Experimental electron-ion dissociative recombination rate constant and temperature dependence data for protonated methanol, ethanol, dimethyl ether and diethyl ether

Abstract

A flowing afterglow with an electrostatic Langmuir probe has been used to determine the electron-ion dissociative recombination (e-IDR) rate constants (αe) and temperature dependencies (300–500K) for a series of small alcohols and ethers. The species covered are protonated methanol (CH3OH2+), protonated ethanol (C2H5OH2+), protonated dimethyl ether ((CH3)2OH+) and protonated diethyl ether ((C2H5)2OH+). The e-IDR rate constants are αe=5.95×10−7 (T/300)−0.57 for protonated methanol, αe=6.20×10−7 (T/300)−0.87 protonated ethanol, αe=5.52×10 −7 (T/300)−0.75 protonated dimethyl ether, and αe=6.48×10 −7 (T/300)−1.05 protonated diethyl ether. The experimental data are discussed in terms of the relevance to the chemical modeling of the interstellar medium.