“…Square-planar complexes, including transition metal porphyrinic complexes, comprise an extremely important class of compounds, being at the center of numerous proteins, enzymes, and one-dimensional conductors. − Assignments of the simplest of these complexes, such as tetracyano complexes, have been well established. − The more complex porphyrinic complexes have had an accepted assignment of the two principal regions, the Q region in the long visible and the Soret region in the near UV, , but recent calculations have suggested that a change in assignments is appropriate. − Polarized electronic spectra have been helpful in making transition assignments, and we have proposed a new set of assignments for metallophthalocyanines (Mpc, where pc = tetraazatetrabenzoporphyrin) using a reduced-symmetry complex and results from earlier SCF-Xα-DOS calculations. − …”