Synthesis Of Heteroatom-Fused Armchair Type Molecular Graphene

Graphene is a one-atom-thick planar sheet of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. According to the edge structure, graphene nanoribbons can be divided into armchair and zigzag comformation. Different from the zigzag structure, the armchair type graphene shows the unique property of the metallicity or semiconductor characteristics in terms of the number of the edge atomics. Molecular graphene, as a segment of two-dimensional graphene, shows special optics and self-assembly properties, and is widely used in organic photoelectric materials, such as light-emitting diodes, field effect transistors, solar cells and so on. Therefore, to design molecular graphene into armchair type may exhibit some superior organic photoelectric properties. In addition, in view that the thiophene skeleton compounds show excellent optical, electrochemical, biological and physical performances, introduction of thiophene skeleton into armchair graphene may show an anticipated application with good physicochemical features and self-assembly performance. This thesis mainly is divided into two parts:Part Ⅰ:The synthesis of sulfur fused armchair molecule grapheme. Firstly,1,3-(3,5-dibromo benzyl) ketone was obtained through the reaction of3,5-dibromo benzyl bromo with tosylmethyl isocyanide (TosMIC); Secondly, the product reacted with benzil to get3,4-diphenyl-2,5-di(3,5-dibromo phenyl) ketone of cyclopentadiene, it further reacted with phenyl acetylene by Diels-Alder reaction to synthesize1,2,4,5-tetraphenyl-3,6-di(3,5-dibromo phenyl) benzene. Thirdly, oxide precursor was achieved through the Suzuki coupling reaction between1,2,4,5-tetraphenyl-3,6-di(3,5-dibromo phenyl) benzene and thiophene borates compounds. Finally, the target compound was successfully synthesized by oxidative cyclization with FeCl3as an oxidant.Part Ⅱ: The physicochemical properties of the sulfur fused armchair molecule graphene. The MALDI-TOF mass, ultraviolet and fluorescence spectra characterizations revealed that compounds exist in the form of aggregate. And TG results showed their high thermal-stability.