Crystallization of colourless hexanitratoneptunate(iv) with anhydrous H⁺ countercations trapped in a hydrogen bonded polymer with diamide linkers

Abstract

Centrosymmetric hexanitratoneptunate(iv) crystallizes with anhydrous proton countercations trapped in a hydrogen bonded polymer with diamide linker molecules to give colourless crystals.

Coordination Chemistry of Actinide Nitrates with Cyclic Amide Derivatives for the Development of the Nuclear Fuel Materials Selective Precipitation (NUMAP) Reprocessing Method

“…Very similar results were also obtained in the reaction of Np 4+ with L25 and L26 in HNO 3 (aq.) . Molecular and crystal structures of these [An(NO 3 ) 6 ] 2– analogues (An = U, Np) were identical to each other (Figure ), featuring T h ‐symmetric [An(NO 3 ) 6 ] 2– units well separated from H + countercations present between the carbonyl O atoms of neighboring DHNRPs, with [DHNRP ··· H + ] n hydrogen‐bonded polymers formed in the crystal structure.…”

“…Indeed, solubility of An 4+ in the presence of stoichiometric amount of L25 or L26 in 3 m HNO 3 (aq.) was of the order of 10 –3 m for An = Th, U, and Np as listed in Table , . Although experiments for Pu 4+ have not been performed yet, the similar sparingly soluble Pu 4+ crystalline compounds of L25 and L26 are expected to be formed in analogy to other tested An 4+ .…”

“…This point explains the reason why Zr 4+ does not form any crystalline compounds with DHNRPs listed in Table . Although ionic radii of twelve‐fold coordinated Np 4+ and Pu 4+ are not available, occurrence of [Np(NO 3 ) 6 ] 2– and [Pu(NO 3 ) 6 ] 2– have been repeatedly reported . From the viewpoint of decontamination of nuclear fuel materials, no precipitation of Zr 4+ with DHNRP is very welcome, as Zr occurring in spent nuclear fuels contains one of the long‐lived FPs, 93 Zr with 1.53 × 10 6 years half‐life…”

Complexation Studies of Eu(III) by a Novel Soft N and Hard O Donor Combined Ligand Including <i>N,N,N',N'</i>-Tetrakis(2-pyridylmethyl)-1,3-diaminopropane-2-amide Structure: UV-vis Titration, X-ray Crystallography, EXAFS Spectroscopy Analysis

“…All of the hydrogen atoms were introduced at ideal positions and refined isotropically based on the corresponding C-atoms. Full matrix leastsquares refinement on F 2 was based on observed reflections and parameters, and converged with unweighted and weighted agreement factors, R1 and wR2, respectively [11]. All calculations were performed by using Crystal Structure 4.3 software package.…”

MOFs with 12-Coordinate 5f-Block Metal Centers

“…As these high CNs are obtained by using coordinating atoms of low Z (i.e., H, He, B), an intriguing question is what is the largest possible CN in molecular complexes or coordination polymers when using more common, much larger coordinating atoms such as nitrogen or oxygen? Actinide centers bearing 12 oxygen atoms have been isolated, which are mostly anionic An­(NO 3 ) 6 2– ion-pair complexes, , while other complexes comprise Th 4+ centers bound by two bidentate O-donor ligands and four NO 3 – , , or six bidentate boron oxyanions . In one case, a thorium center is chelated by two monodentate imidazoles and five bidentate NO 3 – , defining a unique case of a mixed-donor 12-coordinate environment .…”