The key distinction among the Lewis pairs lies in the overall interaction strength, particularly whether it is sufficient to overcome the intrinsic strain energy required to bring the Lewis acid and base from their equilibrium geometries to the final complex geometry. As shown in Figures and, stronger Lewis bases exhibit more stabilizing interactions, including greater electrostatic and orbital contributions. Even Pauli repulsion is enhanced, leading to an earlier deformation of the Lewis acid (vide infra). The interplay between interaction energy (ΔE int ) and strain energy (ΔE strain ) provides critical insight into the bonding characteristics of Lewis acid-base pairs (Figure ). This interplay ultimately determines whether the adduct is strong or weak, shaping its overall bonding characteristics.