Scheele Tarek, Neudecker Tim
University of Bremen, Institute for Physical and Theoretical Chemistry, Leobener Straße 6, D-28359 Bremen, Germany.
Bremen Center for Computational Materials Science, University of Bremen, Am Fallturm 1, D-28359 Bremen, Germany.
Phys Chem Chem Phys. 2023 Oct 25;25(41):28070-28077. doi: 10.1039/d3cp03965j.
Oriented external electric fields (OEEFs) can facilitate chemical reactions by selectively weakening bonds. This makes them a topic of interest in mechanochemistry, where mechanical force is used to rupture specific bonds in molecules. Using electronic structure calculations based on density functional theory (DFT), we investigate the effect of OEEFs on the mechanical force required to activate mechanophores. We demonstrate that OEEFs can greatly lower the rupture force of mechanophores, and that the degree of this effect highly depends on the angle relative to the mechanical force at which the field is being applied. The greatest lowering of the rupture force does not always occur at the point of perfect alignment between OEEF and the vector of mechanical force. Using natural bond orbital analysis, we show that mechanical force amplifies the effect that an OEEF has on the scissile bond of a mechanophore. By combining methods to simulate molecules in OEEFs with methods applying mechanical force, we present an effective tool for analyzing mechanophores in OEEFs and show that computationally determining optimal OEEFs for mechanophore activation can assist in the development of future experimental studies.
定向外部电场（OEEFs）可以通过选择性地削弱化学键来促进化学反应。这使得它们成为机械化学领域的一个研究热点，在机械化学中，机械力被用于断裂分子中的特定化学键。利用基于密度泛函理论（DFT）的电子结构计算，我们研究了定向外部电场对激活机械响应基团所需机械力的影响。我们证明，定向外部电场可以大大降低机械响应基团的断裂力，而且这种效应的程度高度依赖于电场相对于所施加机械力的角度。断裂力的最大降低并不总是发生在定向外部电场与机械力矢量完全对齐的点上。通过自然键轨道分析，我们表明机械力会放大定向外部电场对机械响应基团可断裂键的影响。通过将在定向外部电场中模拟分子的方法与施加机械力的方法相结合，我们提出了一种分析定向外部电场中机械响应基团的有效工具，并表明通过计算确定激活机械响应基团的最佳定向外部电场有助于未来实验研究的开展。
