TIME-DEPENDENT DENSITY FUNCTIONAL THEORY CALCULATIONS OF LARGE COMPACT POLYCYCLIC AROMATIC HYDROCARBON CATIONS: IMPLICATIONS FOR THE DIFFUSE INTERSTELLAR BANDS

摘要

We investigate the electronic absorption spectra of several maximally pericondensed polycyclic aromatic hydrocarbon radical cations with time-dependent density functional theory calculations. We find interesting trends in the vertical excitation energies and oscillator strengths for this series containing pyrene through circumcircumcoronene, the largest species containing close to 100 carbon atoms. We discuss the implications of these new results for the size and structure distribution of the diffuse interstellar band carriers.