Charge-Transfer Interaction between Poly(9-vinylcarbazole) and 3,5-Dinitrobenzamido Group or 3-Nitrobenzamido Group

详细信息    查看全文

• 作者：Ying Yu ; Yuan Yao ; Liyan Wang ; Zesheng Li
• 刊名：Langmuir
• 出版年：2010
• 出版时间：March 2, 2010
• 年：2010
• 卷：26
• 期：5
• 页码：3275-3279
• 全文大小：838K
• 年卷期：v.26,no.5(March 2, 2010)
• ISSN：1520-5827

文摘

We studied the charge-transfer (CT) interaction between poly(9-vinylcarbazole) (PVK) and 3,5-dinitrobenzamido (DBA) group or 3-nitrobenzamido (NBA) group. The complexation equilibrium constant of PVK and N-butyl-3,5-dinitrobenzamide was found to be larger than that of PVK and N-butyl-3-nitrobenzamide using UV−vis spectroscopy. The desorption process of PVK from a DBA-modified substrate was studied with single molecule force spectroscopy. A lot of force−extension curves with a plateau were observed, which indicated the existence of trainlike conformation. The average desorption force of a PVK chain from the DBA-modified substrate was 28 pN. For comparison, the desorption process of PVK from an NBA-modified substrate was also studied, and an average desorption force of 18 pN was obtained. The apparent interaction energy of a CT complex was calculated on the basis of the desorption force and the surface density of electron acceptors. The obtained apparent interaction energies were 14 and 8 kJ·mol⁻¹ for the carbazolyl−DBA complex and carbazolyl−NBA complex, respectively. On the basis of the energy of the frontier molecular orbital of carbazole, 3,5-dinitrobenzamide, and 3-nitrobenzamide, the difference in strength between the interactions was interpreted as the influence of the substituent group on the energy of the frontier molecular orbital.