Phenanthrenequinone's Chemistry And Its Derivatives' Optoelectronic Function

In last two decades, considerable progress of material syntheses, device fabrication technology and theory have been made in the fields of organic light emitting diodes. The related commercial products have been getting into the daily life. Basic functional materials, organic dyes and pigments, with its wealthy chemical structures, a wide range of resources and the diversity of functions, have played irreplaceable roles in the development of optoelectronic field.9,10-phenanthroquinone (PQ) is an important member in the quinone family and has a wide range of applications in the photochemistry, electrochemistry and materials synthesis. Because of the existence of the ortho-carbonyl group and the high conjugated phenanthrene unit with planar structure, PQ has the ability of charge dispersion, and could easily accept superfluous electrons. PQ shows multi-steps reversible reduction process. And the surplus of oxygen atoms is also easy to form multiple hydrogen bonds with a number of proton electron donors. So it is often used as a model compound for electrochemical study and could be used in molecular recognition and sensing areas. The carbonyl group in PQ is often used as a light-sensitive cell in the photochemical reaction causing the migration of electrons or protons. When chelating with the metal ion, the rate of the whole process would be greatly improved. Thus, PQ is of great importantance in photo-dynamics and photochemical reactions.PQ consists of phenanthrene unit and carbonyl group. It can react with different metals to form stable metal-complex structures. It also can react with some nucleophilic reagent such as silicon, phosphorus, oxygen, nitrogen and other non-metallic atom to form cycle-addition or heterocyclic structures, etc.Until now, a comprehensive study on PQ has not been performed. The fragmented reports make it difficult to completely understand the unique properties of PQ derivatives, limiting its development in optoelectronic materials. This doctoral dissertation is based on PQ's chemical structure, through a comprehensive research, such as physical and chemical properties and chemical derivatization, to investigate the detailed chemical properties of PQ and its derivatives in the functional photoelectric fields. By performing several kinds of reactions and the study of related materials'properties, some results and conclusions of PQ in syntheses methodology and organic photoelectronic materials design and preparation had been given.Based on the mechanism of the rapid chemical reaction of PQ with o-amines compounds to gain the phenanthro-pyrazine, we found the reaction rate can be significantly accelerated when PQ is connected with the electron donating group. In Chapter 2, we choose fluorene as an electron donating unit and matrix copolymer PPQF was synthesized. A series of copolymers containing phenanthro-pyrazine unit were gained by adjusting the conjugation degree of o-amines, such as PFBQ, PFBP, PFNP and PFTP. In solution, PPQF has red color but without emission. The emitting colors of PFBQ, PFBP, PFNP and PFTP have been tuned to bright blue, green, orange and red. And their efficiencies have been significantly improved in sequence. To increase the reaction speed and control the structures of targeted products, we also discussed the effect of the reaction conditions, the dynamics, substrate selection and microwave assisted syntheses. Through the continuous optimization, we realized multifunctional tuning simultaneously, such as chemical structures, fluorescence properties, the energy levels and electronic properties.The materials based on phenanthro-pyrazine unit can be used as electron-receptors. It shows excellent planarity which is beneficial for charge transport. In Chapter 3, we have applied this characteristic to prepare polymers with broad absorption and narrow band gap materials, P1 and P2. Through different selection of synthetic route and optimization of polymerization method, it was found that the obtained polymer's quality by Pd-catalyzed polymerization method was better than the one synthesized by Fe-catalyzed polymerization method. Compared to the classic narrow band gap material P3HT, the absorption spectra of the new materials was significantly broadened, and the absorption range from 200 to 400 nm and longer than 600 nm was observed. The onset of the absorption spectra peak of P2 was at 1100 nm, and the band gap was estimated to be 1.20 eV. The LUMO energy level was calculated to be 3.70 eV by electrochemical characterization. Photovoltaic properties were tested, and when P2 was doped with PCBM (1:1), device showed a power conversion efficiency of 1.26%.1H-phenanthro-imidazol structure was obtained though the reaction of PQ with aromatic aldehyde in the presence of ammonium acetate. In Chapter 4, we first reported that fully aromatic substituted phenanthroimidazole derivatives, and was used as an electroluminescent material. The reaction process and mechanism was studied. A series of oligomers were synthesized and BPPI demonstrated efficient blue emission, high thermodynamic stability and excellent film-forming. In the single-carrier devices, it shows more balanced carrier injection properties. And the performance of double-layered device exhibits the luminous efficiency of 6.8cd/A, which is better than the level of multi-layered device containing an independent electron injection layer. When this aromatic phenanthroimidazole unit was introduced to a conjugated polymer backbone, the polymer still remains a good blue fluorescence emission. Comparing with PF, the thermodynamic stability has been significantly increased. PFPIMOCN exhibited excellent deep blue emission, a CIE coordinates of (0.17,0.08), and brightness could reach to 1200 cd/m2. From the experimental and theoretical analysis, phenanthroimidazole unit is an excellent blue fluorescent materials block in maintaining high fluorescence efficiency, improving the thermodynamic stability and adjusting the energy level.Through the analysis of chemical structure of PQ and a summary of related work, we have a deep understanding of the nature of the relationship between PQ's structure and properties. Starting from its chemical reactions, a breakthrough of the methodology was achieved in the field of application by controlling its reaction processes and conditions. From the characteristics of its two chemical derivatives' structures, we studied their applications in optoelectronic fields. In a word, by the study of the chemical property and its derivatives'photoelectronic function, aimed to expand PQ's application in the synthesis methodology, the preparation of new functional materials, and to give enlightenment to the research of other organic dyes.