Syntheses, Single-Crystal Structures, and Structural Chemistry of Hexafluoridouranates(V), UF ( = Li-Cs, Ag, Tl, HO), and the Dodecafluoridodiuranate(V) Ba[UF]·1.36HF.

We present the syntheses of the hexafluoridouranates(V) UF ( = Li-Cs, Ag, Tl, HO) and of the dodecafluoridodiuranate(V) Ba[UF]·1.36HF. With the exception of AgUF and HOUF, all compounds were synthesized by reacting the respective metal fluorides with β-UF in anhydrous hydrogen fluoride (aHF).

Effects of the Inverse Trans-Influence in a Berkelium(III) Phosphine Oxide Complex.

An example of a Bk phosphine oxide complex has been prepared to examine and quantify the effects of the inverse -influence (ITI) on a late actinide complex. This has been accomplished through a comparison of and Bk-ligand bonds in the meridional berkelium(III) complex, BkBr(OPCy) (OPCy = tricyclohexylphosphine oxide). A detailed bond metric analysis was completed that includes the shortest published distance for a Bk-O bond, attributed to the smaller coordination number of Bk of six in -BkBr(OPCy).

High-Pressure Effects on an Octa-Hydrated Curium Complex: An Experimental and Theoretical Investigation.

An octa-hydrated curium compound [Cm(HO)](Hdtp)(dtp)·HO (, Hdtp = 2,3-di(tetrazol-5-yl)pyrazine) along with its lanthanide analogues [Ln(HO)](Hdtp)(dtp)·HO (, Ln = La-Nd, Sm-Lu) were synthesized and characterized using single crystal X-ray diffraction and spectroscopic methods. Bond length analysis of Cm(III)-OH (where refers to the coordination number) was compared to Ln(III)-OH (Ln = Nd and Sm), indicating similar M(III)-OH bond lengths because of their similar eight-coordinate ionic radii of these M(III) cations. Owing to the reduced coordination number, the Cm(III)-OH bond lengths were shorter than previously reported Cm(III)-OH bonds in [Cm(HO)](CFSO).

Synthesis and Characterization of Homo- and Heteroleptic Neptunium(IV) Heteroarylalkenolate Complexes.

Heteroleptic An (An = U, Np) chlorido-ketoenaminate complexes of the type [AnCl(TFB-BuA)(THF)] ( type: , ; TFB-BuA = 4-(-butylamino)-1,1,1-trifluorobut-3-en-2-one) and the homoleptic Np heteroarylalkenolate complexes [Np(PyTFP)] (, PyTFP = 1-(pyridin-2-yl)-3,3,3-trifluoroprop-1-en-2-ol) and [Np(DMOTFP)] (, 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 can change to form two different complex isomers, as seen by paramagnetic chemical shifts in NMR experiments.

Investigation of Pressure Effects in the Bimetallic Transplutonium Tetrazolate Complexes [(An(pmtz)(HO))(μ-pmtz)](pmtz)·HO (An = Cm, Bk, and Cf).

Understanding the effects of pressure on actinide compounds is an integral part of safe nuclear waste storage in deep geologic repositories and provides a means of systematically altering the structure and properties. However, detailing how the effects of pressure evolve across the actinide series in the later elements is not typically undertaken because of the challenges of conducting research on these unstable isotopes. Here, a family of bimetallic actinide complexes, [(An(pmtz)(HO))(μ-pmtz)](pmtz)·HO (An = Cm, Bk, and Cf, pmtz = 5-(pyrimidyl)tetrazolate; , , and ), are reported and represent the first structurally characterized bimetallic berkelium and californium compounds.

Transformation of Mononuclear Plutonium(III) Tetrazolate Complexes into Dinuclear Complexes in the Solid State.

The salt metathesis reaction of Na(pmtz)·HO [pmtz 5-(pyrimidyl)tetrazolate] and PuBr·HO in an aqueous media leads to the formation of the mononuclear compound [Pu(pmtz)(HO)]·(3 + ) HO (, = ∼8) that is isotypic with the lanthanide compounds [Ln(pmtz)(HO)]·(3 + ) HO (Ln = Ce-Nd). Dissolution and recrystallization of in water yields the dinuclear compound {[Pu(pmtz)(HO)](μ-pmtz)}(pmtz)·14HO (), which is isotypic with the lanthanide compounds {[Ln(pmtz)(HO)](μ-pmtz)}(pmtz)·14HO (Ln = Nd and Sm). Like their nine-coordinate ionic radii, the M-O and M-N bond lengths in / and /, respectively, are within error of one another.

Discrete Mono-, Di-, and Trinuclear Anions [MoOF], [MoOF], [MoOF], [MoOF], [MoOF], and the Infinite Chain Anion [MoOF] Obtained from Reactions of MoOF: Synthesis and Analysis of the Structure-Chemical Relations of the Compounds.

The herein-reported oxyfluoridometallate salts were synthesized and structurally characterized during the studies of the Lewis acidity of OF ( = Mo, W) with various fluoride ion donors (RbF, CsF, TlF, AgF, SrF, BaF, PbF) in different solvents (aqHF 48%, aHF, BrF, ClF). Phase-pure MoOF was either synthesized by hydrolysis of MoF with SiO in anhydrous HF (aHF) or by reactions of BrF with MoO or MoO, respectively. The compound was characterized by infrared and Raman spectroscopy, solid-state quantum-chemical calculations, as well as powder and single-crystal X-ray diffraction.

Isolation of a californium(II) crown-ether complex.

The actinides, from californium to nobelium (Z = 98-102), are known to have an accessible +2 oxidation state. Understanding the origin of this chemical behaviour requires characterizing Cf materials, but investigations are hampered by the fact that they have remained difficult to isolate. This partly arises from the intrinsic challenges of manipulating this unstable element, as well as a lack of suitable reductants that do not reduce Cf to Cf°.

Double Addition vs. Ring Closure: Systematic Reactivity Study of CO(NCO) and CO(NCS) towards Hydrogen Halides.

The reactivity of carbonyl diisocyanate, CO(NCO) , and carbonyl diisothiocyanate, CO(NCS) with nucleophiles shows different patterns: Whereas carbonyl diisocyanate adds two equivalents of nucleophile forming carbonyl bis(carbamoylhalides), carbonyl diisothiocyanate only adds one equivalent and undergoes intramolecular ring closure, resulting in the formation of substituted thiadiazines. In this study we have reacted both carbonyl diisocyanate and carbonyl diisothiocyanate with the full series of hydrogen halides HF to HI, isolating carbonyl bis(carbamoylfluoride) (1), -chloride (2), -bromide (3), and -iodide (4) as well as (6-chloro-2,3-dihydro-2-thioxo-4H-1,3,5-thiadiazin-4-one (5), and 6-bromo-2,3-dihydro-2-thioxo-4H-1,3,5-thiadiazin-4-one (6). The compounds were analysed by single-crystal X-ray diffraction, NMR spectroscopy, IR and Raman spectroscopy, and elemental analysis.

Neptunium Alkoxide Chemistry: Expanding Alkoxides to the Transuranium Elements.

Two oxo-containing neptunium(IV) -butoxides, [NpO(OBu)] () and [KNpO(OBu)] (), were synthesized using the ligand substitution between neptunium(IV) silylamides and HOBu, whereas the salt metathesis between [NpCl(DME)] (DME = dimethoxyethane) and various amounts of LiOBu resulted in the formation of oxo-free alkoxides [Np(OBu)(py)] (; py = pyridine) and [Li(THF)][Np(OBu)] (; 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.

Syntheses and Characterization of Tetrazolate-Based Lanthanide Compounds and Selective Crystallization Separation of Neodymium and Dysprosium.

Selective crystallization offers new opportunities for separating neodymium and dysprosium, which are considerably important in permanent magnets. Two water-soluble nitrogen-rich tetrazolate-based ligands, dtp (Hdtp = 2,3-di-1-tetrazol-5-ylpyrazine) and Hibt [Hibt = 4,5-bis(tetrazol-5-yl)imidazole], allow the separation of Nd and Dy through selective crystallization. The reactions of Ln with the ligand Na(dtp)·2HO lead to two distinct phases, Na[Ln(dtp)(HO)](dtp)·HO (; Ln = La-Pr) and [Ln(HO)](Hdtp)(dtp)·HO (; Ln = Nd and Sm-Lu).

Synthesis, characterization, and high-pressure studies of a 3D berkelium(III) carboxylate framework material.

A berkelium(III) mellitate, Bk[C(CO)](HO)·2HO, was synthesized and rapidly crystallized by reacting mellitic acid, C(COH), and BkBr·HO 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 Bk display enhanced hypsochromic shifting when compared to other An(III) mellitates.

Photochemistry with Chlorine Trifluoride: Syntheses and Characterization of Difluorooxychloronium(V) Hexafluorido(non)metallates(V), [ClOF ][MF ] (M=V, Nb, Ta, Ru, Os, Ir, P, Sb).

A photochemical route to salts consisting of difluorooxychloronium(V) cations, [ClOF ] , and hexafluorido(non)metallate(V) anions, [MF ] (M=V, Nb, Ta, Ru, Os, Ir, P, Sb) is presented. As starting materials, either metals, oxygen and ClF or oxides and ClF are used. The prepared compounds were characterized by single-crystal X-ray diffraction and Raman spectroscopy.

Cs[Cl F ]: A Propeller-Shaped [Cl F ] Anion in a Peculiar A B Structure Type.

Reaction of CsF with ClF leads to Cs[Cl F ]. It contains a molecular, propeller-shaped [Cl F ] anion with a central μ -F atom and three T-shaped ClF molecules coordinated to it. This anion represents the first example of a heteropolyhalide anion of higher ClF content than [ClF ] and is the first Cl-containing interhalogen species with a μ-bridging F atom.

UF and the High-Pressure Polymorph HP-UF.

A laboratory-scale synthesis of UF is presented that utilizes the reduction of UF with sulfur in anhydrous hydrogen fluoride. An excess of sulfur can be removed by vacuum sublimation, yielding pure UF , as shown by powder X-ray diffraction, micro X-ray fluorescence analysis, infrared and Raman spectroscopy, as well as magnetic measurements. Furthermore, a single-crystalline, high-pressure modification of UF was obtained in a multi-anvil press at elevated temperatures.

New Nuclear Magnetic Moment of ^{209}Bi: Resolving the Bismuth Hyperfine Puzzle.

A recent measurement of the hyperfine splitting in the ground state of Li-like ^{208}Bi^{80+} has established a "hyperfine puzzle"-the experimental result exhibits a 7σ deviation from the theoretical prediction [J. Ullmann et al., Nat.

The [U F ] Anion of Sr[U F ].

The D -symmetric dinuclear complex anion [U F ] of pastel green Sr[U F ] shows a hitherto unknown structural feature: The coordination polyhedra around the U atoms are edge-linked monocapped trigonal prisms, the U atoms are therefore seven-coordinated. This leads to a U-U distance of 3.8913(6) Å.

A 1D Coordination Polymer of UF with HCN as a Ligand.

β-Uranium(V) fluoride was reacted with liquid anhydrous hydrogen cyanide to obtain a 1D coordination polymer with the composition 1∞ [UF (HCN) ], 1∞ [UF F - (HCN) ], revealed by single-crystal X-ray structure determination. The reaction system was furthermore studied by means of vibrational and NMR spectroscopy, as well as by quantum chemical calculations. The compound presents the first described polymeric HCN Lewis adduct and the first HCN adduct of a uranium fluoride.

NOUF6 Revisited: A Comprehensive Study of a Hexafluoridouranate(V) Salt.

We have synthesized NOUF6 by direct reaction of NO with UF6 in anhydrous HF (aHF). Based on the unit cell volume and powder diffraction data, the compound was previously reported to be isotypic to O2 PtF6 , however, detailed structural data, such as the atom positions and all information that can be derived from those, were unavailable. We have therefore investigated the compound by using single-crystal and powder X-ray diffraction, IR, Raman, NMR, EPR, and photoluminescence spectroscopy, magnetic measurements, as well as chemical analysis, density determination, and quantum chemical calculations.

Synthesis of organic (trimethylsilyl)chalcogenolate salts Cat[TMS-E] (E = S, Se, Te): the methylcarbonate anion as a desilylating agent.

A high-yield synthesis of the class of (trimethylsilyl)chalcogenolate organic salts [Cat][TMS-E] (E = S, Se, Te; Cat = BMPyr, DMPyr, NMe4, nBu3MeP) is presented. The title compounds have been prepared by the strictly aprotic reaction between the respective bis(trimethylsilyl)chalcogenide (TMS2E) and methylcarbonate ionic liquids (ILs). This constitutes a novel reaction behavior of methylcarbonate ILs, acting as a nucleophilic desilylating agent and a Lewis base instead of as a Brønsted base.