Actinyl-cation interactions: experimental and theoretical assessment of [Np(vi)O₂Cl₄]²⁻ and [U(vi)O₂Cl₄]²⁻ systems

Abstract

Interactions between the Li+ cation and the neptunyl(vi) oxo observed in both solid state and aqueous solutions.

Optimizing Alkali Metal (M) and Chelate (L) Combinations for the Synthesis and Stability of [M(L)][(C5H4SiMe3)3Y] Yttrium(II) Complexes

“…The structure of 3 is further unusual in that the unit cell contains two (Cp′ 3 Y II ) 1– anions with the charge balanced by a [(THF)­Na 2 (18c6) 2 ] 2+ dication that has two different types of Na 1+ coordination environments. The [Na 2 (18c6) 2 ] 2+ dication has previously been observed in several structures, − but never with a single additional THF molecule. Hence, this structure adds another example to the many variations of countercations composed of alkali metal cations and 18c6 .…”

Use of vibrational spectroscopy to identify the formation of neptunyl–neptunyl interactions: a paired density functional theory and Raman spectroscopy study

“…22 DFT was also used to observe the emergence of an additional ν 1 band in a Np(VI)O 2 2+ /Li + system due to the occurrence of actinyl-cation interactions in solution. 16 These studies highlight the value of DFT to interpret the complex vibrational bands that arise in actinyl systems and can be applied to further understand AAIs within these systems.…”

“…[5][6][7][8][9][10][11][12] In addition, this particular bonding motif imparts significant influence on the chemistry in aqueous and solid-state systems, resulting in overall changes in its redox properties, 13,14 disproportionation reactions, 15 and complex vibrational and electronic spectroscopy. 13,14,16,17 Therefore, it is crucial to understand both the bonding within the actinyl cation and the additional interactions within the solid and solution phases to develop an in-depth, systems-level approach to the chemistry of the high-valent early actinides.…”

“…The symmetry of the system can be perturbed through intermolecular interactions involving the oxo groups, such as actinyl-cation (ACI), actinyl-hydrogen (AHI) and actinyl-actinyl (AAI) interactions, and lead to significant complexity within the vibrational spectra. 14,16,[23][24][25][26][27] Of particular note is AAI interactions (also known as cation-cation interactions or CCIs) because there is a significant amount of spectral complexity observed within the window of interest (600-900 cm −1 ). 28,29 Within systems containing Np(V)O 2 + , the increased Lewis basicity of the oxo groups results in a greater propensity of the neptunyl(V) unit to engage in AAIs.…”

Reactions of Neptunium(V) in Alkali-Metal Hydroxides

“…Their studies showed that often the frequencies observed are coupled modes of multiple vibrations and not normal modes obfuscating the correlation of the observed frequencies with other metrical parameters, as is typically done with complexes of uranium(VI). 34,35 ■ CONCLUSION The syntheses of two new neptunium complexes from strongly alkaline solutions of potassium and rubidium hydroxide are reported here and their structures determined from singlecrystal X-ray diffraction. Raman spectra of these complexes have been recorded and reported.…”