Description of Weak Halogen Bonding Using Various Levels of Symmetry-Adapted Perturbation Theory Combined with Effective Core Potentials

作者：Matczak Piotrn^*

来源：Journal of Chemistry, 2017, 2017: 9031494.

DOI：10.1155/2017/9031494

The present work starts with providing a description of the halogen bonding (XB) interaction between the halogen atom of MH3 X (where M = C-Pb and X = I, At) and the N atom of HCN. This interaction leads to the formation of stable yet very weakly bound MII3 X . . . NCH complexes for which the interaction energy (E-int) between MH3X and IICN is calculated using various symmetry-adapted perturbation theory (SAPT) methods combined with the def2-QZVPP basis set and midbond functions. This basis set assigns effective core potentials (ECPs) not only to the I or At atom directly participating in the XB interaction with HCN but also to the M atom when substituted with Sn or Pb. Twelve SAPT methods (or levels) are taken into consideration. According to the SAPT analysis of E-int, the XB interaction in the complexes shows mixed electrostatic-dispersion nature. Next, the accuracy of SAPT E-int is evaluated by comparing with CCSD(T) reference data. This comparison reveals that high-order SAPT2+(3) method and the much less computationally demanding SAPT(DFT) method perform very well in describing E-int of the complexes. However, the accuracy of these methods decreases dramatically if they are combined with the so-called Hartree-Fock correction.

• 出版日期2017