Synthesis and electrochemical performance of the Li-rich cathode material Li<Subscript>1.17</Subscript>Ni<Subscript>0.12</Subscript>Co<Subscript>0.13</Subscript>Mn<Subscript>0.58</Subscript>O<Subscript>2</Subscript> for lithium-ion batteries

Lithium-riched cathode material for lithium-ion batteries, Li_1.17Ni_0.12Co_0.13Mn_0.58O₂, was synthesized via crystallization from a solution of metal acetates, followed by a thermal treatment of the material obtained as a powder. The phase, elemental, and granulometric compositions of the material were examined, as well as the morphology of the powder particles obtained. The discharge capacity of the material in relation to the charging voltage was found from the results of electrochemical tests, and endurance tests were performed. The discharge capacity upon 85 charge/discharge cycles at voltages in the range 2.8–4.8 and a current of 0.1C was about 180 mA h g^–1.     

Promoted photoelectrochemical activity of BiVO<Subscript>4</Subscript> coupled with LaFeO<Subscript>3</Subscript> and LaCoO<Subscript>3</Subscript>

BiVO₄ has emerged as a promising material for solar water splitting. The poor ability of charge transport and separation always limits its performance for photoelectrochemical water splitting. Herein, we coupled n-type BiVO₄ with p-type LaFeO₃ and LaCoO₃, achieving a photocurrent more than two times as high as bare BiVO₄ at 1.23 V versus a reversible hydrogen electrode. Also, the onset potential was negatively shifted about 260 mV. The promotion of performance is mainly because the space charge layer in BiVO₄ is broadened, and the band bend is enhanced, which facilitates the separation and transport of photo-generated charges.     

(RS)‐6‐Ethyl 2‐carboxy‐1,2,3,4‐tetra­hydro­azulene‐6‐carboxylate

The title compound, C₁₄H₁₆O₄, was obtained during the synthesis of 2,6‐disubstituted azulene derivatives. In the partially reduced azulene skeleton, the absence of a H atom at the ester substitutent position of the seven‐membered ring, as well as lengthened double bonds, indicate a conjugative stabilized system with two overlaid tautomers.     

Two mechanisms of thermal expansion in perovskite SrCo<Subscript>0.6</Subscript>Fe<Subscript>0.2</Subscript>Nb<Subscript>0.2</Subscript>O<Subscript>3-z</Subscript>

Perovskite SrCo_0.6Fe_0.2Nb_0.2O_3-z attracts attention as a promising material with high oxygen conductivity. The sample was investigated by means of high-temperature X-ray powder diffraction and thermogravimetry. Phase transition was detected near 400 °C and accompanied with significant mass loss. The phase transition affects oxygen mobility, important for the synthesis of oxygen permeable membranes. The unit cell parameters are proved to change with temperature after two effects (1) reversible conventional thermal expansion and (2) irreversible contraction-expansion due to the changes in the oxygen content. In situ high-temperature X-ray diffraction experiments allowed us to separate the contributions and to measure them as a function of temperature.     

3‐Acetoxy­cyclo­hex‐4‐ene‐1,2‐di­carboxyl­ic anhydride

The title compound, C₁₀H₁₀O₅, was found to exist as the endo–cis isomer with a pair of enantiomers in the asymmetric unit. The cyclo­hexene ring is folded about the methyl­ene‐to‐CH(acetoxy) vector to give a boat conformation.     

Separation of <Superscript>125</Superscript>IBZM and <Superscript>125</Superscript>ILIS using polyacrylamide-acrylic acid resin

Radioiodination of both S(−)BZM and LIS was carried out using n-bromosuccimide(NBS) as a mild oxidizing agent. The factors affecting on the radiochemical yield such as pH, reaction time, substrate concentration and oxidizing agent have been studied. The chromatographic separation of both ¹²⁵IBZM and ¹²⁵ILIS was carried out using HPLC and poly(acrylamide-acrylic acid) resin P(AAm-AA). The copolymer was prepared by a template polymerization of AA in aqueous solution on PAAm as a template polymer and in the presence of N,N-methylenebisacrylamide (NMBA) as a crosslinker using gamma rays as initiator. The purifications of tracers were carried out using prepared resin compared with TLC and HPLC. The effects of pH buffer, variable elution volumes, flow rate and temperature on the separation process of the resin efficiency have been studied.     

6‐(4‐Methoxy­benzyl­amino)­purin‐3‐ium chloride

The title compound, C₁₃H₁₄N₅O⁺·Cl⁻, belongs to the group of aromatic cytokinins. These compounds affect a variety of important physiological processes in plants and animals as well as in bacteria, including cell division, differentiation and senescence. The structure consists of a 6‐(4‐methoxy­benzyl­amino)­purinium cation and a Cl⁻ anion. The cation moiety exists as the N3‐protonated N7 tautomer. The cation contains nearly planar benzene and purine ring systems, with a dihedral angle of 77.46 (5)°. The crystal structure is stabilized by N_amino—H⋯N_purine hydrogen bonds connecting two adjacent mol­ecules, thus forming centrosymmetric dimers.     

5,8,11‐Trioxa‐2,14‐di­thia­bi­cyclo­[13.4.1]­icosa‐1(19),15,17‐trien‐20‐one

The title compound, C₁₅H₂₀O₄S₂, crystallizes in a chiral space group although it contains mirror symmetry. The tropone ring is inclined at an angle of 50.3 (1)° to the crown ether ring. The planarity of the tropone ring system itself is diminished by as much as 20.8 (4)°.     

Synthesis and crystal structure of the new complex oxide Ca<Subscript>7</Subscript>Mn<Subscript>2.14</Subscript> Ga<Subscript>5.86</Subscript>O<Subscript>17.93</Subscript>

The complex oxide Ca₇Mn_2.14Ga_5.86O_17.93 was synthesized by the solid-state reaction in a sealed evacuated quartz tube at 1000 °C. Its crystal structure was determined by electron diffraction and X-ray powder diffraction. The structure can be represented as a tetrahedral framework, viz., the polyanion [(Mn_0.285Ga_0.715)₁₅O_29.86]^19- stabilized by the incorporated cation [Ca₁₄GaO₆]₁₉₊. The polycation consists of the GaO₆ octahedra surrounded by the Ca atoms, which are arranged to form a cube capped at all places. The tetrahedral framework is partially disordered due to the presence of tetrahedra with two possible orientations in the positions (0, 0, 0) and (x, x, x) with x ≈ 0.15 and 0.17. The relationship between the Ca₇Mn_2.14Ga_5.86O_17.93 structures and related ordered phases with the symmetry F23, as well as the influence of the oxygen content on the ordering in the tetrahedral framework, are discussed.     

cis,cis,cis‐Tetra­methyl 1,2,4,5‐cyclo­hexane­tetra­carboxyl­ate

The title compound, C₁₄H₂₀O₈, was synthesized from the hydrogenation of tetra­methyl 1,4‐cyclo­hexa­diene‐1,2,4,5‐tetra­carboxyl­ate with a catalytic amount of palladium/carbon. All four carbonyl moieties of the methyl ester groups are on the same face of the chair‐conformed ring. The substantial ring distortion associated with the 1,3‐diaxial methoxycarbonyl substituents is reflected in the large difference between bond angles as well as torsion angles, respectively, that in undistorted cyclo­hexanes would be approximately the same.     

(R)‐4‐(4‐Fluoro­phenyl)‐1‐[2‐hydroxy‐2‐(3‐methyl‐1‐benzo­furan‐2‐yl)­ethyl]­piperazinium chloride propan‐1‐ol solvate

The title compound, C₂₁H₂₄FN₂O₂⁺·Cl⁻·C₃H₈O, is a potential drug designed as a hybrid compound with antihypertensive, antioxidant and β‐adrenolytic activity. The cation contains nearly planar benzo­furan and fluoro­phenyl ring systems, as well as a piperazine ring adopting an almost perfect chair conformation. The benzo­furan and piperazine moieties are connected by an ethyl chain, the moieties forming a dihedral angle of 163.12 (13)°. In the crystal structure, ions and propanol solvent mol­ecules are linked via N—H⋯Cl and O—H⋯Cl bonds into linear (010) chains.     

Two pseudo‐enantiomeric forms of N‐benzyl‐4‐hydroxy‐1‐methyl‐2,2‐dioxo‐1H‐2λ6,1‐benzothiazine‐3‐carboxamide and their analgesic properties

The fact that molecular crystals exist as different polymorphic modifications and the identification of as many polymorphs as possible are important considerations for the pharmaceutic industry. The molecule of N‐benzyl‐4‐hydroxy‐1‐methyl‐2,2‐dioxo‐1H‐2λ⁶,1‐benzothiazine‐3‐carboxamide, C₁₇H₁₆N₂O₄S, does not contain a stereogenic atom, but intramolecular hydrogen‐bonding interactions engender enantiomeric chiral conformations as a labile racemic mixture. The title compound crystallized in a solvent‐dependent single chiral conformation within one of two conformationally polymorphic P2₁2₁2₁ orthorhombic chiral crystals (denoted forms A and B). Each of these pseudo‐enantiomorphic crystals contains one of two pseudo‐enantiomeric diastereomers. Form A was obtained from methylene chloride and form B can be crystallized from N,N‐dimethylformamide, ethanol, ethyl acetate or xylene. Pharmacological studies with solid–particulate suspensions have shown that crystalline form A exhibits an almost fourfold higher antinociceptive activity compared to form B.     

3,3,10,10‐Tetra­methyl‐1,2‐di­thia‐5,8‐di­aza­cyclo­deca‐4,8‐diene

The title compound, C₁₀H₁₈N₂S₂, acts as an important precursor for the synthesis of the pharmaceutically important di­amine­di­thiol ligand system. The mol­ecule has a local twofold axis and the arrangement of the S₂N₂ donor atoms in the macrocycle is anticlinal.     

Methyl 4‐O‐benzoyl‐2,3‐O‐isopropyl­idene‐α‐l‐rhamnopyran­oside

The title compound, C₁₇H₂₂O₆, has an exocyclic ester group at the hexopyranosyl sugar residue. The carbonyl group shows a conformation that is eclipsed with respect to the adjacent ring C—H bond. The two ester torsion angles are denoted by syn and cis conformations. One of these torsion angles is indicated to have a similar conformation in solution, as analyzed by NMR spectroscopy and a Karplus‐type relationship.     

2‐Trichloromethylthio‐1H‐iso­indole‐1,3(2H)‐dione (Folpet)

The title compound (C₉H₄Cl₃NO₂S), commonly known as Folpet, belongs to a group of phthalimides which function as fungicides or can be used in the laboratory as sulfurizing agents. The phthalimide moiety is slightly folded with a dihedral angle of 3.5 (4)°. The molecule participates in C—H?O and Cl?Cl intermolecular interactions.     

N‐tert‐Butyl‐N′‐(5,7‐di­methyl‐1,8‐naphthyridin‐2‐yl)­urea

The title compound, C₁₅H₂₀N₄O, has been synthesized as an AADD recognition unit for quadruple hydrogen bonds. All non‐H atoms of the mol­ecule apart from two methyl groups of the tert‐butyl group lie in a common plane. An intramolecular hydrogen bond is formed connecting two N atoms. In the solid state, the title compound crystallizes as a centrosymmetric dimer connected by N—H?O=C interactions with an N?O distance of 2.824 (2) Å.     

Electrophysical properties of layered perovskites LnBaCo<Subscript>2 − <Emphasis Type="Italic">x</Emphasis></Subscript>Cu<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>O<Subscript>5 + δ</Subscript> (Ln = Sm,Nd) for solid oxide fuel cells

The influence of doping with copper oxide on the phase composition, electric conductivity, and linear thermal expansion coefficient (LTEC) of SmBaCo₂O_{5 + δ} and NdBaCo₂O_{5 + δ} was studied. The sample homogeneity region has been determined with using XRD. The samples conductivity decreased as the dopant concentration increased. The character of the temperature dependence of conductivity changed at high copper contents. In a reductive atmosphere, the conductivity of the samples at first decreased and then remained constant. The linear thermal expansion coefficient decreased as the amount of the incorporated dopant increased.     

catena‐Poly[sodium(I)‐μ‐tetra­ethoxy­borato]

The title compound, [Na(C₈H₂₀BO₄)]_n, has twofold crystallographic symmetry, with the Na⁺ cations bound by four O atoms [Na—O = 2.251 (3) Å]. The tetra­ethoxy­borate anion acts as a bridging ligand to form one‐dimensional polymers running along the twofold crystal axis. The crystal was treated as a racemic twin.     

Thermokinetics on the reaction of formation of Dy[(C<Subscript>5</Subscript>H<Subscript>8</Subscript>NS<Subscript>2</Subscript>)<Subscript>3</Subscript>(C<Subscript>12</Subscript>H<Subscript>8</Subscript>N<Subscript>2</Subscript>)]

The enthalpy change of formation of the reaction of hydrous dysprosium chloride with ammonium pyrrolidinedithiocarbamate (APDC) and 1,10-phenanthroline (o-phen?H₂O) in absolute ethanol at 298.15 K has been determined as (-16.12 ± 0.05) kJ?mol^-1 by a microcalormeter. Thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), rate constant and kinetics parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of the reaction have also been calculated. The enthalpy change of the solid-phase reaction at 298.15 K has been obtained as (53.59 ± 0.29) kJ?mol^t-1 by a thermochemistry cycle. The values of the enthalpy change of formation both in liquid-phase and solid-phase reaction indicated that the complex could only be synthesized in liquid-phase reaction.