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

The electronic spectra of porphin, chlorin and their magnesium derivat ives 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 be en analyzed together with the correlation effects. The main result reg ards the T-T spectrum of porphin. To obtain a correct description of t he complete spectrum it is necessary to take account of the correlatio n effects. Gouterman's model of four orbitals is too simple to describ e the region of the Soret band.