The Synthesis And Characterization Of Poly(Para-phenylene Vinylene) With Fluoro Atom In Vinylene Units

The development of organic electroluminescent materials is one of the forefronts and hot areas of the optoelectronic information-displaying materials, on account of the advantages of organic electroluminescent materials compared to inorganic counterpart. Due to easy structural modification, good processability, facile color runability, high luminescence efficiency and so on, poly(p-phenylene vinylene) derivatives (PPVs) are still one of the most popular class of electroluminescent polymers. We designed and synthesized three kinds of PPV derivatives that have fluoro groups in vinylene units. Then we characterized series of their properties. The focus in this thesis mainly contains three following aspects:1. We synthesized hyperbranched PPV derivatives A, B and C. Their quantum efficiency is4.38%,4.04%and6.92%, respectively. Their maximum absorption peaks in THF solution are at376,370and357nm, respectively. Compared with maximum absorption peak in THF solution, their film absorption band are red-shifted about12,9and10nm, respectively. Their photoluminescence peak is about480and490nm in THF solution and solid film, respectively. And their HOMO levels are-5.46,-5.45and-5.43eV, respectively, LUMO levels are-2.39,-2.38and-2.29eV, respectively.2. We synthesized three copolymers that have9,9-dioctyl-2,7-divinylfluorene units on the backbone and introduced fluoro groups in vinylene units—poly{[2,7-difluorenevinylene]-co-[2-methoxyl-5-{2’-ethyl)hexoyl-para-phenyl enedifluorovinylene]}. The quantum efficiency are as high as12.88,10.91and7.14%for A, B and C, respectively. In THF solution the photoluminescence peak is about480nm and red-shift to490nm in solid film. And their HOMO levels are-5.35,-5.36and-5.33eV, respectively, LUMO levels are-2.40,-2.34and-2.27eV, respectively.3. We synthesized PPV derivatives with Ir(III) complex on the main chain. First, we synthesized two polymers with different monomer ration—poly{[2,2’-dipyridine-5,5’-divinylene]-co-[2-methoxyl-5-(2’-ethyl) hexoyl-para-phenylenedifluorovinylene]}. Then, the two copolymers were incorporated with [Ir(2-thiopheneylquinoline)2(Cl)J2dimer bridge. Both the absorption spectrum and the photoluminescence band are blue-shifted and widened compared with the predecessor. And, their quantum efficiency increased0.35and0.42times, respectively.