Organometallic Silicon-Containing Dendrimers and Their Electrochemical Applications

Dendrimers constitute a unique class of macromolecular architectures that differs from all other synthetic macromolecules in its perfectly branched topology, which is constructed from a multifunctional central core and expands to the periphery that becomes denser with increasing generation number (see Chapter 1) [1–5]. Since the pioneering works published in the late 1970s and the mid-1980s [6–8], the design and synthesis of these tree-like, well-defined molecules, which exhibit a unique combination of chemical and physical properties, is a field which has sustained dramatic growth and has generated enthusiastic studies at the frontiers of organic, inorganic, supramolecular and polymer chemistry, and more recently in the fields of nanoscience, biotechnology and medicine [1–5, 9, 10]. Whereas the initial interest in dendrimers was focused on the synthetic and structural characterization challenges that pose their fractal geometries, nanometer sizes and monodisperse nature, in the last decade the emphasis has been placed mainly on modification of the properties of dendritic molecules by their functionalization

Nowadays, one of the most active and promising research areas in dendrimer chemistry is in the integration of transition metals into dendritic structures to create metallodendrimers. Thus, the dendritic scaffold may be used for the spatial arrangement of a large number of transition metal-containing functionalities, either at the periphery or inside the dendritic skeleton (at the core or within the branches) and for the tailoring of properties through the interplay of metallic subunits. Since the first transition-metal containing dendrimers were reported in the early 1990s [11, 12], advances in the synthesis and chemistry of these molecules have not ceased to blossom. Besides the pleasant aesthetics and fundamental synthetic challenges of metallodendrimers, these molecules are also attractive because of their potential applications as functional materials in such diverse fields as catalysis, sensors, molecular electronic devices, light-harvesting antennas, nanoparticles and medical diagnostics [13–21]