Low Temperature Synthesis of Cobalt-Chromium Carbide Nanoparticles-Doped Carbon Nanofibers.

Electrospinning has been used to synthesize cobalt-chromium carbide nanoparticles (NPs)-doped carbon nanofibers (CNFs) (Composite). Electrospun mat comprising of cobalt acetate, chromium acetate and poly(vinyl alcohol) (PVA) has been carbonized at low temperature (850 °C) for 3 h under argon atmosphere to produce the introduced composite. The process was achieved at low temperature due to the presence of cobalt as an activator. Field emission scanning electron microscope (FE-SEM), X-ray diffractometry (XRD), and transmission electron microscopy (TEM) equipped with EDX techniques were used to determine the products characteristics. The results indicated the formation of pure cobalt (Co), Cr7C3 NPs and crystalline CNFs. The Co and Cr7C3 NPs were covered with CNFs. Overall, the proposed NFs open new avenue to prepare different metals-metal carbides-carbon NFs at low temperature and short reaction time.

Synthesis of new morpholine-connected pyrazolidine derivatives and their antimicrobial, antioxidant, and cytotoxic activities.

A simple and convenient one-pot four-component synthesis of morpholine-connected pyrazolidine derivatives 2a-f and 4a-f was developed using direct metal-free catalysis, with the identities of the synthesized compounds confirmed by IR, NMR (1H and 13C), mass spectrometry, and elemental analysis. The prepared compounds were inspected for antimicrobial, antioxidant, and cytotoxic activities. Antimicrobial and antifungal activities against five bacterial and four fungal pathogens, respectively, were investigated using the disc diffusion technique. In antibacterial activity, compounds 2d and 2f (MIC=2µg/mL) exhibited significantly higher activity than the standard ciprofloxacin. The results of antifungal assay showed that the activity of compound 4a (MIC=0.5µg/mL) was significantly higher than the standard clotrimazole. Antioxidant activity was screened based on ABTS+ radical scavenging and linoleic acid peroxidation performance. Compound 4a showed substantial antioxidant (91.3%) activities, as compared with the Trolox standard. Cytotoxicity was evaluated using HepG2 (liver), HeLa (cervical), and MCF-7 (breast) cancer cell lines, with high toxicities observed for 2b (GI50=12.2µm) and 4a (GI50=07.8µm).

Chemical-Bath-Deposited Indium Oxide Microcubes for Solar Water Splitting.

We fabricated films of cubic indium oxide (In2O3) by chemical bath deposition (CBD) for solar water splitting. The fabricated films were characterized by X-ray diffraction analysis, Raman scattering, X-ray photoelectron spectroscopy, and scanning electron microscopy, and the three-dimensional microstructure of the In2O3 cubes was elucidated. The CBD deposition time was varied, to study its effect on the growth of the In2O3 microcubes. The optimal deposition time was determined to be 24 h, and the corresponding film exhibited a photocurrent density of 0.55 mA cm(-2). Finally, the film stability was tested by illuminating the films with light from an AM 1.5 filter with an intensity of 100 mW cm(-2).

Nanotextured pillars of electrosprayed bismuth vanadate for efficient photoelectrochemical water splitting.

We demonstrate, for the first time, electrostatically sprayed bismuth vanadate (BiVO4) thin films for photoelectrochemical water splitting. Characterization of these films by X-ray diffraction, Raman scattering, and high-resolution scanning electron microscopy analyses revealed the formation of nanotextured pillar-like structures of highly photoactive monoclinic scheelite BiVO4. Electrosprayed BiVO4 nanostructured films yielded a photocurrent density of 1.30 and 1.95 mA/cm(2) for water and sulfite oxidation, respectively, under 100 mW/cm(2) illumination. The optimal film thickness was 3 µm, with an optimal postannealing temperature of 550 °C. The enhanced photocurrent is facilitated by formation of pillar-like structures in the deposit. We show through modeling that these structures result from the electrically-driven motion of submicron particles in the direction parallel to the substrate, as they approach the substrate, along with Brownian diffusion. At the same time, opposing thermophoretic forces slow their approach to the surface. The model of these processes proposed here is in good agreement with the experimental observations.

Quick high-temperature hydrothermal synthesis of mesoporous materials with 3D cubic structure for the adsorption of lysozyme.

Three-dimensional cage-like mesoporous FDU-12 materials with large tuneable pore sizes ranging from 9.9 to 15.6 nm were prepared by varying the synthesis temperature from 100 to 200 °C for the aging time of just 2 h using a tri-block copolymer F-127(EO106PO70EO106) as the surfactant and 1,3,5-trimethyl benzene as the swelling agent in an acidic condition. The mesoporous structure and textural features of FDU-12-HX (where H denotes the hydrothermal method and X denotes the synthesis temperature) samples were elucidated and probed using x-ray diffraction, N2 adsorption, 29Si magic angle spinning nuclear magnetic resonance, scanning electron microscopy and transmission electron microscopy. It has been demonstrated that the aging time can be significantly reduced from 72 to 2 h without affecting the structural order of the FDU-12 materials with a simple adjustment of the synthesis temperature from 100 to 200 °C. Among the materials prepared, the samples prepared at 200 °C had the highest pore volume and the largest pore diameter. Lysozyme adsorption experiments were conducted over FDU-12 samples prepared at different temperatures in order to understand their biomolecule adsorption capacity, where the FDU-12-HX samples displayed high adsorption performance of 29 µmol g-1 in spite of shortening the actual synthesis time from 72 to 2 h. Further, the influence of surface area, pore volume and pore diameter on the adsorption capacity of FDU-12-HX samples has been investigated and results are discussed in correlation with the textural parameters of the FDU-12-HX and other mesoporous adsorbents including SBA-15, MCM-41, KIT-5, KIT-6 and CMK-3.

Biological Screening of Newly Synthesized BIAN N-Heterocyclic Gold Carbene Complexes in Zebrafish Embryos.

N-Heterocyclic carbene (NHC) metal complexes possess diverse biological activities but have yet to be extensively explored as potential chemotherapeutic agents. We have previously reported the synthesis of a new class of NHC metal complexes N-heterocyclic with acetate [IPr(BIAN)AuOAc] and chloride [IPr(BIAN)AuCl] ligands. In the experiments reported herein, the zebrafish embryos were exposed to serial dilutions of each of these complexes for 10-12 h. One hundred percent mortality was observed at concentrations≥50 µM. At sub-lethal concentrations (10-30 µM), both compounds influenced zebrafish embryonic development. However, quite diverse categories of abnormalities were found in exposed embryos with each compound. Severe brain deformation and notochord degeneration were evident in the case of [IPr(BIAN)AuOAc]. The zebrafish embryos treated with [IPr(BIAN)AuCl] exhibited stunted growth and consequently had smaller body sizes. A depletion of 30%-40% glutathione was detected in the treated embryos, which could account for one of the possible mechanism of neurotoxicity. The fact that these compounds are capable of both affecting the growth and also compromising antioxidant systems by elevating intracellular ROS production implies that they could play an important role as a new breed of therapeutic molecules.

Highly magnetic nanoporous carbon/iron-oxide hybrid materials.

The preparation of size-controllable Fe2O3 nanoparticles grown in nanoporous carbon with tuneable pore diameters is reported. These hybrid materials exhibit strong non-linear magnetic properties and a magnetic moment of approximately 229 emu g(-1), which is the highest value ever reported for nanoporous hybrids, and can be attributed to the nanosieve effect and the strong interaction between the nanoparticles and the carbon walls.

Gravity-driven hybrid membrane for oleophobic-superhydrophilic oil-water separation and water purification by graphene.

We prepared a simple, low-cost membrane suitable for gravity-driven oil-water separation and water purification. Composite membranes with selective wettability were fabricated from a mixture of aqueous poly(diallyldimethylammonium chloride) solution, sodium perfluorooctanoate, and silica nanoparticles. Simply dip-coating a stainless steel mesh using this mixture produced the oil-water separator. The contact angles (CAs) of hexadecane and water on the prepared composite membranes were 95 ± 2° and 0°, respectively, showing the oleophobicity and superhydrophilicity of the membrane. In addition, a graphene plug was stacked below the membrane to remove water-soluble organics by adsorption. As a result, this multifunctional device not only separates hexadecane from water, but also purifies water by the permeation of the separated water through the graphene plug. Here, methylene blue (MB) was removed as a demonstration. Membranes were characterized by high-resolution scanning electron microscopy (HRSEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectroscopy to elucidate the origin of their selective wettability.

Nutritional assessment and antioxidant activities of different varieties of Vigna radiata.

Three cultivars of Vigna radiata, namely, NM-92, NM-98, and NM-06, were analyzed for their proximate composition. The samples were also tested by HPLC for amino acid content. The data showed that all the varieties had same moisture level. The maximum ash content (4.29%) was present in NM-92, and crude fat (2.26%) was highest in NM-98 while NM-06 contained maximum amount of crude protein. About eighteen types of amino acids were detected in each of the three varieties. Acidic amino acids, that is, aspartic and glutamic acids, were in considerable amount ranged from 13 to 23% followed by leucine, isoleucine, alanine, valine, lysine, phenyl alanine, serine, and arginine which fell in the range of 3-8% of total protein. The maximum amount (13.00 and 22.80%) of aspartic and glutamic acids was present in NM-98. Similarly arginine (6.83%) and serine (5.45%) were also in highest amount in this variety. Leucine (7.46%) was maximum in NM-92 variety. NM-06 contained almost all the amino acids in lesser quantity except for few like threonine, proline, glycine, and alanine. It was concluded from the present study that varieties were of different nutritional value and HPLC was a sensitive method for amino acids determination. Antioxidant activities of all three varieties were also assayed and showed significant results.

Bis(4-meth-oxy-benzyl-ammonium) dihydrogen diphosphate.

In the title compound, 2C(8)H(12)NO(+)·H(2)P(2)O(7) (2-), the linked PO(4) groups of the diphosphate anion are almost eclipsed and the P-O-P angle is 134.45 (7)°. In the crystal, infinite ribbons of H(2)P(2)O(7) (2-) anions propagate in [100], being linked by strong O-H⋯O hydrogen bonds. The 4-meth-oxy-benzyl-ammonium cations bond to the diphosphate chains by N-H⋯O and C-H⋯O links, and are themselves linked by C-H⋯π inter-actions.

N'-(2,4-Di-nitro-phen-yl)acetohydrazide monohydrate.

In the crystal structure of the title compound, C8H8N4O5·H2O, the organic and lattice water mol-ecules are linked together via N-H⋯O and O-H⋯O hydrogen bonds. A C-H⋯O inter-action is also observed between the organic mol-ecules. These hydrogen bonds and inter-actions lead to the formation of a three-dimensional network. An intra-molecular N-H⋯O hydrogen bond also occurs. The dihedral angle between the acetyl group and the almost planar hydrazide moiety [maximum deviation from the least-squares plane is 0.209 (2) Šfor one of the nitro O atoms] is 88.5 (3)°.

5-Amino-1H-1,2,4-triazol-4-ium hydrogen oxalate.

In the title salt, C2H5N4 (+)·C2HO4 (-), the hydrogen oxalate anions form corrugated chains parallel to the c axis, linked by inter-molecular O-H⋯O hydrogen bonds. The 5-amino-1H-1,2,4-triazol-4-ium cations are connected into centrosymmetric clusters via weak C-H⋯N hydrogen bonds forming nine-membered rings with an R 3 (3)(9) motif. These clusters are inter-connected via anions through N-H⋯O hydrogen bonds, building a three-dimensional network.

Poly[bis-(piperazine-1,4-diium) [(µ4-cyclo-hexa-phosphato)dilithium] tetra-hydrate].

In the title compound, {(C4H12N2)2[Li2(P6O18)]·4H2O} n , the phosphate ring anion, located around an inversion center, adopts a chair conformation. Adjacent P6O18 rings are linked via corner-sharing by LiO4 tetra-hedra, generating anionic porous {[Li2(P6O18)](4-)} n layers parallel to (101). The piperazine-1,4-diium cations occupy the pores and develop hydrogen bonds with the inorganic framework. An extensive network of N-H⋯O and O-H⋯O hydrogen-bonding inter-actions link the components into a three-dimensional network and additional stabilization is provided by weak C-H⋯O hydrogen bonds.

Bis[1-(2,3-di-methyl-phen-yl)piperazine-1,4-diium] bis-(oxonium) cyclo-hexa-phosphate dihydrate.

In the title compound, 2C12H20N2 (2+)·2H3O(+)·P6O18 (6-)·2H2O, a protonated water mol-ecule bridges the centrosymmetrical anionic P6O18 ring via O-H⋯O hydrogen bonds. The centrosymmetric hydrogen-bonded rings formed by four oxonium cations and four phosphate anions can be described by an R 4 (8)(36) graph-set motif. The ring motifs are connected by hydrogen bonds into inorganic layers perpendicular to [100]. The 1-(2,3-di-methyl-phen-yl)piperazine-1,4-diium cations are located between the layers, compensating their negative charge and establishing N-H⋯O hydrogen bonds with the O atoms of the anionic framework.

Understanding the effect of flower extracts on the photoconducting properties of nanostructured TiO2.

Here we report an easy method to improve the optoelectronic properties of commercially available TiO2 nanopowder using extracts of various flowers viz. Calendula Orange (CO), Calendula Yellow (CY), Dahlia Violet (DV), Dahlia Yellow (DY), Rabbit flower (RF), Sweet Poppy (SP), Sweet Williams (SW) and their Mixed Extracts (ME). Various analysis techniques such as UV-Vis, FTIR, FESEM, XRD, and Raman spectroscopy were used to characterize for elemental, structural and morphological properties of the unmixed/mixed TiO2 nanopowder. TiO2 nanopowder was also calcined at 550 degrees C. Thick films of the these unmixed/mixed powder were printed, using conventional screen printing method, on fluorine doped tin oxide (FTO) substrate with organic binders and dried at 45 degrees C. The photoconducting properties are investigated as a function of wavelength from ultra-violet (UV) to infra-red (IR) region at a constant illumination intensity. Photocurrent gradually decreases when irradiated from UV to IR region. In case of unmixed and uncalcined TiO2, conductance decreased continuously whereas when extracts are added, a flat region of conductance is observed. The overall effect of extracts (colour pigments) is seen as an increase in the photoconductance. Highest photoconductance is observed in case of DY flower extract. Anthocyanins, present in flowers are known to have antioxidative properties and hence can contribute in photoconduction by reducing the surface adsorbed oxygen. This investigation indicates the potential use of flower extracts for dye sensitized solar cell (DSSC).

Photoconducting properties of a unit nanostructure of ZnO assembled between microelectrodes.

The photoconducting properties of a unit microflower of zinc oxide are investigated as a function of wavelength from UV to IR region at constant illumination intensity. Synthesized flowers were trapped in 2 microm gap, between pre-prepared gold microelectrodes, using AC dielectrophoresis. Photocurrent drastically increases upon illumination in the UV region, whereas it gradually reduces when irradiated in visible and IR region. Higher photoconductivity in UV region is correlated to band to band transition upon illumination. In visible region, deep level transitions are expected which intern exhibits comparatively low photocurrent. Photoconduction in IR region is only due to the adsorbed surface oxygen species. This investigation suggests the potential application of ZnO nanostructures for various optoelectronic device applications.

Dilithium disodium nickel(II) cyclo-hexa-phosphate dodeca-hydrate, Li(2)Na(2)NiP(6)O(18)·12H(2)O.

The crystal structure of Li(2)Na(2)NiP(6)O(18)·12H(2)O is characterized by the presence of six-membered P(6)O(18) (6-) phosphate ring anions (inter-nal symmetry -1) having a chair conformation and three different cations, viz. Li(+), Na(+) and Ni(2+), to counterbalance the anionic charge. All atoms are in general positions except for nickel, which lies on a special position with site symmetry 2. Lithium has a tetra-hedral environment (LiO(4)), and sodium and nickel have octa-hedral environments [NaO(6) and Ni(H(2)O)(6), respectively]. The P(6)O(18) rings are linked via corner sharing by NaO(6) octa-hedra and LiO(4) tetra-hedra to form a three-dimensional framework presenting tunnels running along [010] in which the six-coordinated Ni(2+) cations are located. The structure is stabilized by a network of O-H⋯O hydrogen bonds.

Bis(3-azoniapentane-1,5-diaminium) cyclo-hexa-phosphate dihydrate: a monoclinic polymorph.

In the title hydrated mol-ecular salt, 2C(4)H(16)N(3) (3+)·P(6)O(18) (6-)·2H(2)O, the complete cyclo-hexa-phosphate anion is generated by crystallographic inversion symmetry. The six P atoms of the P(6)O(18) (6-) anion form a chair conformation and the organic cation has a corrugated linear geometry. In the crystal, the cations and the anions are connected by N-H⋯O hydrogen bonds into slabs propagating in the ac plane. The water mol-ecules link the slabs by accepting N-H⋯O links and forming O-H⋯O links. The triclinic polymorph was reported by Gharbi et al. [(1995). J. Solid State Chem.114, 42-51].

Propane-1,3-diammonium dichromate(VI).

The title compound, (C(3)H(12)N(2))[Cr(2)O(7)], consists of a discrete dichromate anion with an eclipsed conformation and a propane-1,3-diammonium cation. Both kinds of ions have a mirror plane passing through the bridging O atom and the central methyl-ene C atom of the Cr(2)O(7) (2-) and C(3)H(12)N(2) (2+) moieties, respectively. Anions and cations are alternately stacked to form columns parallel to the b axis. Ions are linked by intra- and inter-column hydrogen bonds of types N-H⋯O and C-H⋯O, involving O atoms of the dichromate anions as acceptors, and ammonium or methyl-ene groups as donors.

Antimicrobial properties of some bis(iminoacenaphthene (BIAN)-supported N-heterocyclic carbene complexes of silver and gold.

The AgCl, AgOAc, AuCl, and AuOAc complexes of the new bis(imino)acenaphthene(BIAN)-supported N-heterocyclic carbene ligand and the precursor imidazolium salt have been investigated with respect to their antimicrobial activities against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Psudomonas aeruginosa. The most active antimicrobial is the precursor imidazolium salt, which has a minimum inhibitory concentration (MIC) value of <40 µg/mL. The MIC values for the silver complexes IPr(BIAN)AgCl and IPr(BIAN)AgOAc against Gram-positive S. aureus are comparable to that for AgNO3, while those against Gram-negative E. coli and P.aeroginosa are significantly larger. Similar behavior was evident for the gold acetate complex IPr(BIAN)AuOAc. However, in the case of the gold chloride analogue, the MIC values are virtually identical for both the Gram-positive and the Gram-negative bacteria.