Perylene Diimide Dyes Aggregates: Optical Properties and Packing Behavior in Solution and Solid State

Abstract

An electron acceptor and a donor of perylene diimide dyes (4a, 4b) were synthesized in an effective way. And the π–π interactions between perylene diimide dyes were discussed in solution and in solid state. The existence of weak π–π interactions in 4a, 4b and their mixture was confirmed with UV/vis and fluorescence spectra in dilute solution. Furthermore, the 1H-NMR studies displayed strong π–π interactions in concentrated solution. The packing behavior in solid state was discussed with solid state fluorescence, confocal fluorescence micrograph, scanning electron microscopy and powder X-ray diffraction, indicating stronger intermolecular interactions of 4a–4b than that of 4a–4a or 4b–4b.