A screened potential molecular-orbital calculation of the π-electron systems of metalloporphin, metallochlorin, and metallobacteriochlorin

Abstract

The excitation energies and oscillator strengths of the lowest (π,π*) excited states of metalloporphin, ‐chlorin, and ‐bacteriochlorin were calculated by the screened potential molecular‐orbital theory. The screened potential incorporates instantaneous polarization effects in the molecular Hartree–Fock field. The model reproduced the spectra of the lowest excited states fairly well without use of empirical parameters. The calculated energies of the lowest excited triplets and the Q singlet state were in good agreement with those observed, while the B state was correctly predicted only for the reduced resonance integrals.