Department of Chemistry, University of Alberta, 11227 Saskatchewan Dr, Edmonton, Alberta T6G 2G2, Canada.
Chem Commun (Camb). 2019 Dec 7;55(94):14218-14221. doi: 10.1039/c9cc07512g. Epub 2019 Nov 11.
Polytellurophenes represent an emerging class of π-conjugated polymers that possess important characteristics for flexible electronics, such as narrow HOMO-LUMO gaps (E) and charge mobilities that can be orders of magnitude larger than their ubiquitous polythiophene counterparts. Herein we use the reactivity of pinacolboronate (BPin) groups attached to tellurophene scaffolds to directly prepare new 2,5-diiodinated monomers, which are then polymerized to afford new low E oligomers and polymers. Specifically, mixtures of (cycloalkyl)tellurophene oligomers (of 5 to 12 repeat units) with ring-fused 5- and 6-membered cyclic side chains were prepared via Yamamoto coupling, with a dramatic narrowing of band gap noted when less bulky 5-membered cycloalkyl side groups were present, due to enhanced tellurophene ring coplanarity. Grignard metathesis (GRIM) was also used to gain access to the first poly(3-aryltellurophene) with 94% regioregularity, along with a low E of 1.3 eV and an onset of light absorption at ca. 1000 nm.
聚碲吩是一类新兴的π共轭聚合物，具有用于柔性电子的重要特性，如较窄的 HOMO-LUMO 能隙 (E) 和电荷迁移率，其数值可比普遍的聚噻吩同类物大几个数量级。在此，我们利用连在碲吩骨架上的频哪醇硼酸酯 (BPin) 基团的反应活性，直接制备了新的 2,5-二碘代单体，然后聚合得到了新的低 E 齐聚物和聚合物。具体来说，通过 Yamamoto 偶联制备了（环烷基）碲吩寡聚物（5 到 12 个重复单元）与稠合的 5- 和 6-元环状侧链的混合物，当存在较小体积的 5 元环烷基侧基时，带隙显著变窄，这是由于碲吩环共面性增强所致。Grignard 复分解（GRIM）也被用于获得第一个具有 94%区域规整度的聚（3-芳基碲吩），同时具有低 E 值为 1.3 eV，吸收起始波长约为 1000nm。
