Philicity scales using molecular quantum similarity and chemical reactivity indices within density functional theory

In this manuscript, we postulate a possible relationship of philicity within a molecular set of electrocyclic reactions. Philicity has been studied by the Chattaraj and co-workers (J. Phys. Chem. A. 2003, 107, 25). This important concept was obtained using the electrophilicity index and Fukui functions. Recently, the present author has published a possible way to quantify philicity using molecular quantum similarity and chemical reactivity indices (see, J. Math. Chem. 2023, 61, 165). In this work, philicity was related with the molecular quantum similarity framework to obtain a possible way to relate philicity using 21 electrocyclic reactions using the cyclobutene reaction as a reference. The main idea is to postulate philicity scales. This methodology can open up a possible path to find systematic relationships in each molecular ensemble using the selectivity defined in the density functional theory context. With these scales, we can relate the effect of the substituent on the electrocyclic opening reaction on the molecular set.