Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30059 Kraków (Poland).
Angew Chem Int Ed Engl. 2015 Jan 19;54(4):1336-40. doi: 10.1002/anie.201406053. Epub 2014 Dec 4.
While it is a common concept in chemistry that strengthening of one bond results in weakening of the adjacent ones, no results have been published on if and how this effect protrudes further into the molecular backbone. By binding molecules to a surface in the form of a self-assembled monolayer, the strength of a primary bond can be selectively altered. Herein, we report that by using secondary-ion mass spectrometry, we are able to detect for the first time positional oscillations in the stability of consecutive bonds along the adsorbed molecule, with the amplitudes diminishing with increasing distance from the molecule-metal interface. To explain these observations, we have performed molecular dynamics simulations and DFT calculations. These show that the oscillation effects in chemical-bond stability have a very general nature and break the translational symmetry in molecules.
虽然在化学中，一个普遍的概念是一个键的增强会导致相邻键的减弱，但关于这种效应是否以及如何进一步延伸到分子主链，尚未有结果发表。通过将分子以自组装单层的形式结合到表面上，可以有选择地改变一个主要键的强度。在这里，我们报告说，通过使用二次离子质谱，我们首次能够检测到吸附分子中连续键的稳定性的位置振荡，其幅度随着与分子-金属界面的距离增加而减小。为了解释这些观察结果，我们进行了分子动力学模拟和 DFT 计算。这些结果表明，化学键稳定性的振荡效应具有非常普遍的性质，并破坏了分子的平移对称性。
