Redox properties electrochemical-chemical reactivity

In order to build up dendrimers crqrable of exhibiting redox activity and light-induced functions, appropriate building blocks have to be used. In the last 20 years, extensive investigations carried out on the photochemical and electrochemical properties of transition metal compounds have shown that Ru(II) and Os(ll) complexes of aromatic M-heterocycles (Figure 1), e.g., Ru(bpy)j and Os(bpy)j (bpy = 2,2 -bipyridine), exhibit a unique combination of chemical stability, redox properties, excited state reactivity, luminescence, and excited state lifetime. Furthermore all these properties can be tuned within rather broad ranges by... 

Electrochemical measurements are commonly carried out in a medium that consists of solvent containing a supporting electrolyte. The choice of the solvent is dictated primarily by the solubility of the analyte and its redox activity, and by solvent properties such as the electrical conductivity, electrochemical activity, and chemical reactivity. The solvent should not react with the analyte (or products) and should not undergo electrochemical reactions over a wide potential range. 

Compared to the large body of electrochemical data, there have been fewer studies on the chemical reactivity of bis(dithiolene) complexes. In light of the rich redox chemistry of bis(dithiolene) complexes and the redox-active nature of the dithiolene ligands, it is not surprising that much of the reactivity observed is related to the redox properties and is often centered on the dithiolene ligands. 

This study provided a few examples which illustrate the application of molecular electrochemistry to the investigation of coordination compounds with unsaturated-C or -N ligands, in a number of perspectives, namely directed towards the elucidation of reaction mechanisms (either in their synthesis or in further reactions), the rationalization and prediction of their redox or electronic properties (for both the unsaturated ligands and their binding metal centres), the recognition of correlations between electrochemical and other physico-chemical parameters, and the electroinduction of chemical reactivity (electroactivation of those ligands or their coordination metal sites). 

One-electron redox couples. Fe(CN)6 is a redox system that is often used to probe the reactivity of electrodes. It is often presumed that this redox couple undergoes electron transfer via a simple outer sphere mechanism, which imphes that it is not sensitive to the physical, chemical and electronic properties of the electrode surface. Reversible to quasi reversible kinetics of the inorganic redox analyte Fe(CN)G were reported for diamond electrodes, and it was found that films with no extensive electrochemical history can retain a high degree of activity for... 

---