Fluorescent Ferroelectrics of Hydrogen-Bonded Pyrene Derivatives.
Organic materials with diverse molecular designs show multifunctional properties such as coupled ferroelectric, optical, ferromagnetic, and transport properties. We report the design of an alkylamide-substituted pyrene derivative displaying fluorescent ferroelectric properties coupled with electron transport properties. In solution phase, this compound displayed concentration-dependent fluorescence, whereas in xerogels, a fluorescent green organogel (>0.1 mM) and entangled nanofibers were observed. A discotic hexagonal columnar liquid crystalline phase was observed above 295 K due to intermolecular hydrogen bonding and π-stacking interactions. The direction of the hydrogen-bonded chains could be inverted by the application of an external electric field along the π-stacked column, resulting in ferroelectric polarization-electric field (P-E) hysteresis. The local electric field arising from the ferroelectric macrodipole moment arrangement along the π-stacking direction affected the electron transport properties on the π-stack of pyrenes, thus confirming the current-switching phenomena according to P-E hysteresis. We report that multifunctional properties such as ferroelectricity, fluorescence, and electron transport switching were successfully achieved in hydrogen-bonded dynamic π-molecular assemblies.
†Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.
Hayato
H
Anetai
‡Department of Applied Physics, Waseda University, Tokyo 169-8555, Japan.
Yoshifumi
Y
Wada
†Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.|§Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Takashi
T
Takeda
†Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.|§Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Norihisa
N
Hoshino
§Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Shunsuke
S
Yamamoto
§Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Masaya
M
Mitsuishi
‡Department of Applied Physics, Waseda University, Tokyo 169-8555, Japan.
Taishi
T
Takenobu
†Graduate School of Engineering, Tohoku University, Aoba-ku, Sendai 980-8578, Japan.|§Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577, Japan.
Tomoyuki
T
Akutagawa
ferroelectrics; fluorescence; hydrogen bond; liquid crystal; organogel