Shape-Persistent Oligothienylene-Ethynylene-Based Dendrimers: Synthesis, Spectroscopy and Electrochemical Characterization
作者:Amaresh Mishra、Chang-Qi Ma、René A. J. Janssen、Peter Bäuerle
DOI:10.1002/chem.200901242
日期:2009.12.14
dendrons and dendrimers were estimated from optical and redox measurements and the calculated band gaps were within the range of 3.3 to 2.4 eV, typical for oligo‐ and polythiophenes. Electrochemical polymerizations of several desilylated compounds were performed and characterization of the films is reported. Preliminary bulk heterojunction solar cells that utilise these ethynylated dendrimers as the donor
结合Pd催化的Sonogashira型交叉偶联和氧化均偶联步骤,成功合成了一系列新的结构良好的,直至第三代(G3)的低聚亚乙基-亚乙炔基树枝状大分子。树突的氧化均偶联成功地提供了直至第二代(G2)的树状聚合物。相比之下,G4树状聚合物是通过四倍的Sonogashira型交叉偶联反应有效制备的。由于存在不同的π共轭发色团,所有化合物均显示出宽广且无结构的吸收和发射光谱。随着世代的增加,观察到了π–π *吸收带的红移和吸收系数的增加。与我们小组先前报道的全噻吩树状聚合物相比,亚乙炔基插入共轭树状聚合物主链中会导致色变。由于有效的分子内电荷转移(ICT)过程,所有树状化合物均具有荧光并显示出中等的量子效率。循环伏安法测量还揭示了存在多个π共轭途径,这些途径为更高的世代显示出非常宽泛的氧化波。这些树突和树状聚合物的HOMO-LUMO能级是通过光学和氧化还原测量得出的,计算出的带隙在3.3至2.4