| مستخلص: |
The interaction between rare gas atoms and trifluoromethylhalidesand iodomethane is investigated using ab initioanddensity functional theory (DFT) methods: MP2, CCSD, B3LYP, M06, M06-L,M06-2X, M06-HF, X3LYP, PBE, B97-D, B3LYP-D3, and M06-L-D3, in combinationwith the aug-cc-pVTZ and aug-cc-pVTZ-PP basis sets. A weakly attractiveinteraction is observed for all complexes, whose strength increasesas the rare gas and halogen bond donor become more polarizable, andas the group bound to the halogen bond donor becomes more electron-withdrawing.The separation between iodine and krypton in the complex CF3I···Kr, calculated at the MP2 and B3LYP-D3 levelsof theory, agrees very well with recent experimental results (Stephens,S. L.; Walker, N. R.; Legon, A. C. J. Chem. Phys.2011, 135, 224309). Analysis of theability of theoretical methods to account for the dispersion interactionpresent in these complexes leads to the conclusion that MP2 and B3LYP-D3,which produce very similar results, are the better performing methods,followed by B97-D and the M06 suite of functionals; the popular B3LYPas well as X3LYP perform poorly and significantly underestimate theinteraction strength. The orbitals responsible for the interactionare identified through Edmiston–Ruedenberg localization; itis shown that, by combining the key orbitals, it is possible to observea molecular orbital picture of a σ-hole interaction. [ABSTRACT FROM AUTHOR] |
