Study On Synthesis And Properties Of Monomers And Polymers Containing Thiophene [2,3-b] Thiophene

Thiophene and its derivatives are a class of compounds with a variety of superior performance, such as optical, electrical, and magnetic properties, etc, and many of the thiophene and its derivatives have been used in the engineering of new materials. With the further research to understand the relationship between the structure and properties of thiophene and its derivatives, more high performance thiophene and its derivatives have been synthesized to meet the needs of high-tech field. In optical signal processing, information storage, fluorescent display, chemical energy storage and many other technologies, they have potential applications. Therefore, synthesis and study their properties of thiophene and its derivatives is very important significance.Among the many derivatives of thiophene and its derivatives, Thiophene[2,3-b]thiophen-e is an aromatic polycyclic system with a large degree of conjugation. It is well known that these compounds with a large degree of conjugation should own better capability of fluorescence emission, so it can be used as a fluorescence emission group in the field of fluorescence chemical sensing. One of our work were to synthesize fluorescence probe containing thiophene[2,3-b]thiophene structural units, and study their recognition performance.Because of its electron-rich ability, thiophene[2,3-b]thiophene can be applied to conjugated polymer photovoltaic materials as an electron donor. If the thiophene[2,3-b]thiop-hene structural unit is leaded into the polymer main chain, rigidity of the polymer can be increased, and overall structure is more firm and stable, and crystallization and stability are improved. Because of those, they are likely to show better optical properties. Another research were to synthesize conjugated polymer containing thiophene[2,3-b]thiophene structural units, and study their properties.The special research contents are listed as follows:1. Successfully, we designed and synthesized the compounds of 2,5-dibromo-3,4-dimeth-ylthieno[2,3-b]thiophene,3,4-bis((octyloxy)methyl)thieno[2,3-b]thiophene,2,5-dibromo-3,4-bis((octyloxy)methyl)thieno[2,3-b]thiophene,3,4-bis((1,4,7,10-tetrao-xa-13-aza-cyclopentad-ecan-13-yl)methyl)thieno[2,3-b]thiophene,2,5-dibromo-3,4-bis((1,4,7,10-tetraoxa-13-azacyc-lopentadecan-13-yl)methyl)thieno[2,3-b]thiophene,2,7-diethynyl-9,9-dioctyl-9H-fluorene. Several kinds of intermediates and target products were characterized by FT-IR,'H-NMR, 13C-NMR, GC-MS, MALDI-TOF-MS, and elemental analysis.2. Using Fe(Ⅲ) catalysis, we successfully synthesized Poly3,4-bis((octyloxy)methy- 1)thieno[2,3-b]thiophene P1, and optimized the polymerization process conditions and parameters.3. With Pd(PPh3)4 as catalyst, using the Suzuki coupling reaction, we successfully synthesized 2,5-dibromo-3,4-dimethylthieno[2,3-b]thiophene and 2,7-diethynyl-9,9-dioctyl-9H-fluorene of the polymer P2,2,5-dibromo-3,4-bis((octyloxy)methyl)thieno[2,3-b]thiophe-ne and 2,7-diethynyl-9,9-dioctyl-9H-fluorene of the polymer P3,2,5-dibromo-3,4-bis((1,4,7, 10-tetraoxa-13-azacyclopentadecan-13-yl)methyl)thieno[2,3-b]thiophene and 2,7-diethynyl-9,9-dioctyl-9H-fluorene of the polymer P4, and optimized the polymerization process conditions and parameters.4. For 3,4-bis((1,4,7,10-tetraoxa-13-aza-cyclopentadecan-13-yl)methyl)thieno[2,3-b]thi-ophene,2,5-dibromo-3,4-bis((1,4,7,10-tetraoxa-13-azacyclopentadecan-13-yl)methyl)thieno-[2,3-b]thiophene, the fluorescent sensing properties was tested. The study found that the two compounds can be used as fluorescent sensors to detect barium ion.5. The thermal and spectral properties were studied by TGA, UV-vis absorption spectra, and fluorescence spectra. The results show that this is a potential novel class of polymer materials.