title: Simulated infrared spectra of triflic acid during proton dissociation.
abstract: Vibrational analysis of triflic acid (TfOH) at different water uptakes was conducted. This molecule mimics the sulfonate end of the Nafion side-chain. As the proton leaves the sulfonic acid group, structural changes within the Nafion side-chain take place. They are revealed by signal shifts in the infrared spectrum. Molecular modeling is used to follow structural modifications that occur during proton dissociation. To confirm the accuracy of the proposed structures, infrared spectra were computed via quantum chemical modeling based on density functional theory. The requirement to use additional diffuse functions in the basis set is discussed. Comparison between simulated infrared spectra of 1 and 2 acid molecules with different water contents and experimental data was performed. An accurate description of infrared spectra for systems containing 2 TfOH was obtained.
authors.affiliation: Department of Chemistry, Université de Sherbrooke, Sherbrooke, Québec, Canada J1K 2R1.
authors.forename: Patrick
authors.initials: P
authors.lastname: Laflamme
authors.forename: Alexandre
authors.initials: A
authors.lastname: Beaudoin
authors.forename: Thomas
authors.initials: T
authors.lastname: Chapaton
authors.forename: Claude
authors.initials: C
authors.lastname: Spino
authors.forename: Armand
authors.initials: A
authors.lastname: Soldera
mesh_terms: D005465:Fluorocarbon Polymers; D008698:Mesylates / Q000737:chemistry*; D056004:Molecular Dynamics Simulation; D011522:Protons; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry*
chemical_list: D005465:Fluorocarbon Polymers; D008698:Mesylates; D011522:Protons; D014867:Water; C040402:perfluorosulfonic acid; C012077:trifluoromethanesulfonic acid