Electronic absorption spectra of the iron(II) complexes of 2,2'-bipyridine, 2,2'-bipyrimidine, 1,10-phenanthroline, and 2,2':6',2''-terpyridine and their reduction products

The electrochemical analysis of iron(2) complexes of 2,2'-bipyridine, 2,2'-bipyrimidine, 1,10-phenanthroline and 2, 2':6',2''-terpyridine showed that all the complexes undergo a three-step one-electron reversible reduction except for terpyridine complexes which involve a two-step one-electron reduction. Moreover, all the four complexes featured a single one-electron reversible oxidation with electrochemical potentials ranging from +0.785 to +1.036. In addition, the application of ultraviolet-vis-near-infrared spectroscopy in the examination of the products provided reliable results.