Hydrogen bonding of single acetic acid with water molecules in dilute aqueous solutions

Abstract

In separation processes, hydrogen bonding has a very significant effect on the efficiency of isolation of acetic acid (HOAc) from HOAc/H 2 O mixtures. This intermolecular interaction on aggregates composed of a single HOAc molecule and varying numbers of H 2 O molecules has been examined by using ab initio molecular dynamics simulations (AIMD) and quantum chemical calculations (QCC). Thermodynamic data in aqueous solution were obtained through the self-consistent reaction field calculations and the polarizable continuum model. The aggregation free energy of the aggregates in gas phase as well as in aqueous system shows that the 6-membered ring is the most favorable structure in both states. The relative stability of the ring structures inferred from the thermodynamic properties of the QCC is consistent with the ring distributions of the AIMD simulation. The study shows that in dilute aqueous solution of HOAc the more favorable molecular interaction is the hydrogen bonding between HOAc and H 2 O molecules, resulting in the separation of acetic acid from the HOAc/H 2 O mixtures with more difficulty than usual. acetic acid, hydrogen bond, ab initio, molecular dynamics, free energy

Impacts of Organic Ligands on Forsterite Reactivity in Supercritical CO2 Fluids

“…It is important that the scCO 2 in this study is water-saturated, as the addition of a water cosolvent to scCO 2 fluids enhances their solvation properties . The organic acids are hydro- and CO 2 -philic, and experience binding interactions with both components of the wet scCO 2 fluid. ,− In fact, once the organics are scavenged by the scCO 2 , they too act as cosolvents, increasing the solubilities of organics in the fluid. ,,, Due to the notoriously poor ability of CO 2 to solvate inorganic metal complexes ,, and the lack of in situ verification of the measurements, the lack of evidence for Ca or Mn in the reacted samples from EXP 2 and EXP 3 is not surprising. Furthermore, we are not aware of any studies that have measured the solubility of metal–acetate complexes in CO 2 .…”

Separation of chemical groups from bio-oil water-extract via sequential organic solvent extraction

“…Therefore, chloroform would be the preferred choice for the extraction of alcohols and furans from the biooil aqueous phase. Levoglucosan and organic acids such as acetic acid can form hydrogenbonding with water in the bio-oil aqueous phase [6,43]. Although chloroform has a high polarity, it barely breaks the hydrogen bond in extraction.…”

Hydrogen Bonding in Hydrates with one Acetic Acid Molecule

“…[23][24][25] Gao et al 26 investigated the H-bonding in the mono-and dihydrates of a single HAc molecule from a density functional theory with three large basis sets. Pu et al [27][28][29] reported more hydrates combined quantum chemical calculations (QCC) and ab initio molecular dynamics simulations (AIMD). These works suggested that the structure of the favorable hydrates involves head-on rings (see Section 2 for the definition).…”

“…Recently, the presence of the monohydrates and dihydrates of acetic acid, trifluoroacetic acid, and propionic acid was determined by the high-resolution microwave spectroscopic. − Gao et al investigated the H-bonding in the mono- and dihydrates of a single HAc molecule from a density functional theory with three large basis sets. Pu et al − reported more hydrates combined quantum chemical calculations (QCC) and ab initio molecular dynamics simulations (AIMD). These works suggested that the structure of the favorable hydrates involves head-on rings (see Section 2 for the definition).…”