Synthesis and Properties of Light-Emitting Polythiophene Derivatives Bearing Terphenyl Mesogenic Pendant
Synthesis and Properties of Light-Emitting Polythiophene Derivatives Bearing Terphenyl Mesogenic Pendant
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DOI：
10.1080/15421400903568047
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发表时间：
2010-03
影响因子：
0.7
通讯作者：
Lie Chen;Yiwang Chen;Weihua Zhou;Fan Li;Xiaohui He;B. Tang
中科院分区：
文献类型：
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作者：
Lie Chen;Yiwang Chen;Weihua Zhou;Fan Li;Xiaohui He;B. Tang
采用脱卤缩聚法合成了一系列第三位含三联苯基液晶侧链的聚噻吩。通过Suzuki反应和酯化反应依次合成了噻吩单体2，5-溴-3-{[（4-（4′-氰基）三苯氧基）羰基]甲基}噻吩[M（CN）]和2，5-溴-3-{[（4-（4′-甲氧基）三苯氧基）羰基]甲基}噻吩[M（OCH 3）]。采用核磁共振、红外光谱、热重、差示扫描量热、偏光显微镜、紫外光谱、光致发光等手段对单体和聚合物的结构和性能进行了表征和评价。所有的聚合物都是稳定的，当加热到≥300°C时，它们的重量几乎没有损失。该聚合物具有良好的溶解性，可溶于CHCl 3、THF、DMF等常用溶剂中。在加热和冷却过程中，单体均呈现出对映SmAd相，并呈双层排列。由于三联苯介晶侧链和刚性聚噻吩主链之间存在短间隔的亚甲基酯，聚合物在高温下不能表现出液体堆积。发色团三联苯核的存在赋予聚合物高的光致发光。当它们的CH_2Cl_2溶液被光激发时，聚合物发出约400 nm的强紫外光。
A series of polythiophenes containing terphenyl mesogenic side chain at the third position through ester bonding was synthesized by dehalogenative polycondensation. The thiophene monomers 2,5-bromo-3-{[(4-(4′-cyano)terphenyloxy)carbonyl]-methyl]}-thiophene [M(CN)] and 2,5-bromo-3-{[(4-(4′-methoxy)terphenyloxy)-carbonyl]methyl}-thiophene [M(OCH3)] were prepared via Suzuki reation and esterification reactions, in sequence. The structures and properties of the monomers and polymers were characterized and evaluated with nuclear magnetic resonance, infrared spectroscopy, thermogravimetry, differential scanning calorimetry, polarized optical microscopy, ultraviolet spectroscopy, and photoluminescence. All of the polymers were stable, losing little of their weights when heated to ≥300°C. The polymers showed good solubility and could be dissolved in common solvents such as CHCl3, THF, DMF, etc. The monomers exhibited enantiotropic SmAd phases with a bilayer arrangement in the heating and cooling processes. Due to short spacer methylene ester between the bulk terphenyl mesogenic side chain and rigid polythiophene main chain, the polymers could not exhibit liquid crystallinty at elevated temperature. The existence of the chromophoric terphenyl core endows the polymers with high photoluminescence. When their CH2Cl2 solutions were photoexcited, the polymers emitted a strong UV light about 400 nm.