Pulse Radiolysis Study of the Reactions of Hydrogen Atoms in the Ionic Liquid Methyltributylammonium Bis[(trifluoromethyl)sulfonyl)]imide

Published

November 1, 2003

Author(s)

J Grodkowski, James F. Wishart, Pedatsur Neta

Abstract

Reactions of hydrogen atoms with pyrene, phenanthrene, benzophenone, 2-propanol, and crotonic acid in the ionic liquid methyltributylammonium bis (trifluoromethylsulfonly)imide (R₄NNTf₂) were studied by pulse radiolysis. Radiolysis of the ionic liquid leads to formation of dry electrons and solvated electrons, which are scavenged by H₃O⁺ to produce H atoms. Hydrogen atoms react very rapidly with pyrene (3.8 x 10⁹ L mol^-1 s^-1) and phenanthrene (2.9 x 10⁹ L mol^-1 s^-1) to form H-adduct radicals with sharp absorption peaks at 405 and 395 nm, respectively. They also react with benzophenone to form ring adducts but the reaction is much slower. By competition kinetics with pyrene the rate constants for reaction of H atoms with 2-PrOH and with crotonic acid were extimated to 6 x 10⁷ L mol^-1 s^-1 and 4.6 x 10⁹ L mol^-, respectively. All the rate constants, except for benzophenone, are similar to the values measured or estimated for the same reactions in aqueous solutions. The reactions with aromatic hydrocarbons must diffusion-controlled but are faster that riffusion-controlled reactions for solvated electrons in the same ionic liquid.

Citation

Journal of Physical Chemistry A

Volume

107

Issue

No. 46

Pub Type

Journals

Keywords

aromatic hydrocarbons, ionic liquids, kinetics hydrogen atoms, pulse radiolysis

Citation

Grodkowski, J. , Wishart, J. and Neta, P. (2003), Pulse Radiolysis Study of the Reactions of Hydrogen Atoms in the Ionic Liquid Methyltributylammonium Bis[(trifluoromethyl)sulfonyl)]imide, Journal of Physical Chemistry A (Accessed April 24, 2024)