Table 4: B3LYP/6-311++G(d,p) Total Binding Energies ( 𝐸 A B C ), 𝐸 A B , 𝐸 B C , and 𝐸 C A binding energies in the trimer geometry and cooperative energies (Δ 𝐸 c o o p ) for the CH3CHO, CH2FCHO, and CH3CFO complexes with two water molecules (with BSSE-corrections in kcal mol−1)a.

System 𝐸 A B C 𝐸 b A B 𝐸 A C 𝐸 B C Δ 𝐸 c o o p

CH3CHO·2H2O (A)−13.04−4.64 (183.8)−1.52−4.56−2.32
CH3CHO·2H2O (B)−13.48−4.73 (185.3)−1.66−4.50−2.59
CH2FCHO 2H2O(A)−13.00−3.60 (170.1)−2.31−4.59−2.50
CH2FCHO·2H2O (B)−12.49−3.71 (172.4)−1.72−4.54−2.52
CH3CFO·2H2O (A)−12.41−3.60 (171.4)−1.87−4.62−2.32

aA = carbonyl derivative, B and C = water. bThe numbers in parentheses are the Proton Affinities of the O atom of the C=O group (kcal mol−1) taken from [22].