Electron transport in bipyridinium films.
Bipyridinium dications are versatile building blocks for the assembly of functional materials. In particular, their reliable electrochemical response has encouraged the design of electroactive films. Diverse and elegant experimental strategies to coat metallic and semiconducting electrodes with bipyridinium compounds have, in fact, emerged over the past two decades. The resulting interfacial assemblies span from a few nanometers to several micrometers in thickness. They incorporate from a single molecular layer to large collections of entangled polymer chains. They transport electrons efficiently from the electrode surface to the film/solution interface and vice versa. Electron self-exchange between and the physical diffusion of the bipyridinium building blocks conspire in defining the charge transport properties of these fascinating electroactive assemblies. Often, the matrix of electron-deficient bipyridinium dications can be exploited to entrap electron-rich analytes. Electrostatic interactions promote the supramolecular association of the guests with the surface-confined host matrix. Furthermore, chromophoric sites can be coupled to the bipyridinium dications to produce photosensitive arrays capable of harvesting light and generating current. Thus, thorough investigations on the fundamental properties of these functional molecule-based materials can lead to promising applications in electroanalysis and solar energy conversion, while contributing to advances in the basic understanding of electron transport in interfacial assemblies.
Raymo
Françisco M
FM
Center for Supramolecular Science, Department of Chemistry, University of Miami, 1301 Memorial Drive, Florida 33146-0431, USA. fraymo@miami.edu
Alvarado
Robert J
RJ
D004563:Electrochemistry; D004566:Electrodes; D036103:Nanotechnology; D010621:Phenazopyridine / Q000737:chemistry*; D011726:Pyridinium Compounds / Q000737:chemistry*; D055672:Static Electricity
D011726:Pyridinium Compounds; D010621:Phenazopyridine