The Nature of the Interaction of Organoselenium Molecules with Diiodine

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Molecules, spectroscopy, kinetics, environment, & general theory, 2011-09, Vol.115 (35), p.10069-10077
• Main Authors: Madzhidov, Timur I, Chmutova, Galina A, Martín Pendás, Ángel
• Format: Article
• Language: English
• Subjects: A: Molecular Structure, Quantum Chemistry, General Theory; Charge transfer; Complexation; Electron density; Electronic structure; Electrostatics; Exchange; Nitrogen atoms; Topology
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp2056078

The electronic structure of charge-transfer complexes of organoselenium compounds with diiodine has been studied at several levels of theory (Hartree–Fock, second order Møller−Plesset, and density functional theory). The complexation energies, optimized geometries, and the topology of the electron density and its Laplacian distribution, including domain averaged properties, have been analyzed. Special attention was paid to the influence of basis set superposition error on the energy of complexation. A tendency of organoselenium molecules to form more covalent intermolecular bonds with electron acceptors than with nitrogen atoms or other conventional electron donors has been revealed. The changes in atomic charges under complexation follow the main trends expected for the charge transfer. By means of the interacting quantum atoms (IQA) approach it has been found that the Se···I interaction is dominated by its quantum mechanical exchange-correlation contribution, the electrostatic interaction having a minor, repulsive role. IQA data have also been used to explain the value of the Se···I–I valence angle, as well as the topological charges on the iodine atoms in the complexes studied.