Theoretical investigation of molecular interactions between sulfur ylide and hypohalous acids (HOX, XF, Cl, Br, and I)

In the present study, the complexes of sulfur ylide (SY) with hypohalous acids (HOX; XF, Cl, Br, and I) were theoretically studied using the MP2/aug-cc-pVTZ computational level. Four types of structures were obtained for these complexes including two kinds of hydrogen bonds (HBs) (SY: HOXI and SY: HOXII) and two kinds of halogen bonds (SY: XOHI and SY: XOHII). According to the energetic results, the SY:XOHI complexes are stronger for XBr and I, while the SY:HOXI complexes are favorable for XCl and Br; also, the SY:HOXII complexes are stronger than SY:XOHII except for SY:IOHII, which is stronger than its counterpart (SY:HOIII). Moreover, on comparing SY:HOXI and II HBs complexes, the former is more stable than the latter, while between the SY:XOHI and II halogen bond complexes (XCl, Br, and I), the SY:XOHI ones are more stable. The strength, properties, and nature of interactions were also analyzed using the natural bond orbital and atoms in molecules theories. [GRAPHICS] .