Double-decker Silsesquioxanes: Current Chemistry and Applications

Polyhedral oligomeric silsesquioxanes (POSS) with a rigid inorganic Si-O-Si core and flexible and reactive and/or inert organic coronae have attracted much attention. Their unique structures, in addition to their physical properties, e.g. low dielectric constant or high thermal stability, are especially interesting. The well-defined organization of silsesquioxanes is important due to their possible use as precursors and components of versatile inorganic/organic hybrid materials. This paper presents a short overview of the two parallel paths in current research on double-decker silsesquioxanes (DDSQ), i.e. the synthesis and properties of both molecular and macromolecular compounds based on a DDSQ core. Over the last decade the number of publications concerning DDSQ based compounds has increased showing the growing interest in this field. Several reviews on different aspects of POSS have been prepared; however, because of the relatively "young age" of the double-decker silsesquioxane there has not been a review of the above topic.