Simple synthesis of organo-iron complexes from iron-sandwich raw materials using visible light

Piano-stool organo-iron complexes [CpFeL1L2L3]+ bearing a variety of ligands (Cp = η5-C5H5, L = neutral 2-electron ligand) can be readily synthesized by visible photolysis of any member of the family of [FeCp(arene)][PF6] sandwich complexes (arene = η6-arene) including those in which the arene is mono-, bis or trisubstituted. A short review is provided for these reactions and processes and their applications in organo-iron synthesis.