Cyclopentadienyl substituents

To conclude the matter of monoferrocene molecules we consider those cases in which the cyclopentadienyl substituents form bridges between the two rings. Such derivatives are named ferrocenophanes. The best known ferrocenophanes are those which contain saturated (tri- or tetra-methylene) carbon chains. Like ferrocenes, these molecules also exhibit reversible one-electron oxidation to the corresponding ferrocenium ions. 

Attempts have been performed to analyse (in terms of rate constants) the steric-to-electrochemical factors which can influence the interaction of ferrocenium derivatives with reduced GOD, or the ability of ferrocenes to act as mediators in the enzymatic oxidation of glucose as a function of cyclopentadienyl substituents.63... 

As the size of the cyclopentadienyl substituent increases, the less stereoselective site is more likely to choose the same monomer enantioface as the more stereoselective site. The [m] dyad fraction increases accordingly. Figure 2.22 plots the observed polymer melting temperature as a function of the [m] dyad composition. " Several polymers exhibit no strong endotherm via differential scanning calorimetry (DSC) and are essentially amorphous. Above [ni] 70%, normal DSC traces are obtained and the melting temperature is proportional to the isotacticity as quantified by [ni]. 

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