Acidities and basicities of carboxylic acids. Correlations between core-ionization energies, proton affinities, and gas-phase acidities

Journal Article · Wed Aug 16 00:00:00 EDT 1978 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00485a033· OSTI ID:6549032

Smith, S R; Thomas, T D

Core-ionization energies for a number of carboxylic acids and esters have been measured with the view of establishing the relative importance of initial-state charge distribution and final-state charge rearrangement in determining core-ionization energies, proton affinities, and gas-phase acidities. Results are reported for RCOOH (R = H, CH/sub 3/, CF/sub 3/, CF/sub 2/H), for RCOOCH/sub 3/ (R = H, CH/sub 3/, CF/sub 3/), for RCOOC/sub 2/H/sub 5/ (R = H, CH/sub 3/, CF/sub 3/, CF/sub 2/H, CFH/sub 2/, CClH/sub 2/, CBrH/sub 2/), and for acetone and methyl carbonate. A linear correlation with slope -1.6 is found between core-ionization enegies and proton affinities for double-bonded oxygen. Compounds in which initial-state effects are important and those in which final-state effects are important fit the correlation line equally well. Although there is no simple correlation between anion proton affinity (the negative of acidity) and core-ionization energies, the data are consistent with an expected negative correlation when inductive effects are important and a positive correlation when relaxation is important. A quantitative analysis of these results is in good agreement with theoretical results obtained by Davis and Shirley. Correlations among the various core-ionization energies indicate that positive charge on a carboxyl group, whether produced by core ionization or by protonation, is extensively delocalized by valence-electron rearrangement.

• Research Organization: Oregon State Univ., Corvallis
• OSTI ID: 6549032
• Journal Information: J. Am. Chem. Soc.; (United States), Vol. 100:17
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETONE
CHARGE DISTRIBUTION
IONIZATION POTENTIAL
MOLECULAR STRUCTURE
CARBOXYLIC ACID ESTERS
CARBOXYLIC ACIDS
AFFINITY
BASES
ELECTRONS
FINAL-STATE INTERACTIONS
GASES
INDUCTION
LEAST SQUARE FIT
PH VALUE
PHOTOELECTRON SPECTROSCOPY
RELAXATION
VALENCE
ELECTRON SPECTROSCOPY
ELEMENTARY PARTICLES
ESTERS
FERMIONS
FLUIDS
INTERACTIONS
KETONES
LEPTONS
MAXIMUM-LIKELIHOOD FIT
NUMERICAL SOLUTION
ORGANIC ACIDS
ORGANIC COMPOUNDS
SPECTROSCOPY
400301* - Organic Chemistry- Chemical & Physicochemical Properties- (-1987)