Kuhlmann Jochen E, Liu Sherri S Y, Dirnberger Klaus, Zharnikov Michael, Ludwigs Sabine
IPOC - Functional Polymers, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany.
Applied Physical Chemistry, Heidelberg University, Im Neuenheimer Feld 253, 69120, Heidelberg, Germany.
Chemistry. 2021 Dec 6;27(68):17255-17263. doi: 10.1002/chem.202103257. Epub 2021 Nov 25.
In this manuscript we present a versatile platform for introducing functional redox species into tailor-made 3D redox polymer networks. Electrochemical characterization based on cyclic voltammetry is applied to verify the immobilization of the redox species within the conducting networks. Ultimately this strategy shall be extended to (photo)electrocatalytic applications which will profit from the conducting polymer matrix. Soluble precursor copolymers are synthesized via radical copolymerization of vinyltriphenylamine (VTPA) with chloromethylstyrene (CMS) in different ratios, whereas CMS is subsequently converted into azidomethylstyrene (AMS) to yield poly(VTPA-co-AMS) copolymers. Spin-coating of poly(VTPA-co-AMS) on gold electrodes yields thin films which are converted into stable polymer network structures by electrochemical crosslinking of the polymer chains via their pendant triphenylamine groups to yield N,N,N',N'-tetraphenylbenzidine (TPB) crosslinking points. Finally, the resulting redox-active, TPB-crosslinked films are functionalized with ethynylferrocene (EFc) as a representative redox probe using a click reaction. Main experimental tools are polarization modulation infrared reflection absorption spectroscopy and scan rate dependent cyclic voltammetry. Especially the latter proves the successful conversion and the immobilization of redox probes in the polymer matrix. The results are compared with the reference system of azide-terminated self-assembled monolayers on gold substrates, allowing to distinguish between free and immobilized EFc species.
在本论文中，我们展示了一个通用平台，用于将功能性氧化还原物种引入定制的三维氧化还原聚合物网络。基于循环伏安法的电化学表征被用于验证氧化还原物种在导电网络中的固定化。最终，该策略将扩展到（光）电催化应用，这将从导电聚合物基质中受益。通过乙烯基三苯胺（VTPA）与氯甲基苯乙烯（CMS）以不同比例进行自由基共聚合成可溶性前体共聚物，随后将CMS转化为叠氮甲基苯乙烯（AMS）以制备聚（VTPA-co-AMS）共聚物。将聚（VTPA-co-AMS）旋涂在金电极上得到薄膜，通过聚合物链通过其侧链三苯胺基团进行电化学交联，形成稳定的聚合物网络结构，从而产生N，N，N'，N'-四苯基联苯胺（TPB）交联点。最后，使用点击反应，用乙炔基二茂铁（EFc）作为代表性氧化还原探针，对所得的具有氧化还原活性的TPB交联薄膜进行功能化。主要实验工具是偏振调制红外反射吸收光谱和扫描速率依赖的循环伏安法。特别是后者证明了氧化还原探针在聚合物基质中的成功转化和固定化。将结果与金基底上叠氮基封端的自组装单分子层的参考体系进行比较，从而区分游离和固定的EFc物种。
