Development and Characterisation of Highly Conjugated Functionalised Ferrocenylene Macrocycles

Multiple synthetic pathways were explored for the preparation of ethynylarene-containing ferrocenylene macrocyles. Accordingly, the synthesis of novel bis- and tris-ferrocenylene macrocycles, containing a diethynylpyridine bridging group was achieved, and evidence is also provided for a number of linear-analogues formed as by-products. The electrochemical properties of the macrocycles were examined, and it was shown that the number of observable redox processes does not necessarily correlate with the number of redox active centres. Additionally, examination of the comproportionation constants of the tris-ferrocenylene macrocycle demonstrated that the monocationic and dicationic species could be assigned to class II and I/II borderline of the Robin-Day classification, respectively. The synthesis of these molecules presents an opportunity towards the development of conjugated ferrocenylene macrocycles for electronic applications.

Automated summary

Multiple synthetic pathways were explored for the preparation of ethynylarene-containing ferrocenylene macrocycles. Novel bis- and tris-ferrocenylene macrocycles, as well as linear-analogues formed as by-products, were successfully synthesized. The number of observable redox processes was found to be independent of the number of redox active centres. The tris-ferrocenylene macrocycle exhibited properties corresponding to class II and I/II borderline of the Robin-Day classification. The synthesis of these molecules presents an opportunity for the development of conjugated ferrocenylene macrocycles for electronic applications.