Sexton Thomas More, Howard J Coleman, Tschumper Gregory S
Department of Chemistry and Biochemistry , University of Mississippi , University , Mississippi 38677-1848 , United States.
Department of Chemistry , Virginia Tech , Blacksburg , Virginia 24061 , United States.
J Phys Chem A. 2018 May 31;122(21):4902-4908. doi: 10.1021/acs.jpca.8b03397. Epub 2018 May 14.
Even though (HO) and (HF) are arguably the most thoroughly characterized prototypes for hydrogen bonding, their heterogeneous analogue HO···HF has received relatively little attention. Here we report that the experimental dissociation energy ( D) of this important paradigm for heterogeneous hydrogen bonding is too large by 2 kcal mol or 30% relative to our computed value of 6.3 kcal mol. For reference, computational procedures similar to those employed here to compute D (large basis set CCSD(T) computations with anharmonic corrections from second-order vibrational perturbation theory) provide results within 0.1 kcal mol of the experimental values for (HO) and (HF). Near the CCSD(T) complete basis set limit, the electronic dissociation energy for HO···HF is ∼4 kcal mol larger than those for (HO) and (HF) (∼9 kcal mol for the heterogeneous dimer vs ∼5 kcal mol for the homogeneous dimers). Results reported here from symmetry-adapted perturbation theory computations suggest that this large difference is primarily due to the induction contribution to the interaction energy.
尽管（HO）和（HF）可以说是氢键最具特征的原型，但它们的非均相类似物HO···HF却相对很少受到关注。在此我们报告，这种非均相氢键重要范例的实验解离能（D）相对于我们计算得到的6.3千卡/摩尔的值大了2千卡/摩尔或30%。作为参考，与这里用于计算D的程序类似（使用大基组CCSD（T）计算并结合二阶振动微扰理论的非谐校正），对于（HO）和（HF），计算结果与实验值的偏差在0.1千卡/摩尔以内。在CCSD（T）完全基组极限附近，HO···HF的电子解离能比（HO）和（HF）的电子解离能大约4千卡/摩尔（非均相二聚体约为9千卡/摩尔，而均相二聚体约为5千卡/摩尔）。这里从对称适配微扰理论计算报告的结果表明，这种巨大差异主要是由于诱导对相互作用能的贡献。
