Department of Chemistry Seminar - Rational Synthesis of Graphene Molecules with Non-Alternant Topologies
Speaker: Prof. Junzhi LIU
Institution: Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong
Hosted By: Prof. Ding PAN
Incorporation of the non-hexagonal rings into graphene molecules (NGs) can significantly affect their electronic and optoelectronic properties, as well as the chemical reactivities.[1-4] In this abstract, we will introduce the bottom-up organic synthesis of graphene molecules with non-alternant topologies (Figure 1), e.g. seven-five-seven-membered rings (7-5-7) and four continuous heptagons. To gain new insight into the effect on their electronic and optical properties, various experimental measures, including cyclic voltammetry, Raman, steady UV-vis absorption, and theoretical calculations were carried out. Compared with the aromatics with only hexagonal rings, the NGs with non-alternant topologies present distinct anti-aromatic character with narrower HOMO-LUMO energy gaps. In contrast to the successes achieved with varied NGs with non-alternant topologies, we also try to the development of facile and effective methods to synthesize lovely molecules bearing N-doped joined nonhexagons, including pentagon-heptagon pairs and pentagon-octagon pairs. Our work not only provides a new way to the synthesis of novel graphene molecules with non-alternant topologies, but also offers the possibility to tune their electronic and optical properties.
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