Theoretical Investigation on the Selective Adsorption of ReO4− by Functional Monomers: The Role of Hydrogen Bonding and Anion–Heterocycle Interactions

Understanding the adsorption mechanisms of anions onto functional monomers is crucial for various applications in environmental remediation and chemical separation. In this study, we investigated the interactions of ReO4−, Cl−, SO42−, and F− with several organic functional monomers featuring aliphatic chains, cyclic saturated or unsaturated rings, and NH/NH2 functional groups through density functional theory calculations. Employing a rigorous multilevel optimization strategy, we explored the geometric and energetic features of their complexes, focusing on hydrogen bonding and anion–heterocycle interactions. Our results highlight the strong affinity of ReO4−, Cl−, SO42− for amine-type functional monomers, while also revealing the distinct interaction patterns of F− with aromatic rings containing nitrogen. This comprehensive analysis elucidates diverse binding mechanisms, providing insights into designing effective adsorbents for selective anion capture.