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

New terpyridine-functionalised analogues of the in,in-[{RuII(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 macroyclic 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 CeIV chemical oxidant in aqueous triflic acid.