Correlations between photoelectron and uv absorption spectra of polycyclic hydrocarbons. The pyrene series

In continuation of earlier work on the relationships between the PE and optical spectra of polycyclic aromatic hydrocarbons, the PE spectra of 34 pyrene-type molecules are correlated with electronic spectra. As in other series of hydrocarbons considered so far, the p-band in the optical spectra is related to the first IP, whereas the α- and β-bands can be related to higher IP's. Regularities observed in the PE spectra of linearly annellated, plane- and centro-symmetrically annellated pyrenes are discussed.