Work

Interplay of Hydrogen, Halogen, and Aromatic interactions in Schiff Base Cocrystals: A Hirshfeld surface and energy-based study

Year: 2025

Type: article

Abstract: Two cocrystals formed between Schiff base derivatives and biphenyl-4-carboxylic acid were synthesized and structurally characterized. The Schiff bases differ by para -substitution with either fluorine or bromine on a perfluorinated aromatic ring. Single-crystal X-ray diffraction revealed a complex interplay. This study examines supramolecular interactions, including classical O–H···N hydrogen bonds, C–H···F contacts, halogen contacts (e.g., Br···π and Br···Br), and π–π stacking interactions. Hirshfeld surface analysis and two-dimensional fingerprint plots were used to visualize and quantify the predominant intermolecular contacts, while energy framework calculations estimated the energetic contributions to crystal packing. Differential scanning calorimetry revealed that the brominated cocrystal exhibits a slightly higher melting enthalpy and temperature, consistent with its larger lattice energy and increased halogen-bonding contribution to crystal cohesion. The nature and geometry of the para-substituent significantly influence the supramolecular architecture, illustrating the competitive and cooperative roles of hydrogen, halogen, and aromatic interactions in cocrystal formation.

Source: Journal of Molecular Structure

DOI: 10.1016/j.molstruc.2025.145108

Authors: Addi Dana Sánchez-Pacheco, Simón Hernández-Ortega, Jesús Valdés-Martínez

Institution: Universidad Nacional Autónoma de México

Language: English

Topic: Crystallography and molecular interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,360

Funders: Consejo Nacional de Ciencia y Tecnología, Universidad Nacional Autónoma de México, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México