Zierkiewicz Wiktor, Michalczyk Mariusz, Scheiner Steve
Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland.
Phys Chem Chem Phys. 2018 Feb 14;20(7):4676-4687. doi: 10.1039/c7cp08048d.
The interaction between KrOF or XeOF and the 1,2, 1,3, and 1,4 diazines is characterized chiefly by a Kr/XeN aerogen bond, as deduced from ab initio calculations. The most stable dimers take advantage of the σ-hole on the aerogen atom, wherein the two molecules lie in the same plane. The interaction is quite strong, as much as 18 kcal mol. A second class of dimer geometry utilizes the π-hole above the aerogen atom in an approximate perpendicular arrangement of the two monomers; these structures are not as strongly bound: 6-8 kcal mol. Both sorts of dimers contain auxiliary CHF H-bonds which contribute to their stability, but even with their removal, the aerogen bond energy remains as high as 14 kcal mol. The nature and strength of each specific interaction is confirmed and quantified by AIM, NCI, NBO, and electron density shift patterns. There is not a great deal of sensitivity to the identity of either the aerogen atom or the position of the two N atoms in the diazine.
从头算计算推断，KrOF或XeOF与1,2 - 二嗪、1,3 - 二嗪和1,4 - 二嗪之间的相互作用主要以Kr/Xe - N气原键为特征。最稳定的二聚体利用气原原子上的σ - 空穴，其中两个分子位于同一平面内。这种相互作用相当强，高达18千卡/摩尔。第二类二聚体几何结构在两个单体近似垂直排列的情况下利用气原原子上方的π - 空穴；这些结构的结合力没有那么强：6 - 8千卡/摩尔。这两类二聚体都含有辅助的CHF氢键，这有助于它们的稳定性，但即使去除这些氢键，气原键能仍高达14千卡/摩尔。通过AIM、NCI、NBO和电子密度转移模式证实并量化了每种特定相互作用的性质和强度。对于气原原子的身份或二嗪中两个N原子的位置，没有很大的敏感性。
