Structural, Mossbauer, and EPR investigations on two oxidation states of a five-coordinate, high spin synthetic heme. Quantitative interpretation of zero-field parameters and large quadrupole splitting

The syntheses of the ferric and ferrous forms of the (acetato)iron 'pivalimide-picket-fence' porphyrin are subjected to structural, Mossbauer and EPR analyses. Specifically, the ferrous form is subjected to x-ray diffraction. Results indicate that there is a large positive quadropole splitting in the ferrous form of the acetato-porphyrinato complex. The crystal-field model is also used to explain the effect of distortions in one of the synthesis.