfactant molecules, the interaction with Cerium Oxide nanoparticles was determined.Naphthalene Diimides interacted in a special manner with Cerium Oxide nanoparticles rendering hydrolytic inertness and novel photochromic behavior. The organic dye is XII proposed to adsorb in the crevices of the particles and furthermore forming stable dimers that accounts for the new photoactivities observed.