Theroretical Study On Structure And Charge Transport Properties Of Aromatic Molecular-Bowl Hydrocarbons

Since corannulene was first prepared by Barth Lawton in 1966 and characterized as a bowl-shaped polynuclear aromatic hydrocarbon, buckybowls have been extensively studied both experimentally and theoretically. Buckybowls have been the major of intense research due to their unique(chemical and physical) properties and their potential applications in molecular electronic devices, such as in organic and polymer light emitting diodes(OLEDs and PLEDs), organic solar cells, and organic field effect transistors(OFESs) and nonlinear optical(NLO) material. Corannulene and sumanene are two fundamentally important buckybowls, which can be viewed as C20 and C21 fragments of buckminsterfullerene(C60) along the C5 and C3 axes, respectively. The major works are as follows:(1) We have studied the transport properties of sumanene and heterasumanene using density functional theory(DFT). And we have considered both monomers and dimers of seven representative systems, including sumanene and six heterasumanenes. In order to gauge the effect of heteroatom on heterasumanene, the simulated properties include geometries, adiabatic ionization potential(IP), adiabatic electron affinity(EA), molecular interaction and transport properties are calculated by using DFT. TFS and TOS can as high-performance electron OFET candidate that can operate under ambient conditions. A significant increase in electron mobility when C=O is present on its benzylic position is predicted. The TBS which is predicted to display ambipolar charge transport behavior in such a way that main carrier hoping path-way could move through the one-dimensional columnar convex-concave stacking. For TPS, TTS and TSS, we find the μHole is bigger than μElectron, this suggested that they act as hole transporter in organic electronics. In addition, a detailed potential energy curves, binding energy and RDG for dimer configuration analysis has been performed in order to characterize intermolecular interactions in terms of π…π stacking which contribute to the stabilization of the columnar stack at molecular scale.(2) By using quantum chemical calculation, we have investigated the changes in the corannulene buckybowl structure, which greatly affect its transport properties when functionalized with different electron-withdrawing imide groups. Herein, a range of properties and structure–property relationships of various imide-functionalized corannulenes are explored and rationalized in detail. DFT has been carried out on a series of corannulene to obtain insights into the electronic structure, energy, IP, EA, aromaticity property and reorganization energy. With the increase of imide groups, HOMO and LUMO energy levels are low, and the IP and EA value increases, the same number of five membered ring or six-member ring imide groups in different location had little impact on the level; The aromaticity of the five-member ring centers for all the corannulene systems has been investigation though NICS(1)ZZ value, which show moderate positive values and they exhibit antiaromaticity of the systems. And five-membered ring imide group is greater than the influence of the six-member ring imide groups. To investigate their charge transport properties, we calculated reorganization energy, which indicated that the λHole and λElectron reorganization energies of five-membered ring imide groups fused corannulene are almost equality; they should be a good bipolar transport material. However, λHole>λElectron of six-membered ring imide groups fused corannulene, which means that they may be as candidate for n-type transporter. Our work presents a bright future for the application of buckybowls in organic electronics.