气相键合配合物中的阴离子-阴离子相互作用。溶剂环境的影响。

Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.

Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322-0300, USA.

Molecules. 2021 Apr 7;26(8):2116. doi: 10.3390/molecules26082116.

Ab initio calculations are applied to the question as to whether a AeX anion (Ae = Kr, Xe) can engage in a stable complex with another anion: F, Cl, or CN. The latter approaches the central Ae atom from above the molecular plane, along its C axis. While the electrostatic repulsion between the two anions prevents their association in the gas phase, immersion of the system in a polar medium allows dimerization to proceed. The aerogen bond is a weak one, with binding energies less than 2 kcal/mol, even in highly polar aqueous solvent. The complexes are metastable in the less polar solvents THF and DMF, with dissociation opposed by a small energy barrier.

从头算方法被应用于研究 AeX 阴离子（Ae=Kr、Xe）是否能够与另一个阴离子（F、Cl 或 CN）形成稳定的配合物的问题。后者沿 Ae 原子的 C 轴从分子平面上方接近中心 Ae 原子。虽然两个阴离子之间的静电斥力阻止了它们在气相中的结合，但将系统浸入极性介质中可以允许二聚体的形成。气原子键是一种弱键，即使在高度极性的水溶剂中，其结合能也小于 2 kcal/mol。在极性较小的 THF 和 DMF 溶剂中，这些配合物是亚稳定的，解离受到小的能垒的阻碍。