5,5 '-alkylsubsituted indigo for solution-processed optoelectronic devices

作者：Watanabe Motonori^*; Uemura Naoki; Ida Shintaro; Hagiwara Hidehisa; Goto Kenta; Ishihara Tatsumi^*

来源：Tetrahedron, 2016, 72(29): 4280-4287.

DOI：10.1016/j.tet.2016.05.069

• Indigo
• Substituent effect
• Solution process
• Precursor method
• Photo current

A series of allcylated indigos were synthesized. Alkylated indigos were characterized by NMR, mass spectrometry, absorption spectra, cyclic voltammetry, and density functional theory (DFT) calculations. Propyl and butyl group substituted indigo was most soluble in chloroform and 1,2-dicrolobenzene, and these solubility were 65-89 times increased as compared to the parent indigo. DFT calculations suggested that the presence of the alkyl chains at the 5.5'-position increases the energy of the highest occupied molecular orbital, while reducing the energy of the lowest unoccupied molecular orbital. This theoretical finding was in good agreement with the experimental results. Crystal structures obtained by X-ray diffraction showed one-dimensional pi pi stacking. Alkylated molecules were converted to leuco structure, and these structures were then converted to the corresponding indigos in the film state. After deposition of the films on TiO2/FTO substrate, oxidative photocurrents were observed.

• 出版日期2016-7-21