Table 3.

Calculated gas- and solution-phase energetics of hydrate formation [RCHO + H₂O → RCH(OH)₂] and calculated experimental hydration equilibrium constants

Compound	Keq (exp)*	ΔErxn, gas phase, kcal/mol†	ΔErxn, PCM, kcal/mol‡	Keq (calc)§
C6H5COCH3	9.3  × 10−6	+2.3	+8.5	3.6  × 10−5
(CH3)2CO	1.4  × 10−3	−0.4	+4.4	7.2  × 10−3
C6H5CHO	8  × 10−3	+1.1	+5.2	2.6  × 10−3
(CH3)3CCHO	2.3  × 10−1	−2.0	+1.2	4.4  × 10−1
CH3CHO	1.06	−3.4	−0.3	3.08
CCl3CHO	3  × 103	−5.3	−1.3	1.1  × 102
H2CO	2.3  × 103	−7.5	−5.2	1.7  × 103
CF3CHO	2.9  × 104	−9.6	−9.2	3.0  × 105
HNO		+7.6	+8.0	6.9  × 10−5

exp, experimental; calc, calculated. 

^*Data taken from refs. 44–46. 

^† B3LYP/6-311+G* + ZPE. 

^‡ PCM-B3LYP/6-311+G*//B3LYP/6-311+G*+ZPE. 

^§ From linear regression of calculated ΔE_rxn in solution (column 4) versus experimental K_eq (column 2); log K_eq = −0.56 (ΔE_rxn,PCM) + 0.32.