Proton- and metal cation-enhanced excited state intramolecular proton transfers of 2-(2-hydroxyfluorophenyl)benzoxazole having imidazole moiety

作者：Tanaka Kiyoshi^*; Sano Kei Ichi; Katoh Takuya; Iwata Satoru; Nemoto Kouhei; Kurushima Tohru

来源：Journal of Fluorine Chemistry, 2006, 127(8): 1073-1078.

DOI：10.1016/j.jfluchem.2006.05.009

• heterocycles
• 2-(2-hydroxyfluorophenyl)benzoxazole
• excited state intramolecular proton transfer
• fluorescence
• metal cation

2-(2-Hydroxyfluorophenyl)benzoxazole having an imidazole moiety 1 was synthesized by the two step reactions starting from 2-(pentafluorophenyl)benzoxazole. Protonation at the 3-imidazole nitrogen atom of 1 enhances the green emission around 500 nm, where the positive character caused by the protonation is inductively communicated to the hydroxy group, to recover its intramolecular hydrogen bonding, leading to the ESIPT process. Addition of Al3+ or Zn2+ to 1 enhances both the green emission and the blue emission around 450 nm in chloroform-acetonitrile.

• 出版日期2006-8