Synthesis Of Related9,9’-Spirobifluorene Compound

9,9’-spirobifluorene (9,9’-spirobifluorene) is a typical helical molecule, which is an important intermediate for the synthesis of various spiro-fluorene derivative. Since its debut in1930, it’s nature of the study received extensive attention. Today spirobifluorene derivatives have been widely applied to the field of fluorescent material, a variety of electroluminescent organic light emitting material and the solar cells.Due to its structural characteristics spirobifluorene, which have lower solubility, resulting in poor workability. If we can improve this problem, spirobifluorenyl compounds will have a more broad application space. The alkyl chain is introduced to improve the solubility of the compound, which was widely used in organic chemistry. So, ethoxy was introduced at four positions2,3,6,7of spirobifluorene molecule, which can improving their solubility in organic solvents and study its effect on the compound.In this thesis,2’,7’-dibromo-2,3,6,7-Tetraethoxy-9,9’-spirobifluorene (J) was was synthesized by8steps. Through to test its properties, which confirmed the structure was right, the ethoxy was Successfully introduced at four positions2,3,6,7of spirobifluorene molecule. Then5kinds of spirobifluorene related small molecules based on2’,7’-dibromo-2,3,6,7-tetraethoxy-9,9’-spirobifluorene (J) was synthesized, which include compounds2,3,6,7-tetraethoxy-9,9’-spirobifluorene (K),2,3,6,7-four ethoxy-2’,7’-bithiophene-9,9’-spirobifluorene (L),2,3,6,7-tetraethoxy-2’, T-diphenyl-9,9’-spirobifluorene (M),2,3,6,7-tetraethoxy-2’,7’-bis (3,4-ethylene dioxythiophene)-9,9’-spirobifluorene (N) and2,7-dibromo-9,9’-spirobifluorene (O). By testing and study their UV and fluorescence properties, we found that the introduction of ethoxylate in Spirobifluorene small molecules can not only improve the solubility, but also can redshift UV absorption and fluorescence emission wavelength and Increase the range of absorption broadening. With these features, spirobifluorenyl compounds have good prospects in the field of organic photovoltaic.Finally, four kinds of Spirobifluorene oligomers (P, Q, R, S) was synthesized. Oligomer P was compostied based on9,9’-spirobifluorene and thiophene in ratio of1:1; Q was compostied based on2,3,6,7-tetraethoxy-9,9’-spirobifluorene and thiophene in ratio of1:1; R was compostied based on2,3,6,7-tetraethoxy-9,9’-spirobifluorene and thiophene in ratio of1:3; S was compostied based on2,3,6,7-tetraethoxy-9,9’-spirobifluorene and EDOT in ratio of1:1. And studing the UV and fluorescence properties for above moleculars. After testing, we found that the introduction of ethoxy in the oligomers have a positive role in promoting to improve the solubility of the oligomer, UV absorption spectrum width, UV absorption and fluorescence emission wavelength redshifts, but also have a negative impact to the degree of polymerization. And we also found that the great conjugated structure have positive impact to the UV absorption, but have less effects to emission of the flurescene, conjugated structure of the composition is the key factor of the result.