Self-Assembly of Flexible One-Dimensional Coordination Polymers on Metal Surfaces
Self-Assembly of Flexible One-Dimensional Coordination Polymers on Metal Surfaces
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DOI：
10.1021/ja1010527
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发表时间：
2010-05-19
影响因子：
15
通讯作者：
Barth, Johannes V.
中科院分区：
文献类型：
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作者：
Heim, Daniel;Ecija, David;Barth, Johannes V.
我们采用从头合成的卟啉模块在 Cu(111) 和 Ag(111) 表面构建一维 (1D) Cu 配位聚合物。分子模块的编程几何结构和功能及其构象灵活性和底物相互作用产生了蜿蜒的金属有机聚合物组件，基于不寻常的二重铜-吡啶基配位基序。对扫描隧道显微镜 (STM) 数据的分析揭示了两种对映体的出现，这是由于表面限制对二维手性构象异构体模块进行解卷积造成的。立体异构体表现出位点特异性表面锚定，由此每个物种可能具有三个离散的方向。它们的顺序和相互排列决定了金属有机链的方向和曲率。 Cu（111）和Ag（111）上的Cu配位聚合物非常相似，它们的形成分别是由固有吸附原子和共蒸发吸附原子诱导的，这表明横向键合基序主要独立于基材。此外，分子操纵实验显示了铜配位多卟啉聚合物整个片段的集体运动。
We employed a de novo synthesized porphyrin module to construct one-dimensional (1D) Cu-coordinated polymers on Cu(111) and Ag(111) surfaces. The programmed geometry and functionality of the molecular module together with its conformational flexibility and substrate interaction yields sinuous metal-organic polymeric assemblies, based on an unusual two-fold Cu-pyridyl coordination motif. An analysis of scanning tunneling microscopy (STM) data reveals the occurrence of two enantiomers, resulting from the surface confinement that deconvolutes the module in 2D-chiral conformational isomers. The stereoisomers exhibit site-specific surface anchoring, from whence three discrete orientations are possible for each species. Their sequence and mutual arrangement determine direction and curvature of the metal-organic chains. The Cu-coordinated polymers are very similar on both Cu(111) and Ag(111), where their formation is induced by intrinsic and coevaporated adatoms, respectively, which indicates that the lateral bonding motif is predominantly independent of the substrate. In addition, molecular manipulation experiments show the collective motion of entire segments of the Cu-coordinated multi-porphyrin polymers.