1. INTRODUCTION Pharmaceutical contamination by ibuprofen and atenolol is an increasing environmental concern [1]. High-silica zeolites, with their regular porosity and chemical stability, are promising materials for selective removal of these molecules from water [2]. However, molecular-level understanding of host–guest interactions under hydrated conditions remains limited. This study combines neutron and X-ray powder diffraction to directly locate the drugs and co-adsorbed water in zeolite Y, revealing framework distortions induced by adsorption (Fig. 1). 2. RESULTS AND DISCUSSION Diffraction data reveal a symmetry reduction from cubic (Fd3̅m) to acentric triclinic (F1) upon drug loading, with anisotropic lattice distortions and moderate unit-cell expansion. Ibuprofen is incorporated as a neutral species, stabilized mainly by steric confinement and dispersive interactions of the aromatic ring and isobutyl group. Atenolol is protonated, with uptake driven by electrostatic charge compensation. In both systems, adsorption geometry is dictated by functional group distribution rather than molecular chirality (Tab. 1, 2). Combined ab initio framework refinement and Simulated Annealing enabled precise localization of the guest molecules within the zeolite supercages. 3. EXPERIMENTAL FAU-type zeolite Y (Si/Al = 30) was batch-loaded with deuterated ibuprofen or atenolol in D₂O for five days at room temperature. Samples were dried under nitrogen and analyzed by X-ray powder diffraction (Bruker D8) and high-resolution neutron diffraction (D2B, ILL, λ = 1.594 Å, 1.5 K), following approaches demonstrated in previous studies [3]. Rietveld refinements (GSAS/EXPGUI) applied geometric restraints to the framework and guest molecules, followed by Simulated Annealing for guest localization with limited molecular flexibility. Refined occupancies were compared to steric and charge-compensation limits of the framework. 4. CONCLUSIONS High-silica zeolite Y exhibits pronounced structural adaptability upon adsorption of ibuprofen and atenolol, with systematic symmetry reduction and anisotropic lattice distortions. Ibuprofen is stabilized mainly by steric confinement and dispersive interactions, atenolol by polar contacts and charge compensation. Chirality plays a minor role, while functional group distribution governs adsorption. The study provides a detailed molecular-level understanding of host–guest interactions under hydrated conditions, informing the design of zeolitic materials for selective removal of pharmaceutical micropollutants. References [1] Austin, T., Bregoli, F., Höhne, D., Hendriks, A. J., & Ragas, A. M. (2022), Environmental Research, 209, 112777. [2] Mancinelli, M., & Martucci, A. (2025), Sustainable Chemistry, 6(1), 9. [3] Beltrami, G., Martucci, A., Pasti, L., Chenet, T., Ardit, M., Gigli, L., Cescon, M., & Suard, E. (2020), ChemistryOpen, 9(10), 978–982.
Combined Neutron and X-ray Diffraction Study of Ibuprofen and Atenolol Adsorption in Zeolite Y
Luca Adami
;Maura Mancinelli;Luisa Pasti;Tatiana Chenet;Caterina D'Anna;Annalisa Martucci
2026
Abstract
1. INTRODUCTION Pharmaceutical contamination by ibuprofen and atenolol is an increasing environmental concern [1]. High-silica zeolites, with their regular porosity and chemical stability, are promising materials for selective removal of these molecules from water [2]. However, molecular-level understanding of host–guest interactions under hydrated conditions remains limited. This study combines neutron and X-ray powder diffraction to directly locate the drugs and co-adsorbed water in zeolite Y, revealing framework distortions induced by adsorption (Fig. 1). 2. RESULTS AND DISCUSSION Diffraction data reveal a symmetry reduction from cubic (Fd3̅m) to acentric triclinic (F1) upon drug loading, with anisotropic lattice distortions and moderate unit-cell expansion. Ibuprofen is incorporated as a neutral species, stabilized mainly by steric confinement and dispersive interactions of the aromatic ring and isobutyl group. Atenolol is protonated, with uptake driven by electrostatic charge compensation. In both systems, adsorption geometry is dictated by functional group distribution rather than molecular chirality (Tab. 1, 2). Combined ab initio framework refinement and Simulated Annealing enabled precise localization of the guest molecules within the zeolite supercages. 3. EXPERIMENTAL FAU-type zeolite Y (Si/Al = 30) was batch-loaded with deuterated ibuprofen or atenolol in D₂O for five days at room temperature. Samples were dried under nitrogen and analyzed by X-ray powder diffraction (Bruker D8) and high-resolution neutron diffraction (D2B, ILL, λ = 1.594 Å, 1.5 K), following approaches demonstrated in previous studies [3]. Rietveld refinements (GSAS/EXPGUI) applied geometric restraints to the framework and guest molecules, followed by Simulated Annealing for guest localization with limited molecular flexibility. Refined occupancies were compared to steric and charge-compensation limits of the framework. 4. CONCLUSIONS High-silica zeolite Y exhibits pronounced structural adaptability upon adsorption of ibuprofen and atenolol, with systematic symmetry reduction and anisotropic lattice distortions. Ibuprofen is stabilized mainly by steric confinement and dispersive interactions, atenolol by polar contacts and charge compensation. Chirality plays a minor role, while functional group distribution governs adsorption. The study provides a detailed molecular-level understanding of host–guest interactions under hydrated conditions, informing the design of zeolitic materials for selective removal of pharmaceutical micropollutants. References [1] Austin, T., Bregoli, F., Höhne, D., Hendriks, A. J., & Ragas, A. M. (2022), Environmental Research, 209, 112777. [2] Mancinelli, M., & Martucci, A. (2025), Sustainable Chemistry, 6(1), 9. [3] Beltrami, G., Martucci, A., Pasti, L., Chenet, T., Ardit, M., Gigli, L., Cescon, M., & Suard, E. (2020), ChemistryOpen, 9(10), 978–982.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
