The Role of Molecular Electrostatic Potentials in the Formation of a Halogen Bond in Furan⋅⋅⋅XY and Thiophene⋅⋅⋅XY Complexes

Abstract

The halogen bonding of furan⋅⋅⋅XY and thiophene⋅⋅⋅XY (X=Cl, Br; Y=F, Cl, Br), involving σ- and π-type interactions, was studied by using MP2 calculations and quantum theory of "atoms in molecules" (QTAIM) studies. The negative electrostatic potentials of furan and thiophene, as well as the most positive electrostatic potential (V(S,max) ) on the surface of the interacting X atom determined the geometries of the complexes. Linear relationships were found between interaction energy and V(S,max) of the X atom, indicating that electrostatic interactions play an important role in these halogen-bonding interactions. The halogen-bonding interactions in furan⋅⋅⋅XY and thiophene⋅⋅⋅XY are weak, "closed-shell" noncovalent interactions. The linear relationship of topological properties, energy properties, and the integration of interatomic surfaces versus V(S,max) of atom X demonstrate the importance of the positive σ hole, as reflected by the computed V(S,max) of atom X, in determining the topological properties of the halogen bonds.

N···I Halogen Bonding Interactions: Influence of Lewis Bases on Their Strength and Characters

“…The newly developed density functional M06-2X is a high-nonlocal functional with twice the amount of nonlocal exchange. − On the basis of the recent study of Bauzá et al, the M06-2X method could give good results for both anionic and neutral halogen-bonding complexes, and M06-2X/aug-cc-pVTZ provides a good estimation of the XB energies when compared with CCSD(T)/aug-cc-pVTZ ones. Combined with the M06-2X or MP2 method, the aug-cc-pVDZ (aug-cc-pVDZ-PP) basis set is adequate to study the XB. − In this work, the M06-2X method was used to study all the monomers and complexes. The aug-cc-pVDZ-PP basis set applied to optimize the iodine atom, which includes the small-core energy-consistent relativistic pseudopotentials to account for relativistic effects.…”

Is π halogen bonding or lone pair⋯π interaction formed between borazine and some halogenated compounds?

“…4 Dihalogen molecules can form p halogen bonds with some usual p systems, such as benzene, thiophene, furan, and pyridine, and the structures and properties of these complexes have been extensively studied using experimental and theoretical methods. [5][6][7] However, C-XÁ Á Áp halogen bonds have more important practical value in crystal engineering, 8 drug design, 9 and proteinligand complexation, 10 although only sporadic studies have been performed for them. 11 The induction interaction plays a dominant role in stabilizing benzene-X 2 (X = Cl, Br, I) complexes, 12 while the dispersion interaction is primarily responsible for the stability of benzene-halocarbon complexes.…”

Regular/abnormal variation in the strength and nature of the halogen bond between H2Te and the dihalogens: Prominent effect of methyl substituents

“…We thus computed the electrostatic potentials on the 0.001 electrons bohr −3 isosurface of the monomers. It is well known that a σ‐hole is found along the bond end of a dihalogen molecule XY and in Figure we show the MEP map of ClF, while the most positive value (V s,max ) for the σ‐hole of the halogen atom participating in the halogen bond for all dihalogen molecules are listed in Table . As expected, the V s,max value becomes larger for the heavier halogen atom X or when adjacent to a halogen Y with a greater electron‐withdrawing ability.…”