Photoabsorption spectra of helicenes

Abstract

In this work, photoabsorption spectra of some polycyclic aromatic hydrocarbons (PAHs) from time-dependent auxiliary density functional theory (TD-ADFT) are presented. In particular photoabsorption spectra of oligoacenes from three up to six fused rings, phenanthrene, benzo[c]phenanthrene, pentahelicene and hexahelicene are given. These spectra are presented to see semi-quantitative differences between isomers. The energy interval, from 1 up to 30 eV, of these spectra fill the gap left by the scarce spectroscopic data for helicenes.