The N⋯HF Interactions in the X-Pyridazine⋯ (HF)_𝟐 Complexes: Substituent Effects and Energy Components

Table 3

Electron densities 𝜌 (in e/au³) at the N⋯H BCP in the X-pyridazine⋯(HF)_n(𝑛=1,2) complexes and individual H-bond energies 𝐸 (in kcal mol⁻¹) calculated for the complex 1.

	Complex 1		Complex 2	Complex 3
	𝜌BCP×10^2	𝐸	𝜌BCP×10^2	𝜌BCP×10^2
N(CH3)2	5.46, 5.23	−𝟏𝟒.𝟒𝟏,−13.44	6.03	6.16
NHCH3	5.40, 5.15	−𝟏𝟒.𝟐𝟑,−13.18	5.95	5.95
NH2	5.32, 5.05	−𝟏𝟑.𝟖𝟓,−12.73	5.82	5.97
CH3	4.99, 4.95	−𝟏𝟐.𝟑𝟔,−12.21	5.69	5.69
C2H5	5.02, 5.00	−𝟏𝟐.𝟕𝟔,−12.67	5.73	5.74
OCH3	5.08, 4.91	−𝟏𝟐.𝟗𝟖,−12.29	5.60	5.79
OH	5.02, 4.79	−𝟏𝟐.𝟔𝟔,−11.75	5.56	5.65
H	4.83, 4.83	−𝟏𝟐.𝟎𝟒,−12.04	5.54	5.54
OF	4.70, 4.55	−𝟏𝟏.𝟑𝟕,−10.81	5.19	5.35
CN	4.45, 4.43	−𝟏𝟎.𝟐𝟐,−10.15	5.01	5.07
NO2	4.42, 4.45	−𝟏𝟎.𝟎𝟖,−10.19	4.90	4.90
F	4.71, 4.57	−𝟏𝟏.𝟒𝟔,−10.92	5.23	5.36
Br	4.69, 4.61	−𝟏𝟏.𝟑𝟑,−11.02	5.24	5.33
Cl	4.69, 4.60	−𝟏𝟏.𝟑𝟔,−11.02	5.25	5.35

The bold and italicized values correspond to the N₁⋯H and N₂⋯H hydrogen bonds, respectively.