Contrasting Effect of Alkylation on the Ordering Structure in Isomeric Naphthodithiophene-Based Polymers

详细信息    查看全文

• 作者：Itaru Osaka ; Yoshinobu Houchin ; Masayuki Yamashita ; Takeshi Kakara ; Noriko Takemura ; Tomoyuki Koganezawa ; Kazuo Takimiya
• 刊名：Macromolecules
• 出版年：2014
• 出版时间：May 27, 2014
• 年：2014
• 卷：47
• 期：10
• 页码：3502-3510
• 全文大小：599K
• 年卷期：v.47,no.10(May 27, 2014)
• ISSN：1520-5835

文摘

Semiconducting polymers with alkylated naphtho[1,2-b:5,6-b鈥瞉dithiophene (NDT3) and naphtho[2,1-b:6,5-b鈥瞉dithiophene (NDT4) are synthesized and characterized. The solubility of the present polymers is significantly improved as compared to the nonalkylated counterparts with preserving the good charge transport properties. Interestingly, the effect of alkylation is found to be quite distinct between the NDT3 and NDT4 cores. In the NDT3-based polymers, alkylation leads to the more ordered backbone structure and thus the increased crystalline order in the thin film. On the other hand, in the NDT4-based polymers, alkylation is detriment to the backbone ordering, which gives rise to the face-on orientation or amorphous like film structure. This difference can be qualitatively explained by the different alkyl placement; all the neighboring alkyl groups are in the anti arrangement in the NDT3-based polymers, whereas the arrangement is a mixture of anti and syn in the NDT4-based polymers, which likely causes steric impact on the backbone. These observations make us better understood how the alkylation affect the ordering structures, which would be an important guideline for the design of superior semiconducting polymers.