Predicting the electrochemical behavior of Fe(II) complexes from ligand orbital energies

An attractive strategy for harvesting solar energy is to use dye-sensitized solar cells employing earth-abundant Fe (II) chromophores. These dyes need to meet several criteria to be effective for this purpose, including air stability, and an ability to be regenerated by common electrolytes. Both of these properties are related to the Fe(III/ II) reduction potentials. Here we show how the Fe(III/II) reduction potentials of Fe(II) complexes can be estimated from a single experimental Fe(III/II) reduction potential and computationally cheap calculations on single isolated ligands. This method requires refinement, but could prove highly useful for large-scale computational screening and design of Fe(II) dyes.