Faculty of Chemistry, Jagiellonian University, Gronostajowa 2, 30-387 Kraków, Poland.
Selvita Services Sp. Z o.o., Bobrzyńskiego 14, 30-348 Kraków, Poland.
Int J Mol Sci. 2022 May 31;23(11):6162. doi: 10.3390/ijms23116162.
Donor-acceptor (D-A) conjugated polymers are promising materials in optoelectronic applications, especially those forming ordered thin films. The processability of such conjugated macromolecules is typically enhanced by introducing bulky side chains, but it may affect their ordering and/or photophysical properties of the films. We show here the synthesis of surface-grafted D-A polymer brushes using alternating attachment of tailored monomers serving as electron donors (D) and acceptors (A) via coupling reactions. In such a stepwise procedure, alternating copolymer brushes consisting of thiophene and benzothiadiazole-based moieties with precisely tailored thickness and no bulky substituents were formed. The utilization of Sonogashira coupling was shown to produce densely packed molecular wires of tailored thickness, while Stille coupling and Huisgen cycloaddition were less efficient, likely because of the higher flexibility of D-A bridging groups. The D-A brushes exhibit reduced bandgaps, semiconducting properties and can form aggregates, which can be adjusted by changing the grafting density of the chains.
供体-受体（D-A）共轭聚合物是光电应用中很有前途的材料，特别是那些形成有序薄膜的聚合物。通过引入庞大的侧链，可以提高此类共轭高分子的加工性能，但可能会影响其有序性和/或薄膜的光物理性质。我们在这里展示了使用偶联反应通过交替连接作为电子供体（D）和受体（A）的定制单体来合成表面接枝的 D-A 聚合物刷。在这种分步过程中，形成了由噻吩和苯并噻二唑基部分组成的交替共聚物刷，具有精确调整的厚度和没有庞大取代基。显示出 Sonogashira 偶联可以产生具有精确厚度的密集堆积分子线，而 Stille 偶联和 Huisgen 环加成效率较低，可能是因为 D-A 桥接基团的灵活性更高。D-A 刷表现出减小的能带隙、半导体性质并且可以形成聚集体，其可以通过改变链的接枝密度来进行调整。
