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Via flux-assisted synthesis, we discovered three novel salt-inclusion materials, t-[Na2Cl]GaS2, o-[Na2Cl0.9I0.1]GaSe2, and t-[Na2Cl0.9I0.1]GaSe2, and two new selenides, Na2GaSe3 and Na4Ga2Se5, by changing the flux from NaCl/NaI to NaBr/NaI, respectively.

A novel series of heterometallic f-block-frameworks including the first examples of transuranic heterometallic 238U/239Pu-metal-organic frameworks (MOFs) and a novel monometallic 239Pu-analog are reported. In combination with theoretical calculations, we probed the kinetics and thermodynamics of heterometallic actinide(An)-MOF formation and reported the first value of a U-to-Th transmetallation rate. We concluded that formation of uranyl species could be a driving force for solid-state metathesis. Density of states near the Fermi edge, enthalpy of formation, band gap, proton affinity, and thermal/chemical stability were probed as a function of metal ratios. Furthermore, we achieved 97% of the theoretical maximum capacity for An-integration. These studies shed light on fundamental aspects of actinide chemistry and also foreshadow avenues for the development of emerging classes of An-containing materials, including radioisotope thermoelectric generators or metalloradiopharmaceuticals.

In targeting reduced valent lanthanide chalcogenides, we report the first nanoparticle synthesis of the mixed-valent ferromagnets Eu3 S4 and EuSm2 S4 . Using divalent lanthanide halides with bis(trimethylsilyl)sulfide and oleylamine, we prepared nanoparticles of EuS, Eu3 S4 , EuSm2 S4 , SmS1.9 , and Sm3 S4 . All nanoparticle phases were identified using powder X-ray diffraction, transmission electron microscopy was used to confirm morphology and nanoparticle size, and magnetic susceptibility measurements for determining the ordering temperatures and valence. The UV/Vis, Raman and X-ray photoelectron spectroscopies for each phase were compared. Surprisingly, the phase is influenced by the halide and the reaction temperature, where EuCl2 formed EuS while EuI2 formed Eu3 S4 , highlighting the role of kinetics in phase stabilization. Interestingly, at lower temperatures EuI2 initially forms EuS, and converts over time to Eu3 S4 .

Inverse weberites are of interest as geometrically frustrated magnetic materials due to their unique cation arrangement. We have synthesized nine isostructural materials that adopt the inverse weberite crystal structure, which consists of cross-linked kagome layers. These materials, having the general formula MIIMIIIF5(H2O)2 (MII = Co, Mn, Ni, Zn; MIII = Ga, Cr, Fe, V), were synthesized using mild hydrothermal conditions, which yielded phase-pure samples after optimization of the reaction conditions. Their crystal structures and optical, thermal, and magnetic behavior were characterized using single-crystal X-ray diffraction, UV-vis spectroscopy, thermogravimetric analysis, and measurement of the magnetic susceptibility and isothermal magnetization data, respectively. Three distinct types of magnetism were observed, including simple paramagnetism, antiferromagnetism, and canted antiferromagnetism; the last type is accompanied by a high frustration index fin the range 4.16-8.09. We demonstrated that the magnetic behavior of inverse weberites depends on the presence or absence of unpaired-electron-containing cations on the two distinct crystallographic sites, which can be employed for the prediction of the magnetic properties of other compounds in this rich and diverse family.

Geometrically frustrated systems play an important role in studying new physical phenomena and unconventional thermodynamics. Charge ordered defect pyrochlores AM2+M3+F6 offer a convenient platform for probing the interplay between electron distribution over M2+ and M3+ sites and structural distortions; however, they are limited to compounds with M2+/3+ = V, Fe, Ni, and Cu due to difficulties in the simultaneous stabilization of other 3d elements in the +2 and +3 oxidation states. Herein, we employ Cl- anions under hydrothermal conditions for the mild reduction of Mn2O3 in concentrated HF to obtain the CsMn2+Mn3+F6 composition as a phase pure sample and study its properties. The magnetism of CsMn2F6 was characterized by measuring the magnetic susceptibility and isothermal magnetization data, and a magnetic transition to a canted antiferromagnet state was found at 24.1 K. We determined the magnetic structure of CsMn2F6 using powder neutron diffraction, which revealed successive long-range ordering of the Mn2+ and Mn3+ sites that is accompanied by a second transition. The role and strength of magnetic exchange interactions were characterized using DFT calculations.

A series of alkali metal rare-earth borates were prepared via high-temperature flux crystal growth, and their structures were characterized by single crystal X-ray diffraction (SXRD). Na

The Boron-Chalcogen Mixture method was used to obtain single crystals of the previously extremely difficult to synthesize lanthanide orthothioborates to investigate their structures and their structurally connected optical behavior, such as second harmonic generation. Using a combined halide and polychalcogenide flux, the BCM method yielded single crystals of LnBS

Single crystals of three new compounds, Na

We demonstrate a fast solution phase ligand exchange process to generate AgBiS2 nanocrystal inks using a cinnamic acid derivative as an additive to accelerate the phase transfer to polar solvents. ...

Hexaferrites have a wide range of technological applications as well as a rich and complicated structural chemistry, with iron oxide layers inducing highly anisotropic ferrimagnetism that remains i...

Single crystals of new rubidium rare earth thiophosphates with the formulas Rb3Ln(PS4)2 (Ln = La, Ce, Pr), Rb3−xNaxLn(PS4)2 (Ln = Ce, Pr; x = 0.50, 0.55), and RbEuPS4 were crystallized out of a molten RbCl flux. The compounds Rb3Ln(PS4)2 (Ln = La, Ce, Pr) and Rb3−xNaxLn(PS4)2 (Ln = Ce, Pr; x = 0.50, 0.55) both crystallize in the monoclinic crystal system adopting the space groups P21 and P21/c, respectively, while RbEuPS4 crystallizes in the orthorhombic crystal system adopting the space group Pnma. A survey of all known rubidium rare earth thiophosphates grown using an alkali halide flux revealed trends suggesting that the Rb3Ln(PS4)2 and Rb3−xNaxLn(PS4)2 families of compounds can be actively targeted over a wide range of temperatures by employing RbCl as at least a component of the flux. Fluorescence measurements were performed on all compounds obtained, revealing resolved f–f transitions in Rb3Pr(PS4)2 and Rb2.45(2)Na0.55(2)Pr(PS4)2 and only single broad emission peaks for Rb3Ce(PS4)2 and Rb2.50(6)Na0.50(6)Ce(PS4)2, behavior characteristic for cerium(III) compounds.

Two series of new lanthanide thiophosphates with partial Ca occupancy of the Ln sites, Cs0.3(Ca0.3Ln0.7)PS4 (Ln = Ce, Pr, Nd, Sm, Gd, Tb, and Dy) and Cs0.5(Ca0.5Ln0.5)PS4 (Ln = Pr, Nd, Sm, Gd, and Tb), were synthesized using a CsI flux and structurally characterized. The first series with an idealized formula of Cs0.3(Ca0.3Ln0.7)PS4 crystallizes in the Rm space group and belongs to a new structure type that consists of a channel containing [(Ca0.3Ln0.7)PS4]0.3− framework, where the channels are occupied by severely disordered Cs+ cations. A second new series with formula Cs0.5(Ca0.5Ln0.5)PS4 crystallizes in the monoclinic C2/c space group and exhibits a layered structure consisting of [(Ca0.5Ln0.5)PS4]0.5− layers with Cs+ cations located between the layers for charge balance. Together with the parent structure type, LnPS4, these three structure types illustrate how the LnPS4 structure changes with Cs+ cation incorporation, reducing its dimensionality from 3D to 2D. The magnetic properties of Cs0.3[(Ca0.3Ce0.7)PS4] and Cs0.3[(Ca0.3Pr0.7)PS4] were studied and revealed no magnetic transition down to 2 K.

A series of rubidium rare earth thiophosphates with the formula Rb4Ln2(P2S6)(PS4)2 (Ln = La, Ce, Pr, Nd, Sm, and Gd) were synthesized using the high temperature molten flux crystal growth method utilizing a RbBr flux. Single crystals of all title compounds, as well as phase pure powders of the La-, Ce-, and Sm-containing compositions, were obtained. Single crystals of the title compounds were characterized by single crystal and powder X-ray diffraction for structure and phase identification. Rb4Ln2(P2S6)(PS4)2 crystallizes in the monoclinic crystal system adopting the P21/n space group for the large rare earths (Ln = La, Ce, Pr) and the C2/c space group for the smaller rare earths (Ln = Nd, Sm, Gd). This Rb4Ln2(P2S6)(PS4)2 series is a rare example of thiophosphates containing both tetrahedral [PVS4]3- and dimeric [PIV2S6]4- thiophosphate units that, in this structural family, link corrugated rare earth sulfide chains into sheets. The band gaps of the materials were determined from UV-Vis data and the fluorescence spectrum of Rb4Ce2(P2S6)(PS4)2 was collected. Optical band gaps were estimated to be 2.9 and 2.4 for the Nd and Sm analogues, respectively.

Salt-Inclusion Materials (SIMs) are a diverse and interesting class of materials. However, their synthesis has been largely serendipitous. The targeted synthesis of SIMs requires both synthetic and...

Single crystals of four new uranyl titanates have been grown via the flux growth method using mixed alkali halide fluxes. Na2(UO2)(TiO)O3 and KNa(UO2)(TiO)O3 have analogous layered structures containing titanyl (TiO2+) units coordinated into TiO5 square pyramids. Cs2(UO2)TiO4 crystallizes in the Cs2USiO6 structure type and is a rare example of a structure containing TiO4 tetrahedra. Cs2(UO2)Ti2O6 crystallizes in a new tunnel structure and contains the also rare TiO5 trigonal bipyramids. DFT studies were performed to understand the bonding in the observed titanate polyhedra. Furthermore, the luminescence properties of the compounds are reported, and leaching studies are reported for Cs2(UO2)Ti2O6.

Deep blue, prism-shaped, X-ray diffraction quality single crystals of a new quaternary rubidium cobalt germanate, exact composition Rb2Co1.85Ge1.15O6, were grown by soaking a pre-reacted polycrystalline powder in a molten RbCl/RbF eutectic flux (melting point = 546 °C) at 700 °C in a silver reaction vessel. The complex was characterized by single crystal X-ray diffraction and its elemental composition was semi-quantitatively confirmed by energy dispersive spectroscopy (EDS). Rb2Co1.85Ge1.15O6 crystallizes in the noncentrosymmetric orthorhombic space group C2221 with lattice parameters a = 6.5971(2) A, b = 9.8791(3) A and c = 10.8819(3) A in the K2ZnSi2O6 structure type. The crystal structure consists of a three-dimensional network, composed of Co and mixed Co/Ge tetrahedra, and features cavities occupied by Rb cations. X-ray diffraction quality single crystals of a novel rubidium cobalt germanate, Rb2Co1.85Ge1.15O6, were grown by soaking a pre-reacted powder, targeted for preparing Rb4.51Co2.35Ge5.10O15F1.96, in a RbCl-RbF eutectic melt at 700 °C. The complex was characterized by single crystal X-ray diffraction and found to crystallize in the orthorhombic space group C2221 in the K2ZnSi2O6 structure type.

Na n MAn 6 F 30 is an extremely versatile framework structure for incorporating tetravalent actinides (An) and cerium along with divalent or trivalent d -metals (M); moreover, the structure exhibits a high resistance to harsh chemical conditions. This extreme robustness can potentially be exploited for the sequestration of Pu in a stable matrix; however, no Na n MPu 6 F 30 compounds have been reported so far. Herein, we present four new plutonium fluorides that have been prepared as single crystals via mild hydrothermal synthesis methods. Structural characterizations revealed their compositions to be Na 3 AlPu 6 F 30 , Na 3 FePu 6 F 30 , Na 3 CoPu 6 F 30 , and Na 2.4 Mn 1.6 Pu 6 F 30 . Surprisingly, in the plutonium series it was found that Co 2+ and Mn 2+ precursors oxidized to form Na 3 Co III Pu 6 F 30 and Na 2.4 Mn II/III 1.6 Pu 6 F 30 , whereas the analogous reactions for cerium result in reduction of the transition metal, even when beginning with a M 3+ precursor. While cerium is often used as a surrogate for plutonium, this work serves as an example that deviations between their chemistries do occur.

Actinide chalcogenides are of interest for fundamental studies of the behavior of 5f electrons in actinides located in a soft ligand coordination environment. As actinides exhibit an extremely high affinity for oxygen, the synthesis of phase-pure actinide chalcogenide materials free of oxide impurities is a great challenge and, moreover, requires the availability and use of oxygen-free starting materials. Herein, we report a new method, the boron-chalcogen mixture (BCM) method, for the synthesis of phase-pure uranium chalcogenides based on the use of a boron-chalcogen mixture, where boron functions as an "oxygen sponge" to remove oxygen from an oxide precursor and where the elemental chalcogen effects transformation of the oxide precursor into an oxygen-free chalcogenide reagent. The boron oxide can be separated from the reaction mixture that is left to react to form the desired chalcogenide product. Several syntheses are presented that demonstrate the broad functionality of the technique, and thermodynamic calculations that show the underlying driving force are discussed. Specifically, three classes of chalcogenides that include both new (rare earth uranium sulfides and alkali-thorium thiophosphates) and previously reported compounds were prepared to validate the approach: binary uranium and thorium sulfides, oxide to sulfide transformation in solid-state reactions, and in situ generation of actinide chalcogenides in flux crystal growth reactions.

Two polymorphs of a new cesium ferrogermanate zeotype, CsFeGeO4, were synthesized using the molten CsCl-CsF flux growth approach at 900 °C. The orthorhombic polymorph, referred to as (1), crystalli...

RbMgF3, a perovskite halide, serendipitously crystallized from a reaction between MgCl2 and TiO2 in molten RbCl/RbF eutectic flux (melting point = 546 °C) and was characterized by single crystal X-ray diffraction. RbMgF3 crystals can also be grown directly in higher yield using a molten RbCl–RbF flux layered over MgCl2 or MgF2 contained in a silver tube at 575 °C. RbMgF3 crystallizes in the hexagonal space group P63/mmc in the 6H hexagonal perovskite structure type with lattice parameters a = 5.8368(2) A and c = 14.2087(5) A. The crystal structure exhibits face-sharing Mg2F9 octahedra connected via corner-sharing MgF6 octahedra. Elemental composition for RbMgF3 was semi-quantitatively confirmed by energy dispersive spectroscopy (EDS). X-ray diffraction quality single crystals of RbMgF3 were grown from a molten RbCl/RbF eutectic flux at 850 °C and used for structure determination using single crystal X-ray diffraction. The compound crystallizes in the hexagonal space group P63/mmc in the 6H hexagonal structure type.