CH 2 CHOH 2 + + PN: A Proton-Transfer Triple Play
Date
2005
Authors
Petrie, Simon
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
Quantum chemical calculations are used to explore the proton-transfer reactivity of O-protonated vinyl alcohol, CH2CHOH2+, with phosphorus nitride, PN. This reaction is relevant to the chemical evolution of interstellar clouds, since O-protonated vinyl alcohol has been postulated (and tentatively identified) as a product of the association reaction between interstellar H3O+ and C2H 2, while PN is the most widespread and abundant phosphorus-containing molecule seen in astrophysical environments. Furthermore, the reaction exhibits an unusual mechanistic feature, namely, an extended "proton-transport catalysis" mechanism, which we characterize here as a "proton-transfer triple play". The reaction proceeds initially by proton transfer from CH2CHOH2+ to PN, then from PMT to CH 2CHOH, and finally from CH3CHOH+ to PN, where the emphasized atom indicates the resultant site of protonation/deprotonation. Thus, the ultimate overall bimolecular proton-transfer reaction is expected to occur as CH2CHOH2+ + PN → CH 3CHO + PNH+; that is, the apparent favored product channel exhibits not only proton transfer but also keto/enol tautomerization. The triple-play mechanism can be rationalized in terms of the proton affinities of vinyl alcohol, acetaldehyde, and phosphorus nitride, which here are satisfactorily reproduced by high-level ab initio calculations. Other neutrals with a proton affinity appropriate for the possible triple-play mechanism converting CH2CHOH2+ to CH3CHO are also identified, with a view to encouraging experimental investigation of this mechanism.
Description
Keywords
Keywords: Alcohols; Aldehydes; Astrophysics; Catalysis; Charge transfer; Phosphorus compounds; Quantum theory; Proton transfer; Protonation; Quantum chemical (QM) calculations; Vinyl alcohols; Protons
Citation
Collections
Source
Journal of Physical Chemistry A
Type
Journal article
Book Title
Entity type
Access Statement
License Rights
Restricted until
2037-12-31
Downloads
File
Description