Plutonium(iv) complexation by diglycolamide ligands—coordination chemistry insight into TODGA-based actinide separations

Abstract

Complexation of Pu(IV) with TMDGA, TEDGA, and TODGA diglycolamide ligands was followed by vis-NIR spectroscopy. A crystal structure determination reveals that TMDGA forms a 1 : 3 homoleptic Pu(IV) complex with the nitrate anions forced into the outer coordination sphere.

Redox behavior of gas phase Pu(IV)-monodentate ligand complexes: an investigation by electrospray ionization mass spectrometry

“…TMDGA, which is a multidentate ligand, forms a 1:3 Pu(IV):TMDGA complex with the anions forced into the outer coordination sphere [54,62]. While multi-charged Pu species are reported for Pu-TMDGA complexes, the Pu species observed in this report are only mono-charged.…”

A Tetrapositive Metal Ion in the Gas Phase: Thorium(IV) Coordinated by Neutral Tridentate Ligands

“…[21] Similarly, ligated Th(L) 3 4+ is likely a solution complex, in accord with the intense Th(L) 3 4+ peak in the ESI mass spectrum and the appearance of the Th(L) 3 4+ ·ClO 4 À complex. The recently reported Vis-NIR spectrum of crystalline Pu IV (L) 3 4+ exhibited similarities to that for this solid dissolved in solution, indicating that the Pu IV (L) 3 4+ complex exists in solution.…”

“…TMOGA is the smallest homologue of diglycolamide extractants that exhibit a particular propensity for separation of trivalent lanthanides and actinides. [19][20][21] Thorium has a low fourth ionization energy, 28.8 eV, [22] which is below the third ionization energies of transition metals for which gas-phase ligated trications have been observed. [19][20][21] Thorium has a low fourth ionization energy, 28.8 eV, [22] which is below the third ionization energies of transition metals for which gas-phase ligated trications have been observed.…”

“…Sodium and calcium were observed as Na(L) + and Ca(L) 2 2+ at m/z 210.9 and 207.9. [20,21] These actinide complexes with nine-coordination TPP geometry are examples of uncommon chiral molecules with 5f-elements. The Th(L) 3 4+ peak in Figure 2 is dominant in the spectrum, suggesting this is a particularly stable gas-phase tetracation.…”

A Tetrapositive Metal Ion in the Gas Phase: Thorium(IV) Coordinated by Neutral Tridentate Ligands

“…[18] The structures of several diglycolamide-supported lanthanide and actinide complexes have been reported. [19][20][21] Thorium has a low fourth ionization energy, 28.8 eV, [22] which is below the third ionization energies of transition metals for which gas-phase ligated trications have been observed. [9] The expected strong interaction of TMOGA with Th 4+ offers the possibility of stabilization of Th 4+ /TMOGA complexes in the gas phase.…”