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Developing superior deep-ultraviolet (deep-UV) nonlinear optical (NLO) materials is a great challenge because of the contradiction between deep-UV transparency and enhanced second harmonic generation (SHG), especially for deep-UV NLO phosphates in which the constituent P–O groups have relatively small microscopic SHG coefficients. Here we report a new noncentrosymmetric phosphate Cs2LiPO4 (I), whose crystal structure consists of [LiPO4]∞ layered structural units with a novel honeycomb-like topology. As compared with the benchmark deep-UV NLO material KBe2BO3F2, I is beryllium-free, and it is relatively easy to grow its large single crystals because of its congruent melting. Furthermore, it not only is deep-UV transparent but also exhibits an unexpectedly enhanced SHG response of 1.8 × KH2PO4 that hits a new high in deep-UV NLO phosphates. These results demonstrate that I satisfies the key requirements of being a promising deep-UV NLO candidate. Theory calculations and structural analysis reveal that the e...

Single crystals (SCs) of the compounds Eu3Ag2In9 and EuCu2Ge2 were synthesized through the reactions run in liquid indium. Eu3Ag2In9 crystallizes in the La3Al11 structure type [orthorhombic space group (SG) Immm] with the lattice parameters: a = 4.8370(1) A, b = 10.6078(3) A, and c = 13.9195(4) A. EuCu2Ge2 crystallizes in the tetragonal ThCr2Si2 structure type (SG I4/mmm) with the lattice parameters: a = b = 4.2218(1) A, and c = 10.3394(5) A. The crystal structure of Eu3Ag2In9 is comprised of edge-shared hexagonal rings consisting of indium. The one-dimensional chains of In6 rings are shared through the edges, which are further interconnected with other six-membered rings forming a three-dimensional (3D) stable crystal structure along the bc plane. The crystal structure of EuCu2Ge2 can be explained as the complex [CuGe](2+δ)– polyanionic network embedded with Eu ions. These polyanionic networks present in the crystal structure of EuCu2Ge2 are shared through the edges of the 011 plane containing Cu and Ge ...

A solid-state combinatorial chemistry approach, which used the A–Ge–O (A = Li, K, Rb) system doped with a small amount of Mn4+ as an activator, was adopted in a search for novel red-emitting phosphors. The A site may have been composed of either a single alkali metal ion or of a combination of them. This approach led to the discovery of a novel phosphor in the above system with the chemical formula Li3RbGe8O18:Mn4+. The crystal structure of this novel phosphor was solved via direct methods, and subsequent Rietveld refinement revealed a trigonal structure in the P31m space group. The discovered phosphor is believed to be novel in the sense that neither the crystal structure nor the chemical formula matches any of the prototype structures available in the crystallographic information database (ICDD or ICSD). The measured photoluminescence intensity that peaked at a wavelength of 667 nm was found to be much higher than the best intensity obtained among all the existing A2Ge4O9 (A = Li, K, Rb) compounds in t...

The binary zirconium and hafnium polyazides [PPh4]2[M(N3)6] (M=Zr, Hf) were obtained in near quantitative yields from the corresponding metal fluorides MF4 by fluoride–azide exchange reactions with Me3SiN3 in the presence of two equivalents of [PPh4][N3]. The novel polyazido compounds were characterized by their vibrational spectra and their X-ray crystal structures. Both anion structures provide experimental evidence for near-linear M-N-N coordination of metal azides. The species [M(N3)4], [M(N3)5]− and [M(N3)6]2− (M=Ti, Zr, Hf) were studied by quantum chemical calculations at the electronic structure density functional theory and MP2 levels.

New layered honeycomb tellurates, BiM(III)TeO6 (M = Cr, Mn, Fe) were synthesized and characterized. BiM(III)TeO6 (M = Cr, Fe) species crystallize in a trigonal space group, P31c (No. 163), of edge-sharing M3+/Te6+O6 octahedra, which form honeycomb-like double layers in the ab plane with Bi3+ cations located between the layers. Interestingly, the structure of BiMnTeO6 is similar to those of the Cr/Fe analogues, but with monoclinic space group, P21/c (No. 14), attributed to the strong Jahn–Teller distortion of Mn3+ cations. The crystal structure of BiM(III)TeO6 is a superstructure of PbSb2O6-related materials (ABB′O6). The Cr3+ and Fe3+ cations are ordered 80% and 90%, respectively, while the Mn3+ ions are completely ordered on the B-site of the ABB′O6 structure. BiCrTeO6 shows a broad antiferromagnetic transition (AFM) at ∼17 K with a Weiss temperature (θ) of −59.85 K, while BiFeTeO6 and BiMnTeO6 show sharp AFM transitions at ∼11 K with θ of −27.56 K and at ∼9.5 K with θ of −17.57 K, respectively. These d...

Novel melilite-type Ca2Ga2SiO7:Eu3+ red-emitting phosphors with different Eu3+ contents were synthesized via high-temperature solid-state reaction. The crystal structure, optical absorption, and photoluminescence properties were investigated, while density functional theory calculations were performed on the host lattice. The excitation spectra indicate that phosphors can be effectively excited by near-UV light for a potential application in white-light-emitting diodes. Because of the abnormally high intensity emission at about 700 nm arising from the 5D0 → 7F4 transition of Eu3+, the phosphors Ca2Ga2SiO7:Eu3+ show a deep-red emission with chromaticity coordinates (0.639, 0.358).

The atomic radii obtained by relativistic all-electron DFT calculations correlate remarkably well with van der Waals radii derived from crystal structures.

The crystallographic, electronic transport and thermal properties of Ca 2 PdGe 3 and Ca 2 PtGe 3 are reported. The compounds crystalize in an ordered variant of the AlB 2 crystal structure, in space group P 6/mmm , with the lattice parameters a = 8.4876(4) A/8.4503(5) A and c = 4.1911(3) A/4.2302(3) A for Ca 2 PdGe 3 and Ca 2 PtGe 3 , respectively. The resistivity data exhibit metallic behavior with residual-resistivity-ratios (RRR) of 13 for Ca 2 PdGe 3 and 6.5 for Ca 2 PtGe 3 . No superconducting transition is observed down to 0.4 K. Specific heat studies reveal similar values of the Debye temperatures and Sommerfeld coefficients: Θ D = 298 K, γ = 4.1 mJ mol − 1 K − 2 and Θ D = 305 K, γ = 3.2 mJ mol − 1 K − 2 for Ca 2 PdGe 3 and Ca 2 PtGe 3 , respectively. The low value of γ is in agreement with the electronic structure calculations.

In search of environmentally benign insecticides with high activity, low toxicity, and low residue, a series of novel anthranilic diamide containing propargyl ether were designed and synthesized. All compounds were characterized by H-1 NMR spectroscopy, high-resolution mass spectrometry, or elemental analysis. The single crystal structure of 18g was determined by X-ray diffraction. The insecticidal activities against Lepidoptera pests of the new compounds were evaluated. Their insecticidal activities against oriental armyworm (Mythimna separata) and diamondback moth (Plutella xylostella) indicated that most of the compounds showed moderate to high activities at the tested concentration.

Li 4 MgOsO 6 was synthesized by two different solid-state reaction procedures. The crystal structures were determined by X-ray powder diffraction technique and it was revealed that Li 4 MgOsO 6 crystallizes in two different crystal symmetries in ordered rock salt structure type, namely monoclinic C2/m and orthorhombic Fddd . The unit cell constants for the monoclinic system are a =5.1074(4) A, b= 8.8182(4) A, c= 5.0902(2) A, and β =109.845 ( 4)° and those of the orthorhombic structure are a =5.8485(1) A, b =8.3821(1) A, and c =17.6212(3) A. In both systems, Os 6+ ions reside exclusively in a specific crystallographic position while Li + and Mg 2+ ions exhibit mix occupancy. The temperature dependent magnetic susceptibility data for both S=1 osmate systems do not support the occurrence of any magnetic transition down to 2 K. The Curie–Weiss fit to the paramagnetic regime of the magnetic susceptibility data reveal highly negative θ value (−114.81 K and −121.87 K for C2/m and for Fddd systems , respectively ) , which are indicative of predominant antiferromagnetic (AFM) interactions in both systems. The experimental effective magnetic moment ( μ eff ) value for the monoclinic phase is 2.13 μB and that of the orthorhombic system is 2.34 μB . Due to the rather strong AFM interactions and lack of magnetic transition down to 2 K, both of these novel osmates are placed in the class of highly frustrated magnets. Low temperature magnetic susceptibility (below 2 K) and dynamic magnetic properties studies (μsr studies) are in order to better understand the magnetic ground states of these two polymorphs of Li 4 MgOsO 6 .

The phase relations in the Tl–Te–I system have been experimentally investigated over the entire concentration range mainly by thermal analysis (DTA), X-ray diffraction (XRD) applied to equilibrated alloys. The isothermal section at 300 K, liquidus surface projection and the phase diagrams of the six isopleth sections have been constructed. The homogeneity ranges and primary crystallization fields for the all phases, as well as, the character and temperature of non- and monovariant equilibria were determined in the system. The crystal structure of the Tl5Te2I compound has been determined by single crystal X-Ray diffraction. It is found to be stoichiometric and isostructural which crystallize in the In5Bi3 structure type with four formula units in the tetragonal system, space group I4/mcm, а = 9.001(2); c = 13.291(4) A.

Needle-shaped, dark purple crystals of anhydrous sodium permanganate are prepared by evaporation of aqueous solutions of Na2SO4 and Ba(MnO4)2 after removal of the precipitate.

Reactions between XeF2, TiF4 and UV-irradiated elemental F2 in anhydrous HF yielded XeF5TiF5 (XeF6·TiF4), [XeF5]5[Ti10F45] (XeF6·2TiF4), and [XeF5][Ti3F13] (XeF6·3TiF4) upon crystallization. [XeF5]5[Ti10F45] crystallizes in two crystal modifications at low (α-phase, 150 K) and ambient (β-phase, 296 K) temperatures. The crystal structure determination of [XeF5]5[Ti10F45] reveals the largest known discrete decameric [Ti10F45]5− anion built from ten TiF6 octahedra, sharing vertices, in the shape of a double-star. [XeF5]+ cations are completely ordered in the α-phase, while one of three crystallographically unique [XeF5]+ cations is two-fold disordered in the β-phase. The anionic part of [XeF5][Ti3F13] is built from tetrameric Ti4F20 and octameric Ti8F36 units sharing vertices and alternatively linked into ([Ti3F13]−)∞ columns. The charge balance is maintained by [XeF5]+ cations which form secondary Xe⋯F contacts with fluorine atoms of ([Ti3F13]−)∞ groups. The main structural feature of XeF5TiF5 is an infinite chain of distorted TiF6 octahedra joined by cis vertices.

This paper describes a sintering technique for ceramics and ceramic-based composites, using water as a transient solvent to effect densification (i.e. sintering) at temperatures between room temperature and 200 °C. To emphasize the incredible reduction in sintering temperature relative to conventional thermal sintering this new approach is named the "Cold Sintering Process" (CSP). Basically CSP uses a transient aqueous environment to effect densification by a mediated dissolution-precipitation process. CSP of NaCl, alkali molybdates and V2 O5 with small concentrations of water are described in detail, but the process is extended and demonstrated for a diverse range of chemistries (oxides, carbonates, bromides, fluorides, chlorides and phosphates), multiple crystal structures, and multimaterial applications. Furthermore, the properties of selected CSP samples are demonstrated to be essentially equivalent as samples made by conventional thermal sintering.

Colorless block-shaped crystals of the title compound are prepared from aqueous solutions of Mn(NO3)2, NaN3, and cyclohexylamine hydrochloride (room temperature, 2 d, 50% yield).

We herein report the synthesis, crystal structure, and electrochemical performances of a new Li-based vanadium oxysulfate phase, Li2VO(SO4)2, whose structure is built on vanadyl-containing VO5 square-based pyramids and SO4 groups linked by vertices to form layers. Li2VO(SO4)2 presents a redox activity at 4.7 V vs Li+/Li0 with a reversible capacity of 50 mA·h/g, while the chemically similar but structurally different Na2VO(SO4)2 delivers a capacity of 60 mA h/g at 4.5 V vs Na+/Na0. Density functional theory calculations are also performed to rationalize our findings in terms of redox activity and phase stability.

Benzo[h]-naphth[1,2-f]quinazolines and benzo[h]-phenanthren[9,10-f]quinazoines were synthesized from intermediates 4-(2-hydroxyphenyl)-5-(naphthalen-1-yl)pyrimidines and 4-(2-hydroxyphenyl)-5-(phenanthren-1-yl) pyrimidines by the intramolecular dehydration of photocyclization. The intermediates were obtained by the condensation of 3-arylchromone with formamidine, acetamidine or guanidine refluxing in ethanol, respectively. Irradiation of the corresponding intermediates by a high-pressure mercury lamp in 19:1 (v/v) EtOH H2O or 18:1:1 (v/v) EtOH H2O-Dioxane lead to target products. This photocyclization showed advantages including catalyst-free and mild reaction condition. Moreover, water was the only by-product of this reaction. The crystal structure of 2-amino-12-methoxy-benzo[h]-naphth[1,2-f]quinazoline was determined and the fluorescence properties of these polybenzoquinazolines were also investigated.

The title compound is prepared by melting a 2:1:1 molar mixture of MnO, BaO, and B2O3 in a CsCl/RbCl flux (evacuated silica tubes, 1.

The structure of triclinic disodium hafnium disilicate, Na2HfSi2O7, has been determined by laboratory powder X-ray diffraction and refined by the Rietveld refinement. The structure is a framework made of alternate layers of HfO6 octa­hedra and SiO4 tetra­hedra linked by common O atoms. Sodium atoms are located in the voids of the framework, aligned into tunnels along the [010] direction. Na2HfSi2O7 is isostructural with the parakeldyshite Na2ZrSi2O7 phase.

Polycrystalline U3O7 powder was synthesized by oxidation of UO2 powder under controlled conditions using in situ thermal analysis, and by heat treatment in a tubular furnace. The O/U ratio of the U3O7 phase was measured as 2.34 ± 0.01. The crystal structure was assessed from X-ray diffraction (XRD) and selected-area electron diffraction (SAED) data. Similar to U4O9−e (more precisely U64O143), U3O7 exhibits a long-range ordered structure, which is closely related to the fluorite-type arrangement of UO2. Cations remain arranged identical to that in the fluorite structure, and excess anions form distorted cuboctahedral oxygen clusters, which periodically replace the fluorite anion arrangement. The structure can be described in an expanded unit cell containing 15 fluorite-like subcells (U15O35), and spanned by basis vectors A = ap – 2bp, B = −2ap + bp, and C = 3cp (lattice parameters of the subcell are ap = bp = 538.00 ± 0.02 pm and cp = 554.90 ± 0.02 pm; cp/ap = 1.031). The arrangement of cuboctahedra in U3O...

A simple and convenient method to generate 4-aryl-substituted 1H-2-(trichloromethyl)-1,3-diaza-1,3-butadienes from aryl(chlo­ro)methaniminium salts (best known as Vilsmeier–Haack reagents) and trichloroacetamidine has been developed. These 4-aryl-1H-1,3-diaza­butadienes are isolable, relatively stable during silica gel chromatography, and can be crystallized. The analysis by X-ray diffraction demonstrated that in the solid state these 1,3-diazabutadienes have an s-cisoid conformation. The principal characteristic of these 1,3-diazabutadienes is their reactivity towards electron-deficient acetylenes, reacting under mild reaction conditions to produce 4-aryl-2-(trichloromethyl)pyrimidines in good yields.

Monoclinic and triclinic modifications of nitrosonium nitratonickelate NO[Ni(NO3)3] as well as triclinic modification of nitrosonium nitratocobaltate NO[Co(NO3)3] (isostructural to triclinic NO[Ni(NO3)3]) have been synthesized by a new synthetic approach. Single crystal XRD studies revealed the similarity of all these structures in which octahedrally coordinated metal atoms are connected through N O 3 − bridges forming three-dimensional distorted cubic framework with NO+ cations located in the framework cavities.

A new layered metal phosphate, Li2Sr2Al(PO4)3, was synthesized in the form of either a single-crystal or polycrystalline powder using the molten hydroxide flux method or a solid-state reaction, respectively. Li2Sr2Al(PO4)3 crystallizes to the P21/n (Z=4) monoclinic space group with lattice parameters a≈4.95 A, b≈22.06 A, c≈8.63 A, and β≈91.5°. The structure is composed of stacked [LiSrAl(PO4)2] layers alternating regularly with [LiSrPO4] layers. In the [LiSrAl(PO4)2] sublattice, the AlO6 octahedra and PO4 tetrahedra are tilted cooperatively to form an anionic, corrugated, two-dimensional [Al(PO4)2]3− framework that can be regarded as a “distorted-glaserite” structure. The [LiSrPO4] sublattice is that of a layered block containing a six-membered ring formed from alternating linkages of LiO4 and PO4 tetrahedra. The six-membered rings show a boat-type arrangement with the up(U) or down(D) pointing sequence, UUDUUD. The interspace between the two sublattices generates a two-dimensional pathway for Li+ ion conduction. The impedance measurement indicated that Li2Sr2Al(PO4)3 had a moderate ion conductivity (σ≈1.30×10−4 S cm−1 at 667 K), with an activation energy Ea≈1.02 eV.

Single crystals of NbF4, niobium(IV) tetra­fluoride, were synthesized by disproportionation of Nb2F5 at 1273 K in a sealed niobium tube, extracted and studied by single-crystal X-ray diffraction. Previous reports on the crystal structure of NbF4 were based on X-ray powder diffraction data and the observed isotypicity to SnF4 [Gortsema & Didchenko (1965). Inorg. Chem. 4, 182–186; Schafer et al. (1965). J. Less Common Met. 9, 95–104]. The data obtained from a single-crystal X-ray diffraction study meant the atomic coordinates could now be refined as well as their anisotropic displacement parameters, leading to a significant improvement of the structural model of NbF4. In the structure, the Nb atom is octahedron-like surrounded by six F atoms of which four are bridging to other NbF6 octa­hedra, leading to a layer structure extending parallel to the ab plane.

Eu2+-activated M5(PO4)3X (M = Ca, Sr, Ba; X = F, Cl, Br) compounds providing different alkaline-earth metal and halide ions were successfully synthesized and characterized. The emission peak maxima of the M5(PO4)3Cl:Eu2+ (M = Ca, Sr, Ba) compounds were blue-shifted from Ca to Ba (454 nm for Ca, 444 nm for Sr, and 434 nm for Ba), and those of the Sr5(PO4)3X:Eu2+ (X = F, Cl, Br) compounds were red-shifted along the series of halides, F → Cl → Br (437 nm for F, 444 nm for Cl, and 448 nm for Br). The site selectivity and occupancy of the activator ions (Eu2+) in the M5(PO4)3X:Eu2+ (M = Ca, Sr, Ba; X = F, Cl, Br) crystal lattices were estimated based on theoretical calculation of the 5d → 4f transition energies of Eu2+ using LCAO. In combination with the photoluminescence measurements and theoretical calculation, it was elucidated that the Eu2+ ions preferably enter the fully oxygen-coordinated sites in the M5(PO4)3X:Eu2+ (M = Ca, Sr, Ba; X = F, Cl, Br) compounds. This trend can be well explained by “Pauling’s...