Ab Initio quantum mechanical charge field study of hydrated bicarbonate ion: Structural and dynamical properties

Abstract

The ab initio quantum mechanical charge field molecular dynamics (QMCF MD) formalism was applied to simulate the bicarbonate ion, HCO(3)(-), in aqueous solution. The difference in coordination numbers obtained by summation over atoms (6.6) and for the solvent-accessible surface (5.4) indicates the sharing of some water molecules between the individual atomic hydration shells. It also proved the importance to consider the hydration of the chemically different atoms individually for the evaluation of structural and dynamical properties of the ion. The orientation of water molecules in the hydration shell was visualized by the theta-tilt surface plot. The mean residence time in the surroundings of the HCO(3)(-) ion classify it generally as a structure-breaking ion, but the analysis of the individual ion-water hydrogen bonds revealed a more complex behavior of the different coordination sites.

Reversed interfacial fractionation of carbonate and bicarbonate evidenced by X-ray photoemission spectroscopy

“…[8][9][10][11][12][13][14][15][16][17][18][19] Recent theoretical studies, employing molecular dynamics and ab initio quantum calculations, have sought to characterize the thermodynamic and mechanistic details of their hydration and chemical reactions. [20][21][22][23][24][25][26][27] The nature of the ions and their effects on the water structure at the air/water interface critically influence the uptake of atmospheric gases such as carbon dioxide, which is subsequently hydrolyzed to bicarbonate and carbonate. The aqueous bicarbonate and carbonate ions present at the air/water interface have previously been examined by vibrational sum a) Author to whom correspondence should be addressed.…”

The hydration structure of dissolved carbon dioxide from X-ray absorption spectroscopy

“…The chemical reaction of CO 2 with water to form carbonic acid is clearly the central feature of these carbonate equilibria, and has been addressed by many experiments [5,16,[18][19][20][21][22][23][24][25][26] and calculations [17,[27][28][29][30][31][32][33][34][35][36] with conflicting results. Details of the neutral CO 2 solvation by bulk water prepare the reaction pathway, and are thus a determining factor in this chemistry.…”

Carbon dioxide in aqueous environment—A quantum mechanical charge field molecular dynamics study

“…Very recently, the importance of the role of water vapor has regained attention33 and has been shown to have been underestimated. Therefore, an ab initio quantum mechanical charge field molecular dynamics (QMCF‐MD) simulation34 was performed on CO 2 in water, as the QMCF methodology has proven successful applied in investigations of the hydration structure of composite oxo anions35–38. The main emphasis of this simulation study was focused on the physico–chemical properties of CO 2 molecules in an aquesous enviroment as present in aerosols or droplets in the atmosphere and to an analysis of interactions between solute and solvent, thus facilitating an interpretation of the properties of CO 2 , when it is associated with abundance of water molecules in the atmosphere.…”