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Abstract: In this work, CeO2−xNx materials have been prepared by the solution combustion method. All the prepared materials were characterized by powder-XRD, TEM, ICP-AES, RAMAN and XPS techniques. XRD and TEM confirmed 6-18 nm particles of CeO2−xNx materials (UC10, UC7, UC4 and UC1). Among different materials, UC10 showed the highest number of oxygen vacancies (Raman). With increase in U/C (fuel/oxidizer) ratio, the particle size decreased, whereas the specific surface area and oxygen vacancies increased. The oxygen vacancies are created because of charge imbalance and lattice distortion in ceria. The presence of N in ceria causes smaller crystallites and large specific surface area. XPS indicates N-Ce-O environment in CeO2−xNx materials. It is observed that oxygen vacancies created by nitrogen doping play an important role in cerium oxynitrides for CO oxidation reaction. The catalytic order of CeO2−xNx materials is as follows: UC10 > UC7 > UC4 > UC1. This is due to the larger number of oxygen vacancies possessed by UC10 material as compared to others. UC10 also showed an excellent 24 h time-on-stream stability for CO oxidation. The apparent activation energy of UC10 is found to be 51.1 kJ mol−1. This shows that CeO2−xNx materials are highly active and stable for CO oxidation.Graphical Abstract: [ABSTRACT FROM AUTHOR]

A series of boron-nitrogen polymers (PEIPAs) were synthesized to provide a green alternative for flame retardant finishing on cotton fabrics. An organic boron compound, phenylboronic acid (PA) was successfully bonded to the branched polyethylenimine, which was confirmed by H NMR and FTIR analysis. Thermogravimetric analysis showed that the polymer with molar ratio 1:1 of ethylenimine:PA (PEIPA 1:1), presented the optimal thermal-oxidative stability. PEIPA 1:1 was easily applied on cotton fabrics through a simple dipping method with high uptake in acetone medium. The fabric with 33.8 wt% add-on got self-extinguishing ability. SEM analysis on the char morphology of the treated fabrics revealed the fire protection by the coating through intumescent flame retardant mechanism. TGIR analysis showed the coated fabric has significant reduction in the flammable volatiles production. Further improvement of the coating washing durability was achieved by a novel formaldehyde-free cross-linking treatment. The new washing stable coating achieved LOI values 29.6 and 23.2% before and after repeated launderings respectively with 30 wt% add-on. Cone calorimetry analysis showed that the total heat releases of PEIPA 1:1 treated sample and cross-linked sample (PEIPA 3:1/NeoFR treated) were decreased by 30.3 and 45.5% respectively. Smoke analysis revealed that the treated fabrics have significant decrease in CO/CO ratio, indicating an effective flame inhibition in gas phase. The novel coatings, simple to synthesize and easy to apply with low waste, are suitable alternative to toxic halogenated flame retardants for cellulosic products. [ABSTRACT FROM AUTHOR]

Heteroatom-rich organoboron compounds have attracted attention as modulators of enzyme function. Driven by the unmet need to develop chemoselective access to boron chemotypes, we report herein the synthesis of α- and β-aminocyano(MIDA)boronates from borylated carbonyl compounds. Activity-based protein profiling of the resulting β-aminoboronic acids furnishes selective and cell-active inhibitors of the (ox)lipid-metabolizing enzyme α/β- hydrolase domain 3 (ABHD3). The most potent compound displays nanomolar in vitro and in situ IC50 values and fully inhibits ABHD3 activity in human cells with no detectable crossreactivity against other serine hydrolases. These findings demonstrate that synthetic methods that enhance the heteroatom diversity of boron-containing molecules within a limited set of scaffolds accelerate the discovery of chemical probes of human enzymes. [ABSTRACT FROM AUTHOR]

Very recently, borophene (atomic-thin two-dimensional boron sheet) has been successfully synthesized on the Ag(111) surface by deposition. Two kinds of structures were found. However, the identification of the monolayer boron sheets grown on the metal substrate, as well as the stability of different 2D boron sheets, is controversial. By performing the first-principles calculations, present study investigates the atomic structure, stability, and electronic properties of the most possible boron sheets grown on metal surface, namely, buckled triangular, β, and χ types of crystal lattice. Our result shows that all the three freestanding sheets are thermodynamically unstable and all are metallic. On the other hand, our result indicates the Ag(111) substrate stabilize these sheets. Additionally, our simulated STM images of these monoatomic-thin boron sheets on Ag(111) surface reproduce the experiment observations well and clearly identify the as-grown boron sheets. [ABSTRACT FROM AUTHOR]

Four boron- dipyrrine (BODIPY) based dyes with π-extended substituents in 8-position of dipyrrin ligand have been synthesized and characterized. Photophysical properties of the obtained compounds have been investigated in different individual solvents. Deposits of solvent polarity and viscosity were evaluated. BODIPY with 8-biphenyl substituent was found to be the fluorescent molecular rotor in contrast to more extended substituents. The complex nature of solvent-solute interactions leads to the poor applicability of standard multiparameter approaches to BODIPY solvatochromic properties. Fluorescence intensity was found to increase in case of solvent polarity growth, it is not typical for BODIPY. Taking that into account the BODIPY with π-extended substituents could be used for fluorescence viscosity measurements, and as the fluorescent media polarity indicators in analytical chemistry and biochemistry. [ABSTRACT FROM AUTHOR]

In this study, the synthesis of boron dipyrromethene dyes containing mono, bis-2-naphthyloxyhexyloxy and 4-(benzyloxy)phenoxyhexyloxy groups has been reported. Boron dipyrromethene dyes were synthesized from the mono, bis-benzaldehyde derivatives with 2,4-dimethylpyrrole in dichloromethane in the presence of trifluoroacetic, 2,3-dichloro-5,6-dicyano-p-benzoquinon, triethyl amine and boron trifluoride diethyl etherate, respectively. Electrochemical characterization of boron dipyrromethene dyes were carried out with voltammetric measurements. Electrochemical studies show that boron dipyrromethene dyes containing mono, bis-2-naphthyloxyhexyloxy and 4-(benzyloxy)phenoxyhexyloxy groups have reversible one reduction potentials unlike irreversible one oxidation potentials. [ABSTRACT FROM AUTHOR]

Boric acid is often added into coolant as neutron capture agent for pressurized water reactor, whose amount is influenced by its abundance and purity. Therefore, the preparation of enriched B boric acid with high purity is beneficial to nuclear industry. B is also used in developing tumor-specific boronated drugs in boron neutron capture therapy. The boronated drug can be administered to patient intravenously, intratumorally, or deposited at tumor site in surgical excision. Thus, enriched B boric acid is of practical significance in the field of medicine. Self-made boron trifluoride-methanol-complex solution was selected as one of the experimental reagents, and the preparation of B acid was realized by one-step reaction for the complexes with water and calcium chloride. The determination of electrical conductivity in reaction process proves that the optimum reaction time was 16-20 h. Furthermore, the effect of reaction time, ratio of calcium chloride to complex as well as the amount of water on the purity and yield of boric acid was investigated. Finally, the optimum reaction time was 20 h, the optimal solid-liquid ratio (molar ratio) was 3:1, and the amount of water was 1 L of deionized water for each mol of the complex. HO was added in the reaction process to remove Fe. After recrystallization, IR spectra of B boric acid was measured and compared with standard to verify the product of boric acid. The feasibility of the preparation method was determined by the detection of XRD of boric acid. To observe the morphology by polarizing microscope, crystal structure was obtained. The purity of the final product is 99.95 %, and the yield is 96.47 %. The ion concentration of boric acid accords with the national standard of high purity, which was determined by ICP. [ABSTRACT FROM AUTHOR]

This paper considers the coordination state of boron and aluminum ions in barium aluminoborate glass with a constant ratio of BaO: BO = 0.5 and a variable ratio of AlO: BaO = 0-3. The dependence of the concentrations of boron and aluminum atoms with a variable coordination number on the AlO content was estimated by IR, B and Al NMR spectroscopy. The nonlinear nature of the obtained dependences was attributed to variations in the aluminum oxide properties. At a content of less than 30 mol % AlO serves primarily as a network former, while an increase in the AlO concentration results in its higher modifying role in the studied glass. [ABSTRACT FROM AUTHOR]

New oxyquinoline boron complexes MesBQ ( I) and MesBQ ( II), where QH is 8-hydroxyquinoline and QH is 2-methyl-8-hydroxyquinoline, (CIF files CCDC 1051351 ( I) and 1051352 ( II)) are synthesized and structurally characterized. Their photoluminescence (PL) and electroluminescence (EL) properties are studied. The compounds have an intense green PL. The EL characteristics of complexes I and II doped in poly-N-vinylcarbazole (PVK) differ substantially. Compound I generates green luminescence with a brightness of 356 cd/m2, whereas white EL with a brightness of 36 cd/m is observed in the case of compound II. [ABSTRACT FROM AUTHOR]

The effect of different concentrations of N on the electronic and optical properties of BNP (0 ≤ x ≤ 1) boron ternary alloys was studied using the full potential linearized augmented plane wave method within the density functional theory (DFT) and time-dependent DFT (TDDFT). The exchange-correlation potential is described in generalized gradient approximation (GGA) within the Perdew et al. scheme. Also, we have used the GW formalism to improve the band gap results, and the calculated band gap within GW shows substantial improvement over GGA. The real and imaginary parts of the dielectric function ε( ω), optical reflectivity R( ω), absorption coefficient α( ω), refractive index and electron energy loss function are computed by random phase approximation for DFT and adiabatic local density approximation for TDDFT. The interband transitions responsible for the structures in the spectra are specified. It is shown that, for ternary alloys, N 2 p states and N 2 s, P 3 d states play a major role in optical transitions as initial and final states, respectively. The results for these alloys indicate that the band gap increases, the static dielectric constant decreases, and all existing structures move toward higher energies by increasing the concentration of nitrogen atoms. The results are compared with other available theoretical and experimental data. [ABSTRACT FROM AUTHOR]

xBO-(1 − x) (60SiO-15AlO-15MgO-10CaO) glasses with various x around 5-30 mol% at the step of 5 mol% are prepared by the melting-quenching method at 1,450 °C for 3 h. The IR data indicate that replacing other components by BO levels up the amount of [BO] tetrahedron and boron-oxygen rings, forcing [AlO] tetrahedron to drop gradually. The glass transition temperature (T), crystallization temperature (T) and thermal stability (∆T) rise when BO is present in lower concentrations (≤20 mol%); accordingly the glass network enhances. However, further increase in concentration of BO (>20 mol%) reduces the T, T and ∆T. We utilize temperature-gradient furnace to measure the G6 glass, while the re-melt sample and crystallized phase are observed from polarizing microscope destroying microstructure. As BO content move up, falls in dielectric constant (ε) and loss (tanδ) can be associated with drop of cations polarizability as well as concentration, along with glass network rigidity ascending. [ABSTRACT FROM AUTHOR]

Crystalline boron carbide (BC) powder was synthesized by carbothermal reduction of condensed boric acid-cellulose product and effect of structural homogeneity of precursor on low-temperature synthesis of BC was investigated on basis of cellulose-derived structural development. The formation of condensed products was confirmed by FTIR and TGA analyses. The pyrolyzed products of cellulose precursor at 400 °C for 2 h were composed of fine dispersion of carbon fibers with BO particles. The formation of carbon fibers favored conversion kinetics of BC synthesis. The formation of crystalline BC started and completed at 1100 and 1200 °C, which was one of the lowest temperatures reported for polymeric precursor route. Morphology of synthesized BC transformed from polyhedral to equiaxed as synthesis temperature was raised from 1150 to 1200 °C. Nitrogen physisorption measurements revealed that synthesized BC powders had mesopores with high surface area indicating large interfacial area of BO/carbon fibers resulting in more nucleation sites. [ABSTRACT FROM AUTHOR]

An efficient, convenient and green method has been introduced for the synthesis of biologically active xanthene derivatives through a one-pot condensation of aldehydes, 2-naphthol, and dimedone/naphthols in the presence of boron sulphonic acid (B(HSO)) as an efficient heterogeneous reusable solid acid catalyst under solvent-free conditions with good to excellent yields. Different types of aromatic and aliphatic aldehydes were used in the reaction and in all cases the products synthesized successfully. In addition, short reaction times, straightforward procedure, non-toxicity, and reusability of the catalyst are other noteworthy advantages of the present method. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The title compound tetraphenylborate salt of bambuterol (Bambec), N-(2-(3,5-bis((dimethylcarbamoyl)oxy)phenyl)-2-hydroxyethyl)-2-methylpropan-2-aminium tetraphenylborate ( 4), was prepared in 73 % yield by the reaction of 5-(2-( tert-butylamino)-1-hydroxyethyl)-1,3-phenylene bis(dimethylcarbamate) hydrochloride (bambuterol hydrochloride) ( 2) with sodium tetraphenylborate ( 3) in deionized water, at ambient temperature, through anion exchange reaction. The structure of the title borate salt was characterized by IR, mass and H NMR analyses. Colorless crystals of 4 suitable for an X-ray structural analysis were obtained by slow evaporation from acetonitrile. Compound 4 crystallizes in the monoclinic, space group P2/ c, with a = 8.8931 (2) Å, b = 20.4639 (6) Å, c = 21.4393 (6) Å, β = 93.640 (2)°, V = 3893.81 (18) Å, Z = 4. Graphical Abstract: Synthesis, characterization and X-ray structure of tetraphenylborate salt of bambuterol (Bambec), the drug for the treatment of asthma, bronchospasm, emphysema, and chronic obstructive pulmonary disease. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Diphenylboron chelate of cyanoacetic acid hydrazide and O-methyl lactims were used to synthesize pyrrolidin-, piperidin-, and azepan-2-ylidene derivatives of 3-aminopyrazol-5-one. [ABSTRACT FROM AUTHOR]

This paper presents the effect of residual stresses due to deep boron diffusion on microaccelerometer structure. The microaccelerometer structure was simulated at various residual stresses using finite element method. The residual stress due to the diffusion process was estimated to be 450 MPa by using Raman spectroscopy. After fabricating the microaccelerometer structure, the deflection (~2 μm) of the moving comb fingers due to the stress was found to be in good agreement with the simulated value (2.1 μm). Sensitivity of the accelerometers was measured to be ~50 mV/g for 0-30 g range. In the initial range (0-5 g), the output of the accelerometers are depicting nonlinearity as anticipated from the simulated results. [ABSTRACT FROM AUTHOR]

Two novel borates [(CH)NH][BO(OH)] ( I) and Na[HTMED][BO(OH)] ( II) have been synthesized under solvothermal conditions, and characterized by elemental analyses, FT-IR spectroscopy, and single crystal X-ray diffraction. Crystal data for I: monoclinic, P2/c, a = 9.3693(11) Å, b = 14.0375(17) Å, c = 10.0495(9) Å, β = 91.815(9)°, Z = 4. Crystal data for II: monoclinic, P2/c, a = 11.6329(2) Å, b = 11.9246(3) Å, c = 10.2528(2) Å, β = 100.178(2)°, Z = 4. Their crystal structures both have 3D supramolecular framework with large channels constructed by O-H···O hydrogen-bonding among the polyanions of [BO(OH)] or [BO(OH)] clusters. The templating organic amines cations in I and II are both located in the channels of 3D supramolecular frameworks, respectively, and interact with the polyborate frameworks both electrostatically and via hydrogen bonds of N-H···O. Na[HTMED][BO(OH)] is the first example of heptaborate co-templated by alkali metal and organic base, which is also rare in borates. The photoluminescence property of the synthetic sample of Na[HTMED][BO(OH)] in the solid state at room temperature was also investigated by fluorescence spectrophotometer. [ABSTRACT FROM AUTHOR]

Using time-dependent density functional theory, we investigate the excited-state properties of a series of emissive dyes combining the properties of coumarins and fluoroborate compounds. These boron-iminocoumarins (borico) compounds have been synthesized very recently by Frath et al. (Chem Commun 49:4908, ) . We determine both their vertical and 0-0 energies, reproduce and analyze their characteristic experimental band shape, investigate the nature of the excited-states in large dyads containing two different fluoroborate complexes and design red-shifted compounds. We also consider an additional panel of fused coumarin-BODIPY emitters. [ABSTRACT FROM AUTHOR]

A series of six boron difluoride complexes of 3-hydroxyflavone derivatives is described. These dyes were synthesized very simply and exhibited bright visible emission in solution (up to unity) as well as emission in the solid state. Complexation to boron difluoride was shown to impart donor–acceptor character to the excited state of these dyes, which further shifted the emission towards the visible part of the spectrum. Furthermore, differences were noticed following the strength of the donor and the acceptor. Light emission from the π-stacked molecules was quenched relative to the solution behaviour which was interpreted in terms of both packing and electronic properties of the molecular dyes. The packing arrangement was found to be a function of the substituent on the 3-hydroxyflavone derivatives. [ABSTRACT FROM AUTHOR]

The article discusses a scientific experiment on the cationic polymerization of 5-ethylidene-2-norbornene (ENB) in the existence of boron compounds. It states that the study has discovered the use of catalysts in the ENB polymerization, molecular weight characteristics, and yields. Moreover, it mentions the failure of triphenylborane in the isomerization polymerization of norbornene derivatives.

Structural evolution during the synthesis of B2-NiAl intermetallic compound by mechanical alloying of equiatomic elemental mixtures was studied by Rietveld analysis, DSC and HTXRD. The lattice parameter, crystallite size, microstrain, amount of phase and ordering of the B2 phase were monitored as a function of milling time. Formation of the B2-NiAl phase shows a sigmoidal behavior, which suggests that Johnson-Mehl-Avrami nucleation and interface-controlled growth are the responsible mechanisms in the transformation. Almost complete transformation (~ 97 mol%) was obtained after 25 h of milling. A specific phase transformation sequence during milling was not absolutely determined, however, the sequence Ni + Al → NiAl → NiAl → B2-NiAl was identified by HTXRD. This sequence was confirmed by DSC. The transformation temperature of the B2-NiAl phase and the presence of additional intermetallic compounds show a direct dependence on the Ni-Al layer spacing. Using a production-scale Simoloyer horizontal Attritor Mill, the presence of NiAl phase was observed prior to the full synthesis of B2-NiAl. [ABSTRACT FROM AUTHOR]

A novel method, based on the combustion of boric acid-sucrose xerogel was developed to synthesize nanocrystalline boron carbide powder. This xerogel was pyrolyzed at 1273 K. Boron carbide was obtained by heating this precursor at 1823 K. The yield of boron carbide was improved by the use of a novel graphite crucible designed for this purpose. The xerogel and the precursor were characterized by using Fourier transform infrared spectroscopy. The constituent phases were identified by using X-ray diffraction while their elemental composition was established with the help of chemical assay. The microstructure of the final product was examined with the help of scanning electron microscopy and transmission electron microscopy. This study demonstrates that the yield of boron carbide would be enhanced to about 48% while the free carbon content in the final product could be reduced to about 6 wt%. These are significant improvements over similar studies reported so far on the gel-based preparation of boron carbide. [ABSTRACT FROM AUTHOR]

A series of new boron-containing tyrosine derivatives [BHO(CH)O-4-CHCHCH-(NH)COOH] and [BHO(CHCH)O-4-CHCHCH(NH)COOH] ( n = 10, 12) were prepared by ring opening of the cyclic oxonium derivatives of the decahydro- closo-decaborate and dodecahydro- closo-dodecaborate anions, respectively, with ethyl N-trifluoroacetyl-L-tyrosinate. [ABSTRACT FROM AUTHOR]

β-Lactosylamine derivatives containing one to three disaccharide residues with the bromine atom at the terminal position of aglycon were synthesized. Conjugation of these derivatives with 1-mercapto-1,2-dicarba- closo-dodecaborane was carried out in DMSO, which was accompanied by deboronation to form nido-ortho-carborane (7,8-dicarba- nido-undecaborate) glycoconjugates in up to 70% yield. The hydrolytic stability of glycoconjugates and the binding efficiency of their triethylammonium salts to castor-bean galectin ( Ricinus communis aggluinin, RCA) were estimated. Glycoconjugates are decomposed in an aqueous solution by ∼15% at 37 °C in three days. The glycoconjugate salt with one β-lactosylamine residue binds to galectin analogously to lactose; after indroduction of the second β-lactosylamine residue into glycoconjugate, the binding efficiency increases ∼6-fold due to the cluster effect. [ABSTRACT FROM AUTHOR]

Arising from Y. Tian et al. 493, 385-388 (2013)Tian et al. report synthesis of 'nanotwinned' cubic boron nitride ('nt-cBN'). These authors claim that its unprecedented Vickers hardness of 108 GPa is due to nanotwinning, and that hardening of cBN is continuous with decreasing twin thickness down to the smallest size investigated, in contrast to the expected reverse Hall-Petch effect. We demonstrate here that it has been known for tens of years that 'nt-cBN' (refs 2-4) hardens owing to a complex of phenomena associated with its microstructure and defects; we also consider that Tian et al. provide no proof that the hardness of 'nt-cBN' is larger than 85 GPa, which is the previously reported maximum for nanostructured boron nitride. Thus the claim of continuous hardening down to a few nanometres twin thickness is, in our opinion, unjustified. There is a Reply to this Brief Communication Arising by Tian, Y. et al. Nature 502, http://dx.doi.org/10.1038/nature12621 (2013). [ABSTRACT FROM AUTHOR]

A monolayer hexagonal boron nitride (h-BN) film with controllable domain morphology and domain size (varying from less than 1 μm to more than 100 μm) with uniform crystalline orientation was successfully synthesized by chemical vapor deposition (CVD). The key for this extremely large single crystalline domain size of a h-BN monolayer is a decrease in the density of nucleation seeds by increasing the hydrogen gas flow during the h-BN growth. Moreover, the well-defined shape of h-BN flakes can be selectively grown by controlling Cu-annealing time under argon atmosphere prior to h-BN growth, which provides the h-BN shape varies in triangular, trapezoidal, hexagonal and complex shapes. The uniform crystalline orientation of h-BN from different nucleation seeds can be easily confirmed by polarized optical microscopy (POM) with a liquid crystal coating. Furthermore, seamlessly merged h-BN flakes without structural domain boundaries were evidence by a selective hydrogen etching after a full coverage of a h-BN film was achieved. This seamless large-area and atomic monolayer of single crystalline h-BN film can offer as an ideal and practical template of graphene-based devices or alternative two-dimensional materials for industrial applications with scalability. [ABSTRACT FROM AUTHOR]