Intermolecular interaction between the pendant chain of perfluorinated ionomer and methanol

Shingo Urata, Jun Irisawa, Akira Takada, Seiji Tsuzuki, Wataru Shinoda, Masuhiro Mikami

Research output: Contribution to journalArticlepeer-review

9 Citations (Scopus)


A comparison between water and methanol on the interaction with a pendant chain model for perfluorosulfonic ionomers (PFI), CF3OCF 2CF2SO3-, was made by using molecular orbital calculation. Intermolecular interaction energy (E int) of the most stable complex for CF3OCF 2CF2SO3- + CH3OH, where methanol associates with sulfonic acid group, is -10.38 kcal/mol at the MP2/aug-cc-pVDZ//B3LYP/6-31 + G* level, and it is almost the same with that of CF3OCF2CF2SO3- + H2O complex (-10.58 kcal/mol). Since an association of methanol to the sulfonic acid group is quite advantageous in energy, it is expected that, similarly to water, methanol would likely populate around the acidic site. On the contrary, according to a systematic Eint analysis for 500 random configurations, dissimilar distribution of Eint was observed for methanol compared with water. This is because methyl group substitution reduces oxygen surface area and causes more attractive dispersion energy with CF 3OCF2CF2SO3- by about 1.0 kcal/mol on average compared with water. To see how the difference in the interaction energy affects the solvation structure of methanol and water to the PFI, molecular dynamics simulations of a CF3OCF2CF 2SO3- molecule in methanol solutions have also been carried out at the methanol concentration of 10-90 mol%. Consequently, water probably associates with the sulfonic acid group-pushing methanol close to hydrophobic sites. It was also observed that methanol molecule tends to point its methyl group toward the solute at hydrophobic sites. These results demonstrated that methanol should locate in the vicinity of hydrophobic site compared with water due to methyl group substitution.

Original languageEnglish
Pages (from-to)1312-1320
Number of pages9
JournalJournal of Fluorine Chemistry
Issue number9-10
Publication statusPublished - Oct 2005
Externally publishedYes


  • Intermolecular interaction
  • Ionomer
  • Molecular dynamics simulation
  • Molecular orbital calculation

ASJC Scopus subject areas

  • Biochemistry
  • Environmental Chemistry
  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry


Dive into the research topics of 'Intermolecular interaction between the pendant chain of perfluorinated ionomer and methanol'. Together they form a unique fingerprint.

Cite this