Selective supramolecular fullerene-porphyrin interactions and switching in surface-confined C60-Ce(TPP)2 dyads.
Selective supramolecular fullerene-porphyrin interactions and switching in surface-confined C60-Ce(TPP)2 dyads.
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DOI：
10.1021/nl301534p
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发表时间：
2012-07
期刊：
影响因子：
10.8
通讯作者：
Saranyan Vijayaraghavan;D. Écija;W. Auwärter;Sushobhan Joshi;K. Seufert;A. Seitsonen;Kentaro Tashiro;J. Barth
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文献类型：
--
作者：
Saranyan Vijayaraghavan;D. Écija;W. Auwärter;Sushobhan Joshi;K. Seufert;A. Seitsonen;Kentaro Tashiro;J. Barth
有机分子、超分子复合物和供体-受体系统在界面处的控制是开发用于调节纳米电子学或有机光电子学中的电荷-载流子传输路径的新型混合体系结构的关键问题。然而，目前很少有人知道关于堆叠的非共价相互作用稳定的分子纳米结构的复杂功能。本文在单分子水平上研究了单晶Ag（111）载体上通过货车德瓦耳斯相互作用稳定的模型给体-受体二联体的几何结构和电子性质。我们结合扫描隧道显微镜/光谱学（STM/STS）和第一性原理计算模拟研究揭示了C（60）分子在Ce（TPP）（2）卟啉双层阵列上的位置选择性定位，富勒烯以顶部碗状四吡咯大环的π系统为中心。在货车德瓦尔斯复合物中，C（60）笼的三个特定取向被确定为可以通过STM操作协议可逆地切换。每种构型都呈现出不同的导电性，这解释了三稳态分子开关和对内耦合的可调谐性。此外，STS数据证明悬停的C（60）单元与金属衬底的电子去耦，这是物理应用的先决条件。
The control of organic molecules, supramolecular complexes and donor-acceptor systems at interfaces is a key issue in the development of novel hybrid architectures for regulation of charge-carrier transport pathways in nanoelectronics or organic photovoltaics. However, at present little is known regarding the intricate features of stacked molecular nanostructures stabilized by noncovalent interactions. Here we explore at the single molecule level the geometry and electronic properties of model donor-acceptor dyads stabilized by van der Waals interactions on a single crystal Ag(111) support. Our combined scanning tunneling microscopy/spectroscopy (STM/STS) and first-principles computational modeling study reveals site-selective positioning of C(60) molecules on Ce(TPP)(2) porphyrin double-decker arrays with the fullerene centered on the π-system of the top bowl-shaped tetrapyrrole macrocycle. Three specific orientations of the C(60) cage in the van der Waals complex are identified that can be reversibly switched by STM manipulation protocols. Each configuration presents a distinct conductivity, which accounts for a tristable molecular switch and the tunability of the intradyad coupling. In addition, STS data evidence electronic decoupling of the hovering C(60) units from the metal substrate, a prerequisite for photophysical applications.