Supramolecular ordering, thermal behavior, and photophysical, electrochemical, and electroluminescent properties of alkoxy-substituted yne-containing poly(phenylene-vinylene)s
Supramolecular ordering, thermal behavior, and photophysical, electrochemical, and electroluminescent properties of alkoxy-substituted yne-containing poly(phenylene-vinylene)s
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DOI：
10.1021/ma0488111
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发表时间：
2004-10-05
期刊：
影响因子：
5.5
通讯作者：
Grummt, UW
中科院分区：
文献类型：
--
作者：
Egbe, DAM;Carbonnier, B;Grummt, UW
本文报道了具有一般结构单元（-Ph-CdropC-Ph-CH=CH-Ph-CH =CH-）的烷氧基取代的无缺陷的含炔聚（亚苯基-亚乙烯基）15 a-d，它是通过氟代二醛7 [1，2-双（4-甲酰基-2，5-二烷氧基苯基）乙炔]与各种2，5-二烷氧基-对亚二甲苯基双（二乙基膦酸酯）14 a-d的烯化反应合成的。还报道了1-溴-2，5-二烷氧基苯甲醛（用于合成7的起始材料）的新合成路线，其允许接枝所有类型的烷氧基侧链。四种聚合物材料的体状态属性已被分析，使用各种实验方法，提供信息的热行为，以及在不同的尺寸尺度上的自组装形态。结晶超结构的球晶或棒状形态，由侧链分开的聚合物骨架层组成，被确定为对称烷氧基取代的15 a-c的成核和生长过程。观察到光学（E-g（opt））和电化学（E-g（ee））带隙之间的差异取决于接枝侧链的体积（15 c）和长度（15 b）。15 b中的十八烷氧基侧链不仅导致结构良好的光致发光和电致发光光谱以及更高的荧光量子产率，而且允许设计具有相对于辛氧基取代的聚合物15 a（eta（ext）= 0.79%，亮度= 1406 cd/m（2））。尽管聚合物15和聚合物17 [（-Ph-CdropC-Ph-CdropC-Ph-CH=CH-Ph-CH=CH-）]之间的共轭模式存在差异，但发现结构为Ph-CdropC-Ph-CH = CH-Ph-CH = CH-Ph-CdropC-Ph的相同发色团体系负责它们的发射行为，如通过荧光动力学测量（tau，k（f），k（nr））和量子化学计算所证实的。观察到的差异，在其固态的物理性质归因于骨架刚性（作为重复单元中的-CdropC-部分的数量的函数）和侧链的性质的组合效果。此外，与聚合物17相比，聚合物15内较少的-CdropC-单元导致其电致发光参数的超过100倍的改善。
Alkoxy-substituted and defect-free yne-containing poly(phenylene-vinylene)s, 15a-d, having the general constitutional unit (-Ph-CdropC-Ph-CH=CH-Ph-CH=CH-) synthesized through the olefination reactions of the fluorophoric dialdehyde 7 [1,2-bis(4-formyl-2,5-dialkoxyphenyl)acetylene] with various 2,5-dialkoxy-p-xylylenebis(diethylphosphonates), 14a-d, are reported. A new synthetic route to 1-bromo-2,5-dialkoxybenzaldehyde (starting material for the synthesis of 7) allowing the grafting of all types of alkoxy side chains is also reported. Bulk state properties of the four polymeric materials have been analyzed using various experimental methods giving information on the thermal behavior as well as self-assembling morphologies at different size scales. Crystalline superstructures of either spherulitic or rodlike morphology, comprised of polymeric backbone layers separated by the side chains are identified to develop by nucleation and growth process for symmetrically alkoxy substituted 15a-c. Discrepancy between optical (E-g(opt)) and electrochemical (E-g(ee)) band gaps was observed to be dependent on the bulkiness (15c) and length (15b) of the grafted side chains. Octadecyloxy side chains in 15b not only lead to well structured photoluminescence and electroluminescence spectra and higher fluorescence quantum yields but also allow the design of LED-devices of the configuration ITO/PEDOT/polymer/Ca with improved parameters (eta(ext) = 2.15%, luminance = 5760 cd/m(2)) relative to the octyloxy-substituted polymer 15a (eta(ext) = 0.79%, luminance = 1406 cd/m(2)). Despite the differences in the conjugation pattern between polymers 15 and polymers 17 [(-Ph-CdropC-Ph-CdropC-Ph-CH=CH-Ph-CH=CH-)], an identical chromophore system of structure Ph-CdropC-Ph-CH=CH-Ph-CH=CH-Ph-CdropC-Ph was found to be responsible for their emissive behavior as confirmed by fluorescence kinetics measurements (tau, k(f), k(nr)) and quantum chemical calculations. The differences observed in their solid-state photophysical properties are ascribed to the combined effects of the backbone rigidity (as a function of the number of -CdropC- moieties in the repeating unit) and the nature of the side chains. Moreover less -CdropC- units within polymers 15 lead to the more than 100-fold improvement of their electroluminescent parameters compared to polymers 17.