Author, as appears in the article.: Watfa, Nancy; Melgar, Dolores; Haouas, Mohamed; Taulelle, Francis; Hijazi, Akram; Naoufal, Daoud; Avalos, Josep Bonet; Floquet, Sebastien; Bo, Carles; Cadot, Emmanuel;
Department: Química Física i Inorgànica Enginyeria Química
URV's Author/s: Bo Jané, Carles / Bonet Avalos, José
Keywords: Diffusion in liquids Diffusion Computational chemistry
Abstract: The effectiveness of the interactions between various alkylammonium cations and the well-defined spherical Keplerate-type {Mo132} capsule has been tracked by 1H DOSY NMR methodology, revealing a strong dependence on the self-diffusion coefficient of the cationic guests balanced between the solvated and the plugging situations. Analysis of the data is fully consistent with a two-site exchange regime involving the 20 independent {Mo9O9} receptors of the capsule. Furthermore, quantitative analysis allowed us to determine the stability constants associated with the plugging process of the pores. Surprisingly, the affinity of the capsule for a series of cationic guests increases continuously with its apolar character, as shown by the significant change of the stability constant from 370 to 6500 for NH4+ and NEt4+, respectively. Such observations, supported by the thermodynamic parameters, evidence that the major factor dictating selectivity in the trapping process is the so-called hydrophobic effect. Computational studies, using molecular dynamics simulations, have been carried out in conjunction with the experiments. Analysis of the radial distribution functions g(r) reveals that NH4+ and NMe4+ ions behave differently in the vicinity of the capsule. The NH4+ ions do not exhibit well-defined distributions when in close vicinity. In contrast, the NMe4+ ions displayed sharp distributions related to different scenarios, such as firmly trapped or labile guest facing the {Mo9O9} pores. Together, these experimental and theoretical insights should aid in the exploitation of these giant polyoxometalates in solution for various applications. © 2015 American Chemical Society.
Thematic Areas: Química Materiais Interdisciplinar General chemistry Farmacia Engenharias iv Engenharias iii Engenharias ii Colloid and surface chemistry Ciências biológicas ii Ciências biológicas i Ciências agrárias i Ciência de alimentos Chemistry, multidisciplinary Chemistry (miscellaneous) Chemistry (all) Chemistry Catalysis Biochemistry Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
Author's mail: carles.bo@urv.cat josep.bonet@urv.cat
Author identifier: 0000-0001-9581-2922 0000-0002-7339-9564
Record's date: 2024-09-07
Papper version: info:eu-repo/semantics/acceptedVersion
Link to the original source: https://pubs.acs.org/doi/10.1021/jacs.5b01526
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Journal Of The American Chemical Society. 137 (17): 5845-5851
APA: Watfa, Nancy; Melgar, Dolores; Haouas, Mohamed; Taulelle, Francis; Hijazi, Akram; Naoufal, Daoud; Avalos, Josep Bonet; Floquet, Sebastien; Bo, Carles; (2015). Hydrophobic Effect as a Driving Force for Host-Guest Chemistry of a Multi-Receptor Keplerate-Type Capsule. Journal Of The American Chemical Society, 137(17), 5845-5851. DOI: 10.1021/jacs.5b01526
Article's DOI: 10.1021/jacs.5b01526
Entity: Universitat Rovira i Virgili
Journal publication year: 2015
Publication Type: Journal Publications
Repositori URV