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Energy storage technology has received significant attention for portable electronic devices, electric vehicle propulsion, bulk electricity storage at power stations, and load leveling of renewable sources, such as solar energy and wind power. Lithium ion batteries have dominated most of the first two applications. For the last two cases, however, moving beyond lithium batteries to the element that lies below-sodium-is a sensible step that offers sustainability and cost-effectiveness. This requires an evaluation of the science underpinning these devices, including the discovery of new materials, their electrochemistry, and an increased understanding of ion mobility based on computational methods. The Review considers some of the current scientific issues underpinning sodium ion batteries.

Single crystals of Na4NiP2O7F2 are prepared by a flux reaction of NiO with excess Na2PO3F (Au crucible in silica tube, 675 °C, 8 h; cooling to 400 °C within 10 h).

This article is about the progress of palladium compounds as a catalyst for Heck-Mizoroki and Suzuki-Miyaura coupling reactions. Industrial catalysts with broad applicability need continuous catalyst development process through modification of ligand design, geometry and functionality. Recently catalysts have been synthesized through attachment of the activated palladium complexes on the surface of polymer support, particularly, insoluble in reaction medium. An appropriate mixture of palladium salt and ligand is also used as an important modification in some cases to get better results. We surveyed the important palladium compounds synthesized up to early 2014 for Heck-Mizoroki and Suzuki-Miyaura coupling reactions and summarize their progress in terms of ligand modification and other associated parameters.

Owing to almost unmatched volumetric energy density, Li-ion batteries have dominated the portable electronics industry and solid state electrochemical literature for the past 20 years. Not only will that continue, but they are also now powering plug-in hybrid electric vehicles and electric vehicles. In light of possible concerns over rising lithium costs in the future, Na and Na-ion batteries have re-emerged as candidates for medium and large-scale stationary energy storage, especially as a result of heightened interest in renewable energy sources that provide intermittent power which needs to be load-levelled. The sodium-ion battery field presents many solid state materials design challenges, and rising to that call in the past couple of years, several reports of new sodium-ion technologies and electrode materials have surfaced. These range from high-temperature air electrodes to new layered oxides, polyanion-based materials, carbons and other insertion materials for sodium-ion batteries, many of which hold promise for future sodium-based energy storage applications. In this article, the challenges of current high-temperature sodium technologies including Na-S and Na-NiCl2 and new molten sodium technology, Na-O2 are summarized. Recent advancements in positive and negative electrode materials suitable for Na-ion and hybrid Na/Li-ion cells are reviewed, along with the prospects for future developments.

LiFePO4(OH)0.4F0.6 is hydrothermally prepared from mixtures of FePO4, LiF, and H2O (autoclave, 200 °C, 16 h) and characterized by powder XRD, SEM, and electrochemical measurements.

The compounds (III) and (IV) are screened for their antimicrobial activity against Gram-positive and Gram-negative bacteria.

It has been shown that reactions 5-substituted 2-nitrothiophenes with arylacetonitriles in the presence of potassium hydroxide in methanol lead to the formation of the new [2-(hydroxyimino)-5-R-3(2H)-thienylidene](aryl)acetonitriles. Under proposed reaction conditions, the formation of thieno[2,3-c]isoxazole was not the case. J. Heterocyclic Chem., (2011).

Electrochemical results show that both intercalation of Li in LiVPO4F producing Li2VPO4F and deintercalation yielding VPO4F proceed by a two-phase mechanism.

Metastable olivine phases of crystalline Na[Mn1-xMx]PO4 (M: Fe, Ca, Mg; 0 ≤ x ≤ 0.5) are formed by solid state topotactic reactions of NH4 [Mn1-xMx]PO4·H2O and excess NaOAc (65—100 °C).

It is demonstrated that the tetrahydropyridine derivative (II) undergoes ring-opening reaction with different amidine-type 1,3-N,N-bis-nucleophiles to give pyrimidines in good yields.

Tavorite LiFeSO4F as a cathode material for rechargeable Li-ion cells and the new possible Na-ion battery material NaFeSO4F are synthesized by rapidly heating FeSO4·7H2O for 3 h at 100 °C under N2/7% H2 followed by ball-milling with NaF or LiF, and reacting the mixture solvothermally in tetraethylene glycol (Parr reactor, 220 °C, 60 h (Li), 48 h (Na)).

The N-protected pyridine derivative (I) reacts with various aromatic and aliphatic hydrazines to give 3-methylpyrazoles as single regioisomers.

Epoxidation of both 4β-acetoxyandrost-5-en-17-one and 6β-acetoxyandrost-4-en-17-one by m-chloroperbenzoic acid affords a similar mixture of 4β-acetoxy-5α,6α-epoxy- and 6β-acetoxy-4α,5α-epoxyandrostan-17-one. This is interpreted in terms of a symmetrical ‘acetoxylinium’(1,3-dioxan-2-ylium) ion and a degree of charge separation in the transition state for epoxidation.

Whereas the reaction of 2α,3α-epoxy-5α-hydroxyandrostanes with hydrogen bromide in acetic acid readily gives 4-methyloestratrienes, the presence of an additional 4β-acetoxy, 6α- or 6β-hydroxy group in the substrate leads to the formation of non-aromatic products. The 6α-alcohol gave 3α-acetoxy-2β-bromo-5β-androstane-6,17-dione, the structure of which was confirmed by X-ray crystallography, whilst the 6β-alcohol gave this ketone and 3α,6β-diacetoxy-2α,5α-epoxyandrostan17-one.

Positive electrodes for Li-ion and lithium batteries (also termed “cathodes”) have been under intense scrutiny since the advent of the Li-ion cell in 1991. This is especially true in the past decade. Early on, carbonaceous materials dominated the negative electrode and hence most of the possible improvements in the cell were anticipated at the positive terminal; on the other hand, major developments in negative electrode materials made in the last portion of the decade with the introduction of nanocomposite Sn/C/Co alloys and Si−C composites have demanded higher capacity positive electrodes to match. Much of this was driven by the consumer market for small portable electronic devices. More recently, there has been a growing interest in developing Li−sulfur and Li−air batteries that have the potential for vastly increased capacity and energy density, which is needed to power large-scale systems. These require even more complex assemblies at the positive electrode in order to achieve good properties. This r...

We report new solid state and hydrothermal synthetic routes to (Li,Na)2FePO4F that incorporate carbon-containing additives and result in good electrochemical properties of this Li (or Na) ion electrode material. Single crystal X-ray diffraction analysis of Na2FePO4F prepared by flux growth confirms the unusual structural features of this compound that include pairs of face-sharing metal octahedra and [6 + 1] coordination of the sodium ions. Facile Na−Li ion-exchange occurs upon reflux with lithium salts, upon electrochemical cycling in a cell (vs. Li), and also in a cell simply equilibrated at OCV. The material does not exhibit typical two-phase behavior on electrochemical cycling. A combination of a redox process which occurs with little structural strain, and ion scrambling give rise to a solid solution-like sloping voltage profile on charge−discharge, although localization of the Fe2+/3+ in the mixed valence single phase intermediate, Na1.5FePO4F drives a very small structural distortion. Temperature-d...

Trifluoroacetamide was reacted with diacids in the presence of N-ethyl-N-dimethyl-aminopropylcarbodiimide and of 1-hydroxybenzotriazole to afford cyclic imides of different ring size, providing a single step asymmetric synthesis of thalidomide.

The preparation of some substituted androstane 4- and 6-ketones is described revealing further examples of neighbouring group participation between substituents at C-4 and C-6; the X-ray crystal structure of androstane-4,6,17-trione showed that it existed in a form that was a hybrid of the Δ4- and Δ6-enolates.

Two distinct V(9)O(23) building blocks having different vanadium coordination environments are intergrown in the unusual layered vanadate [N(CH(3))(4)](5)V(18)O(46) (see picture). Lattice strain is relieved by alternation of the vanadate strips formed from the blocks in both directions (akin to a three-dimensional tire tread). The formation of this lattice has implications for the assembly mechanism of this compound and related materials in hydrothermal synthesis.

By diazotization of 2-aminothiazoles and reaction with sodium azide, the derivatives of 2-azidothiazole were synthesized. Conditions of diazotization were selected according to the nature of a substituent in thiazoles. 2-Azidothiazole derivatives were studied in the base-catalysed condensation reactions with activated methylenic compounds to yield new 1-(1,3-thiazol-2-yl)-1H-1,2,3-triazole-4-carboxylic acids.

The crystal structures of polycrystalline rhombohedral γ-Na3Fe2(PO4)3 and Li3Fe2(PO4)3 obtained through Na ↔ Li ion exchange have been determined for the first time, from neutron diffraction data recorded at 473 and 300 K, respectively. Na3Fe2(PO4)3 crystallizes in the space group R3c at 473 K (γ-form, a = 8.7270(2) A, and c = 21.8078(5) A). A progressive transfer of Na+ ions from the M(1) (6-coordinate) to the M(2) (8-coordinate) sites occurs upon raising the temperature from ambient (α-form, τM(1) = 1) to 393 K (β-form, τM(1) = 0.91) and then to 473 K (γ-form, τM(1) = 0.85). This is associated with a significant increase of Fe−Fe distances through the M(1) site and with relaxation of the framework such that the FeO6 octahedra become less distorted. Ion exchange from Na3Fe2(PO4)3 leads to the rhombohedral form of Li3Fe2(PO4)3 (space group R3; a = 8.3162(4) A, and c = 22.459(1) A). The M(1) and M(2) sites of the NASICON structure are empty in Li3Fe2(PO4)3 which is isotypic with Li3In2(PO4)3. Removal of ...

Single crystal studies of the compounds Li17Ge4, Li17Sn4 and Li17Pb4, previously thought to be of stoichiometry Li22M5 (M=Ge, Sn, Pb) are presented. Their space group is F 4 3m, rather than the F23 previously reported for Sn and Pb, with a=18.756(2) A, 19.690(2) A and 19.842(1) A for the Ge, Sn and Pb compounds, respectively, with very good refinements, particularly for the tin structure (R(F≥4σ(F))=1.85% for Ge, 1.91% for Sn and 2.3% for Pb). Comparison with the related structure of Li21Si5 reveals that as one progresses down Group IV, there is a variation in the occupation of the lithium tetrahedra about the tetrahedral Wickoff sites based on the space apportioned by the surrounding metal atoms. Partial or complete occupation of some tetrahedral sites increases from Si to Pb resulting in centred tetrahedral Li5 groups replacing Li4 units, and hence stoichiometries that can be effectively described as Li21Si5 (‘Li16.8Si4’); Li(21+3/16)Ge5 (‘Li17Ge4’); Li(21+5/16)Sn5 (‘Li17Sn4’); and Li(21+1/4)Pb5 (or Li17Pb4).

The new anhydrous borate Na2Co2B12O21 has been synthesized by flux methods and studied by single-crystal X-ray diffraction (space group I2/a with a = 17.1447(15) A, b = 4.5530(5) A, c = 19.4408(15) A, beta = 103.212(5) degrees , V = 1477.4(2) A3, Z = 4). Refinement of its structure reveals it is the first metaborate exhibiting a tunnel network, with internal dimensions of 4.5 x 8.8 A2. Further single-crystal diffraction studies show that the Na+ ions within the tunnels are exchangeable with Li+ along with the absorption of water molecules to form Li2(H2O)2Co2B12O21, making this compound a unique non-siliceous zeotype.

A single-phase, well-crystallized Li5V(PO4)2F2/carbon nanocomposite has been prepared by an optimized solid-state route, and its electrochemical behavior was examined as a positive electrode active material in lithium-ion batteries. The microcrystalline powder was synthesized by the reaction of amorphous VPO4/C with Li3PO4 and LiF. Synthesis of the VPO4/C precursor utilized carbon to reduce V2O5 and simultaneously create a nanoparticle reactive material, with the amount being tailored to result in a small excess at the end of the reaction to increase the bulk electronic conductivity of the final Li5V(PO4)2F2 composite. Quench techniques were used to isolate the metastable two-dimensional Li5V(PO4)2F2 as a pure single phase. 6Li MAS NMR studies identified the crystallographic lithium sites and provided information on lithium-ion mobility and exchange in the two-dimensional layered structure. Lithium cells of the Li5V(PO4)2F2/C composite exhibited a reversible plateau at 4.15 V followed by a second plateau ...

A new lithium vanadium fluorophosphate Li5V(PO4)2F2 has been synthesized by incorporation of LiF into α-Li3V2(PO4)3, and its structure has been determined by single-crystal X-ray diffraction. The sample crystallizes in monoclinic symmetry, space group P21/c (No. 14), with lattice parameters a = 6.3589(4), b = 10.7795(6), c = 10.3836(6), β = 90.019(1)°, and Z = 4. The refinement was performed using a total of 3094 unique reflections, resulting in agreement factors of R and wR(F2) of 0.0422 and 0.0741, respectively. The structure of Li5V(PO4)2F2 consists of layers of vanadium fluorophosphate interleaved with lithium ions. Lithium ions also reside in the channels along the a axis and in the interstitial space within the framework. The synthesis of the title compound from α-Li3V2(PO4)3 represents the first example of framework reduction for a metal phosphate, from a three-dimensional to a two-dimensional structure. Bulk phases of Li5V(PO4)2F2 and its chromium analogue, Li5Cr(PO4)2F2, were also prepared from t...

In situ XRD experiments on an electrochemical cell show that extraction of Li from crystalline Li2CuP (oxidation) is accompanied by a first-order transition in the solid state at room temperature to form a quasi-amorphous delithiated phase. The process is readily reversed on reduction, resulting in recrystallization of the original Li2CuP phase.

Monoclinic lithium vanadium phosphate, alpha-Li(3)V(2)(PO(4))(3), is a highly promising material proposed as a cathode for lithium-ion batteries. It possesses both good ion mobility and high lithium capacity because of its ability to reversibly extract all three lithium ions from the lattice. Here, using a combination of neutron diffraction and (7)Li MAS NMR studies, we are able to correlate the structural features in the series of single-phase materials Li(3-y)V(2)(PO(4))(3) with the electrochemical voltage-composition profile. A combination of charge ordering on the vanadium sites and lithium ordering/disordering among lattice sites is responsible for the features in the electrochemical curve, including the observed hysteresis. Importantly, this work highlights the importance of ion-ion interactions in determining phase transitions in these materials.

The delithiation process in monoclinic Li3V2(PO4)3 has been determined by powder neutron diffraction coupled with 7Li solid-state NMR techniques. Charge ordering of vanadium (V3+/V4+) was observed in Li2V2(PO4)3 as shown by the gray and blue V-O octahedra, respectively, indicating that the electrons are pinned in this phase and hence transport is limited.

A series of lariat ether carboxylic acids, O-benzylhydroxamates, and hydroxamic acids with fluorine-containing substituents is prepared. In general, the presence of fluorine-containing substituents is found to increase the solubility of the lariat ethers in supercritical carbon dioxide. Efficiencies of the fluorine-containing lariat ether carboxylic and hydroxamic acids are compared with those for non-fluorinated analogs in solvent extraction of lanthanide ions from aqueous solutions into chloroform. Responses of the fluorine-containing lariat ether O-benzylhydroxamates towards alkali metal cations in solvent polymeric membrane electrodes are compared with those analogous non-fluorinated compounds.