Ionic hydrogen bond and ion solvation. 6. Interaction energies of the acetate ion with organic molecules. Comparison of CH/sub 3/COO/sup -/ with Cl/sup -/, CN/sup -/, and SH/sup -/

Journal Article · Wed Jun 08 00:00:00 EDT 1988 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00220a021· OSTI ID:7003550

Meot-Ner Mautner, M

The interaction energies of CH/sub 3/COO/sup -/ with protic and aprotic molecules were measured by pulsed high-pressure mass spectrometry. The attachment energies of the first three water molecules are 15.8, 12.8, and 11.8 kcal/mol. The rapid approach to ..delta..H/sub condsn/(H/sub 2/O) shows that ionic interactions are accounted for mostly by the first two solvent molecules. CH/sub 3/COO/sup -/ hydrogen bonds strongly to NH acids such as pyrrole, amides, and aniline, with ..delta..H/sup 0//sub D/ = 25-31 kcal/mol. With the carbon acids CH/sub 3/CHO, CH/sub 3/COCH/sub 3/, and CH/sub 3/CN as ligands, the attachment energies are 14-16 kcal/mol and the interactions may involve multiple O/sup -/..HC bonds. Despite the fact that the ions CH/sub 3/COO/sup -/, Cl/sup -/, CN/sup -/, and SH/sup -/ differ in size, structure, electronegativity, isotropy, and available bonding sites, they bond with similar strengths to most OH, NH, and CH hydrogen donors, from H/sub 2/O to large organic molecules such as the dipeptide analogue CH/sub 3/CO-Ala-OCH/sub 3/. Also, the four ions show similar clustering energies with n H/sub 2/O and HCN molecules (n = 1-4).

• Research Organization: National Bureau of Standards, Gaithersburg, MD (USA)
• OSTI ID: 7003550
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 110:12
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETATES
SOLVATION
ORGANIC COMPOUNDS
SOLVENT PROPERTIES
CHEMICAL BONDS
EXPERIMENTAL DATA
HIGH PRESSURE
HYDROGEN
MASS SPECTROSCOPY
MOLECULES
ORGANIC SOLVENTS
PULSE TECHNIQUES
CARBOXYLIC ACID SALTS
DATA
ELEMENTS
INFORMATION
NONMETALS
NUMERICAL DATA
SOLVENTS
SPECTROSCOPY
400201* - Chemical & Physicochemical Properties