In Situ X-ray Absorption Spectroscopy Studies of Kinetic Interaction between Platinum(II) Ions and UiO-66 Series Metal–Organic Frameworks
- Source:
- Journal of physical chemistry 2014 v.118 no.49 pp. 14168-14176
- ISSN:
- 1520-5207
- Subject:
- Fourier transform infrared spectroscopy, X-radiation, X-ray absorption spectroscopy, absorption, adsorption, aqueous solutions, coordination polymers, ions, ligands, nitrogen dioxide, platinum
- Abstract:
- The interaction of guest Pt(II) ions with UiO-66–X (X = NH₂, H, NO₂, OMe, F) series metal–organic frameworks (MOFs) in aqueous solution was investigated using in situ X-ray absorption spectroscopy. All of these MOFs were found to be able to coordinate with Pt(II) ions. The Pt(II) ions in UiO-66–X MOFs generally coordinate with 1.6–2.4 Cl and 1.4–2.4 N or O atoms. We also studied the time evolution of the coordination structure and found that Pt(II) maintained a coordination number of 4 throughout the whole process. Furthermore, the kinetic parameters of the interaction of Pt(II) ions with UiO-66–X series MOFs (X = NH₂, H, NO₂, OMe, F) were determined by combinational linear fitting of extended X-ray absorption fine structure (EXAFS) spectra of the samples. The Pt(II) adsorption rate constants were found to be 0.063 h–¹ for UiO-66–NH₂ and 0.011–0.017 h–¹ for other UiO-66–X (X = H, NO₂, OMe, F) MOFs, which means that Pt(II) adsorption in UiO-66–NH₂ is 4–6 times faster than that in other UiO-66 series MOFs. FTIR studies suggested that the carboxyl groups could be the major host ligands binding with Pt(II) ions in UiO-66 series MOFs, except for UiO-66–NH₂, in which amino groups coordinate with Pt(II) ions.
- Agid:
- 5593984
- https://doi.org/10.1021/jp5066456