Center for Biosensors and Bioelectronics, The Biodesign Institute, and School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, Arizona 85287, United States.
J Am Chem Soc. 2013 Mar 6;135(9):3319-22. doi: 10.1021/ja3106434. Epub 2013 Feb 25.
We report controlling the formation of single-molecule junctions by means of electrochemically reducing two axialdiazonium terminal groups on a molecule, thereby producing direct Au-C covalent bonds in situ between the molecule and gold electrodes. We report a yield enhancement in molecular junction formation as the electrochemical potential of both junction electrodes approach the reduction potential of the diazonium terminal groups. Step length analysis shows that the molecular junction is significantly more stable, and can be pulled over a longer distance than a comparable junction created with amine anchoring bonds. The stability of the junction is explained by the calculated lower binding energy associated with the direct Au-C bond compared with the Au-N bond.
我们报告了通过电化学还原分子上的两个轴向重氮末端基团来控制单分子结的形成，从而在分子和金电极之间原位生成直接的 Au-C 共价键。我们报告了在两个结电极的电化学势接近重氮末端基团的还原电势时，分子结形成的产率增强。步长分析表明，与使用胺锚固键形成的可比结相比，分子结的稳定性显著提高，并且可以被拉伸更长的距离。与 Au-N 键相比，计算得到的直接 Au-C 键的结合能较低，这解释了结的稳定性。
