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Monoclinic TeB4O8 was obtained in a Walker‐type multianvil apparatus at 10 GPa and 1273 K from TeO2 and B2O3. It crystallizes isotypically to the compounds AnB4O8 (An=Th, U) in the space group C2/c (Z=4) with the lattice parameters a=15.6978(8) Å, b=4.2284(2) Å, c=7.4305(4) Å, β=114.78(1)°, and V=447.80(4) Å3. Further, it has been characterized via X‐ray diffraction experiments and IR spectroscopy. [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]

The novel dysprosium borate DyB5O8(OH)2 was synthesized in a Walker‐type multianvil apparatus at a pressure of 2.5 GPa and a temperature of 673 K. Single‐crystal diffraction data provided the basis for the structure solution and refinement. The compound crystallizes in the acentric monoclinic space group C2 (no. 5) with the lattice parameters a = 7.9288(5), b = 4.4009(3), c = 9.3409(8) Å, and a monoclinic angle of 113.76(1)°. Generally, DyB5O8(OH)2 is comprised of a layer‐like structure consisting of corner sharing [BO4]5– tetrahedra forming dreier and sechser rings, and eightfold coordinated dysprosium cations. Further characterizations were performed by IR and luminescence spectroscopy as well as high‐temperature X‐ray diffraction. [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]

Metastable palladium deficient high-pressure phases with the compositions Pd1- xS2 and Pd1- xSe2 could be obtained via high-pressure/high-temperature syntheses at 7.5 GPa (Pd0.88(1)Se2) and 11.5 GPa (Pd0.94(1)S2) at 1523 K. Compared to the normal-pressure modifications they showed a significant decrease in the c-lattice parameters of Δ c/c = 4.4 % (Pd0.94(1)S2) and Δ c/c = 10.8 % (Pd0.88(1)Se2) accompanied by under-occupied palladium sites. Single-crystal analyses indicated the space group Pbca with lattice parameters and refinement results of a = 552.02(8), b = 555.11(8), c = 720.20(11) pm, R1 = 0.0562, wR2 = 0.0710 (all data) for Pd0.94(1)S2 and a = 587.93(3), b = 593.16(4), c = 685.99(4) pm, R1 = 0.0139, wR2 = 0.0232 (all data) for Pd0.88(1)Se2. XPS investigations revealed a partial oxidation of Pd2+ to Pd4+, which was observed for the first time in palladium chalcogenide chemistry. Magnetic susceptibility measurements confirmed the expected diamagnetic behavior. [ABSTRACT FROM AUTHOR]

A tellurate compound with CoII/CoIII mixed valence states and lithium ions within orthogonally oriented channels was realized in Li3Co1.06(1)TeO6. The single-crystal structure determination revealed two independent and interpenetrating Li/O and (Co,Te)/O substructures with octahedral oxygen coordination of the metal atoms. In contrast to other mixed oxides, a honeycomb-like ordering of CoO6 and TeO6 octahedra was not observed. Li3Co1.06(1)TeO6 crystallizes orthorhombically with the following unit cell parameters and refinement results: Fddd, a = 588.6(2), b = 856.7(2), c = 1781.5(4) pm, R1 = 0.0174, wR2 = 0.0462, 608 F2 values, and 33 variables. Additional electron density in tetrahedral voids in combination with neighboring face-linked and under-occupied octahedral lithium sites offers an excellent possible diffusion pathway for lithium ions. According to the symmetry of the crystal structure the diffusion pathways in Li3Co1.06(1)TeO6 were found in two orthogonal orientations. The CoII/CoIII mixed valence was investigated via X-ray photoelectron spectroscopy (XPS), revealing a composition comparable to that derived from single-crystal X-ray diffractometry. Magnetic susceptibility measurements underlined the coexistence of CoII and CoIII, the title compound, however, showed no magnetic ordering down to low temperatures. The ionic conductivity of Li3Co1.06(1)TeO6 was determined via alternating current (AC) electrochemical impedance spectroscopy and was found to be in the range of 1.6 × 10−6 S cm−1 at 573 K. [ABSTRACT FROM AUTHOR]

The intermetallic aluminum compound HP-CePtAl was synthesized by arc melting of the elements with subsequent high-pressure/high-temperature treatment at 1620 K and 10.5 GPa in a multianvil press. The compound crystallizes in the hexagonal MgZn2-type structure ( P63/ mmc) with lattice parameters of a=552.7(1) and c=898.8(2) pm refined from powder X-ray diffraction data. With the help of single crystal investigations ( wR=0.0527, 187 F2 values, 13 variables), the proposed structure type was confirmed and the mixed Pt/Al site occupations could be refined. Magnetic susceptibility measurements showed a disappearance of the complex magnetic ordering phenomena, which are observed in NP-CePtAl. [ABSTRACT FROM AUTHOR]

The monoclinic lithium platinum selenide Li2Pt3Se4 was obtained via a multianvil high-pressure/high-temperature route at 8 GPa and 1200°C starting from a stoichiometric mixture of lithium nitride, selenium, and platinum. The structure of the ternary alkali metal-transition metal-selenide was refined from single-crystal X-ray diffractometer data: P21/ c (no. 14), a=525.9(2), b=1040.6(2), c=636.5(2) pm, β=111.91(1)°, R1=0.0269, wR2=0.0569 (all data) for Li2Pt3Se4. Furthermore, the isostructural mineral phases jaguéite (Cu2Pd3Se4) and chrisstanleyite (Ag2Pd3Se4) were reinvestigated in their ideal stoichiometric ratio. The syntheses of the mineral phases were also carried out under multianvil conditions. Single-crystal data revealed a hitherto not described structural disorder of the transition metal atoms. [ABSTRACT FROM AUTHOR]

The new lithium transition-metal sulfides Li 2 M 3 S 4 ( M =Pd, Pt) were obtained via multianvil high-pressure/high-temperature syntheses at 8 GPa and 1150 °C starting from a stoichiometric mixture of lithium nitride, sulfur, and palladium or platinum. Single crystal structure analyses indicated the space group P 2 1 / c (no. 14) with the following lattice parameters and refinement results: a =492.9(1), b =1005.9(2), c =614.9(2) pm, β =110.9 (1)°, R 1=0.0165, wR 2=0.0308 (all data) for Li 2 Pd 3 S 4 and a =498.2(1), b =1005.5(2), c =613.0(2) pm, β =110.8(1)°, R 1=0.0215, wR 2=0.0450 (all data) for Li 2 Pt 3 S 4 . The crystal structures are built up from two distinct Pd/Pt sites, one of which is a special position (0,0,0), two sulfur sites, and one lithium site. The atoms Pd2/Pt2 form isolated square planar PdS 4 /PtS 4 units, whereas the Pd1/Pt1 atoms form pairs of square planar PdS 4 /PtS 4 units, which are connected via a common edge. These two structural motives built up a three-dimensional network structure by linking through common corners. The lithium atoms are positioned inside of the so formed channels. Li 2 M 3 S 4 ( M =Pd, Pt) are isostructural to the minerals jaguéite, Cu 2 Pd 3 Se 4 and chrisstanleyite, Ag 2 Pd 3 Se 4 , which are up to now the only representatives of this structure type. Both compounds were studied with respect to their magnetic properties and can be classified as Pauli paramagnetic or diamagnetic. Regarding the possibility of lithium mobility inside the channels, of the structure, solid state 7 Li NMR and high-temperature single crystal investigations revealed localization of the lithium atoms on their crystallographic sites. [ABSTRACT FROM AUTHOR]

The monoclinic intermediate-valent gallide CeCoGa decomposes under high-pressure (HP) (9.5 GPa) high-temperature (HT) (1470 K) conditions into the Laves phases CeCo0.58Ga1.42 (MgCu2 type), CeCo0.72Ga1.28 (MgZn2 type; major product phase), and CeCo2 (MgCu2 type). The structures of the ternary Laves phases were refined from single crystal X-ray diffractometer data: Fd3̅ m, a=778.3(1) pm, wR2=0.0310, 63 F2 values, five variables for CeCo0.58(3)Ga1.42(3) and P63/ mmc, a=547.24(5), c=858.76(7) pm, wR2=0.1009, 195 F2 values, 13 variables for CeCo0.72(1)Ga1.28(1). Partial substitution of cobalt by gallium leads to a significant increase of the distances within the tetrahedral network: 253 pm Co-Co in CeCo2 as compared to 275 pm in CeCo0.58(3)Ga1.42(3) and 265-277 pm in CeCo0.72(1)Ga1.28(1). The crystal chemical consequences are briefly discussed. [ABSTRACT FROM AUTHOR]

Monoclinic CeRuSn with its own structure type transforms to a high-pressure modification at 11.5 GPa and 1470 K (1000 t press, Walker type module). The structure of the high-pressure phase was refined from X-ray single crystal diffractometer data at room temperature. The HP-CeRuSn subcell structure adopts the ZrNiAl type: P6̅2m, a = 751.4(3) and c = 394.6(2) pm, wR2 = 0.0787, 310 F2 values and 15 variables. The Ru2 atoms within the Sn6 trigonal prisms show a strongly enhanced U33 parameter. Weak satellite reflections indicate a commensurate modulation: (3 + 1)D superspace group P31m(1/3,1/3,γ)000, a = 751.4(3) and c = 394.6(2) pm, γ = −1/3, wR2 = 0.0786, 1584 F2 values, 32 variables for the main reflections and wR2 = 0.3757 for the satellites of 1st order. A description of this new superstructure variant of the ZrNiAl type is possible in a transformed 3D supercell with the space group R3m and Z = 9. The driving force for formation of the modulation is strengthening of Ru–Sn bonding within the comparatively large Ru@Sn6 trigonal prisms. Electronic structure calculations point to an almost depleted Ce 4f shell. This is substantiated by temperature-dependent magnetic susceptibility data. Fitting of the data within the interconfiguration fluctuation model (ICF) resulted in cerium valences of 3.41 at 10 K and 3.31 at 350 K. Temperature dependent specific heat data underline the absence of magnetic ordering. [ABSTRACT FROM AUTHOR]

A high-pressure/high-temperature experiment based on the multi-anvil technique has yielded a high-pressure (HP) modification of Ca4Te5O14 ( I) from the starting materials Ca(OH)2 and TeO2. Reaction with the boron nitride crucible used in the high-pressure set-up led also to the formation of the mixed-valent TeIV,VI borate Ca13TeVI2/3TeIV3.75O15(BO3)4(OH)3 ( II) as a minor phase. The crystal structures of both compounds were determined by single-crystal X-ray diffraction [ I: P21/ c, Z = 4, a = 11.0272(1), b = 12.0588(1), c = 10.1038(1) Å, β = 91.849(1)°, R1( F2) = 0.0317, wR2( F2) = 0.0459; II: P63/ m, Z = 2, a = 9.0890(13), c = 18.731(4) Å, R1( F2) = 0.0401, wR2( F2) = 0.0867]. The principal building units of HP-Ca4Te5O14, namely [CaO x] ( x = 7, 8) and TeIVO3 and TeIVO4 polyhedra, are similar to those of the ambient modification, but the structural set-up is markedly different in the two structures with an increase in density of about 6.6 %. Ca13TeVI2/3TeIV3.75O15(BO3)4(OH)3 is the first compound known so far to contain both oxotellurate and oxoborate units. The most remarkable feature of its disordered crystal structure is the centrosymmetric Te3O6 unit consisting of a TeVIO6 octahedron sharing opposite faces with two trigonal TeIVO3 pyramids. The face-sharing of TeVI and TeIV oxopolyhedra is unprecedented in the crystal chemistry of oxotellurates. In both structures I and II, the lone-electron pairs of the TeIV atoms are stereochemically active. [ABSTRACT FROM AUTHOR]

The two series of equiatomic rare earth ( RE ) stannides RE NiSn and RE PdSn were systematically studied with respect to high-pressure modifications. The normal-pressure (NP) low-temperature (LT) modifications were synthesized by arc-melting and subsequently treated under high-pressure ( P max =11.5 GPa) and high-temperature ( T max =1570 K) conditions in a Walker-type multi-anvil press. The pressure and temperature conditions were systematically varied in order to improve the crystallization conditions. The new ZrNiAl-type high-pressure modifications HP- RE NiSn ( RE =Sc, Y, La, Gd–Lu) and HP- RE PdSn ( RE =Y, Sm–Dy) were obtained in 80 mg quantities, several of them in X-ray pure form. Some of the RE PdSn stannides with the heavy rare earth elements show high-temperature (HT) modifications. The structures of HP-ScNiSn, HP-GdNiSn, HP-DyNiSn (both ZrNiAl-type), NP-YbNiSn, and HT-ErPdSn (both TiNiSi-type) were refined from single crystal diffractometer data, indicating full ordering of the transition metal and tin sites. TiNiSi-type NP-EuPdSn transforms to MgZn 2 -type HP-EuPdSn: P 6 3 / mmc , a =588.5(2), c =917.0(3) pm, wR 2=0.0769, 211 F 2 values, 11 variables. The structure refinement indicated statistical occupancy of the palladium and tin sites on the tetrahedral network. The X-ray pure high-pressure phases were studied with respect to their magnetic properties. HP-YPdSn is a Pauli paramagnet. The susceptibility data of HP-TbNiSn, HP-DyNiSn, HP-GdPdSn, and HP-TbPdSn show experimental magnetic moments close to the free ion values of RE 3+ and antiferromagnetic ordering at low temperature with the highest Néel temperature of 15.8 K for HP-TbPdSn. HP-SmPdSn shows the typical Van Vleck type behavior along with antiferromagnetic ordering at T N =5.1 K. HP-EuPdSn shows divalent europium and antiferromagnetic ordering at 8.9 K followed by a spin reorientation at 5.7 K. [ABSTRACT FROM AUTHOR]

The oxidation of an intermetallic phase under high-pressure/high-temperature conditions led to the synthesis of Ce4Ag3Ge4O0.5 exhibiting [OCe2Ce2/2] tetrahedral chains, in which the oxygen atoms statistically occupy the tetrahedral centres. Starting from a 1 : 1 : 1 CeAgGe precursor (NdPtSb type), a multianvil high-pressure/high-temperature experiment at 11.5 GPa and 1250–1300 °C revealed Ce4Ag3Ge4O0.5, crystallizing in the space group Pnma with the following lattice parameters: a = 2087.3(4), b = 439.9(1), and c = 1113.8(2) pm. Magnetic measurements showed Curie–Weiss behavior above 100 K with an experimental magnetic moment of 2.42 µB per Ce atom, close to the value for the free Ce3+ ion, clearly indicating trivalent cerium in Ce4Ag3Ge4O0.5. Full potential GGA+U band structure calculations resulted in metallic properties and a magnetic ground state with one unpaired 4f-electron per cerium in agreement with the experiments. [ABSTRACT FROM AUTHOR]

The new cerium polyborate Ce2B8O15 was synthesized under high-pressure/high-temperature conditions of 6 GPa and 1050 ºC in a Walker-type multianvil apparatus. The single-crystal structure determination revealed that the new compound crystallizes in the space group P2/c with the lattice parameters a = 916.6(2), b = 421.0(1), c = 1248.9(3) pm, β = 116.7(1)º, V = 0.4303(2) nm3, R1 = 0.0356, and wR2 = 0.0504. The crystal structure of Ce2B8O15 exhibits a new fundamental building block (FBB) in borate chemistry that consists of four BO4 tetrahedra and can be written as 4□: [Φ] 〈3□〉|□|. These FBB are interconnected via common corners, forming a complex threedimensional network that contains the Ce3+ cations. Ce2B8O15 represents the most boron rich rare-earth borate synthesized under high-pressure/high-temperature conditions so far. We report about the synthetic conditions, structural details, thermal behaviour, and the IR/Raman spectra of Ce2B8O15. [ABSTRACT FROM AUTHOR]

Using high-pressure/high-temperature synthesis methods, it was possible to increase the number of known borates with a crystal structure derived from gadolinite. Syntheses of Tb2Co(B2O5)2 (8 GPa, 1000 °C) and Tb2Cu(B2O5)2 (11 GPa, 650 °C) were carried out in a Walker-type multianvil device. The crystal structures were determined by single-crystal X-ray diffraction methods and Rietveld refinements of the powder patterns. The new compounds were further characterized by their infrared spectra. The lanthanoid cobalt and copper borates Tb2Co(B2O5)2 and Tb2Cu(B2O5)2 crystallize in the monoclinic space group P21/c (no. 14) with the unit cell parameters a = 4.5630(1), b = 7.2991(2), c = 9.4161(2) Å, and β = 91.14(1)° for the cobalt and a = 4.5757(1), b = 7.3078(2), c = 9.3771(3) Å, β = 90.73(1)° for the copper compound. [ABSTRACT FROM AUTHOR]

Colorless, transparent single crystals of the lanthanum oxoarsenate(III) La[AsO3] emerged after exposing an equimolar mixture of La2O3 and As2O3 to high pressure (11.5 GPa) and high temperature (1000 °C). The air- and water-stable compound crystallizes isotypically with K[ClO3] and thus can be described in the monoclinic space group P21/ m with the lattice constants a = 442.91(4), b = 531.40(5), c = 622.83(6) pm and β = 105.564(3)° for Z = 2. Just like the K+ cations in K[ClO3], the crystallographically unique La3+ cations in La[AsO3] are surrounded by nine oxygen atoms ( d(La3+-O2-) = 254-287 pm). The corresponding [LaO9]15- polyhedra get first interconnected by two edges to form infinite $\rm^{1}_{\infty}${[LaO7]11-} chains running along the a axis. These chains generate $\rm^{1}_{\infty}${[LaO6]9-} layers spreading out parallel to the ab plane by vertex-sharing, which are further connected along [001] by common edges to build double layers. The(O1)2- anions remain terminal and protrude from these double layers in c direction, but finally serve for their condensation in order to erect a three-dimensional anionic $\rm^{1}_{\infty}${[LaO3]3-} network. Charge compensation is achieved by incorporation of As3+ cations in creating isolated, ψ1-tetrahedral [AsO3]3- units ( d(As3+-O2-) = 176-177 pm, [ang](O-As-O)= 96-99°). Their lone pairs align along the c axis targeting at opposing La3+ cations. [ABSTRACT FROM AUTHOR]

Information on very high pressure (VHP) effects on proteins is limited and therefore effects of VHP on chemistry, structure and function of two model proteins in medical use were studied. VHP (8 GPa) application to l-asparaginase (L-ASNase) resulted in faster mobility on clear native gels. VHP induced generation of lower-MW forms of L-ASNase but VHP treatment did not deteriorate asparaginase activity. Electrophoretic patterns in native and denaturing gels were comparable for untreated and pressurized recombinant human growth hormone (rhGH). rhGH function, however, was deteriorated as shown by a bioassay. In L-ASNase and rhGH a series of protein modifications and amino acid exchanges (indicating cleavage of covalent bonds) were revealed that may probably lead to functional and conformational changes. The findings have implications in protein chemistry, structure, and function and are useful for designing biotechnological applications of protein products. [ABSTRACT FROM AUTHOR]

Abstract: The intermetallic compounds REPdZn (RE = Y, La, Pr, Nd, Sm, Gd–Tm, Lu) were synthesized from the elements in sealed tantalum ampoules in a high-frequency furnace. They were characterized by powder and single crystal X-ray diffraction. The REPdZn phases crystallize with an orthorhombic TiNiSi type high- and a hexagonal ZrNiAl type low-temperature modification. The crystal chemical details are discussed for α- and β-YPdZn. High-pressure high-temperature studies (up to 11.5 GPa, 1570 K) on the structurally closely related intermetallic compounds GdAuZn and TbAuZn gave no hint for pressure-induced phase transitions. [Copyright &y& Elsevier]

Abstract: High-pressure chemistry led to the synthesis of the rare-earth borate Pr4B10O21 using a Walker-type multianvil apparatus at 3.5GPa and 1050°C. The tetra-praseodymium(III)-decaborate crystallizes monoclinicly with four formula units in the space group P21/n and lattice parameters of a=710.2(2), b=1948.8(4), c=951.6(2)pm, and β=93.27(3)°. The boron–oxygen network consists of [BO4]5− tetrahedra and [BO3]3− groups; however, the [BO4]5− groups represent the major part (80%) due to the high-pressure conditions during the synthesis. The praseodymium ions are coordinated by 10 and 12 oxygen atoms. Along with a detailed description of the crystal structure, temperature programmed X-ray powder diffraction data are shown, demonstrating the metastable character of this compound. [Copyright &y& Elsevier]

Abstract: The hexagonal high-pressure (HP) modification of NdPtSn was prepared under multianvil high-pressure (10.5 GPa) high-temperature (1425 K) conditions from the orthorhombic normal-pressure (NP) modification. NP- and HP-NdPtSn were studied by X-ray powder and single crystal diffraction: TiNiSi type, Pnma, , , , , 441 values, 20 variable parameters for NP-NdPtSn, and ZrNiAl type, , , , , 248 values, 14 variable parameters for HP-NdPtSn. Temperature dependent susceptibility measurements reveal paramagnetism for HP-NdPtSn above 20 K with an experimental magnetic moment of 3.73(2) Nd mol and a paramagnetic Curie temperature of K. The low-temperature data indicate spin glass behavior with a freezing temperature around 4.5 K. The spin glass anomalies are also evident from specific heat measurements. [Copyright &y& Elsevier]

Abstract: The δ modification of lanthanum meta-oxoborate was discovered during our systematic investigations in the field of oxoborates, synthesized under high-pressure conditions. δ-La(BO2)3 (≡δ-LaB3O6) was obtained at high-pressure (5.5 GPa) and high-temperature (1050 °C) in a Walker-type multianvil apparatus. The monoclinic compound crystallizes with four formula units in the space group , exhibiting lattice parameters of , , , and . Due to the synthesis under high-pressure conditions, the structure exhibits [BO4]5− tetrahedra exclusively, which are connected via common corners. Additionally, 1/6 of the oxygen atoms are bridging three boron atoms (O[3]), leading to a network structure with ten-membered rings of [BO4]5− tetrahedra (), in which the La3+ ions are coordinated by twelve oxygen atoms (). After a discussion of the structure, infrared and temperature-dependent X-ray powder diffraction data are presented. [Copyright &y& Elsevier]

Abstract: The new monoclinic cerium borogermanate Ce6(BO4)2Ge9O22 was synthesized under high-pressure and high-temperature conditions in a Walker-type multianvil apparatus at 10.5GPa and 1200°C. Ce6(BO4)2Ge9O22 crystallizes with two formula units in the space group P21/n with lattice parameters , , pm, and . As the parameter pressure favours the formation of compounds with cations possessing high coordination numbers, it was possible to produce simultaneously BO4-tetrahedra and GeO6-octahedra in one and the same borogermanate for the first time. Furthermore, the cerium atoms show high coordination numbers (C.N.: 9 and 11), and one oxygen site bridges one boron and two germanium atoms (O[3]), which is observed here for the first time. Besides a structural discussion, temperature-dependent X-ray powder diffraction data are presented, demonstrating the metastable character of this high-pressure phase. [Copyright &y& Elsevier]

In this work we report about a new oxoborate β-ZnB4O7 synthesized under high-pressure/high-temperature conditions from zinc oxide ZnO and boron oxide B2O3 with a walker-type multianvil apparatus at 10.5 GPa and 1100 °C. Single crystal X-ray structure determination of β-ZnB4O7 revealed: Cmcm, a=1085.0(1) pm, b=648.9(1) pm, c=517.3(1) pm, Z=4, R1=0.0182, wR2=0.0478 (all data). The compound exhibits a new structure type which is built up from linked tetrahedral BO4-groups (□) forming a network. The most prominent feature of the tetrahedral network is that there is an oxygen, which is coordinated to three borons. The network exhibits channels formed from four- and six-membered rings running along [001]. The Zn2+-cations are positioned in the large six-ring channels, whereas the channels built up by four membered rings remain empty. According to the conception of fundamental building blocks β-ZnB4O7 can be classified with the notation 8□:〈3□〉=〈6□〉=〈3□〉. The relation of the crystal structure of the high-pressure phase β-ZnB4O7 to the normal-pressure phase α-ZnB4O7 is discussed. Furthermore we report about temperature-resolved in situ powder diffraction measurements and IR-spectroscopic investigations on β-ZnB4O7. [Copyright &y& Elsevier]

Using the additional parameter pressure (Walker-type multianvil device), the lead(II) oxidotellurate(VI) PbTeO4 was synthesized at conditions of 8 GPa and 750 °C, and for the first time its crystal structure was determined using single-crystal X-ray diffraction data. PbTeO4 crystallizes with four formula units in the monoclinic space group I2/a with unit cell parameters a = 5.4142(4), b = 4.9471(4), c = 12.0437(11) Å, β = 99.603(3)°, and V = 318.07(5) Å3. UV-Vis measurements revealed UV transparency down to 200 nm. From the diffuse reflectance data experimental band gaps (Eg(direct) = 2.9 eV/Eg(indirect) = 2.8 eV) were determined and compared with calculated values. Temperature-dependent X-ray powder diffraction and complementary thermal analysis measurements revealed a stability range of PbTeO4 up to 625 °C. Additionally, theoretical calculations at DFT level of theory were carried out to obtain the electronic band structure, X-ray powder diffraction patterns, IR/Raman vibrational spectra and Mulliken partial charges. The electron localization function (ELF) was visualized to emphasize the presence of the electron lone pair E in the coordination sphere of the PbII atom. [ABSTRACT FROM AUTHOR]

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]

AlB4O6N, Al0.97Cr0.03B4O6N, and Al0.83Cr0.17B4O6N are the first representatives of the recently established structure‐family of oxonitridoborates containing Al3+. These compounds are isotypic to CrB4O6N and are synthesized in a multi‐anvil press under high‐pressure/high‐temperature conditions of 7.0 GPa/1350 °C. Structural refinement by single‐crystal X‐ray diffraction shows that they crystallize in the space group P63mc (no. 186) with two formula units per cell. Detailed characterization including high‐temperature X‐ray powder diffraction (HT‐XRD), electron probe microanalysis (EPMA), measurements of second harmonic generation (SHG), hardness, photoluminescence properties, vibrational spectroscopy, and band structure calculations reveal intriguing physicochemical properties that strongly resemble the famous material ruby. [ABSTRACT FROM AUTHOR]

To unambiguously clarify the long‐debated crystal structure of the low‐temperature orthoborate π‐YBO3, single‐crystals of the europium‐doped π‐YBO3:Eu3+ were prepared via a high‐pressure/high‐temperature route at 7.5 GPa and 1400 °C. The structure was solved and refined in the monoclinic space group C2/c (no. 15) in the pseudowollastonite structure type, with the lattice parameters a=11.3407(5), b=6.5501(3), c=9.5798(4) Å, and β=113.08(2)°. This structure determination was corroborated by powder X‐ray diffraction and vibrational spectroscopy. 11B as well as 89Y MAS NMR spectroscopy was used to verify that our results are also accurate for the undoped π‐YBO3 and samples with varying europium content prepared under ambient pressure conditions. Additionally, the luminescence properties of the Eu3+ doped π‐orthoborate were determined in comparison with these ambient‐pressure samples. [ABSTRACT FROM AUTHOR]

K 3 WOF 7 :Mn4+ was synthesized via a solid-state synthesis route. Main feature of the structure is a quasi-isolated [WOF 5 – unit. When excited by blue light K 3 WOF 7 :Mn4+ exhibits a red luminescence. • Solid-state synthesis of oxyfluoride phosphor K3WOF7:Mn4+ in two facile steps. • Single-crystal structure determination reveals novel structure type of K3WOF7 with [WOF5]‒ as main units. • Luminescence analysis shows line emission spectrum with maximum wavelength of 627 nm. • Temperature dependent luminescence spectra show a good thermal stability up to 75 °C. Synthesis of K 3 WOF 7 :Mn4+ was accomplished via a facile two-step solid-state method. Characterization of the material was carried out by means of single-crystal and powder X-ray diffraction, energy dispersive X-ray spectrometry, as well as luminescence spectroscopy. The substance crystallizes in the monoclinic crystal system in space group P 2 1 / c (no. 14) with the lattice parameters a = 884.2(1), b = 1379.9(1), c = 679.7(1) pm, and β = 93.04(1)°. The crystal structure features a quasi-isolated [WOF 5 − building block as its main motif. The material exhibits a red luminescence under excitation with blue light. The maximum-intensity emission line is located at λ max ≈ 627 nm and the CIE1931 coordinates of the phosphor are 0.689 and 0.310 for x and y , respectively. [ABSTRACT FROM AUTHOR]

We correct the crystal structure of MnF3, of which the space group was reported as monoclinic C2/c (no. 15) with a = 8.9202, b = 5.0472, c = 13.4748 Å, β = 92.64°, V = 606.02 ų, Z = 12, mS48, T not given, likely 298 K. In the structure model proposed here, we use a unit cell of one third of the former volume. The ruby red crystals of MnF3 were synthesized by a high‐pressure/high‐temperature method, where MnF4 was used as a starting material. As determined on a single crystal, MnF3 crystallizes in the monoclinic space group I2/a (no. 15) with a = 5.4964(11), b = 5.0084(10), c = 7.2411(14) Å, β = 93.00(3)°, V = 199.06(7) Å3, Z = 4, mS16, T = 183(2) K. The crystal structure of MnF3 is related by a direct group‐subgroup transition to the VF3 structure‐type. We performed quantum chemical calculations on the crystal structure to allow the assignment of bands of the obtained vibrational spectra. [ABSTRACT FROM AUTHOR]

γ-Sm(BO2)3 was obtained via a high-pressure/high-temperature approach in a multi-anvil apparatus at 10 GPa and 1673 K. It crystallizes in the orthorhombic space group Pca21 (no. 29) with the lattice parameters a = 18.3088(8), b = 4.4181(2), and c = 4.2551(2) Å. The compound was analysed by means of X-ray diffraction and vibrational spectroscopy. The structure is isotypic to that of the already known meta-oxoborates γ-RE(BO2)3 (RE = La−Nd) and built up of a highly condensed borate framework containing three-, four-, six-, and ten-membered rings. Next to neodymium, samarium represents the second rare earth element that forms the α-, β-, and γ-modification of the four known rare earth meta-oxoborate structure types. [ABSTRACT FROM AUTHOR]

γ-Sm(BO2)3 was obtained via a high-pressure/high-temperature approach in a multi-anvil apparatus at 10 GPa and 1673 K. It crystallizes in the orthorhombic space group Pca21 (no. 29) with the lattice parameters a = 18.3088(8), b = 4.4181(2), and c = 4.2551(2) Å. The compound was analysed by means of X-ray diffraction and vibrational spectroscopy. The structure is isotypic to that of the already known meta-oxoborates γ-RE(BO2)3 (RE = La−Nd) and built up of a highly condensed borate framework containing three-, four-, six-, and ten-membered rings. Next to neodymium, samarium represents the second rare earth element that forms the α-, β-, and γ-modification of the four known rare earth meta-oxoborate structure types. [ABSTRACT FROM AUTHOR]

γ-Sm(BO2)3 was obtained via a high-pressure/high-temperature approach in a multi-anvil apparatus at 10 GPa and 1673 K. It crystallizes in the orthorhombic space group Pca21 (no. 29) with the lattice parameters a = 18.3088(8), b = 4.4181(2), and c = 4.2551(2) Å. The compound was analysed by means of X-ray diffraction and vibrational spectroscopy. The structure is isotypic to that of the already known meta-oxoborates γ-RE(BO2)3 (RE = La−Nd) and built up of a highly condensed borate framework containing three-, four-, six-, and ten-membered rings. Next to neodymium, samarium represents the second rare earth element that forms the α-, β-, and γ-modification of the four known rare earth meta-oxoborate structure types. [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]

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]

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]

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]

A potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction. [ABSTRACT FROM AUTHOR]

The title compounds are obtained via hot pressing of stoichiometric amounts of Li3N, Pd or Pt, and sulfur (multianvil press, 8 GPa, 1150 °C, 10 min; cooling to 500 °C within 2 h). [ABSTRACT FROM AUTHOR]

Hot press annealing of a stoichiometric mixture of Ca(OH)2 and TeO2 yields a high-pressure modification of Ca4Te5O14 (I) (h-BN crucible in multianvil press, 8 GPa, 900 °C, 10 min) and minor amounts of Ca13TeVI2/3TeIV3.75 O15(BO3)4(OH)3 (II) resulting from the reaction with the h-BN crucible used in the high-pressure set-up. [ABSTRACT FROM AUTHOR]

Monoclinic Tb 3 B 12 O 19 (OH) 7 was obtained by multianvil high-pressure/high-temperature syntheses at 6 GPa and 650 °C. The crystal structure was investigated by single-crystal X-ray diffraction methods and space group C 2 (no. 5) with the unit cell parameters a = 24.2299(5) Å, b = 4.4667(1) Å, c = 7.0964(2) Å, β = 94.58(1)°, and two formula units per cell were revealed. Powder X-ray diffraction, infrared spectroscopy and the investigation of its second harmonic generation properties support the proposed structural model. The terbium hydroxyborate borate Tb 3 B 12 O 19 (OH) 7 was synthesized under high-pressure conditions in a Walker-type multianvil device at 6 GPa and 650 °C. The new compound was found to crystzallize monoclinically in the space group C 2 (no. 5) with the unit cell parameters a = 24.2299(5) Å, b = 4.4667(1) Å, c = 7.0964(2) Å, β = 94.58(1) °, and two formula units per cell by single-crystal diffraction methods. Tb 3 B 12 O 19 (OH) 7 was further characterized using powder X-ray diffraction, infrared spectroscopy and the investigation of its second harmonic generation properties. [Display omitted] • Tb 3 B 12 O 19 (OH) 7 was synthesized at 6 GPa and 650 °C in a Walker-type multianvil device. • Its crystal structure is built up by a repetitive [B 6 O 13 ]8- building block. • The new compound displays a non-centrosymmetric crystal structure and a strong second harmonic generation effect. [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]

At ambient conditions, PdSe2 dichalcogenides crystallize in the layered PdS2-type structure. If pressure is applied, the coordination number of palladium atoms increases and the three-dimensional pyrite-type structure with octahedral (PdSe6)4− coordination geometry is observed. For the first time, single crystals of a pyrite-type PdSe2 modification could be obtained and characterized, which were grown by multianvil high-pressure/high-temperature synthesis at 7.5 GPa and 1023 K. The crystals show the expected pyrite-type space group Pa3̅ (no. 205) and refinement results of a=613.26(3) pm, R1=0.0233, and wR2=0.0247 (all data) were received for HP-Pd0.84(1)Se2. The single-crystal data revealed significant defect formation on the palladium site with 16% vacancies, which is in line with the orthorhombic PdX2-type high-pressure polymorphs HP-Pd0.94(1)S2 and HP-Pd0.88(1)Se2. The tendency of vacancy formation on the palladium site could also be verified by EDX measurements. [ABSTRACT FROM AUTHOR]

A new tin(II) borate with the composition SnB8O11(OH)4 was synthesized by a simple hydrothermal process. It crystallizes in the centrosymmetric monoclinic space group P21/n (no. 14) with the lattice parameters a=790.1(1), b=1402.2(2), c=994.8(1) pm, and β=90.40(5)° (Z=4). The new compound SnB8O11(OH)4 is isotypic to PbB8O11(OH)4 and isostructural to BaB8O11(OH)4. The borate layers are built up from fundamental building blocks (FBBs) with the composition [B8O11(OH)4]2−. Four of these FBBs form a nine-membered ring wherein the Sn2+ cations are located. These boron-oxygen layers are further connected by O–H···O hydrogen bond interactions. The characterization of SnB8O11(OH)4 is based on single-crystal X-ray diffraction data, vibrational spectroscopy, DFT calculations, and thermoanalytical investigations including high temperature powder XRD. [ABSTRACT FROM AUTHOR]

In the system Sn-B-O-H, the first tin borate Sn 2 B 3 O 6 (OH) was successfully synthesized by a simple hydrothermal process. The compound crystallizes in the centrosymmetric monoclinic space group P2 1 /n (no. 14) with the lattice parameters a = 443.5(2), b = 1102.5(4), c = 1396.4(5) pm, and β = 95.31(1)° ( Z = 4). Structurally, Sn 2 B 3 O 6 (OH) features infinite chains of B 3 O 8 groups connected along the a axis. The Sn 2+ cations are arranged in form of layers between the anionic borate chains. Interestingly, Sn 2 B 3 O 6 (OH) is the first example of a hydrothermally synthesized tin borate, in which adjacent anionic borate chains are further connected by O–H···O hydrogen bond interactions into a three-dimensional structure. The characterization of Sn 2 B 3 O 6 (OH) is based on single-crystal X-ray diffraction data, vibrational spectroscopy, DFT calculations, and thermoanalytical investigations. [ABSTRACT FROM AUTHOR]

Single crystals of the high-pressure phase of Ce7Au13+xGe10-x are obtained by treatment of CeAuGe at 9.5 GPa and 1473-1523 K in a multi-anvil press. [ABSTRACT FROM AUTHOR]

The indium oxide-borate In4O2B2O7 was synthesized under high-pressure/high-temperature conditions at 12.5 GPa/1420 K using a Walker-type multianvil apparatus. Single-crystal X-ray structure elucidation showed edge-sharing OIn4 tetrahedra and B2O7 units building up the oxide-borate. It crystallizes with Z = 8 in the monoclinic space group P21/n (no. 14) with a = 1016.54(3), b = 964.55(3), c = 1382.66(4) pm, and β = 109.7(1)°. The compound was also characterized by powder X-ray diffraction and vibrational spectroscopy. [ABSTRACT FROM AUTHOR]

The new equiatomic silicides NbOsSi and TaOsSi as well as ZrOsSi, T IrSi ( T = Zr, Hf, Nb, Ta) and T PtSi ( T = Nb, Ta) were prepared from the elements by arc-melting. These silicides crystallize with the orthorhombic TiNiSi type structure, space group Pnma . Irregularly shaped crystals of ZrOsSi, NbOsSi, TaOsSi, ZrIrSi and HfIrSi were separated from the annealed samples and investigated by single-crystal X-ray diffraction ( a = 640.46(7), b = 404.07(5), c = 743.66(8) pm, wR 2 = 0.0285, 390 F 2 values, 20 variables for ZrOsSi; a = 629.78(6), b = 388.72(4), c = 727.48(7) pm, wR 2 = 0.0350, 397 F 2 values, 20 variables for NbOsSi, a = 626.80(6), b = 389.36(4), c = 726.22(7) pm, wR 2 = 0.0501, 385 F 2 values, 20 variables for TaOsSi, a = 653.48(8), b = 395.35(4), c = 739.19(8) pm, wR 2 = 0.0427, 413 F 2 values, 20 variables for ZrIrSi and a = 646.34(12), b = 393.57(7), c = 736.8(14) pm, wR 2 = 0.0582, 371 F 2 values, 20 variables for HfIrSi). The striking structural motifs in the new osmium compounds are three-dimensional [OsSi] networks (Os–Si: 240–251 pm) in which the osmium atoms have strongly distorted tetrahedral silicon coordination. High-pressure/high-temperature experiments (9.5 GPa/1520 K) on TaOsSi gave no hint for a structural phase transition. Temperature dependent measurements of the magnetic susceptibility and the electrical conductivity of NbOsSi and TaOsSi showed superconductivity below T C = 3.5 and 5.5 K, respectively. 29 Si solid state MAS NMR investigations of the prepared silicides approved the structural models and showed a correlation between the observed 29 Si resonance shifts and the electronegativity of the involved refractory metal. [ABSTRACT FROM AUTHOR]