This item still needs to be validated !
ITEM METADATA RECORD
Title: How many water molecules are actively involved in the neutral hydration of carbon dioxide?
Authors: Nguyen, Minh Tho ×
Raspoet, G
Vanquickenborne, LG
VanDuijnen, PT #
Issue Date: 1997
Publisher: AMER CHEMICAL SOC
Series Title: Journal of Physical Chemistry A vol:101 issue:40 pages:7379-7388
Conference: date:UNIV GRONINGEN,DEPT ORGAN & MOL INORGAN CHEM,NL-9747 AG GRONINGEN,NETHERLANDS
Abstract: The detailed reaction pathways for the hydration of carbon dioxide by water and water clusters containing two, three, and four water molecules (CO2+nH(2)O-->H2CO3+(n-1)H2O, n=1-4) have been investigated in both gas phase and aqueous solution using ab initio molecular orbital (MO) theory up to the quadratic configuration interaction QCISD(T)/6-31G(d,p)//MP2/6-31G(d,p) level, both SCRF and PCM models of continuum theory, and a mixed approach based on MO calculations in conjunction with Monte Carlo and reaction field simulations. It is confirmed that the CO2 hydration constitutes a case of active solvent catalysis where solvent molecules actively participate as a catalyst in the chemical process. In aqueous solution the hydration mechanism is multimolecular, where geometric parameters of the solvent fully intervene in the reaction coordinate. The hydration reaction was found to proceed through an attack of a water oxygen to the CO2 carbon in concert with a proton transfer to a CO2 oxygen. The proton transfer is assisted by a chain of water molecules, which is necessary for a proton relay between different oxygens. Owing to a significantly larger charge separation in the transition structures, nonspecific electrostatic interactions between solute and solvent continuum also play a more important stabilizing role. Regarding the answer to the title question, our calculations suggest that although a water tetramer (n=4) seems to be necessary for CO2 hydration in the gaseous phase, a reaction channel involving formation of a bridge containing three water molecules (n=3) is likely to be actively involved in the neutral hydration of CO2 in aqueous solution.
ISSN: 1089-5639
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Quantum Chemistry and Physical Chemistry Section
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy

 




All items in Lirias are protected by copyright, with all rights reserved.

© Web of science