Magnetic properties of ferric hemoproteins and the relation to electronic structure of the prosthetic group.

Recently, it has been shown that the magnetic data of bacterial cytochromes c' and of some model complexes are consistent with a quantum mechanically mixed spin state. This new mixed spin state is to distinguish from thermally mixed pure high-spin and low-spin states. Based on ligand field model, the dependence of the magnetic state of a heme complex on the nature of the axial ligands is discussed.