Synthesis and Electronic and Photophysical Properties of [2.2]- and [3.3]Paracyclophane-Based Donor鈥揇onor鈥测€揂cceptor Triads

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• 作者：Takaaki Miyazaki ; Masahiko Shibahara ; Jun-ichi Fujishige ; Motonori Watanabe ; Kenta Goto ; Teruo Shinmyozu
• 刊名：Journal of Organic Chemistry
• 出版年：2014
• 出版时间：December 5, 2014
• 年：2014
• 卷：79
• 期：23
• 页码：11440-11453
• 全文大小：623K
• ISSN：1520-6904

文摘

Three types of the donor(D)鈥揹onor鈥?D鈥?鈥揳cceptor(A) triads 1鈥?b>6 with different D鈥揂 combinations, carbazole (Cz, D)-[n.n]PCP(D鈥?-1,8-naphthalimide (NI, A) (1-3), 10H-phenothiazine (PTZ, D)-[n.n]PCP(D鈥?-NI(A) (4, 5), and 10-methyl-10H-phenothiazine (Me-PTZ, D)-[2.2]PCP-2,1,3-benzothiadiazole (BTD, A) 6, were synthesized for the elucidation of their photophysical properties. The absorption spectra and electrochemical properties indicated that the chromophores (D, D鈥? and A) do not interact with each other in the ground state. Cz-(CH₂)₃-[2.2]PCP-(CH₂)₃-NI 1 and Cz-(CH₂)₃-[3.3]PCP-(CH₂)₃-NI 2 show an exciplex emission between the PCP and NI moieties in cyclohexane and the intensity of the band is much higher in 2 than in 1, whereas Cz-(CH₂)₂-[2.2]PCP-(CH₂)₂-NI 3 does not show any exciplex emission in cyclohexane. These results indicated that the combination of [3.3]PCP and a trimethylene chain is preferable for the exciplex formation. PTZ-(CH₂)₃-[2.2]PCP-(CH₂)₃-NI 4 shows a broad band at 519 nm in cyclohexane, which is associated with the formation of the exterplex band among the NI, [2.2]PCP, and PTZ moieties, while PTZ-(CH₂)₃-[3.3]PCP-(CH₂)₃-NI 5 does not show the band. Me-PTZ-(CH₂)₂-[2.2]PCP-(CH₂)₂-BTD 6 shows a broad fluorescence band due to both the BTD and PTZ moieties in cyclohexane. In CH₃CN, the fluorescence spectra of 1鈥?b>6 suggest the presence of a photoinduced charge separation process. The study of the photoinduced charge separation process will be soon reported elsewhere.