【作者】 安庆大；

【导师】 杨大智；

【作者基本信息】 大连理工大学 ， 材料学， 2002， 博士

【摘要】 卟啉液晶分子是一种共轭大环化合物，其周边有十二个活性部位可与不同的柔性侧链相连接，且分子的长径比与直径厚度比等均可以调整，因此，可以通过分子设计在卟啉的周边引入柔性侧链合成出新型具有期望性质的卟啉液晶材料。本文针对新型卟啉液晶材料的合成与性能研究，首先对迄今为止已合成出的卟啉类液晶材料的性能及应用进行了全面的总结，选用酰氯（RCOCl）和四-（对羟基苯基） 卟啉（THPPH₂，THPP=Tetra-hydroxyphenylporphyrin）为原料，通过分子设计在四对羟基苯基卟啉的周边即中位苯环对位上引入带有酰氧基的柔性长侧链，合成出4种未见文献报道的新型卟啉自由碱材料即5，10，15，20—四-（对癸酰氧基苯基）卟啉自由碱材料（TDPPH₂，TDPP=Tetra-decanoyloxy phenyl-porphyrin），5，10，15，20—四-（对月桂酰氧基苯基）卟啉自由碱材料（TLPPH₂，TLPP=Tetra-lauryloxyphenyl-porphyrin），5，10，15，20—四-（对肉豆蔻酰氧基苯基）卟啉自由碱材料（TMPPH₂，TMPP=Tetra-myristoyloxyphenyl-porphyrin）及5，10，15，20—四-（对棕榈酰氧基苯基）卟啉自由碱材料（TPPPH₂，TPPP=Tetra-palmitoyloxy phenyl-porphyrin），采用红外光谱监测了反应进程，对合成方法进行了探讨。以上述四种自由碱卟啉和过渡金属氯化物为原料，合成了四个系列过渡金属（Mn、Fe、Co、Ni、Cu、Zn）化合物24种，采用紫外可见光谱监测了反应进程，表征了化合物的结构，对合成方法进行了探讨。 在合成工作基础上，采用紫外可见光谱（UV-vis）、红外光声光谱（FTIR-PAS）、核磁共振氢谱（¹HNMR）、元素分析、摩尔电导等手段研究了卟啉及金属卟啉材料的组成及结构。采用循环伏安技术，研究了卟啉材料的电化学性质，确证了金属卟啉在不同氧化态的电位，并采用顺磁波谱验证了金属卟啉中金属的价态。 最后，采用差示扫描量热法（DSC，DSC=differential scanning calorimetry）和偏光显微镜研究了自由碱卟啉材料及锌卟啉配合物材料的液晶行为，通过DSC曲线及光学织构图对四种自由碱卟啉及其锌卟啉材料的液晶性能进行了比较。结果表明：四种酰氧基苯基卟啉自由碱及锌卟啉材料均表现出较好的液晶性质（相变温度较低，相区较宽），除了＊＊＊＊氏叶琳材料具有一个双折射的中间相，其它3种酚氧基苯基叶嗽材料即TDPPHZ、TLPPHZ、TPPPHZ均具有两个双折射的中间 十。叶琳自由碱液晶材料的相变温度最低始于14．36℃口PPPHO，最高始于52．04C （TMPP比）；相区最窄为51．49℃（TPPPHZ），最宽达108．56℃（TLPPHZ）。一种锌叶琳材料一TMPPZn具有一个中间相，两种锌叶琳材料一TDPPZn和 TLPPZn具有两个双折射的中间相，另外一种锌叶琳材料一TPPPZn均具有三个双折射的中间相。锌叶琳液晶材料的相变温度最低的是TLPPZn，始于一36．40℃，最高的是TPPPZn，始于15．84’C，相区最窄的TLPPZn，为76二8℃，最宽的是TDPPZn，高达175OC。 以锌叶琳为例，分析了金属离子对叶琳液晶性质的影响机制。与自由碱叶琳材料相比，锌离子的引入对酚氧基苯基叶琳中间相的形成具有显著的影响：增加了叶琳材料的液晶相：①降低了叶啦材料的相变温度：四种自由碱叶啦材料由晶体转变到液晶相的温度最低为14．36℃，最高为52刀4℃；当锌离子进入苯环后，叶琳材料由晶体转变到液晶相的温度最高为15．84℃，最低为刁6．叩℃。②增加了叶琳材料的相区：四种自由碱叶琳材料由晶体转变成各相同性液体的相区温度最窄为引．49 ’C，最宽达108．56℃；当锌离子进入苯环后，叶晰材料由晶体转变成各相同性液体的相区温度最窄为 76．18C，最宽达 175”C。 最后，研究了酚氧基（RCG－－）中烷基＊一)碳链长度对叶琳及金属锌叶琳配合物材料液晶性能的影响。更多还原

【Abstract】 Metalloporphyrins have been extensively studied in many functional chemistry fields such as photosensisers, photoconductors, optical actuator and chemical sensors. A great deal of research is being devoted to the understanding of systems, biomimetic and otherwise, that self-assemble into organized structures. Liquid crystals represent one of the best known classes of self-organizing materials, exhibiting properties that range from surfactants that can form micelles, monolayers, and membranes, to the rodlike molecules used in liquid crystal displays, to the recently discovered disc-like liquid crystals. In all of the studies of mesogenic porphyrins, the extended disc-like core has been periphrrally substituted and therefore used as the basis for the construction of discotic materials. All of these compounds will form ordered but fluid structures, and more fluid phases tend to reorder themselves. In this communication, we reported on the synthesis of meso-tetra ( 4-decanoylphenyl ) porphyrin, meso-tetra ( 4-lauroyloxyphenyl ) porphyrin, meso-tetra (4-mystoyloxyphenyl) porphyrin, meso-tetra (4-palmitoyloxy phenyl) porphyrin and its derivatives.Meso-tetra (4-acyloxyphenyl) pophyrin was prepared by usual procedure from acyl chloride and meso-tetra ( 4-hydroxyphenyl ) porphyrin in benzene and obtained in 86.4% yield. Treatment of the free base with zinc chloride in dimethyl formamide (DMF)-dichloromethane(CH2Cl2) yielded corresponding zinc porphyrin complex. The spectral data (UV-visJR/H-NMR) and elemental analysis are in agreement with the assigned structures. The physical behaviors of TDPPH2, TLPPH2, TMPPH2, TPPPH2 and TDPPZn, TLPPZn, TMPPZn, TPPPZn by differential scanning calorimetric (DSC). The results show that four porphyrin free bases and its zinc porphyrins exhibit liquid crystal behaviors. On cooling from the isotropic liquid, TDPPH2, TLPPH2, TPPPH2 gave two broad LC phases separated by sharp peaks in the DSC. TMPPH2 gave a single, highly viscous, birefringent mesophase. The TMPPZn showed single liquid crystalline phase, TDPPZn and TLPPZnshowed two liquid crystalline phases, TPPPZn showed three liquid crystalline phases between the isotropic liquid and crystalline phase, and the phases were separated by sharp peak in the DSC. According to the DSC thermogram of compounds, the free base porphyrin (TPPPHi) has a low phase transformation temperature 14.36?, TMPPH/z has a high phase transformation temperature 52.04 ?. The zinc complex TLPPZn has a low phase transformation temperature - 36.40 ?, TPPPZn has a phase transformation temperature 15.84?. The free base porphyrin TPPPH2 has a narrow mesophase from 14.36? to 65.85? (51.49?) , TLPPH2 has a broad mesophase from 25.95 ? to 134.51? (108.56?) . The zinc complex TLPPZn has a narrow mesophase from -36.40? to 39.78? (76.18 ?), TDPPZn has a broad mesophase from -8.99? to 166.0? (175 ?).The electrochemical behaviors of the porphyrin free base and metal complexes were invesrigated by cyclic voltammorgrans and OTTLE.The effect of central metal was’ investigated, the results showed that the central metal ( Zn ) has a dramatic effect on mesophase formation in the porphyrin complex, which was absent the corresponding free base.The thermotropic behavior of these compounds has been investigated as a function of length of the meso-side carbon chain. The results showed that a function of length of the side chain has a dramatic effect on mesophase formation in the porphyrin free base and complex.The optical textures of the porphyrin free bases and zinc complexes was observed by microscopy and resembles that of a columnar discotic phase.更多还原