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. Author manuscript; available in PMC: 2008 Sep 3.
Published in final edited form as: J Phys Chem B. 2007 Jan 18;111(2):408–422. doi: 10.1021/jp065403l

TABLE 5.

Absolute (Neutral Species) and Conventional (Ionic Species) Solvation Free Energies of Brønsted-Lowry Acids and Bases (kcal/mol)

pKaa
 ΔGS* (neutral)b
 ΔGS*,con (ion)c
ion neutral ΔGgod CH3OH CH3CN DMSO CH3OH CH3CN DMSO CH3OH CH3CN DMSO
NO2− nitrous acid 333.7 7.5 −4.2 −329.6
NO3− nitric acid 317.8 8.9 −5.7 −313.3
CH3CO2− acetic acid 341.4 9.7 22.3 12.3 −7.2 −6.5 −7.4 −337.3 −319.5 −333.9
CH3CH2CO2− propionic acid 340.4 9.7 −7.1 −336.2
NCCH2CO2− cyanoacetic acid 323.7 18.0 −8.5 −309.6
CF3CO2− trifluoroacetic acid 316.7 12.7 −7.4 −308.7
C6H5CO2− benzoic acid 333.0 9.4 20.7 11.0 −9.7 −9.4 −10.3 −331.8 −316.1 −330.2
p-FC6H4CO2− 4-fluorobenzoic acid 330.0 9.2 −8.6 −328.0
C6H5O− phenol 342.9 14.4 27.0 18.0 −8.2 −7.5 −8.1 −333.5 −315.6 −328.4
p-NO2C6H4O− 4-nitrophenol 320.9 11.3 −11.0 −318.5
CH3O− methanol 375.0 29.0 −4.8 −342.2
C2H5O− ethanol 371.3 29.8 −5.3f −337.9
NH4+ ammonia 195.7 10.8 16.5 10.5 −5.0 −4.5 −4.3 177.9 170.7 179.0
CH3NH3+ methylamine 206.6 11.0 18.4 11.0 −4.6 −3.7 −3.6 188.9 179.8 189.9
(CH3)3NH+ trimethylamine 219.4 9.8 −5.0 203.0
C5H10NH2+ piperidine 220.0 11.1 −6.5 200.3
pyridineH+ pyridine 214.7 5.4 12.3 3.5 −6.4 −6.1 −5.6 202.9 193.8 206.3
C6H5NH3+ aniline 203.3 6.1 10.7 3.6 −7.4 −7.3 −7.1 189.5 183.4 193.2
a

Average value from Table 4.

b

Calculated (SM5.43R/mPW1PW/6−31+G(d,p)//mPW1PW/MIDI!) value, unless indicated otherwise.

c

Based on the convention that ΔGS*,con (H+) = 0.

d

For anions, gas-phase acidity of the neutral species. For cations, gas-phase acidity of the ionic species. Experimental data are from reference 169.

eThis conventional solvation free energy was not used.

f

Reference 10.