title: Gas-Phase Interaction of Anions with Polyisobutylenes: Collision-Induced Dissociation Study and Quantum Chemical Modeling.
abstract: The gas-phase interaction of anions including fluoride, chloride, bromide, iodide, ethyl sulfate, chlorate, and nitrate with polyisobutylene (PIB) derivatives was studied using collision-induced dissociation (CID). The gas-phase adducts of anions with PIBs ([PIB + anion](-)) were generated from the electrosprayed solution of PIBs in the presence of the corresponding anions. The so-formed adducts subjected to CID showed a loss of anion at different characteristic collision energies, thus allowing the study of the strength of interaction between the anions and nonpolar PIBs having different end-groups. The values of characteristic collision energies (the energy needed to obtain 50% fragmentation) obtained by CID experiments correlated linearly with the binding enthalpies between the anion and PIB, as determined by density functional theory calculations. In the case of halide ions, the critical energies for dissociation, that is, the binding enthalpies for [PIB + anion](-) adducts, increased in the order of I(-) < Br(-) < Cl(-) < F(-). Furthermore, it was found that the binding enthalpies for the adducts formed with halide ions decreased approximately with the square radius of the halide ion, suggesting that the strength of interaction is mainly determined by the "surface" charge density of the halide ion. In addition, the characteristic collision energy versus the number of isobutylene units revealed a linear dependence.
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Lajos
authors.initials: L
authors.lastname: Nagy
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Ákos
authors.initials: Á
authors.lastname: Kuki
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: György
authors.initials: G
authors.lastname: Deák
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Mihály
authors.initials: M
authors.lastname: Purgel
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Ádám
authors.initials: Á
authors.lastname: Vékony
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Miklós
authors.initials: M
authors.lastname: Zsuga
authors.affiliation: Department of Applied Chemistry and ‡Department of Physical Chemistry, MTA-DE Homogeneous Catalysis and Reaction Mechanisms Research Group, University of Debrecen , Egyetem tér 1, H-4032 Debrecen, Hungary.
authors.forename: Sándor
authors.initials: S
authors.lastname: Kéki