Theoretical Investigation of the Cooperativity in CH₃CHO·2H₂O, CH₂FCHO·2H₂O, and CH₃CFO·2H₂O Systems

Table 1

Properties of the isolated CH₃CHO and H₂O molecules, A and B complexed with 1 and 2 water molecules (distances in Å, σ ^*occupation in e, hyperconjugation energies in kcal mol⁻¹, and frequencies in cm⁻¹).

	Isolated CH3CHO	A(1-1)	A(1-2)	B(1-1)	B(1-2)
𝑟(C1H3)	1.1122	1.1094	1.1094	1.1082	1.1054
𝜈(C1H3)	2871	2905	2906	2923	2964
𝜎^∗(C1H3)	0.071	0.064	0.063	0.062	0.057
%𝑠C1(H3)	30.0	30.0	29.7	30.0	31.7
𝑞(C1)	0.442	0.463	0.474	0.457	0.451
𝑞(H3)	0.092	0.103	0.103	0.116	0.153
𝑟(C4H5)	1.0898	1.0897	1.0910	1.0896	1.0898
𝜈(C4H5)	3136	3142	3125	3139	3136
𝜎^∗(C4H5)	0.0066	0.0071	0.0122	0.0064	0.0065
%𝑠C4(H5)	25.4	26.2	27.05	25.46	25.48
𝑞(C4)	−0.679	−0.689	−0.699	−0.679	−0.680
𝑞(H5)	0.222	0.245	0.262	0.224	0.222
𝑟(C1=O2)	1.206	1.212	1.214	1.212	1.218
𝜈(C1=O2)	1808	1789	1783	1788	1764
LPO2→𝜎^∗(C1H3)	23.64	22.43	22.22	20.71	18.84
LPO12→𝜎^∗(C1H3)	—	—	—	—	2.70
LPO2→𝜎^∗(O9H8)	—	7.11	9.93	7.35	9.34
LPO9(O12)→𝜎^∗(C4H5)	—	0.46	2.95	—	—
	Isolated H2O	A(1-1)	A(1-2)	B(1-1)	B(1-2)
𝑟(OH)	0.9620	0.9711	0.9755^a	0.9711	0.9777^a
			0.9760^b		0.9764^b
𝜈(H2O)	3926,3820	3894,3681	3889,3629^c	3894,3680	3888,3579^c
			3890,3579^d		3890,3603^d
Σ𝑞(H2O)	—	−0.017	+0.009^e	−0.019	−0.004^e
			−0.017^f		−0.017^f

^aO₉H₈ bond. ^bO₁₂H₁₁ bond. 𝑟(OH⋯) in the water dimer is 0.9700 Å. ^cν(H₈O₉H₁₀) ^dν(H₁₁O₁₂H₁₃), ^eΣ𝑞 on (H₈O₉H₁₀) ^fΣ𝑞 on (H₁₁O₁₂H₁₃).