新的酰胺型和偶氮型冠醚液晶的合成与表征

【作者】 张晓静；

【导师】 李自法； 郑世军；

【作者基本信息】 郑州大学 ， 材料学， 2003， 硕士

【摘要】 本论文由以下四部分组成： 一．前言 对液晶的基本概念、液晶态的分类、表征方法、冠醚化合物及其应用、冠醚液晶及其研究现状作了简要的介绍。 二．酰胺型冠醚液晶的合成与表征 从分子设计出发，设计并合成了一类新的酰胺型冠醚液晶化合物，根据化合物分子中末端烷氧基和冠醚环及化合物构型的不同，将其分为四个系列，16个酰胺型冠醚液晶化合物。结构式如下： 系列Ⅰ和系列Ⅱ： 顺式-4,4′-双{4″-[4^（?）-（对-烷氧基联苯基）碳酰氧基]苯甲酰胺基}二苯并-14-冠-4（13Ⅰ） 反式-4,4′-双{4″-[4^（?）-（对-烷氧基联苯基）碳酰氧基]苯甲酰胺基}二苯并-14-冠-4（13Ⅱ） 系列Ⅲ和系列Ⅳ： 顺式-4,4′-双{4″-[4^（?）-（对-烷氧基联苯基）碳酰氧基]苯甲酰胺基}二苯并-18-冠-6（14Ⅰ） 反式-4,4′-双{4″-[4^（?）-（对-烷氧基联苯基）碳酰氧基]苯甲酰胺基}二苯并-18-冠-6（14Ⅱ） 13Ⅰ,13Ⅱ,14Ⅰ,and 14Ⅱ A:R=n-C₆H₁₃;B:R=n-C₈H₁₇;C:R=n-C₁₀H₂₁;D:R=n-C₁₂H₂₅三偶氮型冠醚液晶的合成与表征 从分子设计出发，以顺（反）式一二氨基二苯并一14一冠一4、顺（反）式一二氨基二苯并一18一冠一6和苯酚为原料，通过重氮化和偶联反应合成了一类新的偶氮型冠醚液晶化合物.根据化合物分子中末端烷氧基和冠醚环及化合物构型的不同，将其分为4个系列，16个偶氮型冠醚液晶化合物.结构式如下:系列V和系列VI:顺式一4，4’叔[4’义正烷氧基联苯基卜4反式一4，4‘取t4’(正烷氧基联苯基卜4一碳酞氧基苯基偶氮』二苯并一14一冠·4（6I）一碳酞氧基苯基偶氮」二苯并一14一冠一4（6ll）Ro心(}Coo心喇入eoo^仁以}oRRo.叠心-eoo框知二二以叠eoo.心心.oR6ll系列VII和系列姗:顺式一4，4’取[4‘(正烷氧基联苯基卜4反式一4，4’取[4’(正烷氧基联苯基升4一碳酞氧基苯基偶氮]二苯并一18一冠一6（7I）一碳酞氧基苯基偶氮」二苯并一18一冠一6（7n）Ro册C一伽‘减涂酬心ooC仍帆7Iooe弋}.公oR61，611，7 1 and 7llA:卜n一C4Hg;B:卜n一c6H13;C，R一n一CsH17:D，R=n一C一HZI四结果与讨论 中间体和目标化合物的化学结构经元素分析、确证.具有液晶性的化合物通过DSC、POM和变温IR、UV一Vis、H NMR和MS等方法X一ray衍射等方法测试和表征.优化了合成路线，解决了反应溶剂的选择和产物的分离与纯化等一些关键性的技术和难题.对两类新的酞胺型和偶氮型冠醚液晶化合物，因末端烷氧基和冠醚环以及化合物构型的不同对液晶性能的影响等方面进行了较系统的研究，得到了一些具有规律性的结果，在含二苯并一14一冠一4冠醚环的酞胺型冠醚液晶中，首次发现随化合物分子中末端烷氧基的增大，可形成手性近晶C相;在偶氮型冠醚液晶中，首次发现了反向壁纹影织构.实验结果表明:（一）.酞胺型冠醚液晶化合物中的化合物3、5、13和14和偶氮型冠醚液晶化合物中的化 合物3、6和7均具有热致液晶性.（二）.以上化合物加热至各自的熔点以上都能形成液晶态，在液晶态可观察到向列相的丝 状织构、纹影织构、球粒织构和反向壁织构等和近晶相的扇形织构、破碎焦锥织构、 镶嵌织构、沙地织构、层线织构和光栅织构等.（三）.所有的化合物的液晶态均可经降温后在室温下长期保存下来.（四）.所有的化合物在液晶态均易在外力作用下，沿外力方向取向.（五）.在酞胺型冠醚液晶化合物中，13和14的熔点和液晶态的清亮点均随化合物分子中 末端烷氧基增大逐渐降低，近晶相的范围递增;化合物141的熔点和液晶态的清亮 点均高于化合物131的熔点和液晶态清亮点;化合物14n的熔点和液晶态的清亮点均高于化合物13n的熔点和液晶态清亮点;反式构型的化合物13n和14n的熔点和液晶态的清亮点都分别高于相应顺式构型的化合物131和141的熔点和清亮点.由于分子间氢键的作用，使这类化合物的熔点较高.在偶氮型冠醚液晶化合物中，化合物6和7的熔点和液晶态的清亮点均随化合物分子中末端烷氧基链长增加而逐渐降低，液晶态温度范围较宽;化合物71的熔点和清亮点高于化合物61的熔点和清亮点;化合物7n的熔点和清亮点高于化合物6n的熔点和清亮点;反式化合物6n（除6nD熔点外）和7n的熔点和液晶态的清亮点均高于相应顺式构型化合物61和71的熔点和清亮点.更多还原

【Abstract】 The dissertation consists of four parts.1. PrefaceThe basic concept, classification and characterization of liquid crystal, crown ether compound and its application and crown ether liquid crystal and its current research were briefly introduced.2. Synthesis and characterization of amide type crown ether liquid crystalA new kind of amide type crown ether liquid crystal was synthesized on the base of molecular design, which can be divided into four series, sixteen compounds according to the end alkoxy group, crown ether ring and configuration of the compound. The chemical structures of them are as follows: Series I and IICis-4,4 -bis{4 -[4 -(p-alkoxylbiphenyl)-carbonyloxy]benzamido}dibenzo-14-crown-4(131) Trans-4,4-bis{4 -[4 -(p-alkoxylbiphenyl)-carbonyloxy]benzamido}dibenzo-14-crown-4(13II)13I,13II, 14I, and 14II A: R=n-C6H13 ; B: R=n-C8H17; C: R=n-C10H21; D: R=n-C12H253. Synthesis and characterization of azo type crown ether liquid crystalUsing cis(trans)-diaminodibenzo-14-crown-4 and cis(trans)-diaminodibenzo-18-crown-6 as raw materials, a new kind of azo type crown ether liquid crystal was synthesized through diazotization and coupling reactions on the base of molecular design, which can be divided into four series, sixteen compounds according to the end alkoxy group, crown ether ring and configuration of the compound. The chemical structures of them are as follows:Series IV and V :Cis-4,4 -bis[4 -(n-alkoxylbiphenyl)-4-carboxylphenylazo]dibenzo-14-crown-4 (6I)Trans-4,4 -bis[4 -(n-alkoxylbiphenyl)-4-carboxylphenylazo]dibenzo-14-crown-4(6 II)4. Results and discussionsThe structures of intermediates and final compounds were confirmed by means of IR, UV-Vis, H NMR, Mass spectroscopy and Elemental Analysis. The polarizing optical microscopy, DSC, X-ray scattering were applied to identify the mesophase of the compounds. The influence of end alkoxy group, crown ether ring and configuration of the compound on the liquid crystalline behavior have been researched and some rules were generalized. It has been found for the first time that amide type crown ether liquid crystal containing dibenzo-14-crown-4 can form chiral smectic C phase and azo type crown ether liquid crystal can form inversion walls schlieren texture with the increase of end alkoxy group.Experimental results have shown that: (l)Amide type crown ether liquid crystal compounds 3,5,13,14 and azo type crown etherliquid crystal compounds 3,6,7 have thermotropic liquid crystal properties. (2)0nce heated to their own melting temperature, all the compounds above will go into liquid crystal phase. The typical threaded texture, Schlieren texture, ball granul texture, inversion walls schlieren texture of nematic phase and fan texture ,broken focal-conies texture,mosaic texture, sanded texture, lined texture and grating texture of smectic phase can be observed. (3)The liquid crystal texture of all the compounds can be kept for a long time at roomtemperature upon quenching from the melt. (4)A11 the compounds in their liquid crystal state can be easily oriented in the direction ofexternal force.(5)For amide type crown ether liquid crystal compounds 13 and 14, both melting point(Tm) and isotropization temperature(Tj) decrease and smectic phase length increases with the increase of carbon numbers of the end alkoxy group; Tm and T, of compounds 14 I are higher than those of 13 I ; Tm and Tj of compounds 14II are higher than those of 13II; Tm and Ti of compounds 13II and 14II having trans-configuration are higher than those of their corresponding cis-configuration compounds 13 I and 14 I .The Tm of amide type crown ether liquid crystal compounds is relatively high due to the formation of intermolecular hydrogen bond.For azo type crown ether liquid crystal compounds 6 and 7, both Tm and Tj decrease with the increase of carbon numbers of the end alkoxy group and the temperature range of liquid crystal phase is relatively wide; Tm and Tj of compounds 7 I are higher than those of 6 I ; Tm and Tj of compounds 7II a更多还原