Flat conjugated polymers combining a relatively low HOMO energy level and band gap: polyselenophenes versus polythiophenes
作者:Elena Poverenov、Yana Sheynin、Natalia Zamoshchik、Asit Patra、Gregory Leitus、Igor F. Perepichka、Michael Bendikov
DOI:10.1039/c2jm31035j
日期:——
In this work, we prepared a series of new conjugated polyselenophenes that, in the 3,4-positions of the selenophene ring, have oxygen or sulfur substituents bridged by a phenylene moiety. Such substitution of a conjugated backbone produces a skeleton that has only planar units, does not have stereo centers, and offers the potential to structurally modify the polymer without impairing its conjugation. The reported polyselenophenes exhibit significantly different properties as a function of the heteroatom. The selenophene backbone combined with a phenylene periphery creates the rare combination of a low-band gap, low HOMO energy level, and a flat skeleton, which is desired for many optoelectronic applications. The properties of the phenylene-bridged polyselenophenes were compared with those of their polythiophene analogs. The polyselenophenes obtained in this work have a lower band gap and higher planarity than polythiophenes and their monomers electropolymerize more easily. Theoretical studies support the experimental findings about rigidity and band gap changes.
在这项工作中,我们制备了一系列新的共轭多硒噻吩,在硒噻吩环的3、4位上有氧或硫取代基,通过苯ylene结构桥接。这种共轭主链的取代产生了一个只有平面单元的骨架,没有立体中心,并且可以在不损害其共轭性的情况下对聚合物进行结构改造。所报道的多硒噻吩的性质因杂原子的不同而显著不同。硒噻吩主链与苯ylene外缘结合形成了低带隙、低HOMO能级和扁平骨架的稀有组合,这对于许多光电应用来说是所需要的。与其聚噻吹果的类似物相比,苯ylene桥接的多硒噻吩的性质进行了比较。这项工作中获得的多硒噻吩具有比聚噻吩更低的带隙和更高的平面性,并且其单体的电聚合反应更容易。理论研究支持了关于刚性和带隙变化的实验结果。