Incorporation of a ruthenium–bis(pyridine)pyrazolate (Ru–bpp) water oxidation catalyst in a hexametallic macrocycle

Abstract

New terpyridine-functionalised analogues of the in,in-[{Ru^II(trpy)}₂(μ-bpp)(H₂O)₂]³⁺ water oxidation catalyst (bpp = bis-(2-pyridyl)pyrazolate) have been synthesised and used to create a hexametallic {Fe₂Ru₄} macrocycle. The macrocyclic WOC precursor contains two catalyst units linked by two {Fe(R-trpy)₂} bridges and shows similar catalytic activity for water oxygen when compared to the non-cyclic catalyst precursors. The synthesised complexes were fully characterised by standard voltammetric and spectroscopic techniques (CV, DPV, NMR, MS, UV and IR) and the assessment of their performance as WOCs was performed using a Ce^IV chemical oxidant in aqueous triflic acid.