Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions
Specific Chemical Reactivities of Spatially Separated 3-Aminophenol Conformers with Cold Ca+ Ions
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DOI：
10.1126/science.1242271
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发表时间：
2013-10-04
期刊：
影响因子：
56.9
通讯作者：
Willitsch, Stefan
中科院分区：
文献类型：
--
作者：
Chang, Yuan-Pin;Dlugolecki, Karol;Willitsch, Stefan
许多分子表现出多个旋转异构体（构象异构体），它们在热作用下相互转化，难以分离。因此，精确表征它们在化学反应中的作用已被证明具有挑战性。我们已经探讨了特定的构象的反应性，通过使用一种实验技术的基础上，他们的空间分离的分子束静电偏转。分离的构象异构体与库仑结晶离子的目标在阱中反应。在反应中的Ca+与3-氨基苯酚，我们发现一个两倍大的速率常数的顺式相比，反式构象（区分的O-H键的方向）。这一结果是由符合特定的长程离子-分子相互作用势的差异解释。我们的方法证明了通过选择构象状态来控制反应性的可能性。
Many molecules exhibit multiple rotational isomers (conformers) that interconvert thermally and are difficult to isolate. Consequently, a precise characterization of their role in chemical reactions has proven challenging. We have probed the reactivity of specific conformers by using an experimental technique based on their spatial separation in a molecular beam by electrostatic deflection. The separated conformers react with a target of Coulomb-crystallized ions in a trap. In the reaction of Ca+ with 3-aminophenol, we find a twofold larger rate constant for the cis compared with the trans conformer (differentiated by the O-H bond orientation). This result is explained by conformer-specific differences in the long-range ion-molecule interaction potentials. Our approach demonstrates the possibility of controlling reactivity through selection of conformational states.