Influence of insertion of a noble gas atom on halogen bonding in H 2 O···XCCNgF and H 3 N···XCCNgF (X = Cl and Br; Ng = Ar, Kr, and Xe) complexes

The H 2 O···XCCNgF and H 3 N···XCCNgF (X = Cl and Br; Ng = Ar, Kr, and Xe) complexes have been studied with quantum chemical calculations at the MP2/aug-cc-pVTZ level. The results show that the inserted noble gas atom has an enhancing effect on the strength of halogen bond, and this enhancement is weakened with the increase of noble gas atomic number. The methyl and Li substituents in the electron donor strengthen the halogen bond. The interaction energy increases from −3.75 kcal/mol in H 3 N–BrCCF complex to −9.66 kcal/mol in H 2 LiN–BrCCArF complex. These complexes have been analyzed with atoms in molecules, natural bond orbital, molecular electrostatic potentials, and energy decomposition calculations.