作者机构:
[闻炎豪; 戴志群; 王震; 李潭; 张智勇; 关金涛] Department of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan, 430023, China;[彭增辉] State Key Laboratory of Applied Otticr, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, China
通讯机构:
[Zhang, Z.-Y.] D;Department of Chemistry and Environmental Engineering, China
关键词:
嘧啶乙炔;高介电各向异性;近晶相态液晶;高光学各向异性;合成
摘要:
中心环外侧嘧啶环作为液晶分子的极性介晶基团,能有效增大分子的偶极矩和分子间的作用力,提高分子的介电各向异性,降低液晶的驱动电压,也有利于形成近晶相液晶态。本文试图以嘧啶乙炔为中心结构单元,以异硫氰基为端基,设计合成了嘧啶乙炔类异硫氰基液晶化合物(nBTM-NCS)系列共5个化合物;它们都经过IR、1H-NMR、13C-NMR和MS光谱对其分子结构鉴定,经过差热分析仪 (DSC)和偏光显微镜(POM)对其液晶性能进行检测。实验结果表明,所有化合物的分子结构均正确,具有近晶相态,其熔点较高并呈现奇偶效应;其光学各向异性达到0.45左右,介电常数21~24左右,可作为铁电液晶和聚合物分散液晶材料配方组分。 The pyrimidine ring outside of the rigid core ring of liquid crystal molecules used as a polar mesogenic group, can effectively increase the molecular dipole moment and intermolecular force, improve the dielectric anis-otropy of the compounds, reduce the driving voltage of the liquid crystal, and also favor to form some smec-tic phases. In this paper, where pyrimidine acetyleneisused as the central structural unit and isothiocyanide asthe end group, we could see that a series of liquid crystal compounds (nBTM-NCS) about five compounds were designed and synthesized. The molecular structure of all compounds were identified by IR, 1H-NMR, 13C-NMR and MS spectra, and their liquid crystal properties were measured by differential thermal analyzer (DSC) and polarizing microscope (POM).The experimental results show that all the compounds have the correct molecular structure and smectic phases. The melting point of the compounds is high and it shows a parity effect. Its optical anisotropy reaches about 0.45, and the dielectric constant is about 22 to 24. It can be used as the components for ferroelectric liquid crystals and polymer-dispersed liquid crystal materials.
摘要:
The catalytic activities of three N-methylimidazole-based phosphine ligands in the Suzuki coupling reaction were tested using PdCl2 as the catalyst. The results showed all three phosphine ligands exhibited excellent activity towards the Suzuki reaction, and the catalytic activity decreased with increasing number of imidazole groups. Copyright (C) 2014 John Wiley & Sons, Ltd.
作者机构:
[刘胜; 张智勇; 申烦; 戴志群; 黄江涛] Department of Chemistry and Environment Engineering, Wuhan Polytechnic University, Wuhan, 430023, China;[彭增辉] Changchun Institute of Optics Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, China
通讯机构:
[Zhang, Z.-Y.] D;Department of Chemistry and Environment Engineering, China
关键词:
异硫氰基;含氟联苯乙炔;高双折射率液晶;合成
摘要:
本文合成了4个异硫氰基联苯乙炔类液晶化合物。通过1HNMR、13CNMR、19FNMR、IR和MS谱图鉴定结构正确。用差示扫描热议(DSC)和偏光显微镜(POM)对化合物的相变温度进行了测试,发现所合成目标化合物均呈现向列相,其相变态温度范围在105~137 ℃,其双折射率高于0.47,可作为液晶光栅高双折射率液晶材料的有效组分。 This paper has synthesized four isothiocyanato-diphenyl acetylene liquid crystal compounds.Their structures were identified by IR,1HNMR,13CNMR,19FNMR,MS spectra.Their phase transition temperatures were tested by using differential scanning calorimetric(DSC) and polarizing optical microscopy(POM).It is found that all of the new compounds show nematic phase,and their phase transformation temperature was in the range of 105 ℃ to 137 ℃.Their birefringence are more than 0.47,which can be used as the effective components of high birefringence liquid crystal materials of liquid crystal raster.
作者机构:
[章思汗; 戴志群; 张开诚; 刘可庆; 张智勇] Department of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan, 430023, China;[宣丽] Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033, China
关键词:
含氟三苯二炔类液晶化合物;合成;高双折射率;宽温向列相
摘要:
目前,越来越多的液晶应用要求向列相液晶材料具有高双折射率性能。本文合成了5个高双折射率含氟三苯二炔类液晶化合物(Ⅳ),经过IR,1 H NMR,13 C NMR谱图鉴定,这些化合物的分子结构完全正确;通过DSC和POM对其液晶相态测试的实验结果表明该类液晶化合物具有较低的熔点和相对较宽的向列相温度范围(达到100℃左右);对其折光率测试结果表明这些液晶化合物的双折射率(Δn)值在0.47以上,改善液晶光学性能。
作者机构:
School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan;430023, China;[未本美; 张智勇; 汪海波; 戴志群; 关金涛] School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan ;[未本美; 张智勇; 汪海波; 戴志群; 关金涛] 430023, China
通讯机构:
School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, China
摘要:
An efficient approach for the deprotection of esters has been developed using ionic liquid as nucleophile in the presence of protic acid. Using methyl benzoate as a model compound, the best result was obtained by the combination of 1-methylimidazolium bromide and methane sulfonic acid with a conversion of 96 % after 2 h at 120 C.
作者:
Dai, Z. Q.;Liu, K. Q.;Zhang, Z. Y.*;Wei, B. M.;Guan, J. T.
期刊:
Asian Journal of Chemistry,2013年25(11):6303-6305 ISSN:0970-7077
通讯作者:
Zhang, Z. Y.
作者机构:
[Liu, K. Q.; Wei, B. M.; Guan, J. T.; Zhang, Z. Y.; Dai, Z. Q.] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.
通讯机构:
[Zhang, Z. Y.] W;Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.
关键词:
Cross-coupling;Grignard reagent
摘要:
In the presence of a catalytic amount of iron salts and N,N,N',N'-tetramethylethylene diamine as additive, alkyl bromide reacted with biphenyl magnesium bromide to obtain the cross-coupling product in good yields. The suitable amount of catalyst and the additive are 5 % mol (based on alkyl bromide), 1.3 equiv(based on alkyl bromide), respectively. Under the optimal conditions, the yields of the cross-coupling could reach up to 92.3 %.
摘要:
以4,4′-二羟基二苯甲酮为中心结构基元, 以酯基(—COO—)作为桥键, 烷基(m=5,6,7,8,9,10)为末端基团, 合成了一系列新型香蕉形液晶化合物(mPEPK), 通过IR、1H NMR、13C NMR和MS鉴定这些化合物的结构正确, 并经过差热扫描仪(DSC)和偏光显微镜(POM)测定其相变温度和相态织构。结果表明, 所合成目标化合物具有近晶相, 并且相转变温度较类似结构香蕉型液晶化合物有大幅度降低。 A novel series of bent-core molecules (mPEPK) was prepared with a central bent core based on 4,4-dihydroxybenzophenone (DHBP), ester group bridge(—COO—), and alkyl tails with different carbon numbers (m= 5, 6, 7, 8, 9, 10.). The structures of the titled compounds were confirmed by IR, 1H NMR, 13C NMR, MS spectra, and their transition temperatures and phase textures were investigated by using differential scanning calorimetric(DSC) and polarizing optical microscopy(POM). A part of the compounds exist smectic phase. Comparing with the similar compounds, the target compounds (m-PEPK) have declined to a great extent in liquid crystalline phase transition temperatures.
关键词:
blue phase;cholesteric;liquid crystal;flat panel display
摘要:
As a novel type of liquid crystal display materials, liquid crystal blue phase with a wide viewing angle, fast response, simple fabrication process, etc., is becoming a hot topic in the filed of optoelectronic display. This article introduces the discovery of liquid crystal blue phase, and the related properties of it, and then, summed up blue phase's recent research at home and abroad. Finally, the application of liquid crystal bule phase in the filed of FPD, and the future of development trend are evaluated.