Preparation, characterization and application of a nanostructured composite: Octakis(cyanopropyldimethylsiloxy)octasilsesquioxane

Octakis(cyanopropyldimethylsiloxy)octasilsesquioxane was prepared and characterized by 13C, 29Si NMR (MAS), SEM, FT-IR, XRD and thermogravimetric techniques. The four groups a, b, g, k (to the terminal silicon atom), associated with an acrylonitrile, were clearly seen in the 13C NMR (a-CH2 at 17.9; b-CH2 at 31.3; g-CH2 at 50.4; k-CBBN at 59.0 ppm). The 29Si NMR spectrum of the final product, exhibits only Q type silicon signal, ascribed to Q4 ( 118.0 ppm). The presence of acrylonitrile substituted for octameric cube confers a relative change phase and thermal stability to the material.With regard to the applications for this new material, it was intended, in this case, to react with Na2[Fe(CN)5NH3] by chemical substitution. This composite was incorporated into a carbon paste electrode and the electrochemical studies were performed by cyclic voltammetry. The cyclic voltammogram of the modified graphite paste electrode, showed one redox couples with formal potential (Eox 1=2) = 0.24 V versus SCE.