The hybrid quantum mechanics/molecular mechanics method IMOMM is applied to the calculation of the structure of the oxygenated picket-fence porphyrin complex of iron Fe(TpivPP)(1-MeIm)(O2), with results in good agreement with available X-ray data. An investigation on the role of the picket-fence substituents in the binding of dioxygen through comparison with additional calculations on a system with the "naked" porphyrin complex Fe(P)(1-MeIm)(O2) shows that the presence of the amide groups of the picket-fences contribute to the binding with ca. 5 kcal mol-1. The largest contribution to this stabilization is found to correspond to an O⋯-H(N) interaction.
|Journal||New Journal of Chemistry|
|Publication status||Published - 1 Apr 1998|