A High Pressure Mössbauer Spectroscopy Study of [57FeOEPCl]

Iron porphyrins are widespread in nature, being found as the active sites in hemoglobin, myoglobin and a wide range of cytochromes1. The most common porphyrin is Protoporphyrin IXiron(II)/(III) [PPIXFe(II)/(III)] (haem), however this complex is difficult to crystallise and its chemistry is often modelled using man made porphyrins. We have previously studied [FeIIIPPIXCl]2 by high pressure Mossbauer spectroscopy and found evidence of a change of spin from high spin state to a spin admixed state S = +/− 3/2, +/− 5/2.