Reaction force constant as a descriptor of the principle of non-perfect synchronization

Context: In this study, a small set of 1,3-dipolar cycloaddition reactions that proceed at the same exothermicity is presented. Our main objective was to extend the application of the reaction force constant concept to gain an understanding of the reactivity principles. Inspired by a recent article where we show that the Bell-Evans-Polanyi principle is fulfilled under the condition of an equal degree of (a)synchronicity, here, we demonstrate that the reaction force constant is also a suitable descriptor to quantify the principle of non-perfect synchronization proposed by Bernasconi as a way to understand deviations from the Bell-Evans-Polanyi principle. Methods: Reaction profiles V(ξ), F(ξ), and κ(ξ) were performed at the B3LYP/6-31G(d,p) level of theory. The stabilizing interactions were characterized using the energy decomposition analysis combined with the natural orbitals for chemical valence, EDA-NOCV, method. The present work was done using Gaussian 09 and Multiwfn programs.