Full Quantification of the Light-Mediated Gilch Polymerization
Full Quantification of the Light-Mediated Gilch Polymerization
复制标题
光介导 Gilch 聚合的完全定量
DOI：
10.1021/acs.macromol.8b00607
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发表时间：
2018
期刊：
影响因子：
5.5
通讯作者：
J. J. Michels
中科院分区：
文献类型：
--
作者：
A.‐K. Schönbein;J. Kind;C. M. Thiele;J. J. Michels
烷氧基取代的聚（对苯撑乙烯）（PPV）仍然是光电子学中的主要主力材料，从薄膜电子学到生物成像。一种有吸引力的PPV合成路线是Gilch聚合。然而，由于该反应的自由基性质，获得对分子量和链构成的控制具有挑战性。在这项工作中，我们定量地显示内situUV-辐射NMR光谱如何控制Gilch聚合可以通过紫外光照射增强。这种方法的潜力已被证明，但从未在定量框架内解释，导致缺乏机制和动力学的见解。我们不仅通过原位分析和模拟光化学Gilch聚合反应，而且通过表征起始材料的光解来解释这一点。后者表明溶剂THF可能在Gilch途径和类似的基于双自由基的双自由基途径中充当自由基转移剂。我们进行了两次光聚合试验：（i）在连续UV照射下，和（ii）通过施加短UV脉冲，同时监测混合物的化学响应。由于现有的Gilch聚合模型不足以描述记录的时间-浓度曲线，我们开发了一个新的模型，耦合热和光致聚合。数值曲线拟合量化与两种途径相关的速率常数。我们证明，（i）一个photoactivatedp-quinodimethane speciesQ* 反应（重新）的启动和传播步骤，（ii）光传播是显着快于光引发，和（iii）的光化学反应是相当快的比他们的热类似物，这使得解耦的热和光化学途径在温度低到足以抑制前者。
Alkoxy-substituted poly(p-phenylenevinylenes) (PPVs) continue to be major workhorse materials in optoelectronics, ranging from thin film electronics to bioimaging. An attractive synthetic route toward PPVs is the Gilch polymerization. Nevertheless, obtaining control over molecular weight and chain constitution is challenging due to the free-radical nature of this reaction. In this work we quantitatively show within situUV-irradiation NMR spectroscopy how control over the Gilch polymerization can be enhanced by irradiation with UV-light. The potential of this method has been demonstrated but never interpreted within a quantitative framework, resulting in a lack of mechanistic and kinetic insight. We account for this not only byin situanalyzing and modeling the photochemical Gilch polymerization but also by characterizing the photolysis of the starting material. The latter shows that the solvent THF likely acts as radical transfer agent in the Gilch pathway and similar precursor-based biradical routes. We perform two photopolymerization runs: (i) under continuous UV-irradiation and (ii) by applying a short UV pulse while monitoring the chemical response of the mixture. Since existing models of the Gilch polymerization are inadequate for describing the recorded time–concentration profiles, we develop a new model that couples thermal and photoinduced polymerization. Numerical curve fitting quantifies the rate constants associated with both pathways. We demonstrate that (i) a photoactivatedp-quinodimethane speciesQ* reacts in the (re)initiation and propagation steps, (ii) photopropagation is significantly faster than photoinitiation, and (iii) the photochemical reactions are considerably faster than their thermal analogues, which allows for decoupling the thermal and photochemical pathways at temperatures low enough to suppress the former.
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通过 Gilch 路线合成的聚对亚苯基亚乙烯基的有效氧诱导摩尔质量控制
DOI：
--
发表时间：
2008
期刊：
影响因子：
--
作者：
Thorsten Schwalm;M. Rehahn
通讯作者：
M. Rehahn
氯前驱体路线（CPR）化学制备聚（对亚苯基亚乙烯基）基发光二极管
DOI：
--
发表时间：
1995
期刊：
影响因子：
--
作者：
B. Hsieh;H. Antoniadis;D. C. Bland;W. Feld
通讯作者：
W. Feld
DOI：
10.1002/pol.1966.150040602
发表时间：
1966-01-01
期刊：
JOURNAL OF POLYMER SCIENCE PART A-1-POLYMER CHEMISTRY
影响因子：
--
作者：
GILCH, HG;WHEELWRIGHT, WL
通讯作者：
WHEELWRIGHT, WL
影响因子：
4
作者：
Kuik, Martijn;Vandenbergh, Joke;Blom, Paul W. M.
通讯作者：
Blom, Paul W. M.
影响因子：
15
作者：
Kühn, T;Schwalbe, H
通讯作者：
Schwalbe, H