Tris(1,10‐phenanthroline)iron(II) Complexes — Broad Variation of the Redox Potential by 4,7‐Substitution at the Phenanthroline Ligands[1]

The new 4,7‐donor‐substituted phenanthrolines 2a‐h were synthesized and the corresponding tris(1,10‐phenanthroline)iron(II) complexes 3a‐h studied by cyclic voltammetry. In more detail three novel aza‐crown ether‐linked (phenanthroline)iron complexes were investigated, the redox potentials of which could be fine‐tuned by the addition of group‐Ia,IIa metal cations. All iron(II) complexes showed reversible waves at scan rates between 50 and 500 mV · s ‐1 and could be reversibly oxidized and reduced by chemical means.