Análise cristalográfica e teórica dos arranjos supramoleculares de derivados de Dibromonitrobenzeno e Quinolinonas

Abstract

A theoretical and experimental approach, starting with the structural analysis of organic compounds, is of fundamental importance in the development of new materials, especially for crystal engineering, as the synergy between the two methodologies enhances the understanding of the structure, supramolecular arrangement, and their energetic environment. In this work, five derivates of dibromonitrobenzene were studied, three of which were previously unknown, as well as two previously unknown derivates of quinolinones. All structures were elucidated using the X-ray crystallographic methodology, and their intramolecular and intermolecular interactions were initially analyzed based on geometric data, as well as their supramolecular arrangements. Subsequently, the interactions were analyzed using the Hirshfeld surface, mainly for the analysis of π-type interactions, with their contributions quantified through the respective fingerprints. The Molecular Frontier Orbitals – HOMO and LUMO, and Molecular Electrostatic Potential maps were obtained. The supramolecular arrangements were also analyzed using the Quantum Theory of Atoms in Molecules. The results indicated that crystals derived from dibromonitrobenzene are stabilized by interactions involving halogen atoms, primarily of an electrostatic nature due to the formation of the σ cavity in halogen atoms. On the other hand, crystals derived from quinolinones are stabilized by non-classical hydrogen interactions and hydrophobic interactions of the type π···π and C-H···π types, mainly of an electrostatic nature. In general, substitutions did not significantly alter the distribution of HOMO and LUMO molecular orbitals in both classes of compounds. Both halogens and hydrogen interactions are closed-shell interactions, therefore weak interactions, and dominate molecular packing.