Table 2: Properties of the isolated CH2FCHO and H2O molecules and the A and B complexes between CH2FCHO and one and two water molecules (distances in Å, σ *occupation in e, hyperconjugation energies in kcal mol−1, and frequencies in cm−1).

IsolatedCH2FCHOA(1-1)A(1-2)B(1-1)B(1-2)

𝑟 ( C 1 H 3 ) 1.10961.10771.10771.10651.1053
𝜈 ( C 1 H 3 ) 29142938293829582975
𝜎 ( C 1 H 3 ) 0.0680.0630.0620.0600.056
% 𝑠 C 1 ( H 3 ) 32.131.831.732.533.7
𝑞 ( C 1 ) 0.4080.4270.4400.4210.417
𝑞 ( H 3 ) 0.1170.1250.1240.1410.177

𝑟 ( C 4 H 5 ) 1.09401.09331.09621.09421.0945
𝜈 ( C 4 H 5 H 6 ) 3096,30453106,30583077,30243094,30443090,3041
𝜎 ( C 4 H 5 ) 0.01990.01960.02500.02000.0200
% 𝑠 C 4 ( H 5 ) 25.7425.9727.4625.7025.61
𝑞 ( C 4 ) −0.011−0.021−0.038−0.011−0.011
𝑞 ( H 5 ) 0.1900.2070.2460.1930.191

𝑟 ( C 1 = O 2 ) 1.2031.2081.2101.2081.213
𝜈 ( C 1 = O 2 ) 18161798179317971773

L P O 2 𝜎 ( C 1 H 3 ) 22.9421.4221.3320.8318.15
L P O 9 𝜎 ( C 1 H 3 ) 3.4
L P O 2 𝜎 ( H 8 O 9 ) 5.536.945.519.11
L P O 9 ( O 1 2 ) 𝜎 ( C 4 H 5 ) 0.104.56

Isolated H2OA(1-1)A(1-2)B(1-1)B(1-2)

𝑟 (OH)0.96200.96960.9724a0.96890.9753a
0.9756b0.9746b
𝜈 (H2O)3926,38203896,37253893,3676c3898,37203889,3594c
3892,3579d3892,3631d
Σ 𝑞 (H2O)−0.013+0.006e−0.0190.000e
−0.012f−0.014f

a O 9 H 8 bond. b O 1 2 H 1 1 bond. 𝑟 (OH) in the water dimer is 0.9700 Å. c 𝜈 ( H 8 O 9 H 1 0 ). d 𝜈 ( H 1 1 O 1 2 H 1 3 ). e Σ 𝑞 on ( H 8 O 9 H 1 0 )f Σ 𝑞 on ( H 1 1 O 1 2 H 1 3 ).