ELECTRONIC-SPECTRUM OF PORPHYRINS - CS-INDO-CI STUDY

The electronic spectra of porphin, chlorin and their magnesium derivatives have been studied quantum-mechanically with the CS INDO CI method. Both the S-0-S-n, and T-1-T-n, one-photon absorption spectra have been analyzed together with the correlation effects. The main result regards the T-T spectrum of porphin. To obtain a correct description of the complete spectrum it is necessary to take account of the correlation effects. Gouterman's model of four orbitals is too simple to describe the region of the Soret band.