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A hitherto unknown modification of I2O5 was obtained from high‐pressure/high‐temperature syntheses in a Walker‐type multianvil device at 8 GPa and 250 °C. HP‐I2O5 crystallizes in the monoclinic crystal system with space group P21/c (no. 14) with the unit cell parameters a=12.0612(3) Å, b=4.8613(2) Å, c=6.9585(2) Å, β=100.10(1)° (at 173 K), and four formula units per cell. The single‐crystal structure data are accompanied by powder X‐ray diffraction data at ambient and elevated temperatures. Furthermore, DFT calculations were carried out to investigate the phase transition between the ambient‐pressure polymorph NP‐I2O5 to the newly synthesized high‐pressure phase. [ABSTRACT FROM AUTHOR]

LixMoS2 is not only a lithium battery material, but is also an important precursor for the synthesis of MoS2 nanomaterials. Current syntheses of MoS2, such as in n‐butyllithium/LiBH4 or electrochemically, are not satisfying in terms of defined stoichiometry and crystallinity, so an accurate experimental crystal structure determination of this important and widely used material has been long awaited. A high‐pressure/high‐temperature synthesis yielded highly crystalline 1T′′‐LixMoS2 (x=1, 1.333). 1T′′‐LiMoS2 crystallizes in the space group P1‾ $\bar 1$ with a=6.2482(3) Å, b=6.6336(3) Å, c=6.7480(3) Å, α=119.321(2)°, β=90.010(2)° and γ=90.077(2)°. The arrangement of Mo atoms within the b‐c‐plane confirmed a predicted Peierls distortion. A similar atom distribution pattern to that of Mo is also observed for the lithium atoms. Calculation of bond valence site energies gave an activation barrier of 1.244 eV for 2D lithium‐ion migration. For x=1.333, a phase‐pure synthesis was achieved. [ABSTRACT FROM AUTHOR]

As a consequence of the static Jahn‐Teller effect of the 5E ground state of MnIII in cubic structures with octahedral parent geometries, their octahedral coordination spheres become distorted. In the case of six fluorido ligands, [MnF6]3− anions with two longer and four shorter Mn−F bonds making elongated octahedra are usually observed. Herein, we report the synthesis of the compound K3[MnF6] through a high‐temperature approach and its crystallization by a high‐pressure/high‐temperature route. The main structural motifs are two quasi‐isolated, octahedron‐like [MnF6]3− anions of quite different nature compared to that met in ideal octahedral MnIII Jahn‐Teller systems. Owing to the internal electric field of Ci symmetry dominated by the next‐neighbour K+ ions acting on the MnIII sites, both sites, the pseudo‐rhombic (site 1) and the pseudo‐tetragonally elongated (site 2) [MnF6]3− anions are present in K3[MnF6]. The compound was characterized by single‐crystal and powder X‐ray diffraction, and magnetometry as well as by FTIR, Raman, and ligand field spectroscopy. A theoretical interpretation of the electronic structure and molecular geometry of the two Mn sites in the lattice is given by using a vibronic coupling model with parameters adjusted from multireference ab‐initio cluster calculations. [ABSTRACT FROM AUTHOR]

La3B6O13(OH) was obtained by a high‐pressure/high‐temperature experiment at 6 GPa and 1673 K. The compound crystallizes in the space group P21 (no. 4) with the lattice parameters a=4.785(2), b=12.880(4), c=7.433(3) Å, and β=90.36(10)°, and is built up of corner‐ as well as edge‐sharing BO4 tetrahedra. It represents the first acentric high‐pressure borate containing these B2O6 entities. The compound develops borate layers of „sechser"‐rings with the La3+ cations positioned between the layers. Single‐crystal and powder X‐ray diffraction, vibrational and MAS NMR spectroscopy, second‐harmonic generation (SHG) and thermoanalytical measurements, as well as computational methods were used to affirm the proposed structure and the B2O6 entities. [ABSTRACT FROM AUTHOR]

This article, titled "Pressure-Assisted Synthesis of Highly Crystalline 1T''-LiMoS2," discusses the challenging process of preparing LiMoS2 with high crystallinity. The cover feature of the journal showcases the crystal structure of LiMoS2, which consists of slightly distorted MoS2 layers with lithium in between. The article highlights a high-pressure/high-temperature synthesis method that has allowed researchers to elucidate the crystal structure. The research article by S. Schwarzmüller and co-workers provides more detailed information on this topic. [Extracted from the article]

A laboratory‐scale synthesis of UF4 is presented that utilizes the reduction of UF6 with sulfur in anhydrous hydrogen fluoride. An excess of sulfur can be removed by vacuum sublimation, yielding pure UF4, 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 UF4 was obtained in a multi‐anvil press at elevated temperatures. The high‐pressure polymorph HP‐UF4 was characterized by means of single‐crystal and powder X‐ray diffraction, as well as by magnetic measurements, and presents a novel crystal structure type. Quantum‐chemical calculations show the HP‐modification to be 10 kJ mol−1 per formula unit higher in energy compared to UF4. [ABSTRACT FROM AUTHOR]

LixMoS2 is not only a lithium battery material, but is also an important precursor for the synthesis of MoS2 nanomaterials. Current syntheses of MoS2, such as in n‐butyllithium/LiBH4 or electrochemically, are not satisfying in terms of defined stoichiometry and crystallinity, so an accurate experimental crystal structure determination of this important and widely used material has been long awaited. A high‐pressure/high‐temperature synthesis yielded highly crystalline 1T′′‐LixMoS2 (x=1, 1.333). 1T′′‐LiMoS2 crystallizes in the space group P1‾ $\bar 1$ with a=6.2482(3) Å, b=6.6336(3) Å, c=6.7480(3) Å, α=119.321(2)°, β=90.010(2)° and γ=90.077(2)°. The arrangement of Mo atoms within the b‐c‐plane confirmed a predicted Peierls distortion. A similar atom distribution pattern to that of Mo is also observed for the lithium atoms. Calculation of bond valence site energies gave an activation barrier of 1.244 eV for 2D lithium‐ion migration. For x=1.333, a phase‐pure synthesis was achieved. [ABSTRACT FROM AUTHOR]

The new high-pressure borate HP-Cs1− x(H3O) xB3O5 ( x=0.5-0.7) was synthesized under high-pressure/high-temperature conditions of 6 GPa/900 °C in a Walker-type multianvil apparatus. The compound crystallizes in the monoclinic space group C2/ c ( Z=8) with the parameters a=1000.6(2) , b=887.8(2), c=926.3(2) pm, β=103.1(1)°, V=0.8016(3) nm3, R1=0.0452, and wR2=0.0721 (all data). The boron-oxygen network is analogous to those of the compounds HP-MB3O5, (M=K, Rb) and exhibits all three structural motifs of borates-BO3 groups, corner-sharing BO4 tetrahedra, and edge-sharing BO4 tetrahedra-at the same time. Channels inside the boron-oxygen framework contain the cesium and oxonium ions, which are disordered on a specific site. Estimating the amount of hydrogen by solid-state NMR spectroscopy and X-ray diffraction led to the composition HP-Cs1− x(H3O) xB3O5 ( x=0.5-0.7), which implies a nonzero phase width. [ABSTRACT FROM AUTHOR]

New actinide borates ThB4O8 and UB4O8 were synthesized under high-pressure, high-temperature conditions (5.5 GPa/1100 °C for thorium borate, 10.5 GPa/1100 °C for the isotypic uranium borate) in a Walker-type multianvil apparatus from their corresponding actinide oxide and boron oxide. The crystal structure was determined on basis of single-crystal X-ray diffraction data that were collected at room temperature. Both compounds crystallized in the monoclinic space group C2/ c ( Z=4). Lattice parameters for ThB4O8: a=1611.3(3), b=419.86(8), c=730.6(2) pm; β=114.70(3)°; V=449.0(2) Å3; R1=0.0255, wR2=0.0653 (all data). Lattice parameters for UB4O8: a=1589.7(3), b=422.14(8), c=723.4(2) pm; β=114.13(3)°; V=443.1(2) Å3; R1=0.0227, wR2=0.0372 (all data). The new AnB4O8 (An=Th, U) structure type is constructed from corner-sharing BO4 tetrahedra, which form layers in the bc plane. One of the four independent oxygen atoms is threefold-coordinated. The actinide cations are located between the boron-oxygen layers. In addition to Raman spectroscopic investigations, DFT calculations were performed to support the assignment of the vibrational bands. [ABSTRACT FROM AUTHOR]

A laboratory‐scale synthesis of UF4 is presented that utilizes the reduction of UF6 with sulfur in anhydrous hydrogen fluoride. An excess of sulfur can be removed by vacuum sublimation, yielding pure UF4, 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 UF4 was obtained in a multi‐anvil press at elevated temperatures. The high‐pressure polymorph HP‐UF4 was characterized by means of single‐crystal and powder X‐ray diffraction, as well as by magnetic measurements, and presents a novel crystal structure type. Quantum‐chemical calculations show the HP‐modification to be 10 kJ mol−1 per formula unit higher in energy compared to UF4. [ABSTRACT FROM AUTHOR]