Electronic and Redox Properties of Stacked-Ring Silicon Phthalocyanines from Molecular Orbital Theory.

It is shown that the multi-peaked cyclic voltammograms for silicon phthalocyanine monomer-oligomer sets may be predicted from initial state molecular orbital energy levels if field shifts are used to allow for the charges of the anions and cations. The theory should have broad application for the understanding of the redox properties of other cofacial macrocyclic ring systems and the conductivity of doped cofacial polymers. The molecular orbital energy levels also produce the features of the optical and photoemission spectra of silicon phthalocyanine monomer-oligomer sets in the HOMO-LUMO energy regions, showing the importance of direct pi overlap.