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2017-German-Sydney review

report at ISTR-2017

Konstantin4
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2017-German-Sydney review

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  1. Technetium: new trends in investigation andapplication Konstantin German

  2. The chalenges of Technetium Thermodynamics - NEA_TDB Review made by NEA-TDB summed up the chemical thermodynamics of Tc and its principle gaps: Rard J.A., Rand M.H., Anderegg G., Wanner H., Chemical thermodynamic of technetium. Eds. Sandino Amalia M., Osthols E. NEA (1999) Elsiever Publ. Amsterdam. - it formed the Axes for studies • Time passed being characterized with the controversy of nuclear industry present and future status, drastic for Tc-99 originating mostly as the uranium fission product. • The definite stop in nuclear development would fix Tc further accumulation but now is clearly not the case and we appreciate the authors who were continuing efforts in Tc focused sciences. Joe Rard and the delegates of IST2005

  3. Recent steps • All the gaps should be closed - we know - so indeed one may see : among the gaps named 17 years ago – some are thoroughly studied and important answers were obtained: Tc(VII) in strong acids – closed thanks to our collaboration with F. Poineau and his colleagues from UNLV • The basis for this progress - Chemical medium for stabilisation of instable species and new Instrumental and methodology breakthroughs

  4. IST-2008 , Port-Elizabeth 7-10 Oct. 2008, South Africa IST-2005 , O-arai, Japan 2005 ISTR2014, Pornichet France ISTR-2011 , Moscow 4-8 July 2011, Russia

  5. Eh-pH Pourbaix diagram for Tc • The solubility of Tc(IV) remains independent of pH until around 13.5, when a small increase can be seen which continues to increase linearly with pH. • Modelling suggests that this increase occurs as the species TcO(OH)3− is formed. The formation constant was estimated with data from this study and was found to be logK2=−21.6±0.3. • Authors: Peter Warwick | S. Aldridge | Nick Evans | Sarah Vines - Rad. Acta 2007 TcO(OH)3− Tc(OH)4(H2O)2 E. Breynaert, D. Dom, J. Vancluysen,A. Maes 2007-8

  6. HTcO4 ???

  7. Pertechnic acid [H7O3]4 [TcV 4TcVII16О68]· 4H2OK.German, M. Grigoriev, A. Fedosseev, 2018 • Was first synthesized 60 years ago but as single crystal – just in 2015 • Neither in composition No in structure it has no analog among the chemical elements including even rhenium • [H7O3]4[TcV4TcVII16О68]·16H2O: • a = 11.1743(6), b = 12.8839(6), c = 14.0661(6) Å, • α= 71.128(2), β = 69.015(2), γ = 74.340(2)°, • пр. гр. P-1, Z = 1. • The base of the structure are formed by four octahedra of TcVО6, connected through common apex into a square. • The rest 16 apex connect the tetramer • TcV4О20 with 16 Tc(VII)tetrahera [H7O3]4*[TcV 4TcVII16О68]·4H2O

  8. Tc speciation in solutions & melts by XAFS . • TcO4- - is highly environmental migrating species • Radiolyse in presence of organic components lead to the reduction of Тс(VII) to Tc(V, IV, III) • In chloride melts Tc could be examined (German, Simonoff, Reich, 2000, Grenoble) • Acetate complexes Тс(V, IV, III) exist but the data are scattered and the structure not systematically studied in collaboration with Prof. Grigoriev. • Acetate complexes of Тс(III) could co-exist withTc(VII) • DMSO solutions could make stable Pu3+ in presence of Tc(VII) *German-Fedosseev-Grigoriev 2017 ROBL_ESRF Grenoble Kurchatov Institute (KI) MOSCOW Advanced Photon Source inst. & UNLV

  9. Tc(VII) in strong acids The speciation of Tc(VII) in 12 M sulfuric acid was studied last year by NMR, UV-vis and XAFS spectroscopy, experimental results were supported by DFT calculation and were in agreement with the formation of TcO3OH(H2O)2. F. Poineau, Ph. Weck, K. German, A. Maruk, G. Kirakosyan, W. Lukens, D. Rego, A. Sattelberger, K. Czerwinski , Dalton Trans. 2010 The speciation of Tc(VII) in HClO4 is being reported at this Symposium and supports the TcO4- conversion to new Tc(VII) species in strong acids

  10. New Tc oxides & hydroxides Tc2O5- decomposition of Tc2O5*nH2O at 100oC Tc2O5*nH2O – gamma in NaOH + i-BuOH Tc4O5*14H2O hydrolisis of K3Tc2Cl8 Tc4O5 - thermolisis of Tc4O5*14H2O • Mazzi, 1974 - Tc2O3 InorganicaChimicaActa, Volume 9, 1974, Pages 263-268 G. A. Mazzocchin, F. Magno, U. Mazzi, R. Portanova Possible fractional reduction of polymers Preparation and Characterization of Phosphine Complexes of Technetium Possessing a Metal-Metal Bond Order of 3.5. F. A. Cotton, S.C. Haefner and A. P. SattelbergerInorg. Chem. 1996, 35, 1831. Haefner - Sattelberger [Mo3O4(DMF)9]4+

  11. Study of Tc(IV) uptake with FeOOH under reducing conditions • Reducing agent: 0.02M FeSO4, T = 600С, time = 3 h • Precipitate : FeOOH/Fe2O3 /Tcreduced ThoughTc adsorbed better on iron hydroxide from 0.5–2.0 M NaOH relative to 3.0-4.0 M NaOH, the precipitates formed at lower NaOH concentration were more easily leached by the NaOHleachant, The precipitate should be examined by XAFS Tc leaching with H2O2 was 20 % and with Na2S2O8 was70-100% in 100 days

  12. New Wavelet based structure analyses of X-ray amorphous complexes and solutions ( Re polynuclearTc-DTPA and Tc&Re nanoparticles (German, Zubavichus, Melentiev, Murzin at ISTR2011 Re-Cl Re-O Re-Re

  13. Transmutation target : Tc/Ru recovery • Tc-Ru acidic and pyrochemicalsolubilization problem

  14. Лит. данные по реакции Tc с N2H5+ Конечные хим. формы в реакции Тс(VII) c N2H5+согласно разным авторам варьируют от Tc(2+) до Tc(VII)= необходимы структ. и спектроскоп. данные

  15. Chemical species of Tc at the reducing separation U\Pu step

  16. Formation of the 3rd phase is undesireble in PUREX but for complicated compositions sometimes occures - Тс-DTPA • K. German, A. Melentiev, 2012 and 2016

  17. Tc-DTPA • Chemical analysesTc:L = 1:1 • Dissolution of the Tc-DTPA precipitate in 7 M HNO3 was rather slow : • Deep red intermediate species were observed The precipitate formation was slow: the Tc-DTPA precipitate has appeared on the 4-6-th day from the initial reaction date

  18. Tc peroxides Peroxides could be formed – in strong radiation field as H2O2 derivatives - In purex second step while Pu purification. They are usually unstable but could be stabillized under certain conditions (conc acids, organics). Тс initiate catalytic reactions in presenceH2O2 . two forms of Tc peroxides ( λ = 500 nm and 650 nm) Tc(IV): e 400=2352±59 l/mol·cm; Tc(VI)peroxide: e650=5090±51 л/М.см Tc(V)peroxide; e500=2938±58 л/М.см The last value is close to that of Mo analogue =

  19. Tc(IV)-H2O2-H2SO4влияние концентрации перекиси C(Tc)=0,5 ммоль-л, C(H2SO4)=18 моль-л, t=20 0C, l=1 см 3 2 1 3 2 1 Рис.3Влияние C0(H2O2) на время жизни неустойчивых форм Tc, λ=500нм: 1)0,5 М; 2)0,35 M;3) 0,2 М Рис.4Влияние C0(H2O2) на время жизни неустойчивых форм Tc , λ=650 нм: 1)0,5 М; 2)0,35 M;3) 0,2 М

  20. Влияние концентрации Tc Tc (IV) → Tc (X1;X2) → Tc (VII) C(H2SO4)=18 M; C0(H2O2)=0,2 М; t=20 0C; l=1 см 1 1 λ=500 нм λ=650 нм 2 2 3 4 3 4 Рис.5 Влияние концентрации Tc на продолжительность процесса: 1) 0,5ммоль-л; 2) 0,13 ммоль-л; 3) 0,053 ммоль-л; 4) 0,026 ммоль-л

  21. EXAFS of technetium halogenides а б в

  22. TcO4 recognition studies Константа связывания (logKa) для комплекса с анионом 1:1 с рецептором 1 и 2 по данным UV-visспектроскопии по методу тирования в DMSO при 25ºC

  23. Tc(VII) + S2- • Induction period of the reaction of pertechnetate with Na2S varies from 4 to 100 minutes dependingontheconcentration of reagents, pH and T • Reaction of Tc(VII) with Na2S is completedwithin1 to10hoursdependingontheconcentrationofreagents,pHand T • Reaction isfastifcomparedtoslow Tc2S7(TcS3,33) sedimentation (undermostconditions) -colloidformation • D. Shuh, W. Lukens, C. Burns, Final report on Project Number: EMSP-73778, 2004 Reviewed : ISTR2011- July 5 by German K. E., Peretrukhin V. F, TsivadzeA.Yu.

  24. Thank you for your attention!

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