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Three phosphates MPb4(PO4)3 (M = K, Rb, Cs) have been synthesized by the high temperature melt method. The single-crystal X-ray structural analyses reveal that all of them belong to apatite-type phases and crystallize in the same space group, P63/m (no. 176). They exhibit a three dimensional (3D) structure that is composed of two kinds of channels constructed by [Pb(1)O6] and [PO4]. And the [Pb(2)|K(1)] ([Pb(2)|Rb(1)], [Pb(2)|Cs(1)]) atoms are located in the small channels. Detailed structural comparison indicates that the cations effect on the framework geometry is less obvious among the title compounds and the reported lead apatite-type phosphates, however, although MPb4(PO4)3 (M = K, Rb, Cs) have the similar stoichiometry with MM'4(BO3)3, the different coordination of the B and P atoms, as well as the cations effect make MPb4(PO4)3 and MM'4(BO3)3 crystallize in various space groups. The IR spectra were used to verify the validity of their structure. The TG-DSC analysis results indicate that KPb4(PO4)3 and RbPb4(PO4)3 melt congruently. The UV–Vis–NIR diffuse reflectance spectra indicate that they have no obvious absorption from 300 to 2500 nm. Optical properties as well as band structure calculations have been also performed based on density functional theory methods.

A consolidated review on the emergent supramolecules of thiacalixarenes in crystal engineering and molecular recognition contributed from our group is presented. Our simple synthetic method of thiacalixarenes offered improved yields of larger macrocyclic thiacalix[6/8]arenes by carefully adjusting NaOH concentration, temperature, and reaction time. In crystallographic analysis, complexes of thiacalixarenes with alkali metals and rare earth metals build up fascinating assemblies, such as dimeric formations, hetero-alkali metallic thiacalixarenes, one-dimensional ‘ladder-type’ coordination polymers, and one-dimensional hydrogen-bonded polymers. In addition, halogenated thiacalixarenes having various alkyl ethers assemble each other via three halogen interactions of halogen bonding, halogen–halogen interactions, and halogen-π interactions. Liquid–liquid extraction studies using ligand-functionalized thiacalixarene-based extractants developed for separation of precious metals from the last 10 years are discussed.

Cs4Na3H4 [Se2Pd4W14O56H] ·18H2O·0.3Cs(OAc)·0.2Na(OAc) (I) and Cs9.5Na2.5 [Se4Pd4W28O108H12] ·30H2O (II) are precipitated with aq.

A novel route for synthesis of 2-acyl-1,1,3,3-tetracyanopropenides (ATCN) salts in high yields and excellent purities starting from readily available methyl ketones, malononitrile, bromine, and alkali metal acetates is reported. The starting aryl(heteroaryl) methyl ketones were oxidized to the corresponding α-ketoaldehydes by new a DMSO–NaBr–H2SO4 oxidation system in yields up to 90% within a short reaction time of 8–10 min. The subsequent stages of ATCN preparation are realized in aqueous media without use of any toxic solvents, in accordance with principle 5 of “green chemistry”. Lithium, sodium, potassium, rubidium, and cesium 2-benzoyl-1,1,3,3-tetracyanopropenides were characterized by X-ray diffraction analysis. These salts show a good potential for synthesis of five- and six-membered heterocycles and may serve as potentially useful ligands in coordination and supramolecular chemistry.

Polycrystalline Mx[W6I14] (M: Na, K, Rb, Cs) is prepared by solid state reaction of stoichiometric amounts of MI and W3I12 (

Two new noncentrosymmetric borophosphates, Li3Cs2Ba2B3P6O24, 1 and RbBaBP2O8, 2, have been synthesized via solid-state reactions at high temperature. The single crystal X-ray diffraction technique shows a cubic system, space group P213 (No 198) for 1 with a =12.8530(5) A and tetragonal system I 4 2d (No 122) for 2 with a=7.2810(18) A, c=14.330 (5) A. The main structure motif attributes a 3D framework formed of BO4 and PO4 tetrahedra in both compounds. The powder samples exhibit second harmonic generation (SHG) response, using Kurtz and Perry technique, demonstrated that 1, 2 are about 0.2, 0.5 and 2, 2.5 times than that of KDP and SiO2 in particle size range of 106–150 µm, 46−74 µm respectively.

Alkali metal alkoxides were studied as catalysts for the addition of CS2 to epoxides. A screening of several commercially available alkoxides revealed lithium tert-butoxide as an active and selective catalyst for this reaction. The influence of different reaction parameters as well as the substrate scope under optimized reaction conditions has been studied. Terminal and highly substituted epoxides as well as thiiranes were converted. In total 28 products were prepared and isolated in yields up to 95%. Notably, the reactions were performed under mild conditions without additional solvents. The regio- and stereoselectivity of the reaction has been studied e.g. by converting (R)-styrene and (R)-propylene oxide. Moreover, the test reaction was monitored by (13)C NMR and a plausible mechanism for the conversion of terminal and internal epoxides is given. This proposal is in agreement with the observed regio- and stereoselectivity of the reaction.

The new compounds A2ZnP2Se6 (A = K, Rb, Cs) were synthesized via molten salt flux syntheses. The crystals feature one-dimensional 1/∞[ZnP2Se6]2– chains charge balanced by alkali metal ions between the chains. K2ZnP2Se6 crystallizes in the monoclinic space group P21/c; cell parameters a = 12.537(3) A, b = 7.2742(14) A, c = 14.164(3) A, β = 109.63(3)°, Z = 4, and V = 1216.7(4) A3. Rb2ZnP2Se6 and Cs2ZnP2Se6 are isotypic, crystallizing in the triclinic space group P. Rb2ZnP2Se6 has cell parameters of a = 7.4944(15) A, b = 7.6013(15) A, c = 12.729(3) A, α = 96.57(3)°, β = 105.52(3)°, γ = 110.54(3)°, Z = 2, and V = 636.6(2) A3. Cs2ZnP2Se6 has cell parameters of a = 7.6543(6) A, b = 7.7006(6) A, c = 12.7373(11) A, α = 97.007(7)°, β = 104.335(7)°, γ = 109.241(6)°, Z = 2, and V = 669.54(10) A3.

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.

Highly crystalline sodium and ammonium Jarosites, NaFe3(SO4)2(OH)6 and NH4Fe3(SO4)2(OH)6, have been synthesized employing hydrothermal synthesis routes. The structures consist of anionic layers of vertex-sharing FeO6 octahedra and SO4 tetrahedral units with interlayer space occupied by Na and ammonium ions, respectively. The corner-sharing FeO6 octahedral units form six and three rings similar to hexagonal tungsten bronze sheets also known as kagome lattice. These sodium and ammonium Jarosites are thermally stable up to 400 °C and undergo facile electrochemical lithium insertion through the reduction of Fe3+ to Fe2+. Galvanostatic charge–discharge indicates that up to 2.25 and 2 lithium ions per formula unit can be inserted at an average voltage of 2.49 and 2.26 V to the sodium and the ammonium Jarosites, respectively, under slow discharge rate of C/50. The cycle-life and experimental achievable capacity show strong dependence on particle sizes and synthesis conditions. A small amount of fluoride substitution improves both achievable capacity and average voltage.

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.

The iron chalcogenides FeSe and FeS are superconductors composed of two-dimensional sheets held together by van der Waals interactions, which makes them prime candidates for the intercalation of various guest species. We review the intercalation chemistry of FeSe and FeS superconductors and discuss their synthesis, structure, and physical properties. Before we review the latest work in this area, we provide a brief background on the intercalation chemistry of other inorganic materials that exhibit enhanced superconducting properties upon intercalation, which include the transition metal dichalcogenides, fullerenes, and layered cobalt oxides. From past studies of these intercalated superconductors, we discuss the role of the intercalates in terms of charge doping, structural distortions, and Fermi surface reconstruction. We also briefly review the physical and chemical properties of the host materials—mackinawite-type FeS and β-FeSe. The three types of intercalates for the iron chalcogenides can be placed in three categories: 1.) alkali and alkaline earth cations intercalated through the liquid ammonia technique; 2.) cations intercalated with organic amines such as ethylenediamine; and 3.) layered hydroxides intercalated during hydrothermal conditions. A recurring theme in these studies is the role of the intercalated guest in electron doping the chalcogenide host and in enhancing the two-dimensionality of the electronic structure by spacing the FeSe layers apart. We end this review discussing possible new avenues in the intercalation chemistry of transition metal monochalcogenides, and the promise of these materials as a unique set of new inorganic two-dimensional systems.

RbCl and CsCl react with BrF3 yielding the corresponding decafluoridotribromates(III), MBr3F10 (M = Rb, Cs), which were structurally characterized for the first time. The Br3F10− anion is surprisingly not linear but contains a μ3-bridging fluorine atom and seems to be the first example of μ3-F bridging of Br atoms. The compounds are highly reactive and cannot be handled in glassware. As for the tetrafluoridobromates themselves, they are powerful oxidizers and thus suitable for the dry-chemical recycling of precious metals and additionally feature a significantly higher BrF3 content.

The first neutron diffraction study of a single crystal containing uranyl peroxide nanoclusters is reported for pyrophosphate-functionalized Na44K6[(UO2)24(O2)24(P2O7)12][IO3]2·140H2O (1). Relative to earlier X-ray studies, neutron diffraction provides superior information concerning the positions of H atoms and lighter counterions. Hydrogen positions have been assigned and reveal an extensive network of H-bonds; notably, most O atoms present in the anionic cluster accept H-bonds from surrounding H2O molecules, and none of the surface-bound O atoms are protonated. The D4h symmetry of the cage is consistent with the presence of six encapsulated K cations, which appear to stabilize the lower symmetry variant of this cluster. 31P NMR measurements demonstrate retention of this symmetry in solution, while in situ 31P NMR studies suggest an acid-catalyzed mechanism for the assembly of 1 across a wide range of pH values.

An efficient alkali hydroxide-mediated SNAr reaction of heteroaryl halides has been developed for the practical synthesis of the useful unsymmetrical heteroaryl thioethers and chalcogenides. The usually odorless, easily available, lowly toxic, and easily stored and handled diorganyl dichalcogenides can be used as safer and convenient chalcogen nucleophile precursors and diverse unsymmetrical heteroaryl chalcogenides can be obtained in good to high yields by the method.

Review: recent breakthroughs in SN2-type nucleophilic fluorination reactions using alkali metal fluorides promoted by protic solvents; 50 refs.

New Tl type-I clathrates of K7.62(1)Tl0.38(1)Ge45.34(3) and Rb7.50(1)Tl0.50(1)Ge46 were synthesized via solid-state reaction. Rb7.50(1)Tl0.50(1)Ge46 and K7.62(1)Tl0.38(1)Ge45.34(3) were found to crystallize in space groups Pmn and Iad with lattice parameters of a = 10.81559(7) A and a = 21.4290(2) A, respectively. Theoretical calculations indicated metallic features based on the calculation models of Rb7Tl1Ge46 and K7Tl1Ge46 in the space group of Pm. The densities of states at the Fermi level were predominantly determined by the Ge s and Ge p orbitals of Rb7Tl1Ge46 and K7Tl1Ge46.

The title compounds are obtained upon solvent evaporation of aqueous solutions containing a 0.5:0.5:1 molar mixture of KF, RbF, SbF3 or a 0.3:0.7:1 molar mixture of KF, NH4F, and SbF3, respectively.

In this paper, we have reported a mixing alkali medium method for the preparation of highly emissive CdTe quantum dots (QDs). The pH of the reaction medium was tuned by varying the ratio of ammonia...

Two new quaternary thioarsenates(III) NaAg2AsS3·H2O (1) and KAg2AsS3 (2) with high yields have been successfully prepared through a facile surfactant-thermal method. It is interesting that 2 can only be obtained with the aid of ethanediamine (en), which indicates that weak basicity of solvent is beneficial to the growth of 2 compared with 1. Both 1 and 2 feature the similar two-dimensional (2D) layer structures. However, the distortion of the primary honeycomb-like nets in 2 is more severe than that of 1, which demonstrates that Na+ and K+ cations have different structure directing effects on these two thioarsenates(III). Both experimental and theoretical studies confirm 1 and 2 are semiconductors with band gaps in the visible region. Our success in preparing these two quaternary thioarsenates(III) proves that surfactant-thermal technique is a powerful yet facile synthetic method to explore new complex chalcogenides.

The development of frequency-conversion technology in the infrared region is in urgent need of new excellent infrared nonlinear optical (IR NLO) materials. How to achieve a good balance between laser damage threshold (LDT) and NLO coefficient (dij) for new IR NLO candidates is still a challenge. The combination of the highly electropositive alkali metal (Na) and Zn with d(10) electronic configuration into crystal structure affords one new IR NLO material, Na2ZnGe2S6. It exhibits excellent properties including a wide transparent region (0.38-22 μm), large band gap (3.25 eV), and especially a balance between a strong NLO coefficient (30-fold that of KDP) and a high LDT (6-fold that of AgGaS2), indicating a promising application in the IR region. Moreover, novel common-vertex-linked wavelike ∞[GeS3]n chains are interestingly discovered in Na2ZnGe2S6, which rarely exist in the reported thiogermanides containing alkali metals. In addition, calculated SHG density and dipole moment demonstrate that the large NLO response is mainly attributed to the cooperative effects of the [GeS4] and [ZnS4] units.

Urea-based ionic liquid stabilized on silica-coated Fe3O4 magnetic nanoparticles, {Fe3O4@SiO2@(CH2)3-Urea-SO3H/HCl}, as an unexceptionable and smooth releasing urea fertilizer in alkali soils was synthesized and fully characterized using Fourier transform infrared, UV–visible and energy-dispersive X-ray spectroscopies, X-ray diffraction, scanning and transmission electron microscopies, atomic force microscopy and thermogravimetric analysis. The nanostructure catalyst as a novel, green and efficient catalyst was applied for the synthesis of bis(indolyl)methane derivatives via the condensation reaction between 2-methylindole and aldehydes at room temperature under solvent-free conditions. Also, pyrano[2,3-d]pyrimidinone derivatives were prepared in the presence of the nanomagnetic urea-based catalyst by the one-pot three-component condensation reaction of 1,3-dimethylbarbituric acid, aldehydes and malononitrile under solvent-free conditions at 60 °C. To the best of our knowledge, this is the first report of the synthesis of urea-based ionic liquid stabilized on silica-coated Fe3O4 magnetic nanoparticles. So the present work can open up a new and promising insight in the course of rational design, synthesis and applications of task-specific fertilizer-based nanomagnetic ionic liquids with desirable properties as unexceptionable substances for sustainable processes. Copyright © 2016 John Wiley & Sons, Ltd.

The reaction is promoted by hexamethyldisilazides and the potassium derivative is the most effective one.

In this report we describe catalytic B–N bond formation via cross-dehydrocoupling (CDC) of boranes with amines to construct aminoboranes with a high degree conversion (>90%) and chemo-selectivity using alkali metal hexamethyldisilazides [MN(SiMe3)2] (M = Li, and K) as pre-catalysts. It was observed that the lithium and potassium hexamethyldisilazides proved to be an effective pre-catalyst for aliphatic primary, secondary amines, aromatic primary, and substituted amines. The catalyzed cross-dehydrocoupling reaction using [MN(SiMe3)2] (M = Li and K) as a pre-catalyst displayed a broad substrate scope. Pinacolborane smoothly reacted with a number of aliphatic and aromatic amines under ambient conditions whereas a prolonged reaction time of around 8–12 hours was required for 9-BBN to undergo CDC reactions.

Two new congruent-melting alkali metal diphosphates, Rb2CdP2O7 and Cs2CdP2O7, were synthesized by conventional solid-state reactions. Single-crystal X-ray structural analyses showed that M2CdP2O7 (M = Rb, Cs) feature two-dimensional [CdP2O7](2-) layers that are composed of CdO5 pyramids and P2O7 dimers. The Rb+ and Cs+ cations ions fill the interlayers. The flexible P2O7 dimers could be bent and distorted if the Cs+ ion was substituted by the Rb+ ion, which led to crystallization of the Rb2CdP2O7 compound in the lower symmetry monoclinic space group P2(1)/c (No. 14) and crystallization of the Cs2CdP2O7 compound in the high-symmetry orthorhombic space group Pnma (No. 53). Thermal analyses showed that the two compounds melt congruently and that the melting point of Rb2CdP2O7 compound is lower than that of the Cs2CdP2O7 compound owing to distortion of the P2O7 dimers. IR spectroscopy and UV/Vis-near-IR diffuse reflectance spectroscopy were performed on the reported compounds.

A reinvestigation of the alkali metal thiosulfates has led to the new phase Cs2S2O3 center dot H2O. At first cesium thiosulfate monohydrate was obtained as a byproduct of the synthesis of Cs4In2S5. Further investigations were carried out using the traditional synthesis reported by J. Meyer and H. Eggeling. Cs2S2O3 center dot H2O crystallizes in transparent, colorless needles. The crystal structure of the title compound was determined by single crystal X-ray diffraction at room temperature: space group C2/m (No. 12), unit cell dimensions: a = 11.229(4), b = 5.851(2), c = 11.260(5) angstrom, beta = 95.89(2)degrees, with Z = 4 and a cell volume of V = 735.9(5)angstrom(3). The positions of all atoms including the hydrogen atoms were located in the structure refinement. Cs2S2O3 center dot H2O is isotypic with Rb2S2O3 center dot H2O. Isolated tetrahedra [S2O3](2-) are coordinated by the alkali metal cations, and in addition they serve as acceptors for hydrogen bonding. For both Cs atoms the shortest distances are observed to oxygen atoms of the S2O32- anions where as the terminating sulfur atom has its shortest contacts to the water hydrogen atoms. Thus, an extended hydrogen bonding network is formed. The title compound has also been characterized by IR spectroscopy. IR spectroscopy reveals the vibrational bands of the water molecules at 3385 cm(-1). They show a red shift in the OH stretching and bending modes as compared to free water. This is due both to the S center dot center dot center dot H hydrogen bonding and to the coordination of H2O molecules to the cesium atoms.

Selective oxidation of α,β-unsaturated aldehydes to α,β-unsaturated carboxylic acids was performed using O2 as the oxidant in the presence of a simple iron catalyst. The addition of an alkali metal...

FeNCN can be efficiently used as negative electrode material for alkali metal ion batteries.

The reinvestigation of the pseudo-binary systems MBr–BiBr3 (M = Rb, Cs) revealed two new phases with composition MBi2Br7. Both compounds are hygroscopic and show brilliant yellow color. The crystal structures were solved from X-ray single crystal diffraction data. The isostructural compounds adopt a new structure type in the triclinic space group P. The lattice parameters are a = 755.68(3) pm, b = 952.56(3) pm, c = 1044.00(4) pm, α = 76.400(2)°, β = 84.590(2)°, γ = 76.652(2)° for RbBi2Br7 and a = 758.71(5) pm, b = 958.23(7) pm, c = 1060.24(7) pm, α = 76.194(3)°, β = 83.844(4)°, γ = 76.338(3)° for CsBi2Br7. The crystal structures consist of M+ cations in anticuboctahedral coordination by bromide ions and bromidobismuthate(III) layers 2∞[Bi2Br7]–. The 2D layers comprise pairs of BiBr6 octahedra sharing a common edge. The Bi2Br10 double octahedra are further connected by common vertices. The bismuth(III) atoms increase their mutual distance in the double octahedra by off-centering so that the BiBr6 octahedra are distorted. The CsBi2Br7 type can be interpreted as a common hexagonal close sphere packing of M and Br atoms, in which 1/4 of the octahedral voids are filled by Bi atoms. The structure type was systematically analyzed and compared with alternative types of common packings. The existence of a compound with the suggested composition CsBiBr4 could not be verified experimentally.

CaMFe4As4 (M: K, Rb, Cs) and SrMFe4As4 (M: Rb, Cs) are prepared by solid state reaction of stoichiometric amounts of the elements (stainless steel pipe, 860—920 °C, 2—6 h).

The first indiumsilicate oxysulfide Ba2In2Si3O10S (1) was obtained by an alkali polychalcogenide flux method through a high-temperature solid-state reaction. It crystallizes in the non-centrosymmetric space group Pca21 (No. 29), with a = 23.060(6), b = 5.2954(6), c = 8.779(2) A, and Z = 4. Its three-dimensional (3D) framework is constructed from one-dimensional (1D) infinite ∞1[In2O7S2/2] double octahedral chains bridged by corner-sharing Si tetrahedral trimers [Si3O10]8–, yielding a 3D framework with the channels filled with Ba2+ cations along the b direction. It is unprecedented in that the two distorted indium octahedra in 1 face-share to form a [In2O7S2] dimer in indium oxides and oxide chalcogenides.

Fast pyrolysis bio oil is a liquid biofuel produced by fast pyrolysis of biomass materials. Even though pyrolysis oil consists primarily of carbon, hydrogen and oxygen, contaminations in the form of inorganic elements can be transferred from the original biomass feedstock to the pyrolysis oil during its production. These inorganic elements might limit the potential for utilization in high value applications, for example by poisoning the catalysts used in any subsequent processing steps. In this work, the transfer of inorganic elements from biomass to pyrolysis oil has been investigated. First a literature review was performed in order to determine the possible pathways inorganic elements can follow in the pyrolysis process. An important mechanism in the release of inorganic elements from the solid to the vapor phase was found in reactions between the organic volatiles produced and the inorganic elements present in the solid material. Organic volatiles form bonds with inorganic elements on the solid (pore) surface, after which the composed molecule can be released to the vapor phase. Experimental work on the transfer of inorganic elements during pyrolysis of 16 biomass materials has been carried out. Results show that alkali earth metals (Ca, Mg), transition metals (Fe, Cu, Ni, Cd, Cr, Co, Mn, Zn) and post transition metals (Al, Pb) remain largely on the solid char by-product. Incomplete solid separation from the gaseous stream prior to condensation is then the main route for their transfer to the pyrolysis oil. For the non-metals (S, P) sulfur is transferred primarily due to reactions with organic volatiles, while phosphorus is transferred primarily by physical entrainment of solid char particles. For the alkali metals (Na, K) the entrainment of solid char particles to pyrolysis oil is also the primary pathway, although Na and K are also transferred notably by reactions with volatiles. The influence of the pyrolysis temperature in the normal operating range (400–600 °C) appears to be small. > 95 wt.% of all inorganic elements present in the biomass are typically separated from the pyrolysis oil product. Options are available to increase the separation efficiency even further, showing that the presence of inorganic elements should not be a limiting factor for the application of pyrolysis oil.

Two new non-centrosymmetric (NCS) n = 3 layered perovskites, RbBi2Ti2NbO10 and CsBi2Ti2TaO10, have been synthesized through high temperature solid state reactions. X-ray diffraction analyses suggest that RbBi2Ti2NbO10 crystallizes in the orthorhombic polar space group, Ima2 (No. 46), whereas CsBi2Ti2TaO10 crystallizes in the tetragonal nonpolar space group, P4 (No. 81). Interestingly, CsBi2Ti2TaO10 is the first Dion–Jacobson (DJ)-type layered perovskite with a NCS nonpolar space group. Powder second-harmonic generation (SHG) measurements with 1064 nm radiation reveal that both of the reported materials have SHG efficiencies of approximately 100 times that of α-SiO2 and are phase-matchable (type I). Piezoelectricity measurements suggest that the estimated d33 values for polar RbBi2Ti2NbO10 and nonpolar CsBi2Ti2TaO10 are 170 and 67 pm V–1, respectively. The net polarization direction arising from the constituent distorted polyhedra and the key component causing microscopic deformations in NCS structure are...

Transparent colorless crystals of the title compounds are prepared from of solutions of Na3[C6N9] and RbF or CsF in boiling water by slow evaporation at room temperature.

Despite the promise of extremely high theoretical capacity (2Li + O2 ↔ Li2O2, 1675 mAh per gram of oxygen), many challenges currently impede development of Li/O2 battery technology. Finding suitable electrode and electrolyte materials remains the most elusive challenge to date. A radical new approach is to replace volatile, unstable and air-intolerant organic electrolytes common to prior research in the field with alkali metal nitrate molten salt electrolytes and operate the battery above the liquidus temperature (>80 °C). Here we demonstrate an intermediate temperature Li/O2 battery using a lithium anode, a molten nitrate-based electrolyte (e.g., LiNO3–KNO3 eutectic) and a porous carbon O2 cathode with high energy efficiency (∼95%) and improved rate capability because the discharge product, lithium peroxide, is stable and moderately soluble in the molten salt electrolyte. The results, supported by essential state-of-the-art electrochemical and analytical techniques such as in situ pressure and gas analys...

The soluble molecular selenophosphate salts ACsP2Se8 (A = K, Rb, Cs) crystallize in the orthorhombic space group Ccce with a = 14.982(3) A, b = 24.579(5) A, and c = 13.065(3) A for the Cs salt and a = 14.782(3) A, b = 23.954(5) A, and c = 13.044(3) A for the K analogue. ACsP2Se8 is composed of the molecular 6-membered ring, [P2Se8]2−, in the twist conformation charge balanced by alkali metals. The band gaps of these compounds are 2.44 ± 0.2 eV for Cs2P2Se8, 2.41 ± 0.2 eV for RbCsP2Se8, and 2.36 ± 0.2 eV for KCsP2Se8. The amorphous versions of these materials can be made by water quenching the melt and have band gaps for all ACsP2Se8 of 2.12 ± 0.2 eV. Raman spectroscopic studies exhibit active modes of PSe4 and Se−Se in the compound. Solution 31P NMR studies shed light into the interesting conformational fluxionality of the [P2Se8]2− anion, including a conformation that has not been previously observed. Thermal analysis reveals ACsP2Se8 exhibits a phase transition, which we investigate by in situ synchrotr...

Coupling of α-ketoesters with imines initiated by diethyl phosphite in the presence of alkaline metal hexamethyldisilazides is reported. Base-promoted addition of diethyl phosphite to α-ketoesters, followed by [1,2]-phosphonate/phosphate rearrangement, generates α-phosphonyloxy enolates that are subsequently intercepted by imines. The use of suitable azomethine coupling partners allows selective construction of syn-α-hydroxy-β-amino acid derivatives or trans-aziridine-2-carboxylates in high yields with excellent diastereoselectivities.

The four ternary arsenides ATt3As3 (A=K, Rb; Tt=Ge, Sn) were obtained by reaction of the elements at 600–650 °C. They adopt an orthorhombic structure (space group Pnma, Z=4, with cell parameters ranging from a=9.9931(11) A, b=3.7664(4) A, c=18.607(2) A for KGe3As3 to a=10.3211(11) A, b=4.0917(4) A, c=19.570(2) A for RbSn3As3) containing corrugated [Tt3As3] layers built from Tt-centred trigonal pyramids and tetrahedra forming five-membered rings decorated with As handles. They can be considered to be Zintl phases with Tt atoms in +4, +3, and +1 oxidation states. Band structure calculations predict that these compounds are semiconductors with narrow band gaps (0.71 eV in KGe3As3, 0.50 eV in KSn3As3).

The new one-pot method is found to be general and greener as it avoids the use of environmentally harmful POCl3 and strong alkali required for the previously reported method.

High quality single crystals with sizes up to 2—3 mm/edge of the transition metal vanadates (Va—g) are hydrothermally prepared and their structures are determined by single crystal XRD.

The new mixed alkali metal uranyl silicates (V), (VII), and (VIII) are characterized by single crystal XRD.

A new strategy for thiophene ring formation via the direct C H cyclization of 1-alkynyl-9,10-anthra(4-alkynyl-1-aza-9,10-anthra)quinones to give the corresponding thienoanthraquinones has been developed. A highly effective sulfinating agent was generated in situ by the reaction of elemental sulfur and alkali. It was also shown that this reagent is effective in the cyclization reaction with replacement of the chlorine atom.

Evaporative co-crystallization of MCl (M: Na, K, Rb, Cs) with BiOCl in aqueous HCl and various molar ratios yields the double salts MxBiyCl(x+3y)·zH2O.