Acetone Dimer Hydrogenation under Vacuum Ultraviolet: An Intracluster Trimolecular Dissociation Mechanism

Abstract

Hydrogenation of organic chemicals is one of the most frequent things that people take for granted in mass spectroscopy; however, it could provide important information on spontaneous or stimulated hydrogen transfer in initiating chemical reactions and in determining the product selectivity and conversion efficiency. Here, we present a study of hydrogenation of acetone via vacuum ultraviolet laser ionization mass spectrometry (VUV-LIMS) and density functional theory (DFT) calculations. It is interestingly found that acetone dimer readily captures a hydrogen to form (C3H6O)2H+ in the presence of alcohols, shedding light on the intracluster hydrogen atom transfer via a trimolecular mechanism. This is well consistent with the DFT calculation results of energetics and reaction kinetics. It is worth noting that, although the hydrogen bond interaction of O–H···O is stronger than that of C–H···O, the hydrogen atom transfer (HAT) tends to proceed from the methyl group of the alcohols to acetone. We fully demonstrate the intracluster HAT reactivity of such a simple system and provide new insights into hydrogen bond interactions and molecular cluster chemistry.

First Direct Evidence of Interpartner Hydride/Deuteride Exchanges for Stored Sodiated Arginine/Fructose-6-phosphate Complex Anions within Salt-Solvated Structures

“…[44][45][46][47][48] Such proton/deuteron exchanges (HDX) are also currently applied to study non-covalent system conformations in biomolecules, [49][50][51][52] and/or to highlight gas phase fragmentation patterns. [53][54][55] In the present work, HDX approach was applied to explore the HB and SSA forms of sodiated NCC anions formed between fructose-6-phosphate (F6P) and arginine (R). Fragmentation patterns of deuterium-labeled sodiated NCC anions after complete in-solution mobile proton exchanges were studied using the CID as well as and HCD modes (higher energy dissociation, a non-resonant excitation mode) 56 under variable excitation energy conditions and excitation times.…”

“…Otherwise, in-solution hydrogen/deuterium exchange (HDX) represents a useful tool to investigate structure and fragmentation patterns of complex ions. This method has been primarily introduced to deduce the mobile proton number in small-size molecules in solution or in the gas phase for the study of even-electron molecular species. − Such proton/deuteron exchanges (HDX) are also currently applied to study noncovalent system conformations in biomolecules − and/or to highlight gas-phase fragmentation patterns. − In the present work, the HDX approach was applied to explore the HB and SSA forms of sodiated NCC anions formed between fructose-6-phosphate (F6P) and arginine (R). Fragmentation patterns of deuterium-labeled sodiated NCC anions after complete in-solution mobile proton exchanges were studied using the CID as well as and HCD modes (higher energy dissociation, a non-resonant excitation mode) under variable excitation energy conditions and excitation times.…”