Gas phase catalyzed keto-enol isomerization of cations by proton transport
Van der Rest, G; Mourgues, P; Tortajada, J; Audier, HE
| HERO ID | 1182264 |
|---|---|
| In Press | No |
| Year | 1998 |
| Title | Gas phase catalyzed keto-enol isomerization of cations by proton transport |
| Authors | Van der Rest, G; Mourgues, P; Tortajada, J; Audier, HE |
| Journal | International Journal of Mass Spectrometry |
| Volume | 180 |
| Page Numbers | 293-300 |
| Abstract | In the gas phase, the unimolecular isomerization of the H3COC(O)CH2CO+ cation 1 (m/z 101) into the H3CO(HO)CCHCO+ enol ion 2 by a 1,3-H shift possesses a high energy barrier and is therefore not observed. In contrast, in the cell of a FT-ICR mass spectrometer, interaction with gaseous methanol catalyzes the isomerization of 1 into its more stable isomer 2, which can be characterized by low energy collision with argon. This exothermic reaction is irreversible. Reaction with labeled methanol and ligand exchange experiments indicate the existence of two distinct reactions. By formation of a covalent bond, one reaction yields protonated dimethyl malonate while the second one leads to ion 2 by a 1,3-H transfer catalyzed by methanol. Conversely, loss of methanol from collisionally activated long-lived mit 133 cations formed by protonation of dimethyl malonate yields some mit 101 ions with structure 2, which shows that methanol catalyzes the isomerization of ion 1 within a [1, CH3OH] complex. The efficiency of different catalysts is studied in order to probe the mechanism of the isomerization processes. (C) 1998 Elsevier Science B.V. |
| Doi | 10.1016/S1387-3806(98)14102-7 |
| Wosid | WOS:000077101400031 |
| Is Certified Translation | No |
| Dupe Override | No |
| Comments | Source: Web of Science 000077101400031 |
| Is Public | Yes |
| Keyword | keto-enol isomerization; catalysis-proton transport; FT-ICR mass spectrometry; ion-neutral complexes |
| Is Qa | No |