摘要
通过单分子电子器件,我们可以直观地研究单分子动力学过程,获得系综实验无法得到的信息~([1,2])。氢键是自然界广泛存在的基本作用力,在各种化学、物理、生化过程中起到了关键性作用。我们在单分子层次上研究了一种经典的四重氢键体系的动态变化过程。我们制备了石墨烯单分子异质结,将脲基嘧啶酮四重氢键二聚体通过共价键稳定连接在石墨烯点电极上,并监测其电导变化,观察到由于单个氢键变化导致的多态振荡信号。结合理论模拟和对电流信号的统计分析,我们推测这种四重氢键二聚体发生了氢迁移和烯醇-酮异构变化。
Single-molecule electronic devices offer unique opportunities to investigate the intuitive dynamic process of individual molecules that are not accessible in conventional ensemble experiments.Hydrogen-bond interaction is a fundamental interaction widely existing in nature,which plays a key role in chemical,physical,and biochemical processes.Here,we study the dynamic process of a classical quadrupolar hydrogen bonding system based on graphene-molecule single-molecule junctions.By covalently integrating the ureidopyrimidinone dimer with quadrupolar hydrogen bonds into graphene point contacts,we are able to transduce the hydrogen bond dynamic process into real-time electrical signals.The real-time recordings demonstrate muti-level fluctuations owing to single hydrogen bond transformations.By combining theoretical simulations and statistical analysis,a reasonable explanation for these observations is that proton transfer and keto-enol tautomerism happen.
引文
[1]Jia,C;Ma,B.;Xin,N.;Guo,X.Acc.Chem.Res..2015,48:2565
[2]Choi,Y.;Moody,I.;Sims,P.;Collins,P.Science 2012,335:319
