Protonation-induced red-coloured circularly polarized luminescence of [5]carbohelicene fused by benzimidazole.
Benzimidazole-fused [5]carbohelicene ([5]HeliBI) was newly synthesized to examine the spectroscopic and chiroptical properties. The reversible protonation and deprotonation processes of [5]HeliBI were successfully investigated using (1)H NMR, absorption and fluorescence spectral measurements. We also confirmed the circularly polarized luminescence of protonated [5]HeliBI (H(+)-[5]HeliBI). This is the first observation of red-coloured CPL of a helicene derivative.
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522, Japan. hasobe@chem.keio.ac.jp.
Hayato
H
Sakai
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522, Japan. hasobe@chem.keio.ac.jp.
Takako
T
Kubota
Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan. tkawai@ms.naist.jp and PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan.
Junpei
J
Yuasa
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1Katahira, Aoba-ku, Sendai 980-8577, Japan.
Yasuyuki
Y
Araki
Department of Applied Physics, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan.
Tomo
T
Sakanoue
Department of Applied Physics, Waseda University, 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, Japan.
Taishi
T
Takenobu
Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1Katahira, Aoba-ku, Sendai 980-8577, Japan.
Takehiko
T
Wada
Graduate School of Materials Science, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan. tkawai@ms.naist.jp.
Tsuyoshi
T
Kawai
Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Yokohama, Kanagawa 223-8522, Japan. hasobe@chem.keio.ac.jp.
Taku
T
Hasobe