Isostructural Analysis in Proposed Crystallization Mechanisms at the Molecular Level of Methyl 4‐bromobenzoate and Methyl 4‐iodobenzoate

In this work, we propose molecular‐level crystallization mechanisms, based on non‐classical nucleation theory, using theoretical supramolecular energetic and topological data. The interactions calculated by computational tools were verified and energetically classified by density functional theory (DFT), and their contribution at the contact point was analyzed using quantum atom‐in‐molecule theory (QTAIM). The proposed mechanisms follow the model developed by our research group, in which crystallization is proposed to begin with the most stabilizing cluster interactions (C─H⋯H─C and C─H⋯C are common to both compounds, in addition to O⋯O type interactions for p ‐Br and I⋯I and C─H⋯I for p ‐I), potentially leading to the formation of supramolecular chains (1D). Next, the approximation of these chains, guided by C─H⋯C, C─H⋯X and C⋯X interactions, is proposed to result in supramolecular (2D) layers. Finally, the association between layers, predominantly driven by C─H⋯X type interactions, is proposed to give rise to three‐dimensional structures (3D mesocrystals). Additionally, the isostructuralism between the compounds was evaluated, and it was investigated whether the proposed crystal growth is consistent with the final supramolecular structure, the unit cell, and the crystal habit.