Synthesis and characterization of poly(pyridinium salt)s with organic counterion exhibiting both lyotropic liquid-crystalline and light-emitting properties
Synthesis and characterization of poly(pyridinium salt)s with organic counterion exhibiting both lyotropic liquid-crystalline and light-emitting properties
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DOI：
10.1021/ma010904k
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发表时间：
2001-10-23
期刊：
影响因子：
5.5
通讯作者：
Cebe, JJ
中科院分区：
文献类型：
--
作者：
Bhowmik, PK;Burchett, RA;Cebe, JJ
近年来，含氮聚合物在电致发光聚合物的设计和合成中受到了极大的关注。1-10它们通常由在芳族部分中含有亚胺氮的缺π电子杂环组成。它们通常包括聚乙烯（2，5-亚吡啶基），11聚（对亚苯基），12 - 15聚（2，5-吡啶亚乙烯基），10聚乙烯的类似物（对亚苯基亚乙烯基），12 - 15聚（恶二唑），16聚（三唑），17聚聚（三嗪），18聚（喹啉），19，20聚（喹喔啉），21聚（4-乙烯基吡啶），22聚（苯胺），23和聚（吡咯），23等。与其他π-共辄聚合物不同，所有这些聚合物在主链或侧链中含有氮杂原子，这提供了容易的季铵化反应和氮位点的质子化。因此，它们的发射光谱可以通过向氮位点添加带电物质经由操纵它们的电子结构来随意调谐。1-10除了它们的电致发光特性之外，适当设计的聚合物结构的1 - 10导电24和液晶（LC）25 - 27特性使它们在许多技术应用中成为有吸引力的材料。然而，另外两种主链聚（吡啶盐）是相当感兴趣的。一种典型地由沿着聚合物链的主链的4，4 ′-联吡啶离子沿着组成，所述聚合物链被称为紫精聚合物。它们表现出许多有趣的性质，包括导电性、电致变色性、光致变色性、热致变色性和LC性质。另一个由沿着聚合物主链的4，4 ′-（1，4-亚苯基）双（2，6-二苯基吡啶鎓）离子组成。全芳族体系是理想的，因为它们具有高的热稳定性和化学稳定性。与紫精聚合物一样，它们也表现出许多独特的性质，包括氧化还原行为、电致变色、掺杂7，7，8，8-四氰基醌二甲烷时的导电性和光致变色。34 Harris等人报道了通过环转化聚合反应合成这类含有-BF 4（一种无机配合物）的聚合物及其物理性质的表征。尽管它们的玻璃化转变温度Tg值不能通过DSC测量确定，但它们表现出明显的熔融吸热，最小值高于380 ℃。TGA测量表明它们在熔融转变温度Tm值之前在约360 ℃开始分解。尽管这些聚合物中存在离子基团，但它们不溶于水，但在极性非质子溶剂中可溶于有限程度，并且可以溶液浇铸成坚韧的柔性膜。此外，它们在这些溶剂中的溶解度不足以形成溶致溶液。最近，Huang等人报道了另一系列聚（吡啶鎓盐）与三氟甲磺酸盐作为抗衡物的结果。这些聚合物显着更热和热氧化稳定性比类似的聚（吡啶）盐与-BF 4抗衡。它们也可溶于极性有机溶剂，包括二甲基亚砜（DMSO），二甲基甲酰胺（DMF），二甲基乙酰胺（DMAc），指甲creditors膜容易铸造。在这篇文章中，我们描述了一系列新的芳香族离子聚合物--在本研究中制备和表征的这些离子聚合物I的一般结构和名称显示在方案1中。与BF4相比，
Recently, nitrogen-containing polymers have received unabated attention in the design and synthesis of electroluminescent polymers. 1-10 They typically consist of π-electron-deficient heterocycles containing imine nitrogen in the aromatic moieties. They usually include poly (2, 5-pyridylene), 11 an analogue of poly (p-phenylene), 12-15 poly (2, 5-pyridylenevinylene), 10 an analogue of poly (p-phenylenevinylene), 12-15 poly (oxadiazole), 16 poly (triazole), 17 poly (triazine), 18 poly (quinoline), 19, 20 poly-(quinoxaline), 21 poly (4-vinylpyridine), 22 poly (aniline), 23 and poly (pyrrole), 23 among others. Unlike other π-conjugated polymers, 12-15 all of these polymers contain nitrogen heteroatoms either in the main chains or in the side chains that provide facile quaternization reaction and protonation of the nitrogen sites. Thus, their emission spectra can be tuned at will by adding a charged species to the nitrogen site via by manipulating their electronic structures. 1-10 Besides their electroluminescent properties, 1-10 conducting24 and liquidcrystalline (LC) 25-27 properties of suitably designed polymer structures make them attractive materials in many technological applications. However, the two other main-chain poly (pyridinium salt) s are of considerable interest. One typically consists of 4, 4′-bipyridinium ions along the backbone of the polymer chains that are known as viologen polymers. They exhibit a number of interesting properties including electrical conductivity, 28 electrochromism, 29 photochromism, 30 thermochromism, 31 and LC properties. 32, 33 The other consists of 4, 4′-(1, 4-phenylene) bis (2, 6-diphenylpyridinium) ions along the backbone of the polymer chains. All-aromatic systems are desirable because of their high thermal and chemical stability. They, like viologen polymers, also exhibit a number of unique properties that include redox behavior, electrochromism, conductivity when doped with 7, 7, 8, 8-tetracyanoquinodimethane, and photochromism. 34 Harris et al. reported the synthesis of this class of polymers containing-BF4, an inorganic counterion, by the ring-transmutation polymerization reaction and the characterization of their physical properties. Although their glass transition temperature, Tg, values cannot be determined by the DSC measurements, they exhibit distinct melting endotherms with a minimum above 380 C. The TGA measurements indicate that they start to decompose at about 360 C prior to their melting transition temperature, Tm, values. Despite the presence of ionic groups in these polymers, they are insoluble in water but soluble to a limited extent in polar aprotic solvents and can be solution cast into tough, flexible films. Additionally, the extent of their solubility in these solvents is insufficient to form lyotropic solutions. 34 Recently, Huang et al. reported the results of another series of poly (pyridinium salt) s with triflate as a counterion. These polymers were significantly more thermally and thermooxidatively stable than analogous poly (pyridinium) salts with-BF4 counterion. They were also soluble in polar organic solvents including dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and dimethylacetamide (DMAc) from which fingernail creasable films were easily cast. 35 In this communication, we describe the synthesis of a new series of aromatic ionic polymersspoly (pyridinium salt) sscontaining a bulky organic counterion such as tosylate ion and the characterization of their lyotropic properties in polar protic and aprotic organic solvents. The general structure and designations of these ionic polymers, I, which were prepared and characterized in this study, are shown Scheme 1. In contrast to the-BF4 …