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液晶中间体—4—羟基—4‘—氰基联苯的合成研究 总被引:3,自引:0,他引:3
本文采用从联苯出发,经酰化反应,卤仿反应制备联苯甲酸,后者与氯化亚砜反应,然后经过氨解,脱水制得氰基联苯,再经硝化、还原、重氮化、水解的路线制得4-羟基-4‘-氰基联苯。总得率可达15%以上,与从联苯酚出发的路线相比,成本降低约15%。 相似文献
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报道了以苯胺为原料合成4-溴-4′-氰基联苯的新方法。苯胺通过氮乙酰化后在对位溴代,所得4-溴乙酰苯胺水解后与苯偶联;所制得的4-溴联苯通过乙酰化、氧化后与氯化亚砜反应得到酰氯;氨解后得4-溴-4′-联苯甲酰胺,用氯化亚砜脱水制得4-溴-4′-氰基联苯。 相似文献
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对4-溴-4′-氰基联苯参与交叉偶联反应的可能性进行了较为深入的研究。并对与反应有关的溶剂、催化剂等条件作了对比实验,同时,就4-溴-4′-氰基联苯参与交叉偶联反应的机理等问题进行了讨论。 相似文献
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以4-羟基联苯为原料,经酰化、氨解、脱水三步反应合成了液晶材料重要中间体4-羟基-4′-氰基联苯,总收率达51.8%,其结构经核磁共振、质谱、红外光谱等确证,HPLC含量在99%以上。 相似文献
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合成了双—(反—4—烷基环己烷羧酸)—2,3—二氯—1,4—苯二酯,烷基分别为n-C6H13、n-C7H15、n-C8H17。测定了这些化合物的液晶相变温度,并通过磁场法测定了介电各向异性,Δε均为负值。 相似文献
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4-(trans-4-n-烷基环己基甲氧基)-4''-氰基联苯的合成 总被引:1,自引:1,他引:0
以trans-4-n-烷基环已基甲醇和4-溴-4’-羟基联苯为原料合成了一组4-(trans-4-n-烷基环已基甲氧基)-4’-氰基联苯类液晶化合物,用IR、MS、元素分析确证了化学结构。研究发现铜盐对trans-4-n-烷基环已基甲醇的溴代反应有催化作用;在相转移催化剂的作用下进行醚化获得较高收率;氰代反应以N-甲基-2吡咯烷酮溶剂效果较好。DSC测试结果表明该类液晶化合物具有较高的清亮点。 相似文献
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将铁电液晶作为缺陷层引入一维光子晶体中,基于液晶的电控双折射,形成快速窄带调谐滤波器.用传输矩阵法研究了铁电液晶缺陷光子晶体的可调谐滤波特性,计算了电场对滤波器透射峰的位置、强度、个数和带宽的影响,结果表明该滤波器呈现良好的滤波功能. 相似文献
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论述了利用光纤应力双折射效应研制的挤压式光纤电动偏振控制器的工作原理,并进行了实验验证,分析了输出光偏振态在邦加球上的轨迹及相位延迟量与各通道电压的关系。 相似文献
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The liquid crystal composite materials consist of microdroplers of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization.The director configuration in liquid crystal droplets.the model of orientation of droplets,and the contrast ratios of a cell are investigated.Droplet size,spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets.Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves. 相似文献
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A 7-segment numeric display with electrically controlled colour has been realised which uses the field-dependent birefringence in nematic liquid crystals. The colours obtained are very bright, especially the red and green. 相似文献
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Ferroelectric ceramics exhibit piezoelectric effects and optical birefringence that are electrically controllable. Consequently, these ceramics are applicable to a wide variety of devices. An article in the February issue has already described electrically actuated light valves and electrically controlled optical filters. The present article deals with the piezoelectric behavior of ferroelectric ceramics. Since, macroscopically, these materials are nearly isotropic, a discussion of their piezoelectric behavior can provide uncluttered?and surprising?insight into the theory of piezoelectric energy conversion. 相似文献
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A tunable diode laser incorporating a two-stage birefringent filter in an external cavity is discussed. Tuning of the laser wavelength is accomplished with a nematic liquid-crystal cell with electrically controlled birefringence in each stage of the filter. The laser has a scan range of 26.7 Å for a drive voltage to each of the liquid-crystal cells of <1.7 V RMS 相似文献
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光子晶体液晶光纤的光波导特性 总被引:1,自引:0,他引:1
在光子晶体光纤芯区的圆空气柱中填充向列相液晶,用电场控制液晶分子的排列方向,构成了一种光子晶体液晶光纤.用阶跃有效折射率模型研究了电场、工作光波长及光纤结构参数对可调光子晶体液晶光纤的双折射和模式截止特性,并用E7液晶进行了数值计算.结果表明这种光纤的双折射值随电场增大而增大,增大电场和减小光波长可使光纤由单模传输变成多模传输,减小包层中空气孔的相对孔径引起光纤中单模与多模界面向短长波方向移动,包层的相对孔径小于0.14左右时光纤出现无截止单模传输,此值小于没有液晶填充PCF出现无截止单模传输时的包层相对孔径,电场的变化不会对无截止单模传输产生影响. 相似文献
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Hsin-Ying Wu Cho-Fan Hsieh Tsung-Ta Tang Ru-Pin Pan Ci-Ling Pan 《Photonics Technology Letters, IEEE》2006,18(14):1488-1490
Tunable phase shift up to 360/spl deg/ at 1 THz is demonstrated using electrically controlled birefringence in a vertically aligned nematic liquid crystal (E7) cell, 1.83 mm in thickness. The driving voltage and corresponding field required for a phase shift of 360/spl deg/ at 1 THz are 100 V and 90.5 V/cm, respectively. 相似文献