Redox-Responsive Chiral Dopant for Quick Electrochemical Color Modulation of Cholesteric Liquid Crystal
Redox-Responsive Chiral Dopant for Quick Electrochemical Color Modulation of Cholesteric Liquid Crystal
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DOI：
10.1021/jacs.8b06323
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发表时间：
2018-09-05
影响因子：
15
通讯作者：
Aida, Takuzo
中科院分区：
文献类型：
--
作者：
Tokunaga, Shoichi;Itoh, Yoshimitsu;Aida, Takuzo
在这里，我们报告的第一个氧化还原活性手性掺杂剂D-Fc，它电改变其螺旋扭曲力（HTP）的液晶（LC）介质，并迅速改变反射颜色。D-FC由轴向手性联萘单元和氧化还原活性二茂铁单元组成。掺杂有D-Fc（3.0摩尔%）的4 '-戊氧基-4-氰基联苯的反相LC相产生蓝色反射色。当将一种单电子氧化剂亚硝酰四氟硼酸盐加入到该反相LC相中时，D-Fc被氧化以使其原始HTP值降低13%，从而产生绿色反射色。在支持电解质的存在下，使用具有铟锡氧化物电极的电致变色型玻璃电池电化学调制反射颜色。在+1.5 V的外加电压下，反射光的颜色在0.4 s内由蓝色变为绿色。当施加0 V时，反射颜色返回到其原始蓝色。D-Fc掺杂的NH3 LC的特征在于其在电驱动NH3 LC器件中报道的最快的电化学响应和最低的工作电压。
Here, we report the first redox-active chiral dopant D-Fc, which electrically alters its helical twisting power (HTP) for a cholesteric liquid crystalline (LC) medium and quickly changes the reflection color. D-Fc is composed of an axially chiral binaphthyl unit in conjunction with a redox-active ferrocene unit. A cholesteric LC phase of 4'-pentyloxy-4-cyanobiphenyl, doped with D-Fc (3.0 mol %), developed a blue reflection color. When nitrosyl tetrafluoroborate, a one-electron oxidant, was added to this cholesteric LC phase, D-Fc was oxidized to decrease its original HTP value by 13%, so that a green reflection color was developed. In the presence of a supporting electrolyte, the reflection color was electrochemically modulated using a sandwich-type glass cell with indium tin oxide electrodes. In quick response to the applied voltage of +1.5 V, the reflection color changed from blue to green within 0.4 s. When 0 V was applied, the reflection color returned to its original blue color. The D-Fc-doped cholesteric LC is characterized by its fastest electrochemical response and lowest operating voltage among those reported for electrically driven cholesteric LC devices.