Materials Science and Engineering Department, University of Washington, Seattle, Washington 98195-2120, USA.
J Am Chem Soc. 2009 Sep 16;131(36):12894-5. doi: 10.1021/ja9054977.
The ability of chemists to design and synthesize pi-conjugated organic polymers with precise control remains the key to technological breakthroughs for using polymer materials in electronic and photonic devices. In this communication, the controlled chain-growth polymerization of regioregular poly(3-hexylthiophene) (P3HT) from an external initiator using 1,3-bis(diphenylphosphino)propane (dppp) as a catalyst ligand is reported. The complexes cis-chloro(phenyl)(dppp)nickel(II) and cis-chloro(o-tolyl)(dppp)nickel(II) were synthesized and characterized by (31)P NMR spectroscopy. These complexes served as initiators in the polymerization of 2-bromo-5-chloromagnesio-3-hexylthiophene in THF at room temperature, affording fully regioregular P3HT with controlled molecular weights and narrow molecular weight distributions, as demonstrated by gel-permeation chromatography and (1)H NMR spectroscopy. MALDI-TOF mass spectrometry revealed that the polymers had almost complete incorporation of the initiating aryl group, and when the aryl group was o-tolyl, only Tol/H end groups were observed. Although external initiators have been used previously with a PPh(3) ligand, that methodology led to polymers with broad molecular weight distributions. This is the first example in which complete control over the externally initiated P3HT polymerization has been achieved.
化学家能够精确设计和合成具有共轭π键的有机聚合物，这仍然是将聚合物材料应用于电子和光子器件的技术突破的关键。在本通讯中，报道了使用 1,3-双（二苯基膦基）丙烷（dppp）作为催化剂配体，从外部引发剂可控链增长聚合规正聚（3-己基噻吩）（P3HT）。通过（31）P NMR 光谱学合成并表征了顺式-氯（苯基）（dppp）镍（II）和顺式-氯（邻甲苯基）（dppp）镍（II）络合物。这些络合物在室温下的 THF 中用作 2-溴-5-氯镁基-3-己基噻吩聚合的引发剂，通过凝胶渗透色谱法和（1）H NMR 光谱法证实得到了具有可控分子量和较窄分子量分布的完全规正 P3HT。MALDI-TOF 质谱表明聚合物几乎完全掺入了引发的芳基，当芳基为邻甲苯基时，仅观察到 Tol/H 端基。尽管先前已经使用 PPh（3）配体使用了外部引发剂，但该方法导致聚合物的分子量分布较宽。这是首次实现对外引发的 P3HT 聚合的完全控制的示例。
