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Oxyfluorides come in many different structures and are highly adaptable in composition, not least because of their mixed-anionic nature. Slight changes, unless specifically looked for, can easily go unnoticed. In this paper, we present two oxyfluorides, K3Mo2O5.6F3.4 and K3V2O3.3F5.7, synthesized under high-pressure/high-temperature conditions, and demonstrate the importance of careful analysis of composition, oxidation state and O/F anion distribution for an accurate description of oxyfluorides. Their crystal structures were determined by single-crystal X-ray diffraction and the transition metal cation valences analyzed by X-ray photoelectron spectroscopy (XPS). The O/F anion ratio was calculated using the principle of charge neutrality and the local distribution within the crystallographic framework was studied using bond valence (BV) and charge distribution (CHARDI) calculations. Madelung Part of Lattice Energy (MAPLE) calculations and magnetic measurements provide insight into phase stability and corroborate the mixed-valent nature of the compounds. [ABSTRACT FROM AUTHOR]

We report on the synthesis, structure determination, and characterization of a new series of compounds LnCdB6O10(OH)3 (Ln = Sm–Er). Syntheses were carried out in a Walker-type multianvil device at 7 GPa and 650 °C. Structure determinations revealed the coexistence of an orthorhombic and a monoclinic polymorph, depending on the ionic radius of the lanthanoid cation. The orthorhombic structural variants crystallize non-centrosymmetrically in the space group Pna21 (no. 33), while the monoclinic modifications crystallize in space group P21/c (no. 14). Both modifications display a layered crystal structure built up by a repeating [B6O13]8− building block as their main structural feature. [ABSTRACT FROM AUTHOR]

The orthorhombic phases LaB3.6O7 and PrB3.6O7 were obtained by high‐pressure/high‐temperature syntheses at 11 GPa and temperatures of 1130 °C (LaB3.6O7) as well as 850 °C (PrB3.6O7) using a modified Walker‐type multianvil apparatus. The title compounds crystallize in the space group Pmn21 (no. 31) exhibiting a defective α‐SrB4O7 structure variant with the unit cell parameters a=10.4551(3) Å, b=4.4562(1) Å, c=4.2973(1) Å for LaB3.6O7 and a=10.4305(3) Å, b=4.4257(1) Å, c=4.2815(1) Å for PrB3.6O7. Both compounds were characterized by powder/single‐crystal X‐ray diffraction, vibrational spectroscopy, second harmonic generation, and electron dispersive X‐ray spectroscopy measurements. [ABSTRACT FROM AUTHOR]

NdB6O8(OH)5·H3BO3, triclinic, P 1 ‾ (no. 2), a = 6.8304(7) Å, b = 7.2004(5) Å, c = 12.707(2) Å, α = 95.479(5)°, β = 98.652(6)°, γ = 101.758(5)°, V = 599.7(2) Å3, Z = 2, Rgt(F) = 0.0378, wRref(F2) = 0.0826, T = 289(1) K. [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 zinc borate Zn6.1B6O19H7.8 was synthesized via a high‐pressure/high‐temperature multianvil approach at 10 GPa and 1573 K. The structure of the non‐centrosymmetric compound was investigated by single‐crystal X‐ray diffraction measurements, exhibiting (BO4), (ZnO5), and (ZnO6) units including a distinct disorder on a part of the zinc and boron sites. The IR spectroscopic data on the bulk material confirm the presence of hydroxyl groups in this new borate. [ABSTRACT FROM AUTHOR]

Tm2CrB3O9 was obtained by high-pressure/high-temperature syntheses at 7.5 GPa and 850 °C. The compound crystallizes homeotypically to walstromite in the triclinic space group P 1 ¯ (no. 2) with the unit cell parameters a = 5.9118(4) Å, b = 5.9148(4) Å, c = 8.3575(6) Å, α = 83.64(1)°, β = 71.19(1)°, and γ = 79.93(1)°, and two formula units per cell. Single-crystal and powder diffraction data are accompanied by an infrared spectroscopic investigation and the structural features of this new compound are discussed in detail. [ABSTRACT FROM AUTHOR]

The new zinc borate Zn6.1B6O19H7.8 was synthesized via a high‐pressure/high‐temperature multianvil approach at 10 GPa and 1573 K. The structure of the non‐centrosymmetric compound was investigated by single‐crystal X‐ray diffraction measurements, exhibiting (BO4), (ZnO5), and (ZnO6) units including a distinct disorder on a part of the zinc and boron sites. The IR spectroscopic data on the bulk material confirm the presence of hydroxyl groups in this new borate. [ABSTRACT FROM AUTHOR]

The neodymium borate Nd3B5O11(OH)2 was obtained from Nd2O3, B2O3, and H3BO3 by high‐pressure/high‐temperature synthesis at 13 GPa and 850 °C. Based on single‐crystal diffraction data, a crystal structure in the orthorhombic space group Pnna (no. 52) with the unit cell parameters a=4.5128(1) Å, b=13.3264(3) Å, c=14.1882(4) Å, and four formula units per cell was found. The crystal structure is built up by a framework of corner‐sharing [BO4]5− tetrahedra forming corrugated eight‐, ten‐, and fourteen‐membered rings. Furthermore, the powder X‐ray diffraction pattern and the infrared spectrum of the title compound are reported. [ABSTRACT FROM AUTHOR]

The new zinc borate Zn3B7O13(OH) crystallizes trigonally in the space group R3c (no. 161) with the lattice parameters a = 849.76(3), c = 2099.8(2) pm, V = 1.3131(2) nm3, and six formula units per unit cell (Z = 6). It was synthesized at high-pressure/high-temperature conditions in a multianvil device. Single-crystal and powder X-ray diffraction experiments were conducted. [ABSTRACT FROM AUTHOR]

Five transition metal borates were synthesized in a Walker-type module under high-pressure/high-temperature conditions of 8–9 GPa and 800–1200 °C. They all exhibit the same interpenetrating, anionic borate network B12O2616−, crystallizing in the space group I41/acd, and therefore show high similarities to the borates Ti5B12O26 and Ga5B12O25(OH). Cr5B12O25(OH) and V5B12O25(OH) are isotypic to Ga5B12O25(OH), whereas Mn5Mn0.83B12O26 and Fe5Fe0.14B12O24.3(OH)1.7 feature the partial occupation of an additional, cuboctahedral cavity in the structure. This is due to a partial reduction of the cations to the oxidation state +2, as presented with the novel compound Mn5MnB12O22(OH)4, which only features Mn2+ for charge compensation. These structures feature a twelvefold coordination of manganese and iron. [ABSTRACT FROM AUTHOR]

In this paper, a new high-pressure (HP) polymorph of the otherwise known oxyfluoride K2MoO2F4 is presented. The crystal structure was determined by use of single-crystal X-ray diffractometry and its features are described in detail herein. HP-K2MoO2F4 crystallizes in the monoclinic space group C2/m (no. 12) with the cell parameters a = 13.8579(5), b = 5.8109(2), c = 6.9442(3) Å, β = 90.36(1)°, V = 559.18(4) Å3, and Z = 4 at T = 301(2) K. Bond valence (BV) and charge distribution (CHARDI) calculations were carried out to support the assignment of oxygen and fluorine to the various anion positions and Madelung part of lattice energy (MAPLE) calculations were used to validate the structure model. Infrared spectroscopy provided further information on the structure and water content of the inseparable side phase. [ABSTRACT FROM AUTHOR]

In this paper, a new high-pressure (HP) polymorph of the otherwise known oxyfluoride K2MoO2F4 is presented. The crystal structure was determined by use of single-crystal X-ray diffractometry and its features are described in detail herein. HP-K2MoO2F4 crystallizes in the monoclinic space group C2/m (no. 12) with the cell parameters a = 13.8579(5), b = 5.8109(2), c = 6.9442(3) Å, β = 90.36(1)°, V = 559.18(4) Å3, and Z = 4 at T = 301(2) K. Bond valence (BV) and charge distribution (CHARDI) calculations were carried out to support the assignment of oxygen and fluorine to the various anion positions and Madelung part of lattice energy (MAPLE) calculations were used to validate the structure model. Infrared spectroscopy provided further information on the structure and water content of the inseparable side phase. [ABSTRACT FROM AUTHOR]

The impact of the surrounding ligand field is successfully exploited in the case of Eu2+ to tune the emission characteristics of inorganic photoactive materials with potential application in, e.g. phosphor‐converted white light‐emitting diodes (pc‐wLEDs). However, the photoluminescence of Mn2+ related to intraconfigurational 3d5–3d5 transitions is also strongly dependent on local ligand field effects and has been underestimated in this regard so far. In this work, we want to revive the idea how to electronically tune the emission color of a transition metal ion in inorganic hosts by unusual electronic effects in the metal‐ligand bond. The concept is explicitly demonstrated for the weakly coordinating layer‐like borosulfate ligand in the Mn2+‐containing solid solutions Zn1‐xMnx[B2(SO4)4] (x = 0, 0.03, 0.04, 0.05, 0.10). Zn[B2(SO4)4]:Mn2+ shows orange narrow‐band luminescence at 590 nm, which is an unusually short wavelength for octahedrally coordinated Mn2+ and indicates an uncommonly weak ligand field. On the other hand, the analysis of the interelectronic Racah repulsion parameters reveals ionic Mn−O bonds with values close to the Racah parameters of the free Mn2+ ion. Overall, this strategy demonstrates that electronic control of the metal‐ligand bond can be a tool to make Mn2+ a potent alternative emitter to Eu2+ for inorganic phosphors. [ABSTRACT FROM AUTHOR]

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The synthesis and crystal structure of Zn6B22O39·H2O are described. This new zinc borate was synthesized at 7 GPa and 1523 K in a multianvil device. It crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 818.77(4), b = 768.42(3), c = 1744.82(9) pm, V = 1.09777(9) nm3, and two formula units per unit cell (Z = 2). The structure is closely related to those of M6B22O39·H2O (M = Fe, Co, Ni, Cd) and features non-planar (BO3) units as demonstrated by single-crystal and powder X-ray diffraction techniques. [ABSTRACT FROM AUTHOR]

The compounds Li6MoN4 and Li6WN4 were prepared from the reactants M (M = Mo, W) and Li3N in a radiofrequency furnace at 1000 °C. The lithonitridometallates crystallize in the tetragonal system with the lattice parameters: a = 6.6844(1), c = 4.9294(1) Å for Li6WN4 based on single-crystal X-ray diffraction data and a = 6.6611(3), c = 4.9338(3) Å for Li6MoN4 taken from powder X-ray diffraction data. Colorless to slightly reddish single-crystals of the tungsten compound were isolated and the crystal structure was refined in the space group P42/nmc (no. 137) with Z = 2 and the powder X-ray data of the molybdenum compound were analyzed by a Rietveld refinement. Both structures belong to the Li6[ZnO4] type published by Hoppe et al. in 1987 (Untenecker H., Hoppe R. Z. Anorg. Allg. Chem. 1987, 551, 147–150) and could be doped with Ce3+ for the first time. The investigated compounds show a reddish color impression upon UV to blue irradiation and exhibit a broad emission band with a maximum at λmax = 693 nm (fwhm 97 nm) for Li6MoN4 and at λmax = 653 nm (fwhm 133 nm) for Li6WN4. [ABSTRACT FROM AUTHOR]