Conformational polymorphism of multimeric perylene derivatives observed by using scanning tunneling microscopy

Abstract

We report the observation of a series of perylene bisimide derivatives containing two or three perylene moieties. Dramatically different assembling behavior can be observed under ambient conditions on highly oriented pyrolitic graphite (HOPG) surface with scanning tunneling microscopy (STM). The dihedral angles between the perylene moieties are suggested to be sensitively dependent on the linker units. The linear linker units could make the perylene moieties with spatial configuration be observed on the surface. The length of linear connecting parts would also influence the dihedral angles. The fundamental processes occurring at solid-liquid interfaces have been found, because of the extended observation time or elevated temperatures. All these results would help to comprehend the conformational polymorphism of carrier transport in the organic thin films.