Melville Laboratory for Polymer Synthesis, Department of Chemistry, University of Cambridge, Cambridge, CB2 1EW, United Kingdom.
J Am Chem Soc. 2012 Oct 24;134(42):17769-77. doi: 10.1021/ja3080677. Epub 2012 Oct 12.
We present a fast and efficient in situ synthetic approach to obtain fully π-conjugated polymers with degrees of polymerization up to 23 and near quantitative (>95%) heterobis-functionalization. The synthesis relies on the key advantages of controlled Suzuki chain-growth polymerization: control over molecular weight, narrow polydispersity, and ability to define polymer end groups. The first end group is introduced through the initiator metal complex tBu(3)PPd(X)Br, while the second end group is added by quenching of the chain-growth polymerization with the desired boronic esters. In all cases, polymers obtained at 50% conversion showed excellent end group fidelity and high purity following a simple workup procedure, as determined by MALDI-TOF, GPC, and (1)H and 2D NMR. End group functionalization altered the optoelectronic properties of the bridge polymer. Building on a common fluorene backbone, and guided by DFT calculations, we introduced donor and acceptor end groups to create polymeric molecular wires exhibiting charge transfer and energy transfer as characterized by fluorescence, absorption, and transient absorption spectroscopy as well as by fluorescence lifetime measurements.
我们提出了一种快速有效的原位合成方法，可获得完全π共轭的聚合物，其聚合度高达 23，且具有近定量（>95%）的杂双官能化。该合成依赖于可控铃木链增长聚合的关键优势：控制分子量、窄多分散性以及定义聚合物端基的能力。第一个端基是通过引发剂金属配合物 tBu(3)PPd(X)Br 引入的，而第二个端基是通过用所需的硼酸酯猝灭链增长聚合来添加的。在所有情况下，在 50%转化率下获得的聚合物在经过简单的后处理后，表现出极好的端基保真度和高纯度，这是通过 MALDI-TOF、GPC 和（1）H 和 2D NMR 确定的。端基官能化改变了桥接聚合物的光电性能。基于常见的芴骨架，并通过 DFT 计算进行指导，我们引入了给体和受体端基，以创建表现出电荷转移和能量转移的聚合物分子线，这是通过荧光、吸收和瞬态吸收光谱以及荧光寿命测量来表征的。
