The objective of this volume is to present a full and critical spectral data coverage of the entire major fields relating to tetraphenyl and analogous porphyrins, their precursors, catabolic derivatives, and related systems electronically.

The porphyrins are an important class of naturally occurring macro cyclic compounds that play a very important role in the metabolism of living organisms. They have a universal biological distribution and were involved in the oldest metabolic phenomena on earth. Without porphyrins and their relative compounds, life as we know it would be impossible...