Department of Chemistry, Lash Miller Chemical Laboratories, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6, Canada.
J Am Chem Soc. 2013 Sep 4;135(35):13212-9. doi: 10.1021/ja4073904. Epub 2013 Aug 22.
Electron-deficient π-conjugated polymers are important for organic electronics, yet the ability to polymerize electron-deficient monomers in a controlled manner is challenging. Here we show that Ni(II)diimine catalysts are well suited for the controlled polymerization of electron-deficient heterocycles. The relative stability of the calculated catalyst-monomer (or catalyst-chain end) complex directly influences the polymerization. When the complex is predicted to be most stable (139.2 kJ/mol), these catalysts display rapid reaction kinetics, leading to relatively low polydispersities (∼1.5), chain lengths that are controlled by monomer:catalyst ratio, controlled monomer consumption up to 60% conversion, linear chain length growth up to 40% conversion, and 'living' chain ends that can be readily extended by adding more monomer. These are desirable features that highlight the importance of catalyst design for the synthesis of new conjugated polymers.
缺电子π-共轭聚合物对于有机电子学很重要，但以可控方式聚合缺电子单体具有挑战性。在这里，我们表明 Ni(II)二亚胺催化剂非常适合缺电子杂环的可控聚合。计算出的催化剂-单体（或催化剂链末端）配合物的相对稳定性直接影响聚合。当预测配合物最稳定时（139.2 kJ/mol），这些催化剂表现出快速的反应动力学，导致相对较低的多分散性（约 1.5）、受单体：催化剂比例控制的链长、单体消耗控制可达 60%转化率、线性链长增长可达 40%转化率，以及可以通过添加更多单体轻松扩展的“活”链末端。这些都是理想的特性，突出了催化剂设计对于合成新型共轭聚合物的重要性。
