State Key Laboratory of Physical Chemistry of Solid States, College of Chemistry and Chemical Engineering, Collaborative Innovation Center of Chemistry for Energy Materials, Xiamen University, 361005 Xiamen, China.
Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.
Nat Commun. 2017 May 22;8:15436. doi: 10.1038/ncomms15436.
Charge transport by tunnelling is one of the most ubiquitous elementary processes in nature. Small structural changes in a molecular junction can lead to significant difference in the single-molecule electronic properties, offering a tremendous opportunity to examine a reaction on the single-molecule scale by monitoring the conductance changes. Here, we explore the potential of the single-molecule break junction technique in the detection of photo-thermal reaction processes of a photochromic dihydroazulene/vinylheptafulvene system. Statistical analysis of the break junction experiments provides a quantitative approach for probing the reaction kinetics and reversibility, including the occurrence of isomerization during the reaction. The product ratios observed when switching the system in the junction does not follow those observed in solution studies (both experiment and theory), suggesting that the junction environment was perturbing the process significantly. This study opens the possibility of using nano-structured environments like molecular junctions to tailor product ratios in chemical reactions.
隧穿输运是自然界中最普遍的基本过程之一。分子结的微小结构变化会导致单分子电子性质的显著差异，为通过监测电导变化在单分子尺度上检测反应提供了巨大的机会。在这里，我们探索了单分子断路结技术在检测光致变色二氢薁/乙烯庚富烯体系光热反应过程中的潜力。对断路结实验的统计分析为探测反应动力学和可逆性提供了一种定量方法，包括反应过程中异构化的发生。在结中切换系统时观察到的产物比与溶液研究（实验和理论）中观察到的产物比不一致，这表明结环境显著干扰了该过程。这项研究为使用纳米结构环境（如分子结）来调整化学反应中的产物比开辟了可能性。
