Solution (31)P NMR Study of the Acid-Catalyzed Formation of a Highly Charged {U24Pp12} Nanocluster, [(UO2)24(O2)24(P2O7)12](48-), and Its Structural Characterization in the Solid State Using Single-Crystal Neutron Diffraction.
The first neutron diffraction study of a single crystal containing uranyl peroxide nanoclusters is reported for pyrophosphate-functionalized Na44K6[(UO2)24(O2)24(P2O7)12][IO3]2·140H2O (1). Relative to earlier X-ray studies, neutron diffraction provides superior information concerning the positions of H atoms and lighter counterions. Hydrogen positions have been assigned and reveal an extensive network of H-bonds; notably, most O atoms present in the anionic cluster accept H-bonds from surrounding H2O molecules, and none of the surface-bound O atoms are protonated. The D4h symmetry of the cage is consistent with the presence of six encapsulated K cations, which appear to stabilize the lower symmetry variant of this cluster. (31)P NMR measurements demonstrate retention of this symmetry in solution, while in situ (31)P NMR studies suggest an acid-catalyzed mechanism for the assembly of 1 across a wide range of pH values.
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Mateusz
M
Dembowski
Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Travis A
TA
Olds
Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Kristi L
KL
Pellegrini
Chemical and Engineering Materials Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Christina
C
Hoffmann
Chemical and Engineering Materials Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Xiaoping
X
Wang
Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Sarah
S
Hickam
Instrument and Source Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.
Junhong
J
He
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Allen G
AG
Oliver
Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States.|Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame , Notre Dame, Indiana 46556, United States.
Peter C
PC
Burns