The Aggregation Morphology,and Photoelectric Property Of Pyrene Derivatives

A series of pyrene derivatives with special molecular structures were studied.With the difference molecular structure,their morphology and photoelectric properties of the compounds were studied.The relationship between molecular structure,aggregation morphology and photoelectric properties was summarized.The main contents were as follows:1)Four pyrene-fluoroene derivatives were designed and synthesized.In PFP1 and PFP2,there was nonconjugated pyrene substitution on C9 of the fluorene moiety.There was a special ?-? hyperconjugation effect between nonconjugated pyrene and the pyrene-fluorene conjugation in the system(PFP1 and PFP2),which meat the electron cloud of such two isolated conjugation systems could be delocalized and transferred to each other.Because of delocalization of electron cloud,the molecule size of PFP1 and PFP2 might had been decreased and led to decreased phase transition temperature compared with that of BP1 and BP2.Also due to the electron transfer between the molecules,the intermolecular force between PFP1 and PFP2 were improved,which was the reason that they were more amorphous than BP1 and BP2.The easy electron transfer also made the PFP1 and PFP2 showed improved hole injection and device performance compared with that of BP1 and BP22)Two compounds Py-4TrH and Py-4TrHE with similar structures were designed and synthesized.They had dendritic molecular structure with pyrene as the core,and truxene as the branch.Due to multiple alkyl chains were introduced into the molecular structure of the two compounds,they showed good solubility.The spectrum results indicated that they were blue-emitting and green-emitting materials,and the peak values of fluorescence emission were at 468 nm and 526 nm,respectively.They both had excellent thermal stability.3)Py-4TrH,Py-4TrHE,PYT and PYET formed aggregates by means of recipitation.Then,their aggregation morphologies and films were measured by SEM and AFM testing,respectively.Due to the presence of alkynes in Py-4TrHE and PYET molecules,the steric hindrance of the molecule decreased,which resulted in the movement or rotation of some parts in one molecule,providing to more binding sites in self-assembly process.Py-4TrHE and PYET showed more homogeneous aggregation morphology than Py-4TrH and PYT,respectively.