Ferrocene-based Branched Polymers Dendrimers

As shown, starting from the central nucleus, each subsequent bifurcation leads to the dendrimer being classified as 1st generation, 2nd generation, 3rd generation, and so on. 

As expected, it shows in dichloromethane solution a quasireversible one-electron oxidation ( ° = + 0.54 V, vs. Ag/AgCl).47 

Both the complexes display, in dichloromethane solution, a single oxidation process which involves four ( ° = + 0.40 V, vj. SCE) and eight (jE °/ = -1- 0.44 V, vj. SCE) electrons, respectively. This means that no electronic communication exists among the ferrocenyl units. 

It exhibits a single oxidation process (Ea = + 0.59 V, vs. SCE) affected by some adsorption problems. These adsorption phenomena, which typically affect the electrochemical response of these derivatives, sometimes make it difficult to ascertain by controlled potential coulometry the effective number of electrons involved in the oxidation step. In this case, the (approximate) number of electrons involved per molecule of dendrimer, nd, can be roughly calculated by comparing the cyclic voltammetric responses of the dendrimer with that of the ferrocene monomer using the following empirical equation.27,40 

This complex exhibits in DMF solution a one-electron reduction (Eal = -1.60 V vs. SCE) which is centred on the central [Fe(f 5-C5H5)(/ 6-C6R-6)] 1 core, as well as a single six-electron oxidation (Eo1 = -1-0.44 V), which is centred on the outer, not-interacting ferrocenyl groups. 

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Ferrocene-based Branched Polymers (Dendrimers). One of the topics in macromolecular chemistry is constituted by dendrimers, or hyperbranched macromolecules of tridimensional globular structure, the surface of which is characterized by a large number of functional groups, Scheme 4. Such functionalities impart to the molecules solubility, viscosity and thermal properties different from those of the common linear polymers.38c,d 44... 

The synthesis and properties of star polymers and dendrimers functionalized with ferrocene units has attracted a great deal of attention. The synthesis of high-generation dendrimers functionalized with chiral ferrocenyl units in their structures has been reported. The chiroptical properties of this class of dendrimer was dependent on the number of ferrocenyl groups and their chemical environment, but not on their position within the dendrimer. Deschenaux has reported the synthesis of hquid crystalline ferrocene-based polymers prossessing an enantiotropic smectic A phase. Ferrocene-functionahzed cyclic siloxane (29) and silsesquioxane branched polymers have also been reported. A hyperbranched polymer with a cubic silsesquioxane core was used to mediate the electrocatalytic oxidation of ascorbic acid. 

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