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A theoretical study of the complexes formed between dimethyl sulfoxide (DMSO) and hypohalous acid (HOX, X = Cl, Br, and I) has been carried out at the MP2/aug-cc-pVTZ level. For each HOX, four minima binary complexes were found, two mainly with an OH•••O hydrogen bond and the other two with an OX•••O halogen bond. The hydrogen-bonded complexes are more stable than the halogen-bonded analogues for HOCl and HOBr, while both types of complexes have similar stability in the iodine case. A red shift was found for the associated H–O and X–O bond stretch vibrations and a small blue shift for the distant bonds. As the oxygen of DMSO simultaneously binds with two HOCl molecules, the corresponding interactions are weakened with diminutive effect. This diminutive effect is the largest in the complexes with two OH•••O hydrogen bonds but the smallest in those with two OCl•••O halogen bonds. [ABSTRACT FROM AUTHOR]

A series of halogen-bonded complexes with diborane(4) 1 and its derivatives (Li 2, methyl 3, CN 4) as the halogen acceptors as well as with XCN, XCCH, XCF3, XF (X = Cl, Br, I) as the halogen donors have been investigated by means of quantum chemical calculations at the MP2/aug-cc-pVTZ level. The result shows that the BB bond is a good electron donor in halogen bonding, particularly for the halogen donor XF. Interestingly, for the halogen donor XF, the halogen bond becomes stronger in order of IF < BrF < ClF. It is found that the addition of electron-donating substituents greatly strengthens the halogen bonding interaction to the point where it exceeds that of the majority of H-bonds. When the N atom in 2-BrCN is combined with another interaction, its strength has a further increase due to the cooperative effect. This study combines the boron compounds with halogen bonds and would be significant for expanding their applied fields. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Highlights: [•] Superatoms Li3M (M=Cl, Br, and I) participate in halogen bonding. [•] The heavier halogen in Li3M forms a stronger halogen bond than the lighter one. [•] The electrostatic interaction is of minor importance in the formation of halogen bond. [Copyright &y& Elsevier]

The NH2Br-HOX (X = F, Cl, and Br) complexes have been investigated with quantum chemical calculations at the MP2/aug-cc-pVTZ level. Five isomers are observed for the Cl and Br complexes, whereas only two isomers are found for the F complex. The geometrical, energetic, and spectroscopic parameters have been analyzed for these complexes. The hydrogen-bonded complexes are more stable than the halogen-bonded ones. In most complexes, the associated OH and OX bonds are elongated and show a red shift, whereas the distant bonds are contracted and exhibit a blue shift. The complexes have been analyzed with natural bond orbital and atoms in molecules. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Quantum chemical calculations have been performed to study the halogen bond in HRgF–XCCF (Rg=He, Ar, Kr; X=Cl, Br) complex at the MP2/aug-cc-pVTZ level. The Rg insertion has a great effect on the strength and properties of the halogen bond. The Br bonding is stronger than the Cl bonding. The associated C–X bond is elongated and the respective stretch exhibits a red shift, while the distant H–Rg bond is contracted and the respective stretch displays a blue shift. The strength and properties of halogen bond show an unmonotonic dependence of the rare gas atomic number. The theories of natural bond orbital and atoms in molecules have been used to unveil the nature of halogen bond and the origin of the frequency shift. [ABSTRACT FROM AUTHOR]

Abstract: A computational study of the complexes formed between HNC and HOBr has been undertaken at the MP2/aug-cc-pVTZ theoretical level. Eight dyads and fourteen triads formed through hydrogen bonding and halogen bonding were studied. It was found that the halogen bond is weaker than the hydrogen bond in HNC–HOBr dyad. The C atom in HNC is found to be a better electron donor than the O atom in HOBr. The cooperative effect is present between the hydrogen bond and halogen bond in the triads. The most stable triad corresponds to the complex combined with OH⋯C and NH⋯C hydrogen bonds. However, the largest cooperative effect occurs in the complex combined with NH⋯O and OBr⋯C interactions, in which the cooperative energy is about 23% of the total interaction energy. The cooperative effect is negative when HOBr acts as the proton and halogen donors simultaneously. [ABSTRACT FROM AUTHOR]

The complexes between BH(CO) 2 /BH(N 2 ) 2 and XF 3 /XF 5 are stabilized by a halogen bond and a triel bond. The MEP analyses of BH(CO) 2 /BH(N 2 ) 2 indicate that there are both a region with negative MEPs on the B atom in the vertical direction of the molecular plane and a σ-hole at the B-H bond end. Therefore, the boron atom in BH(CO) 2 /BH(N 2 ) 2 plays a dual role of a Lewis base and an acid in the halogen bond and triel bond, respectively. The halogen and triel bonds are stronger in order of IF 3 < BrF 3 < ClF 3 , IF 5 < BrF 5 < ClF 5 , and BH(CO) 2 < BH(N 2 ) 2 in most complexes. These complexes have large stability since the interaction energy varies from −5 to −115 kcal/mol. The halogen bond belongs to a covalent interaction or a partially covalent interaction in most complexes. The subsystems in these complexes have prominent deformation, accompanied with big charge transfer and large polarization. [ABSTRACT FROM AUTHOR]

Abstract: Quantum chemical calculations have been performed on the complexes formed between HArF and dihalogen molecules (XY=ClCl, ClF, BrCl, and BrF) at the MP2/6-311++G(2d,2p) level. For each complex, two minima were found, which correspond to one hydrogen-bonded complex and one halogen-bonded complex. The halogen-bonded complex with the F atom of HArF is more stable than the hydrogen-bonded complex with the H atom of HArF. A large blue shift of the H–Ar stretching frequency was observed in the hydrogen-bonded complex. However, in the halogen-bonded complex, in which the H–Ar bond is not involved in the interaction, a much large blue shift was observed for the same bond. The natural bond orbital and atoms in molecules analyses have been performed for these complexes. The energy decomposition analysis indicated that the electrostatic interaction plays a main contribution in formation of both complexes although the contribution from the charge-transfer interaction is also important. [ABSTRACT FROM AUTHOR]