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SUMMARY:Study of extraction system “N\,O-donor heterocyclic amide/europi
 um nitrate” by EXAFS and 1H-NMR spectroscopy.
DTSTART;VALUE=DATE-TIME:20220713T145000Z
DTEND;VALUE=DATE-TIME:20220713T151000Z
DTSTAMP;VALUE=DATE-TIME:20260414T130344Z
UID:indico-contribution-475@events.sinp.msu.ru
DESCRIPTION:Speakers: Leonid Starostin (Moscow State University)\nOne of t
 he major problems of nuclear energy is long-term nuclear waste reprocessin
 g and storage. Current technologies are able to partially regenerate nucle
 ar fuel but lead to the accumulation of long-living high-level nuclear was
 te (HLW). Reducing nuclear waste levels requires the effective and selecti
 ve separation of minor actinides from HLW possessing high content of lanth
 anides.\nRecently we study derivatives of diamides of 2\,2'-bipyridyl-6\,6
 '-dicarboxylic acid\, such as bipy-4Hex as an extraction material. For dee
 per understanding of extraction process we study the structure of the euro
 pium complex of this ligand in crystal and solution\, as well as an extrac
 tion system with a ligand and europium nitrate.\nIn order to establish the
  atomic environment of europium we used the experimental EXAFS technique. 
 The absorption spectra of X-ray radiation for crystalline compounds and so
 lutions of europium complexes with nitric acid were measured. Experimental
  data on X-ray spectroscopy were obtained at the STM station of the Kurcha
 tov Synchrotron Radiation Center. The detection was carried out in the “
 transmission” mode and by the output of fluorescent radiation. A visual 
 comparison of the XANES spectra confirms the preservation of the degree of
  oxidation of Eu both in solution and in the crystalline state. Comparison
  of the Fourier transformed spectra of EXAFS shows the identity of the coo
 rdination spheres near Eu ion. In order to clarify the atomic geometry\, t
 he EXAFS spectra were adjusted.\nIn addition\, we used 1H-NMR spectroscopy
  to study extraction systems: the ligand solutions in nitrobenzene-d5 and 
 an aqueous solution of europium nitrate with different concentrations of n
 itric acid were mixed and the spectrum was obtained from the organic layer
 . At concentrations of nitric acid 1M and lower only ligand peaks were obs
 erved in the spectrum\, at higher concentrations of nitric acid\, peaks of
  the complex appeared. For such systems\, we calculated the complex-ligand
  concentration ratio from the spectra and distribution coefficients.\n\nht
 tps://events.sinp.msu.ru/event/8/contributions/475/
LOCATION: НИИЯФ\, ЮК\, Ц-05
URL:https://events.sinp.msu.ru/event/8/contributions/475/
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