Correlation between Noncovalent Bond Strength and\nSpectroscopic Perturbations within the Lewis Base

Me<sub>2</sub>CO was allowed to interact with 20 different Lewis\nacids so as to engage in various sorts of noncovalent interactions,\nencompassing hydrogen, halogen, chalcogen, pnictogen, and tetrel bonds.\nDensity functional theory computations evaluated the interaction energy\nof each dyad, which was compared with spectroscopic, geometric, AIM,\nand energy decomposition elements so as to elucidate any correlations.\nThe red shift of the CO stretching\nfrequency, and the changes in the nuclear magnetic resonance shielding\nof the O and C atoms of acetone, are closely correlated with the interaction\nenergy so can be used to estimate the latter from experimental measurements.\nThe standard AIM measures at the bond critical point, ρ, ∇<sup>2</sup>ρ, and <i>V</i> also correlate with the energy,\nalbeit not as well as the spectroscopic parameters. The σ-hole\ndepth on the Lewis acid is not well correlated with the energetics,\ndue in part to the fact that electrostatics in general are not an\naccurate metric of bond strength.