Bay-Extended, Distorted Perylene Esters Showing Visible Luminescence after Ultraviolet Excitation: Photophysical and Electrochemical Analysis

Perylene derivatives with a unilaterally and bilaterally extended core show luminescence in the visible wavelength range (500–600 nm) that can be excited by absorption in the ultraviolet range (360–370 nm). This unusual behavior is investigated by means of excitation spectroscopy, cyclic voltammetry, and calculations based on (time-dependent) density functional theory. The results indicate that the extended compounds show promising features for optoelectronic applications and even might be used as fluorescent dyes in lasing. This is supported by nonadiabatic ab initio molecular dynamics. With respect to applications in organic optoelectronic nanostructures, nanofilms were prepared via spin-coating and thermal vapor deposition and demonstrated the formation of excimers. The relationship between the excimer-induced bathochromic shift and the interplanar distance of the molecules opens up the possibility to vary the perceived color of a nanofilm via tempering