Synthesis and Electrochemical Properties of Phthalocyanines Bearing Fc(CH2)ns- and Dodecyl Substituents in Non-Peripheral Positions

Phthalocyanines and their metal complexes¹ gain constant attention due to their chemical, thermal and photochemical stability as well as numerous applications including catalysis, as ink-jet printing components, photosensitizers for photodynamic therapy of cancer, memory devices and liquid crystals. The introduction of a ferrocenyl moiety to the core of phthalocyanine macrocycle imparts a new redox active centre in addition to four existing macrocyclic centres. Non-peripherally substituted long alkyl chains contribute to the solubility of the macrocycle, assist in studying catalytic properties and, depending on the type of substituent, convey the possibility of possessing liquid crystal properties.

Here we present the synthesis of above compounds and the results of their electrochemical investigation. Our particular interest lies in the dependence of ferrocenyl redox properties on the electron withdrawing properties of phthalonitrile. It was found to be a function of the linker atom (S) or lack of thereof as well as the chain length (expressed as n above). The redox properties were probed utilising glassy carbon working electrode as well as gold electrode to immobilize sulphide species. Dodecyl chains attached to the core of macrocycle proved increasing solubility of compounds in organic solvents² and also led to liquid crystalline properties.

References

1.   E. Fourie, J. C. Swarts, I. Chambrier, M. J. Cook, Dalton Trans., 1145-1154 (2009).

2.   J. C. Swarts, E. H. G. Langner, N. Krokeide-Hove, M. J. Cook, J. Mater. Chem., 11, 434-443 (2001).