Linear and branched electroactive polymers based on ethylenedioxythiophene–triarylamine conjugates
作者:M'hamed Chahma、Joe B. Gilroy、Robin G. Hicks
DOI:10.1039/b711693d
日期:——
Triphenylamines with one, two, or three 3,4-ethylenedioxythiophene (EDOT) substituents attached to the para-phenyl carbons have been prepared via metal-catalyzed cross-coupling reactions. The amines with two or three EDOTs (compounds 4 and 3, respectively) can be oxidatively electropolymerized (via intermolecular coupling between two EDOT groups at their respective α-carbon atoms) to afford stable, linear and cross-linked polymers, respectively. The linear polymer (poly-4) exhibits two resolved, reversible oxidation waves corresponding to the oxidation of the amine and EDOT centers. These two oxidation processes occur at the same potential in cross-linked poly-3 giving rise to one broad, reversible oxidation wave. The observation of redox processes associated with the EDOT-based chromophores contrasts the properties of related (non-EDOT-containing) polymers for which the thiophene backbone serves only as a conjugated âlinkerâ. These polymers are highly stable to electrochemical oxidation and can be electrochemically cycled hundreds of times with no detectable decomposition; color changes accompany the redox processes, interconverting between reduced (yellow) and oxidized (greenâblue) forms.
对苯基碳上连接有 1 个、2 个或 3 个 3,4-乙撑二氧噻吩 (EDOT) 取代基的三苯胺已通过金属催化的交叉偶联反应制备。具有两个或三个 EDOT 的胺(分别为化合物 4 和 3)可以氧化电聚合(通过两个 EDOT 基团在各自的 α-碳原子上的分子间偶联),分别提供稳定的线性和交联聚合物。线性聚合物 (poly-4) 表现出两个解析的、可逆的氧化波,对应于胺和 EDOT 中心的氧化。这两种氧化过程在交联的 Poly-3 中以相同的电位发生,产生一种广泛的、可逆的氧化波。与基于 EDOT 的发色团相关的氧化还原过程的观察与相关聚合物(不含 EDOT)的性质形成对比,其中噻吩主链仅充当共轭“连接体”。这些聚合物对电化学氧化高度稳定,可以电化学循环数百次而没有检测到分解;颜色变化伴随着氧化还原过程,在还原(黄色)和氧化(绿色→蓝色)形式之间相互转化。