The synthesis and structural characterisation of isostructural [Rb(18-crown-6)][XO4] (X = Tc, Re) confirm a dimeric structure, [Rb(18-crown-6)]2[XO4]2. X-ray diffraction analysis reveals that the dimers feature a [Rb2X2O8] core formed by two macrocycle-bound Rb+ cations bridged by XO4 -. Their arrangements are directed by Rb-O coordination and by two equivalent X & centerdot;& centerdot;& centerdot;O Matere bonds (MaBs). Unlike previously reported MaBs that link these oxoanions into extended supramolecular polymers or layers, the interactions described here occur within the discrete dimeric cluster, representing the first such examples of intramolecular MaBs for pertechnetate and perrhenate. Computational analysis clarifies the origin of these contacts. Molecular electrostatic potential maps reveal sigma-holes at Tc and Re, supporting MaB formation. Quantum theory of atoms in molecules, noncovalent interaction plots, and natural bond orbital calculations independently confirm the presence and stabilising nature of the X & centerdot;& centerdot;& centerdot;O interactions. These results highlight the role of sigma-hole interactions in determining the solid-state architecture of pertechnetate and perrhenate crown-ether complexes and provide insight relevant to oxoanion behaviour in separation processes and nuclear waste management.

Heteroleptic AnIV (An = U, Np) chlorido-ketoenaminate complexes of the type [AnCl2(TFB-tBuA)2(THF)] (An-1 type: U-1, Np-1; TFB-tBuA = 4-(tert-butylamino)-1,1,1-trifluorobut-3-en-2-one) and the homoleptic NpIV heteroarylalkenolate complexes [Np(PyTFP)4] (Np-2, PyTFP = 1-(pyridin-2-yl)-3,3,3-trifluoroprop-1-en-2-ol) and [Np(DMOTFP)4] (Np-3, DMOTFP = 1-(4,5-dimethyloxazol-2-yl)-3,3,3-trifluoroprop-1-en-2-ol) were synthesized and characterized (SC-XRD, NMR, Vis-NIR, MS). While their solid-state structures compare well to those of their uranium analogues, the behavior in solution showed significant differences. The binding motif of the DMOTFP ligand in complex Np-3 can change to form two different complex isomers, as seen by paramagnetic chemical shifts in NMR experiments. Furthermore, the flexibility and the influence of the steric effects at the N-side of the ligands are discussed and compared with its uranium counterpart.

This study aimed to find a rapid extraction system for the preparation of a Seaborgium (Sg) aqueous chemistry experiment in the future. A new approach for extraction of 181W tracer as a lighter homolog of (Sg) by ionic liquids is explored. A natural tantalum target was activated by a beam of 9 MeV proton at Cologne University to produce carrier-free 181W. The preliminary batch extraction experiments of the carrier-free 181W from HCl and H2SO4 solutions have been evaluated. Different batch extraction parameters such as feed acidity, diluent type, ionic strength (KCl feed) and reducing agent as a function of time were explored. The obtained results demonstrated that the highest distribution of carrier-free 181W from 0.001 M acidic solutions using the used ionic liquid is observed. A significant rapid kinetic for the extraction of trace-scale using the used ionic liquid is achieved within 5 sec. The preliminary results are necessary to design the upcoming aqueous experiments of Sg. The next goal will be on-line experiments with the centrifuge system SISAK to develop the aqueous chemistry extraction of Sg using the most promising and adequate experimental setup.

Complexes of N,N,N ',N '-tetramethyl diglycolamide (TMDGA), a hydrophilic diglycolamide (DGA) proposed as an aqueous phase holdback reagent, have been crystallized for the majority of the lanthanide series (excluding promethium), yttrium, and americium to deepen our structural understanding of trivalent metal ion (M3+) DGA coordination compounds in the presence of nitrate counter-anions. The presented collection of 16 complexes with accompanying single-crystal structures, taking formulas [M(TMDGA)(3)][M(NO3)(6)] (M = La, Ce, Pr, Nd, Sm, Am), [M(TMDGA)(3)][M(NO3)(5)(H2O)](1-x)[M(NO3)(4)(H2O)(2)](x)(NO3)(1+x) (M = Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb), [M(TMDGA)(3)](2)[M(NO3)(4)(H2O)(2)](0.75)[M(NO3)(5)(H2O)](1.25)(NO3)(2.75)H2O (M = Lu), and [M(TMDGA)(3)][M(NO3)(5)(H2O)](NO3)CH3OH (M = Y) were all synthesized via solvent diffusion of reaction mixtures containing the metal nitrate M(NO3)(3)nH(2)O and TMDGA. Single-crystal X-ray diffraction analyses of these new structures show that each TMDGA complex comprises of three TMDGA ligands coordinating the metal ion via carbonyl and etheric oxygen atoms forming [M(TMDGA)(3)](3+) cations. Spectroscopy measurements under high pressure displayed notable differences in the f -> f transition shifting between that of Nd(III) and Am(III). Shifting of transitions by 2.0 nm were observed in Nd up to 8.50 +/- 0.09 GPa, while Am saw shifting between 11.0 to 13.5 nm at pressures up to 20.06 +/- 1.90 GPa. The local geometry in these complexes is a distorted spherical capped square antiprism (CSAPR-9) except for of the yttrium complex, which exhibits a distorted spherical tricapped trigonal prismatic (TCTPR-9) geometry. The anions that form concomitantly with the TMDGA complexes are composed of hexanitrato species for the early lanthanide ions (lanthanum to samarium); whereas the remaining smaller lanthanides did not possess sufficiently large ionic radii to coordinate six bidentate nitrate anions, instead, one or two nitrate anions are situated in the outer sphere. The systematic progression of changes in the anionic environments of these complexes outlines the changing coordination habits afforded by the lanthanide contraction.

In this manuscript we evaluate the X-ray structure of five new pertechnetate derivatives of general formula [M(H2O)4(TcO4)2], M=Mg, Co, Ni, Cu, Zn (compounds 1-5) and one perrhenate compound Zn(H2O)4(ReO4)2 (6). In these complexes the metal center exhibits an octahedral coordination with the pertechnetate units as axial ligands. All compounds exhibit the formation of directional Tc⋅⋅⋅O Matere bonds (MaBs) that propagate the [M(H2O)4(TcO4)2], into 1D supramolecular polymers in the solid state. Such 1D polymers are linked, generating 2D layers, by combining additional MaBs and hydrogen bonds (HBs). Such concurrent motifs have been analyzed theoretically, suggesting the noncovalent σ-hole nature of the MaBs. The interaction energies range from weak (~ -2 kcal/mol) for the MaBs to strong (~ -30 kcal/mol) for the MaB+HB assemblies, where HB dominates. In case of M=Zn, the corresponding perrhenate Zn(H2O)4(ReO4)2 complex, has been also synthesized for comparison purposes, resulting in the formation of an isostructural X-ray structure, corroborating the structure-directing role of Matere bonds.

The number of crystal structures of pertechnetates derived from aqueous solutions has been expanded from seven to over 30. We report the conversion of NH4TcO4 to aqueous HtcO4 via acidic cation exchange. This is followed by the synthesis and structural elucidation of pertechnetate salts of alkaline earth (AE), transition metal I and lanthanoids (Ln) elements. Various degrees of hydration and coordination are discussed. Where possible, a comparison with the perrhenate homologues is made. The described syntheses and materials may be used as novel starting materials for extended technetium research. The number of pertechnetate salts has been extended for a majority pprox elements pprox periodic table. A systematic crystallographic study of their coordination and level of hydration gives insight into periodic trends. The picture shows the M-Otc bond lengths of all known pertechnetates. image

Two oxo-containing neptunium(IV) tert-butoxides, [Np3O(OtBu)10] (1) and [K4Np2O(OtBu)10] (2), were synthesized using the ligand substitution between neptunium(IV) silylamides and HOtBu, whereas the salt metathesis between [NpCl4(DME)2] (DME = dimethoxyethane) and various amounts of LiOtBu resulted in the formation of oxo-free alkoxides [Np(OtBu)4(py)2] (3; py = pyridine) and [Li(THF)]2[Np(OtBu)6] (4; THF = tetrahydrofuran). These complexes are the first structurally characterized neptunium(IV) alkoxides using single-crystal X-ray diffraction and solid-state absorption spectroscopy, which provide data for the development of anhydrous metal-organic neptunium chemistry.

An entry from the Inorganic Crystal Structure Database, the world’s repository for inorganic crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the joint CCDC and FIZ Karlsruhe Access Structures service and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The solvent adducts of the tetravalent actinoid chlorides ThCl4 and UCl4 have been isolated with methanol as [ThCl4(MeOH)(4)] 1 and [UCl4(MeOH)(4)] 2, and with ethanol as [ThCl4(EtOH)(4)] 3 and [UCl4(EtOH)(4)] 4. In hydrochloric acid [ThCl2(H2O)(7)](Cl)(2)(H2O)(2) 5 forms, which is isotypic to the known [UCl2(H2O)(7)](Cl)(2)(H2O)(2) 6. The adducts have been analysed using SXRD, IR, CHN, TGA-MS and PXRD. The material can be isolated from saturated organic (1-4) or acidic aqueous (5-6) solutions, however, drying of the isolated material results in loss of HCl and the formation of oxide species, confirmed by the isolation of U3O8 after complete thermal decomposition.

A berkelium(III) mellitate, Bk2[C6(CO2)6](H2O)8·2H2O, was synthesized and rapidly crystallized by reacting mellitic acid, C6(CO2H)6, and BkBr3·nH2O in an aqueous medium. Single crystal X-ray diffraction shows that the compound crystallizes as a three-dimensional framework isostructural with Pu(III), Am(III), and Cm(III) mellitates. UV-vis-NIR spectroscopic studies as a function of pressure were performed using a diamond anvil cell and show that the 5f → 5f transitions of Bk3+ display enhanced hypsochromic shifting when compared to other An(III) mellitates.

Lanthanoid and actinoid silylamides are versatile starting materials. Herein we show how a simple ligand exchange with tert-butanol leads to the formation of the first trimeric heterobimetallic uranyl(VI)-lanthanoid(III) alkoxide complexes. The μ3 coordination of the endogenous uranyl oxo atom results in a significant elongation of the bond length and a significant deviation from the linear uranyl arrangement.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The Front Cover shows that there are occasions on which chemistry shows its human face. Thorium(IV) and uranium(IV), both of which share a love for chloride, saturate themselves quite literally when given the opportunity to take up some alcohol or water, i.e. polar-protic solvents. When either ThCl4 or UCl4 is treated with methanol or ethanol, the molecular solvent adducts [ThCl4(MeOH)4], [UCl4(MeOH)4], [ThCl4(EtOH)4] and [UCl4(EtOH)4] form. The tendency to form the water adduct is so strong that, when a Th adduct is dissolved in hydrochloric acid, two Th−Cl bonds break up and [ThCl2(H2O)7](Cl)2(H2O)2, which is isotypic with the already known [UCl2(H2O)7](Cl)2(H2O)2, forms. At elevated temperature, the materials decompose to form their respective oxides. More information can be found in the Research Article by M. Zegke and co-workers.

Two neptunium(III) mellitates, 237Np2(mell)(H2O)9·1.5H2O (Np-1α) and 237Np2(mell)(H2O)8·2H2O (Np-1β), have been synthesized from 237NpCl4(dme)2 by reduction with KC8 and subsequent reaction with an aqueous solution of mellitic acid (H6mell). Characterization by single-crystal X-ray crystallography and UV-vis-NIR spectroscopy confirms that the neptunium is in its +3 oxidation state and both polymorphs are isostructural to the previously reported plutonium mellitates. Of the two morphologies, Np-1α is indefinitely stable in air, while Np-1β slowly oxidizes over several months. This is due to the change in the energy of the metal-ligand charge-transfer absorption exhibited by these compounds attributed to differing numbers of carboxylate bonds to Np(III), where in Np-1β the energy is low enough to result in spontaneous oxidation.

The first homoleptic thiosemicarbazone complexes of uranium were isolated by reacting uranium tetrachloride in a salt metathesis or acid-base reaction with four equivalents of Na(BzTSC) or H(BzTSC) (BzTSC=benzylthiosemicarbazone), carrying a non-methylated (L1), monomethylated (L2) or dimethylated (L3) terminal amino group, in moderate yields. [U(BzTSCNH(2))(4)] (1), [U(BzTSCNH(CH3))(4)] (2) and [U(BzTSCN(CH3)(2))(4)] (3) show a remarkable stability towards air, with oxidation potentials in THF between +0.43 and +0.53 V and reduction potentials between -2.53 and -2.67 V vs. ferrocene/ferrocenium. The simple methylation of the terminal amino group of the ligand allows for controlled changes in the coordination environments of the complexes. Thermogravimetric analyses indicate that the complexes are stable up to 155 degrees C.

Ammonium pertechnetate reacts in mixtures of trifluoromethanesulfonic anhydride and trifluoromethanesulfonic acid under final formation of ammonium pentakis(trifluoromethanesulfonato)oxidotechnetate(V), (NH 4 ) 2 [TcO(OTf) 5 ]. The reaction proceeds only at exact concentrations and under the exclusion of air and moisture via pertechnetyl trifluoromethanesulfonate, [TcO 3 (OTf)], and intermediate Tc VI species. 99 Tc nuclear magnetic resonance (NMR) has been used to study the Tc VII compound and electron paramagnetic resonance (EPR), 99 Tc NMR and X-ray absorption near-edge structure (XANES) experiments indicate the presence of the reduced technetium species. In moist air, (NH 4 ) 2 [TcO(OTf) 5 ] slowly hydrolyses under formation of the tetrameric oxidotechnetate(V) (NH 4 ) 4 [{TcO(TcO 4 ) 4 } 4 ] ⋅10 H 2 O. Single-crystal X-ray crystallography was used to determine the solid-state structures. Additionally, UV/Vis absorption and IR spectra as well as quantum chemical calculations confirm the identity of the species.