Abstract
Herein, we report a new salt of a pyrophosphate-functionalized uranyl peroxide nanocluster {U24Pp12} (1) exhibiting Oh molecular symmetry both in the solid and solution. Study of the system yielding 1 across a wide range of pH by single-crystal X-ray diffraction, small-angle X-ray scattering, and a combination of traditional 31P and diffusion-ordered spectroscopy (DOSY) NMR affords unprecedented insight into the amphoteric chemistry of this uranyl peroxide system. Key results include formation of a rare binary {U24}·{U24Pp12} (3) system observed under alkaline conditions, and evidence of acid-promoted decomposition of {U24Pp12} (1) followed by spatial rearrangement and condensation of {U4} building blocks into the {U32Pp16} (2) cluster. Furthermore, 31P DOSY NMR measurements performed on saturated solutions containing crystalline {U32Pp16} show only trace amounts (∼2% relative abundance) of the intact form of this cluster, suggesting a complex interconversion of {U24Pp12}, {U32Pp16}, and {U4Pp4-x} ions.
| Original language | English |
|---|---|
| Pages (from-to) | 5478-5487 |
| Number of pages | 10 |
| Journal | Inorganic Chemistry |
| Volume | 56 |
| Issue number | 9 |
| DOIs | |
| State | Published - May 1 2017 |
| Externally published | Yes |
Funding
This material is based upon work supported as a part of the Materials Science of Actinides Center, and Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Award No. DE-SC0001089. Traditional 1D 31P NMR measurements were conducted at the Magnetic Resonance Research Center at the Univ. of Notre Dame. 31P diffusion-ordered spectroscopy NMR measurements were conducted at the Nuclear Magnetic Resonance Facility at UC Davis. Raman spectroscopy and thermogravimetric analysis measurements were conducted at the Materials Characterization Facility of the Center for Sustainable Energy at the Univ. of Notre Dame. Electrospray ionization mass spectroscopy measurements were conducted at the Mass Spectrometry and Proteomics Facility at the Univ. of Notre Dame.