| 摘要: | 摘要 導電高分子由於具有低成本，可低溫製成及可溶劑加工等優點，故在應用上備受矚目。近年來以噻吩(thiophene)為主的低能隙高分子更是主要的研究對象之一。本實驗目的是在Δ4,4´-dicyclopenta[2,1-b: 3,4-b´]dithiophene（DCPDT;DCP）單體上，於不同位置上修飾長碳鏈取代基提供高分子溶解度，主要合成出四種單體： 2,6-dioctyl- Δ4,4´-dicyclopenta[2,1-b:3,4-b´]dithiophene (DODCP)、2,2´-di- octyl-Δ4,4´-di-cyclopenta[2,1-b:3,4-b´]di-thiophene(cis- DODCP)、2,6´-dioctyl-Δ4,4´-dicyclopenta[2,1-b:3,4-b´]dithio -phene(trans-DODCP)、及2,2´-ditetradecyl-Δ4,4´-dicyclo- penta[2,1-b:3,4-b´] dithiophene (cis-DTDDCP)，探討取代基位置不同對聚合所得高分子之能隙的影響。實驗發現化學聚合所得高分子不溶於一般有機溶劑，故無法做成薄膜做以探討不同結構對能隙的影響，但由IR證實確有合成出高分子。而由電化學聚合高分子膜的UV圖發現，三種高分子膜的能隙皆小於1.5 eV，其中PDODCP能隙小於1.3 eV。可知影響高分子能隙的原因除了取代基位置的立體障礙效應（steric effect），主鏈結構的不同也是影響因素之一。 Abstract Low band-gap conjugated polymers have attracted a great attention recently due to their high intrinsic conductivity as well as the optical transparent in the visible light in the doped state. The structure of lots of low band-gap polymer is based on polythiophenes because of their high environmental stability, superior conductivity, processability, and easy for structure modification.Δ4,4´-dicyclopenta[2,1-b:3,4-b´] dithiophene (DCPDT) is one of the monomers for low band-gap polymers. By adding the alkyl substitute groups at different positions to increase the solubility, four derivatives: 2,6-dioctyl-Δ4,4´-dicyclopenta- [2,1-b:3,4-b´] dithiophene (DODCP), cis-2,2´- dioctyl-Δ4,4´-dicyclopenta[2,1-b:3,4-b´] dithiophene (cis-DODCP), trans-2,6´-dioctyl-Δ4,4´-dicyclopenta [2,1-b: 3,4-b´]dithiophene (trans-DODCP), and 2,2´-ditetradecyl-Δ4,4´ -dicyclo -penta[2,1-b:3,4-b´]-dithiophene (cis-DTDDCP) were synthesized. The corresponding polymers prepared by chemical polymerization in FeCl3/CHCl3 were not soluble in organic solvents. Therefore, polymer films were obtained from electrochemical polymerization using LiClO4/CH3CN as electrolyte solution in a typical three-electrode cell. The optical data of the polymer films showed that PDODCP has the lowest band gap (< Eg=1.3 eV) for all polymer films prepared in this study. It is found that band-gap of polymer is affected by the steric effect of substitute groups and main-chain configurations of the polymers. |
