title: First principle investigation of the linker length effects on the thermodynamics of divalent pseudorotaxanes.
abstract: The Gibbs energies of association (Gibbs free (binding) energies) for divalent crown-8/ammonium pseudorotaxanes are determined by investigating the influence of different linkers onto the binding. Calculations are performed with density functional theory including dispersion corrections. The translational, rotational and vibrational contributions are taken into account and solvation effects including counter ions are investigated by applying the COSMO-RS method, which is based on a continuum solvation model. The calculated energies agree well with the experimentally determined ones. The shortest investigated linker shows an enhanced binding strength due to electronic effects, namely the dispersion interaction between the linkers from the guest and the host. For the longer linkers this ideal packing is not possible due to steric hindrance.
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Andreas J
authors.initials: AJ
authors.lastname: Achazi
authors.affiliation: Physikalisch-Chemisches Institut, Justus-Liebig-Universität Gießen, Heinrich-Buff-Ring 58, 35392 Gießen, Germany.
authors.forename: Doreen
authors.initials: D
authors.lastname: Mollenhauer
authors.affiliation: Institut für Chemie und Biochemie, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Paulus
keywords: COSMO-RS; Gibbs energy; density functional theory (DFT); dispersion correction; pseudorotaxanes; solvent effects