Development of iron(III) and ruthenium(II) coordination compounds with N,N′-bis(2-pyridylmethyl)ethylenediamine for water splitting reaction

Hydrogen gas has been increasingly considered a friendly energy source because it does not emit harmful gases into the atmosphere when burned and does not contribute to drastic climate change. One way to produce hydrogen gas is through water electrolysis; however, the kinetic barrier of the water splitting reaction is considerably high, requiring catalysts capable of reducing the overpotential generated at the electrodes. Iron(III) and ruthenium(II) complexes have been studied as alternative materials, acting as active catalysts in the production of clean energy. In this work, mononuclear complexes were synthesized and characterized through analytical, spectroscopic and electrochemical techniques, with the ligand N,N’-bis(2-pyridylmethyl)ethylenediamine (py2en) for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), a complex with labile positions in the coordination sphere, capable of following the proton-coupled electron transfer mechanism in the study of electrocatalysis at different pHs.