Anhydrous photochemical reduction of well-defined uranyl(VI) complexes

Duval, Paul; Kannan, S.

doi:10.1016/j.jallcom.2006.11.035

Cited by 3 publications

(1 citation statement)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Highvacuum treatment at room temperature led to removing the lattice water molecules but not the bonded ones. Irradiation times shorter than 15 min were used for XPS measurements in order to prevent the reduction of uranyl to lower oxidation state [48,50,51]. In addition, B 4 bL 4 is neutral and the P=O donors are linked to methyl groups which are less electron-donating substituents than phenyl groups, so that uranyl reduction as observed with OP(Phe) 3 is unlikely to occur [51].…”

Section: X-photoelectron Spectroscopy Of Uranyl Complexesmentioning

confidence: 99%

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Ramı́rez¹,

Varbanov

Buenzli

et al. 2012

Radiochimica Acta

View full text Add to dashboard Cite

The current interest in functionalized calixarenes with phosphorylated pendant arms resides in their coordination ability towards f elements and capability towards actinide/rare earth separation. Uranyl cation forms 1 : 1 and 1 : 2 (M : L) complexes with a tetra-phosphinoylated p-tertbutylcalix[4]arene, B 4 bL 4 : UO 2 (NO 3 ) 2 (B 4 bL 4 ) n ·xH 2 O (n = 1, x = 2, 1; n = 2, x = 6, 2). Spectroscopic data point to the inner coordination sphere of 1 containing one monodentate nitrate anion, one water molecule and the four phosphinoylated arms bound to UO 2 2+ while in 2, uranyl is only coordinated to calixarene ligands. In both cases the U(VI) ion is 8-coordinate. Uranyl complexes display enhanced metal-centred luminescence due to energy transfer from the calixarene ligands; the luminescence decays are bi-exponential with associated lifetimes in the ranges 220 µs < τ s < 250 µs and 630 µs < τ L < 640 µs, pointing to the presence of two species with differently coordinated calixarene, as substantiated by a XPS study of U(4 f 5/2,7/2 ), O(1s) and P(2p) levels on solid state samples. The extraction study of UO 2 2+ cation and trivalent rare-earth (Y, La, Eu) ions from acidic nitrate media by B 4 bL 4 in chloroform shows the uranyl cation being much more extracted than rare earths.

show abstract

Section: X-photoelectron Spectroscopy Of Uranyl Complexesmentioning

confidence: 99%

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Ramı́rez¹,

Varbanov

Buenzli

et al. 2012

Radiochimica Acta

View full text Add to dashboard Cite

show abstract

Developments in the photophysics and photochemistry of actinide ions and their coordination compounds

Natrajan

2012

Coordination Chemistry Reviews

211

164

View full text Add to dashboard Cite

Activation and Functionalization of the Uranyl Ion by Electrochemical Reduction

Golwankar,

Makoś,

Cajiao

et al. 2024

Inorg. Chem.

View full text Add to dashboard Cite

Interconversion of the oxidation states of uranium enables separations and reactivity schemes involving this element and contributes to technologies for recycling of spent nuclear fuels. The redox behaviors of uranium species impact these processes, but use of electrochemical methods to drive reactions of molecular uranium complexes and to obtain molecular insights into the outcomes of electrode-driven reactions has received far less attention than it deserves. Here, we show that electro-reduction of the uranyl ion (UO 2 2+ ) can be used to promote stepwise functionalization of the typically unreactive oxo groups with exogenous triphenylborane (BPh 3 ) serving as a moderate electrophile, avoiding the conventional requirement for a chemical reductant. Parallel electroanalytical, spectrochemical, and chemical reactivity studies, supported by spectroscopic findings and structural data from X-ray diffraction analysis on key reduced and borylated products, demonstrate that our electrochemical approach largely avoids undesired cross reactions and disproportionation pathways; these usually impact the multicomponent systems needed for uranyl functionalization chemistry. Joint computational studies have been used to map the changes associated with U−O activation and to quantify the free energy differences related to key reactions. Taken together, the results suggest that electrochemical methods can be used for selective interconversion of molecular actinide species, reminiscent of methods commonly employed in transition metal redox catalysis.

show abstract

Anhydrous photochemical reduction of well-defined uranyl(VI) complexes

Cited by 3 publications

References 18 publications

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Uranyl complexes formed with a para-t-butylcalix[4]arene bearing phosphinoyl pendant arms on the lower rim. Solid and solution studies

Developments in the photophysics and photochemistry of actinide ions and their coordination compounds

Activation and Functionalization of the Uranyl Ion by Electrochemical Reduction

Contact Info

Product

Resources

About