Series of Uranyl-4,4′-biphenyldicarboxylates and an Occurrence of a Cation–Cation Interaction: Hydrothermal Synthesis and in Situ Raman Studies
dataset
posted on 2016-02-19, 00:34 authored by Paula M. Cantos, Laurent
J. Jouffret, Richard E. Wilson, Peter C. Burns, Christopher L. CahillThree uranium(VI)-bearing materials
were synthesized hydrothermally using the organic ligand 4,4′-biphenyldicarboxylic
acid: (UO2)(C14O4H8) (1); [(UO2)2(C14O4H8)2(OH)]·(NH4)(H2O) (2); (UO2)2(C14O4H8)(OH)2 (3). Compound 1 was formed after 1 day at 180 °C in an acidic environment
(pHi = 4.03), and compounds 2 and 3 coformed after 3 days under basic conditions (pHi = 7.95).
Coformation of all three compounds was observed at higher pHi (9.00). Ex situ Raman spectra of single crystals of 1–3 were collected and analyzed for signature
peaks. In situ hydrothermal Raman data were also obtained and compared
to the ex situ Raman spectra of the title compounds in an effort to
acquire formation mechanism details. At pHi = 4.00, the
formation of 1 was suggested by in situ Raman spectra.
At an increased pHi (7.90), the in situ data implied the
formation of compounds 1 and 3. The most
basic conditions (pHi = 9.00) yielded a complex mixture
of phases consistent with that of increased uranyl hydrolysis.
