Charge and spin distributions in transition metal porphines and phthalocyanines

Electronic energy levels and charge and spin distributions for iron, copper and silver porphine have been calculated, using the one-electron Hatree-Fock-Slater theory. Calculated spectroscopic properties are compared with the available optical, photoelectron, and hyperfine data, and with previous theoretical efforts. Using density difference contour maps and a Mulliken population analysis based upon the LCAO variational expansion of the eigenfunctions, we make quantitative verification of traditional ideas about bonding and charge transfer in these systems. Contact hyperfine fields and effective <r^-3≳ matrix elements are obtained for various nuclear sites. Effects of substitution on the porphine carbon skeleton are studied in analogous calculations on the metal phthalocyanines. Subtle differences in metal-ligand bonding between porphines and phthalocyanines are revealed in the difference densities.