Molecular mechanics study of the ruffling of metalloporphyrins

Molecular mechanics techniques using a modified version of the program MM2(87) were used to analyze the ruffling of metalloporphyrins as a function of metal ion size, orientation of axial ligands, and orientation of substituents on the porphyrin periphery. The structures chosen for the parametrization, [P(TPP)(OH) 2 ] + , the planar and ruffled forms of low-spin (S=0) [Ni(OEP)], (S=1) (Fe(TPP)], [Zn(TPP)], and (Pb(TPrP)], contain metal ions of very different sizes and hence extents of porphyrin core ruffling