新型含萘基和二乙炔基高双折射液晶分子的合成及光电性能

通过多步Sonogashira偶联反应成功合成分子结构中含萘环的不对称二乙炔衍生物:4-(4-(4-(6-(己氧基)-2-萘基)-1-(1,3-丁二炔基))-3-乙烯基-苯乙炔基)-N,N-二甲基苯胺。 通过核磁共振和元素分析对其结构进行了表征,通过差式扫描量热分析(DSC)、偏光显微镜(POM)和阿贝折射仪研究了其液晶性和双折射特性;通过紫外-可见吸收光谱仪和荧光分光光度计测得其吸收-发射光谱。 测量发现该化合物具有热致型向列相液晶特性和很高的双折射值(Δn=0.47)。 化合物溶液荧光发射波长为470 nm,荧光量子产率高达97%。 应用旋转涂膜的方法制作的双层器件ITO/PEDOT/liquid crystal compound/Mg:Ag(10:1)/Ag(ITO:氧化铟锡,PEDOT:聚3,4-乙撑二氧噻吩),电致发光波长为503 nm,器件显示了较好的电致发光稳定性和二极管整流特性,启动电压较低(6.75 V),在14.75 V时达到最大亮度150 cd/m²。 该化合物有望作为一种潜在的液晶显示材料和电致发光材料。

Synthesis and Photoelectric Properties of Novel Liquid Crystalline Compound Bearing Diethynyl and Naphthyl Groups with High Birefringence

An asymmetric diacetylene derivative bearing naphthyl group, 4-(4-(4-(6-(hexyloxy)-2-naphthalen)-1-(1,3-butadiynyl))-3-vinyl-phenylethynyl)-N,N-dimethylbenzenamine, was successfully synthesized by multi-step Sonogashira reactions. The structure of the compound was confirmed with ¹H and ¹³C NMR spectroscopy and elemental analysis. Its liquid crystalline property and optical birefringence were characterized by differential scanning calorimetry(DSC), polarized light microscopy(POM) and Abbe refractometer. The absorption and emission spectra of the compound were obtained with the ultraviolet-visible absorption spectrometer and fluorescence spectrometer, respectively. The compound exhibits the nematic phase in liquid crystal state and high optical birefringence of 0.47. The peak of the photoluminescence(PL) of the compound in chloroform is at 470 nm and the quantum efficiency is 97%. The double-layer devices ITO/PEDOT/liquid crystal compound/Mg:Ag(10:1)/Ag(ITO:indium tin oxide, PEDOT:poly(3,4-ethylene-dioxythiophene thiophene)) is fabricated with a low onset voltage(6.75 V). The peak of electroluminescence(EL) is at 503 nm, and the maximum brightness value is 150 cd/m²(14.75 V). The diacetylene derivative is a promising material for liquid crystal display or organic light-emitting device.