Intermetallic Compound ReGaGe with Re- and Ge-Embedded Gallium Clusters: Synthesis, Crystal Structure, Chemical Bonding, and Physical Properties.

Transition metal-based endohedral cluster intermetallic compounds are interesting electron phases, which frequently exhibit superconductivity with a peculiar interplay between the critical temperature and valence electron count. We present a new Re-based endohedral gallium cluster compound, ReGaGe. Its unique crystal structure (4 space group, = 8.

Revisited TiNbO as an Anode Material for Advanced Li-Ion Batteries.

TiNbO with a tunnel-type structure is considered as a perspective negative electrode material for Li-ion batteries (LIBs) with theoretical capacity of 252 mAh g corresponding to one-electron reduction/oxidation of Ti and Nb, but only ≈160 mAh g has been observed practically. In this work, highly reversible capacity of 200 mAh g with the average (de)lithiation potential of 1.5 V vs Li/Li is achieved for TiNbO with pseudo-2D layered morphology obtained via thermal decomposition of the NHTiNbO intermediate prepared by K→ H→ NH cation exchange from KTiNbO.

One-step synthesis of vanadium-doped anatase mesocrystals for Li-ion battery anodes.

Here we report a successful one-step synthesis of vanadium-doped anatase mesocrystals by reactive annealing of NHTiOF/PEG2000 mesocrystal precursors with NHVO. The formation solid solution TiVOwith vanadium content up to = 25 at% inheriting the structure of mesocrystals is observed for the first time. The doping mechanism via vapor phase transport of vanadium is proposed.

Uniform arrays of gold nanoelectrodes with tuneable recess depth.

Nanoelectrode arrays are much in demand in electroanalytical chemistry, electrocatalysis, and bioelectrochemistry. One of the promising approaches for the preparation of such systems is templated electrodeposition. In the present study, porous anodic alumina templates are used to prepare Au nanoelectrode arrays.

Permeability of anodic alumina membranes grown on low-index aluminium surfaces.

Porous anodic aluminium oxide (AAO) membranes have various practical applications in separation and purification technologies. Numerous approaches have been utilized to tailor the transport properties of porous AAO films, but all of them assume an isotropic nature of anodized aluminium. Here, the impact of aluminium crystallography on the permeability of AAO membranes is disclosed.

Sensing of Proteins by ICD Response of Iron(II) Clathrochelates Functionalized by Carboxyalkylsulfide Groups.

Recognition of elements of protein tertiary structure is crucial for biotechnological and biomedical tasks; this makes the development of optical sensors for certain protein surface elements important. Herein, we demonstrated the ability of iron(II) clathrochelates (-) functionalized with mono-, di- and hexa-carboxyalkylsulfide to induce selective circular dichroism (CD) response upon binding to globular proteins. Thus, inherently CD-silent clathrochelates revealed selective inducing of CD spectra when binding to human serum albumin (HSA) (, ), beta-lactoglobuline () and bovine serum albumin (BSA) ().

Functionalized heterocycle-appended porphyrins: catalysis matters.

The scope and limitations of the condensation of labile 2,3-diaminoporphyrin derivatives with aromatic aldehydes to provide functionalized imidazole- and pyrazine-appended porphyrins were investigated in detail. The presence of an acidic catalyst in the reaction was found to be a tool that allows the reaction path to be switched. The influence of the electronic origin of the substituents in the carbonyl components of the condensation on the yields and selectivity of the reaction was revealed.

Modification of Poly(4-methyl-2-pentyne) in the Supercritical Fluid Medium for Selective Membrane Separation of CO from Various Gas Mixtures.

The modification of highly permeable films of brominated 1,2-disubstituted polyacetylene, poly(4-methyl-2-penthyne), via incorporation of in situ formed butylimidazolium bromide is reported for the first time. Principal possibility and efficiency of supercritical CO and CHF use as reaction media for the corresponding process, namely for quaternization of butylimidazole by brominated polymer are revealed. As a result, we prepared new membrane materials possessing promising properties such as stability toward organic solvents, good mechanical properties and significantly improved CO-selectivity while maintaining gas permeability at high values.

Hydration and Diffusion of H, Li, Na, Cs Ions in Cation-Exchange Membranes Based on Polyethylene- and Sulfonated-Grafted Polystyrene Studied by NMR Technique and Ionic Conductivity Measurements.

The main particularities of sulfonate groups hydration, water molecule, and alkaline metal cation translation mobility were revealed by nuclear magnetic resonance (NMR) and ionic conductivity measurements techniques in cation-exchange membranes MSC based on cross-linked sulfonated polystyrene (PS) grafted on polyethylene with ion-exchange capacity of 2.5 mg-eq/g. Alkaline metal cation hydration numbers (h) calculated from temperature dependences of H chemical shift of water molecule for membranes equilibrated with water vapor at RH = 95% are 5, 6, and 4 for Li, Na, and Cs ions, respectively.

Electron-Precise Semiconducting ReGaGe: Extending the IrIn Structure Type to Group 7 of the Periodic Table.

Intermetallic compounds with semiconducting properties are rare, but they give rise to advanced materials for energy conversion and saving applications. Here, we present ReGaGe, a new electron-precise narrow-gap intermetallic semiconductor. The compound crystallizes in the IrIn structure type (space group 4/, = 6.

Perfluorosulfonic Acid Membranes Thermally Treated and Modified by Dopants with Proton-Acceptor Properties for Asparaginate and Potassium Ions Determination in Pharmaceuticals.

The influence of incorporation of the dopants with proton-acceptor properties into perfluorosulfonic acid cation exchange membranes (MF-4SC and Nafion), and their treatment conditions on the characteristics of Donnan potential (DP)-sensors (analytical signal is the Donnan potential) in the aqueous solutions containing asparaginate and potassium ions in a wide pH range was investigated. A silica, surface modified by 3-aminopropyl and 3-(2-imidazolin-1-yl)-propyl groups, was used as the dopant. The membranes were subjected to mechanical deformation and thermal treatment at various relative humidities.

Effect of One- and Two-Electron Reduction of Terbium(III) Double-Decker Phthalocyanine on Single-Ion Magnet Behavior and NIR Absorption.

Reduction of terbium(III) double-decker phthalocyanine, TbPc (1), by sodium fluorenone ketyl in the presence of bis(triphenylphosphoranylidene)ammonium cations yields one-electron-reduced (PPN){Tb(Pc)}·2.5CHCl (2) containing the dianionic Pc macrocycles, whereas a stronger NaCpCo(CO) reductant in the presence of an excess of cryptand yields two-electron-reduced {Cryptand(Na)}{(Pc)Tb(Pc)} (3) containing the Pc radical trianionic macrocycle. Isolated pairs of the {Tb(Pc)} anions are formed in 2, whereas compound 3 has unique 3D packing of the macrocycles with weak π-orbitals overlapping in all three directions.

Layered Compounds BaFMgPn (Pn = P, As, Sb, and Bi), Transition-Metal-Free Representatives of the 1111 Structure Type.

Four new transition metal-free pnictide representatives of the LaOAgS structure type were predicted by DFT calculations and found in the BaFMgPn (Pn = P, As, Sb and Bi) family. The compounds adopt the tetragonal space group P4 /nmm with the unit cell parameters a/ c 4.3097(1) Ã…/9.

Exploitation of knowledge databases in the synthesis of zinc(II) malonates with photo-sensitive and photo-insensitive ,'-containing linkers.

Photoinitiated solid-state reactions are known to affect the physical properties of coordination polymers, such as fluorescence and sorption behaviour, and also afford extraordinary architectures ( three-periodic structures with polyorganic ligands). However, the construction of novel photo-sensitive coordination polymers requires an understanding of the factors which govern the mutual disposition of reactive fragments. A series of zinc(II) malonate complexes with 1,2-bis(pyridin-4-yl)ethylene and its photo-insensitive analogues has been synthesized for the purpose of systematic analysis of their underlying nets and mutual disposition of -donor ligands.

Extension and functionalization of an encapsulating macrobicyclic ligand using palladium-catalyzed Suzuki-Miyaura and Sonogashira reactions of iron(ii) dihalogenoclathrochelates with inherent halogen substituents.

A new approach for performing Suzuki-Miyaura and Sonogashira reactions of iron(ii) dihalogenoclathrochelates, optimizing their reaction conditions (such as temperature, solvent and a palladium-containing catalyst) and the nature of other reagents (such as arylboron components) is elaborated. These palladium-catalyzed reactions are very sensitive to the nature of the macrobicyclic substrates. The reactivity of the leaving halogen atoms correlates with their ability to undergo an oxidative addition, decreasing in the order: I > Br > Cl, and iron(ii) diiodoclathrochelate underwent these C-C cross-couplings under their "classical" conditions.

Induced chirality of cage metal complexes switched by their supramolecular and covalent binding.

An ability of the ribbed-functionalized iron(ii) clathrochelates to induce a CD output in interactions with a protein, covalent bonding or supramolecular interactions with a low-molecular-weight chiral inductor, was discovered. The interactions of CD inactive, carboxyl-terminated iron(ii) clathrochelates with serum albumin induced their molecular asymmetry, causing an appearance of strong CD signals in the range of 350-600 nm, whereas methyl ester and amide clathrochelate derivatives remained almost CD inactive. The CD spectra of carboxyl-terminated clathrochelates on supramolecular interactions or covalent bonding with (R)-(+)-1-phenylethylamine gave a substantially lower CD output than with albumin, affected by both the solvent polarity and the isomerism of clathrochelate's ribbed substituents.

Solid-State Reactions of Eicosaborate [B H ] Salts and Complexes.

A series of salts and complexes containing trans- and iso-isomers of octadecahydro-eicosaborate [B H ] dianion is synthesized and characterized using FTIR and B NMR spectroscopies and X-ray diffraction techniques. Both isomers are found to act as four-, bi-, or zero-dentate ligands in reactions with copper(II), silver(I), and lead(II) through apical and/or equatorial boron atoms. Solid-state photo- and thermoinitiated reactions of octadecahydro-eicosaborate isomerization and solvent cleavage occurring in these compounds in a single-crystal-to-single-crystal manner are studied in situ.

Size-Dependent Structure Relations between Nanotubes and Encapsulated Nanocrystals.

The structural organization of compounds in a confined space of nanometer-scale cavities is of fundamental importance for understanding the basic principles for atomic structure design at the nanolevel. Here, we explore size-dependent structure relations between one-dimensional PbTe nanocrystals and carbon nanotube containers in the diameter range of 2.0-1.

Structural and Thermodynamic Stability of the "1111" Structure Type: A Case Study of the EuFZnPn Series.

Two new compounds with the LaOAgS structure, EuFZnAs (1) and EuFZnSb (2), were obtained via solid state reaction. Both compounds are tetragonal (P4/nmm) with the cell parameters a = 4.1000(1) Ã… and c = 9.

Impact of the coordination environment on the magnetic properties of single-molecule magnets based on homo- and hetero-dinuclear terbium(iii) heteroleptic tris(crownphthalocyaninate).

A series of Tb(III) triple-decker heteroleptic crownphthalocyaninate complexes consisting of a homodinuclear compound [(15C5)4Pc]Tb[(15C5)4Pc]Tb(Pc) (), and two novel heterodinuclear compounds [(15C5)4Pc]Tb[(15C5)4Pc]Y(Pc), () and [(15C5)4Pc]Y[(15C5)4Pc]Tb(Pc) (), have been synthesized. All compounds were characterised using UV-Vis spectroscopy, HR-ESI-MS, MALDI-TOF-MS, and (1)H NMR spectroscopy, followed by exploration into the effects of lanthanide coupling and ligand field symmetry on the magnetic properties of these complexes using SQUID magnetometry. Magnetic measurements on the homonuclear Tb(III) complex () displayed non-negligible ferromagnetic coupling between magnetic ions, eliciting a high zero-field energetic barrier to the magnetic relaxation of Ueff = 229.

Experimental and Computational Insight into the Chemical Bonding and Electronic Structure of Clathrate Compounds in the Sn-In-As-I System.

Inorganic clathrate materials are of great fundamental interest and potential practical use for application as thermoelectric materials in freon-free refrigerators, waste-heat converters, direct solar thermal energy converters, and many others. Experimental studies of their electronic structure and bonding have been, however, strongly restricted by (i) the crystal size and (ii) essential difficulties linked with the clean surface preparation. Overcoming these handicaps, we present for the first time a comprehensive picture of the electronic band structure and the chemical bonding for the Sn(24-x-δ)InxAs(22-y)I8 clathrates obtained by means of photoelectron spectroscopy and complementary quantum modeling.

Crystal structure of poly[μ2-aqua-aqua-(μ2-4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olato)hemi-μ4-oxalato-barium(II)].

In the title coordination polymer, [Ba(C5HN2O6)(C2O4)0.5(H2O)2] n , the tenfold coordination of the Ba centre consists of four O atoms from the two 4-nitro-2,5,6-trioxo-1,2,5,6-tetra-hydro-pyridin-3-olate (L) anions, three O atoms of two oxalate anions and three water mol-ecules. The Ba-O bond lengths fall in the range 2.

Pressure control of magnetic clusters in strongly inhomogeneous ferromagnetic chalcopyrites.

Room-temperature ferromagnetism in Mn-doped chalcopyrites is a desire aspect when applying those materials to spin electronics. However, dominance of high Curie-temperatures due to cluster formation or inhomogeneities limited their consideration. Here we report how an external perturbation such as applied hydrostatic pressure in CdGePâ‚‚:Mn induces a two serial magnetic transitions from ferromagnet to non-magnet state at room temperature.

Supervised extensions of chemography approaches: case studies of chemical liabilities assessment.

Chemical liabilities, such as adverse effects and toxicity, play a significant role in modern drug discovery process. In silico assessment of chemical liabilities is an important step aimed to reduce costs and animal testing by complementing or replacing in vitro and in vivo experiments. Herein, we propose an approach combining several classification and chemography methods to be able to predict chemical liabilities and to interpret obtained results in the context of impact of structural changes of compounds on their pharmacological profile.

Novel derivatives of hypervalent germanium: synthesis, structure, and stability.

Syntheses of a series of novel germanium complexes, viz. RN(CH(2)CH(2)NC(6)F(5))(2)GeHal(2) (, R = Me, Hal = Cl; , R = Me, Hal = Br; , R = PhCH(2), Hal = Cl; , R = PhCH(2), Hal = Br), as well as MeN[CH(2)(2-C(4)H(3)N)](2)GeHal(2) (, Hal = Cl; , Hal = Br), by the reaction of GeHal(4) with dilithium salts of corresponding triamines are presented. PhCH(2)N(CH(2)CH(2)NSiMe(3))(2)GeCl(2) () was prepared analogously from triamine .