Design And Synthesis Of Finely Structured Non-planar Carbon Nanoribbons

As a new type of one-dimensional nanomaterial,nanoribbons have unique characteristics because of their size effect,quantum effect and interface effect,so they have great prospects in optics,magnetism and electricity and is concerned by scientists.Graphene nanoribbons(GNRs)is a one-dimensional product in which the width of graphene is limited to less than 100 nm,and its special structure brings about special edge effects(such as edge configuration,edge chaos,and different edge treatments,etc).The special edge effects are the most essential feature that distinguishes it from graphene,and it is also a source of many special properties.GNRs inherit many of the excellent properties of graphene and overcome the defect of graphene which has zero band gap.Therefore,compared with graphene,GNRs have greater potential practical value in the field of electronics.Polycyclic aromatic hydrocarbons(PAHs)have good characteristics that contain charge transfer and modifiable structural.These characteristics make them useful in organic semiconductor devices.Its potential application as an organic photoelectric material has drawed great concern.As an important class of PAHs,hexabenzocorone has great research value.Hexabenzocorone has two different types of plane and curved surface.Compared with the planar hexabenzocorone,the aromatic core of the distorted hexabenzocorone(c-HBC)and its derivatives is distorted and has strong self-assembly properties.The c-HBC forms a hexagonally ordered columnar liquidcrystalline phase.The coaxial aromatic core of this stack can act as aconduit for the charge,and the exterior of the molecule can behave as an insulating sheath.At the same time,this non-planar structure can well match the materials with convex structures,such as fullerenes,and provide a way for the separation and purification of fullerenes.The curved hexabenzocorone(c-HBC)is the main research content of our laboratory.It is very meaningful to study and synthesize nanoribbons based on HBC.In this paper,a novel series of polycyclic aromatic hydrocarbons have been designed and synthesized to explore the relationship between molecular structures and photoelectric properties.Details are as follows:(1)HBC dimer was designed and synthesized.HBC dimer contains two types: chain and chainless dimer which were synthesized by two methods respectively.The presence of the dodecyloxy chain can ensure the solubility of the dimer,while the non-chain dimer is used to adjust the solubility of the dimer in order to obtain its crystal structure.The two styles are complementary and related to each other.(2)HBC oligomers were designed and synthesized.HBC precursors were used as the substrates.The oligomers were successfully synthesized by Suzuki coupling reaction.A series of dehydrogenation products are obtained by the photocyclization reaction.This type of oligomers can achieve atomic precision control,and because the HBC precursor is located at the periphery of the nanoribbons,the middle portion which is continuously transformable is protected.