Highly dichroic benzo-2,1,3-thiadiazoledyes containing five linearly π-conjugated aromatic residues, with fluorescent emission ranging from green to red, in a liquid crystal guest–host system
作者:Xuelong Zhang、Rumiko Yamaguchi、Keiichi Moriyama、Masami Kadowaki、Takako Kobayashi、Tsutomu Ishi-i、Thies Thiemann、Shuntaro Mataka
DOI:10.1039/b512493j
日期:——
A number of fluorescent benzothiadiazole dyes have been synthesised and their optical properties, when dispersed in a liquid crystal host phase, examined. These dyes have five linearly Ï-conjugated aromatic ring systems (both with and without ethene and 1,3-butadiene spacers). The liquid crystalline host medium, used was the nematic phase of MLC-2039. The emission colours observed ranged from green to red, depending on the unsaturated chains attached at the 4- and 7- positions of the bezo-2,1,3-thiadiazole core. A highly dichroic and efficient fluoresence was observed. The dye 4,7âbis[5-bis(phenylethenyl)thiophen-2-yl]-2,1,3-benzothiadiazole is of particular importance. This is the first example of a dye emitting strong red fluorescence (633 nm). When dispersed in MLC-2039, dichroic ratio values up to 12.3 were obtained.
合成了一系列荧光苯并噻二唑染料,并在液晶主体相中分散时研究了它们的光学性质。这些染料具有五个线性π-共轭芳香环系统(包括带有和不带有亚乙烯基和1,3-丁二烯间隔基的情况)。所用的液晶主体介质是MLC-2039的向列相。观测到的发射颜色从绿色到红色不等,具体取决于连接在苯并-2,1,3-噻二唑核心的4-和7-位上的不饱和链。观察到高度二色性和高效的荧光。特别重要的是染料4,7-双[5-双(苯乙烯基)噻吩-2-基]-2,1,3-苯并噻二唑。这是首个发射强烈红色荧光(633 nm)的染料例子。在MLC-2039中分散时,得到了高达12.3的二色比值。