Picco Agustín S, Knoll Wolfgang, Ceolín Marcelo, Azzaroni Omar
Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, CONICET, CC 16 - Suc. 4, 1900 La Plata, Argentina.
Austrian Institute of Technology (AIT), Donau-City-Strasse 1, 1220 Vienna, Austria.
ACS Macro Lett. 2015 Jan 20;4(1):94-100. doi: 10.1021/mz500688r. Epub 2014 Dec 31.
Self-organized metallo-supramolecular heterostructures have potential applications that include molecular electronics, photovoltaics, and magnetic devices, among other examples. The main challenge that scientists typically face when designing advanced supramolecular materials is to achieve structurally defined assemblies by resolving conflicting demands on the topological and/or chemical features of the constituting building blocks. Accordingly, the formation of well-defined metallo-supramolecular arrays using ill-defined, highly polydisperse, self-assemblable starting compounds marks a profound departure from traditional supramolecular paradigms. The present work describes the first observation of spontaneous mesophase transformation of well-defined metallo-supramolecular assemblies in solution as a result of the complexation of transition metal ions into the ionophilic domains of highly branched unimolecular micelles constituted of -acylated hyperbranched polyethylenimine. Experimental results based on a combination of different synchrotron-based techniques provide unprecedented experimental evidence revealing that ion-induced self-assembly of amphiphilic hyperbranched polymers can be used to achieve highly ordered metallo-supramolecular structures not only in solution but also on solid surfaces. We believe that this emerging conceptual framework can open extremely interesting new synthetic and technological opportunities in the area of self-assembly of well-defined metallo-supramolecular architectures obtained from building blocks with poor structural regularity but easily provided in large quantities by simple and inexpensive preparative chemistries.
自组装金属超分子异质结构具有潜在应用，包括分子电子学、光伏和磁性器件等。科学家在设计先进超分子材料时通常面临的主要挑战是，通过解决对构成构件的拓扑和/或化学特征的相互冲突的要求来实现结构明确的组装体。因此，使用定义不明确、高度多分散、可自组装的起始化合物形成定义明确的金属超分子阵列，标志着与传统超分子范式的重大背离。本工作描述了首次观察到溶液中定义明确的金属超分子组装体由于过渡金属离子络合到由ω-酰化超支化聚乙烯亚胺构成的高度支化单分子胶束的亲离子域中而发生的自发中间相转变。基于不同同步辐射技术组合的实验结果提供了前所未有的实验证据，表明两亲性超支化聚合物的离子诱导自组装不仅可以在溶液中而且可以在固体表面上用于实现高度有序的金属超分子结构。我们相信，这个新兴的概念框架可以在由结构规整性差但通过简单且廉价的制备化学方法容易大量提供的构件获得的定义明确的金属超分子结构的自组装领域中开启极其有趣的新合成和技术机会。
