title: Halogen bonding. The role of the polarizability of the electron-pair donor.
abstract: The nature of F-BrX-R interactions (with X = F, Cl, Br, I and R = -H, -F) has been investigated through theoretical calculation of molecular potential electrostatic (MEP), molecular polarizability, atoms in molecules (AIM) analysis and energetic decomposition analysis (EDA). A detailed analysis of the MEPs reveals that considering only the static electrostatic interactions is not sufficient to explain the nature of these interactions. The molecular polarizabilities of X-R molecules suggest that the deformation capacity of the electronic cloud of the lone pairs of the X atom plays an important role in the stability of these complexes. The topological analysis of the L(r) = -¼∇(2)ρ(r) function and the detailed analysis of the atomic quadrupole moments reveal that the BrX interactions are electrostatic in nature. The electron acceptor Br atom causes a polarization of the electronic cloud (electronic induction) on the valence shell of the X atom. Finally, the electrostatic forces and charge transfer play an important role not only in the stabilization of the complex, but also in the determination of the molecular geometry of equilibrium. The dispersive and polarization forces do not influence the equilibrium molecular geometry.
authors.affiliation: Laboratorio de Estructura Molecular y Propiedades, Área de Química Física, Departamento de Química, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avda. Libertad 5460, (3400) Corrientes, Argentina. djr_duarte@hotmail.com.
authors.forename: Darío J R
authors.initials: DJ
authors.lastname: Duarte
authors.affiliation: Laboratorio de Química Teórica y Experimental, Departamento de Química. Facultad Regional Resistencia, Universidad Tecnológica Nacional, French 414, (3500) Resistencia, Chaco, Argentina.
authors.forename: Gladis L
authors.initials: GL
authors.lastname: Sosa
authors.affiliation: Laboratorio de Estructura Molecular y Propiedades, Área de Química Física, Departamento de Química, Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Avda. Libertad 5460, (3400) Corrientes, Argentina. djr_duarte@hotmail.com.
authors.forename: Nélida M
authors.initials: NM
authors.lastname: Peruchena
authors.affiliation: Instituto de Química Médica, CSIC, Juan de la Cierva, 3, E-28006 Madrid, Spain.
authors.forename: Ibon
authors.initials: I
authors.lastname: Alkorta