Study Of Electronic And Aggregation Structures Of D-A Type Perylene Diimide Derivertives

Perylene Diimide(PDI)is a typical n-type organic semiconductor material.From the perspective of chemical structure,the non-substituted perylene diimide molecule with a large plane conjugation group is easy to form intermolecular strongly ?-? interaction,which is easy to be chemically modified in the imide and bay regions.From the point of view of electronic structure,the perylene diimide has a lower frontier orbital level and is commonly used as an electron acceptor element.In this paper,a series of perylene diimide derivatives with D-A structure were designed and synthesized based on the chemical structure and electronic energy level structure of PDI.We have studied the photoinduction of intramolecular electron transfer,electron energy level structure regulation and molecular aggregation structure.Therefore,this paper mainly includes the following three aspects:1.By introducing different electron-donating groups at the position of the perylene imide N-node,the D-A structural molecules are constructed.The effects of the electron level structure and the distance on the electron-transfer process were studied by using steady-state and time-resolved spectroscopy combined with theoretical calculations.The results are important for understanding the charge transfer between the non-fullerene receptors and the donor in the organic solar cells.2.In the perylene diimide bay region,a phenyl substituent with weak electron donation property is introduced,and the perylene imide fused ring ? plane structure is increased by oxidative reaction.The influence of the phenyl substituents on the electron energy level structure of perylene diimide was studied by electron absorption spectroscopy and theoretical calculation.The number of conjugate ? electrons in the direction perpendicular to the minimum transition dipole shows a abnormal law towards the molecular frontier orbit.The results are of great significance to understand and design the two-dimensional conjugate system.3.In the perylene diimide bay region,a hexamulomeric group with a large ?-planar structure was introduced.The characteristics of the aggregation structure were studied by electron diffraction and XRD diffraction.It was found that the perylene diimide and the hexachlorocarbene unit were assembled to form the hole and electron transport channel of donor and acceptor respectively.The results are important for the regulation of supramolecular aggregation,and the aggregates obtained may be used in molecular electronic devices.