Faculty of Pure and Applied Sciences, University of Tsukuba , Tsukuba 305-8571, Japan.
ACS Nano. 2016 Dec 27;10(12):11211-11218. doi: 10.1021/acsnano.6b06278. Epub 2016 Dec 2.
Single-molecule junctions have been extensively studied because of their high potential for future nanoscale device applications as well as their importance in basic studies for molecular science and technology. However, since the bonding sites at an electrode and the molecular tilt angles, for example, cannot be determined experimentally, analyses have been performed assuming the structures of such interactive key factors, with uncertainties and inconsistencies remaining in the proposed mechanisms. We have developed a methodology that enables the probing of conformational dynamics in single-molecule junctions simultaneously with the direct characterization of molecular bonding sites and tilt angles. This technique has revealed the elemental processes in single-molecule junctions, which have not been clarified using conventional methods. The mechanisms of the molecular dynamics in 1,4-benzenedithiol and 4,4'-bipyridine single-molecule junctions, which, for example, produce binary conductance switching of different types, were clearly discriminated and comprehensively explained.
单分子结因其在未来纳米尺度器件应用方面的巨大潜力以及在分子科学和技术基础研究方面的重要性而受到广泛研究。然而，由于例如电极上的键合位点和分子倾斜角度等无法通过实验确定，因此在分析中假设了这些相互作用关键因素的结构，所提出的机制仍然存在不确定性和不一致性。我们已经开发出一种方法，能够在直接表征分子键合位点和倾斜角度的同时探测单分子结中的构象动力学。这项技术揭示了使用传统方法无法阐明的单分子结中的基本过程。例如，产生不同类型二进制电导开关的 1,4-苯二硫醇和 4,4'-联吡啶单分子结的分子动力学机制得到了明确区分和全面解释。
