- 作者: 何東英
- 作者服務機構: Department of Chemistry, National Taiwan University, Taipei, Taiwan 116, R.O.C.
- 中文摘要: Photoinduced electron transfer from the singlet excited state of 2-styrylthiophenes (1a-1f) to p-DCB (p-dicyanobenzene) has been proposed from the negative value of DGET (the free energy of the electron transfer) calculated by the Rehm-Weller equation. This leads to the formation of radical cations of 1a-1f and a radical anion of p-DCB. The p-nitro derivative 1g can not result in the radical cation due to the positive DGET value which results from the unfavorable singlet excitation energy (E0,0) and oxidation potential. Regioselective amination by ammonia to the radical cations of 1a-1e has occurred to afford 1-amino-1-aryl-2-(thien-2-yl)ethanes (2a-2e) in reasonable yields (50-90%). The regioselectivity arises from the attack of ammonia at the localized positive charge on C-1 of the ethene bond of the radical cations of 1a-1e.
- 英文摘要: --
- 中文關鍵字: Photosensitization; Electron transfer; Nucleophilic addition; Regioselectivity.
- 英文關鍵字: Photosensitization; Electron transfer; Nucleophilic addition; Regioselectivity.