Understanding Decomposition Mechanism of Acetone under Electric Pulsed Discharge: Generation of C₃O⁺ and C₃H₄O⁺ ions

Abstract

Gas‐phase investigations on acetone, under the influence of electric pulsed discharge has provided distinct insight related to its decomposition. Time‐of‐flight mass spectrometry has been utilized to identify different products generated upon dissociation/ionization of acetone, under the influence of electric discharge. In addition to molecular (C3H6O+) and protonated acetone (C3H7O+) ions, predominant ions signal corresponding to C3H4O+, C3O+ and CH3CO+ were observed in the mass spectrum. Under discharge condition, acetone undergoes soft dissociation/ionization producing C3H4O+ and C3O+ ions, which are distinctive from usual fragment ions reported upon decomposition of acetone, in the gas‐phase. Though metastable in nature, significant ion yield has been obtained for C3O+ ions. Computational studies have been carried out to understand the mechanism of acetone decomposition in gas‐phase. Based on experimental and computational findings, generation of these ions (C3O+ and C3H4O+) has been ascribed to step‐wise H2 elimination reaction originating from acetone molecule, followed by ionization of resultant fragments under the influence of electric pulsed discharge. Present studies are of relevance for plasma pyrolysis of volatile organic compounds and laboratory astrochemical investigations.