Conducting poly(o-anisidine)-coated steel electrodes for supercapacitors

Conducting poly(o-anisidine) coatings were obtained on low carbon steel in aqueous oxalic acid solution by using the galvanostatic technique. The coatings were characterised by potential-time relations, UV-VIS absorption spectroscopy, scanning electron microscopy, and X-ray diffraction measurements. The electrochemical performance of coated steel electrodes was evaluated on the basis of galvanostatic charge-discharge performance and electrochemical impedance spectroscopy in 0.5 M H₂SO₄. Maximum charging current was found in the case of the coating obtained at a current density of 8 mA cm^?2 for 600 s duration at the supply voltage of 0.5 V. The estimated capacitance of the coated steel electrode for charging is 42.67 mF and 7.2 mF for discharging. It was also found that there was an increase in capacitance as a function of supply voltage and the maximum value was obtained at 0.5 V. The study reveals the possibility of using conducting poly(o-anisidine)-coated low carbon steel from oxalic acid medium as supercapacitor electrode materials.     

A “Push–Pull” Stabilized Phosphinidene Supported by a Phosphine-Functionalized β-Diketiminato Ligand

The use of a bis(diphenyl)phosphine functionalized β-diketiminato ligand, [HC{(CH₃)C}₂{(ortho-[P(C₆H₅)₂]₂C₆H₄)N}₂]⁻ (PNac), as a support for germanium(II) and tin(II) chloride and phosphaketene compounds, is described. The conformational flexibility and hemilability of this unique ligand provide a versatile coordination environment that can accommodate the electronic needs of the ligated elements. For example, chloride abstraction from [(PNac)ECl] (E=Ge, Sn) affords the cationic germyliumylidene and stannyliumylidene species [(PNac)E]⁺ in which the pendant phosphine arms associate more strongly with the Lewis acidic main group element centers, providing further electronic stabilization. In a similar fashion, chemical decarbonylation of the germanium phosphaketene [(PNac)Ge(PCO)] with tris(pentafluorophenyl)borane affords a “push–pull” stabilized phosphinidene in which one of the phosphine groups of the ligand backbone associates with the low valent phosphinidene center.     

Investigation of the Thermal Properties of Alkali Metal Thorium Phosphates and Their Application for the Sorption of Uranyl Ion from Acidic Medium

Thermo physical properties of potassium, rubidium and cesium thorium phosphate compounds were investigated. All compounds were synthesized by conventional solid state method. Formation of orthorhombic AMThP₃O₁₀, tetragonal AM₂Th(PO₄)₂ and monoclinic AMTh₂(PO₄)₃; [AM=K, Rb and Cs] was confirmed using Powder X-ray diffraction (XRD) technique. Structural study of CsThP₃O₁₀ was carried out for the first time from Rietveld refinement of XRD data. Thermal stability of all compounds was established using Thermogravimetric analysis (TGA) technique. When heated at 1673 K for 30 h in air, all the compounds decompose to ThO₂. High temperature X-ray diffraction (HT-XRD) data of the compounds, synthesized during present study, were collected in an inert atmosphere from ambient to 973 K and their thermal expansion coefficients were calculated. These compounds show positive thermal expansion up to 973 K. Molar heat capacities for all phosphates were measured between 300–863 K using Differential Scanning Calorimeter. Alkali metal thorium phosphates, AMThP₃O₁₀ and AMTh₂(PO₄)₃, showed efficient uptake of uranyl ion from aqueous acidic medium predominantly following Langmuir isotherm and Webber Morris intra particle diffusion kinetics.     

Heteroallene Capture and Exchange at Functionalised Heptaphosphane Clusters

Despite being known for decades the chemical reactivity of homoatomic seven-atom phosphorus clusters towards small molecules remains largely unexplored. Here, we report that neutral tris(silyl) functionalised heptaphosphane (P₇(SiR₃)₃) cages are capable of heteroallene capture between the P−Si bonds of the cluster. A range of isocyanates and an isothiocyanate were investigated. In the case of isocyanates, silyl bonding at oxygen or nitrogen is regioselectively directed by the functional group on the isocyanate and substituents on the silyl moiety. Above all, we find that captured isothiocyanate molecules can be exchanged for isocyanate molecules, indicative of small molecule catch and release. Small molecule catch and release at these Zintl-derived clusters reveals their potential application as chemical storage materials or as reusable probes.     

Effective synthesis of some novel pyrazolidine-3,5-dione derivatives via Mg(II) catalyzed in water medium and their anticancer and antimicrobial activities

Molecular Diversity - Novel pyrazolidine-3,5-dione derivatives (2a–g, 4a–g, and 6a–g) were synthesized by an easy-to-perform Mg(II) acetylacetonate-catalyzed reaction with high...     

Structural,optical and magnetic study of (1−x)ZnO–xMgO composites prepared through solid state reaction method

We report the study of structural, optical and magnetic properties of (1−x)ZnO–xMgO (x=0.35, 0.40, 0.45 and 0.50) composites prepared by solid state reaction method. X-ray diffraction pattern confirms the presence of both the phases associated with ZnO (hexagonal) and MgO (cubic), which is revealed through the existence of (1 1 1) and (2 0 0) peaks in addition to ZnO peaks. The lattice parameter c as calculated using X-ray analysis undergoes shrinkage with increasing content of MgO. Microstructural analysis suggests that there is no variation in spherical elongated shape of grains with increasing concentration of MgO, where the average grain size is found to be ∼600 nm. The band gap as calculated from optical absorption spectra obtained by diffuse reflectance method recorded at room temperature is tuned from 3.16 to 3.55 eV. Photoluminescence spectra consist of near band edge UV emission (389 nm) and defect level emission (503 nm). The increase of MgO concentration leads to blue shift of UV emission peaks. The magnetic measurements conducted using SQUID at 5 K temperature reveals ferromagnetism along with paramagnetic and superparamagnetic components. Saturation magnetisation (M_s) is observed to be enhanced with MgO doping.     

Mixed moments of L-functions

In this paper we will study the main term of mixed moments of L-functions associated to holomorphic cusp forms of integral weight on congruence subgroups of odd and squarefree level. 2000 Mathematics Subject Classification Primary—11F67, 11M41, 11F30     

A kernel for automorphic L-functions

The full multiple Dirichlet series of an automorphic cusp form is defined, in classical language, as a Dirichlet series of several complex variables over all the Fourier coefficients of the cusp form. It is different from the L-function of Godement and Jacquet, which is defined as a Dirichlet series in one complex variable over a one-dimensional array of the Fourier coefficients. In GL(2) and GL(3), the two notions are simply related. In this paper, we construct a kernel function that gives the full multiple Dirichlet series of automorphic cusp forms on GL(n,R). The kernel function is a new Poincaré series. Specifically, the inner product of a cusp form with this Poincaré series is the product of the full multiple Dirichlet series of the form times a function that is essentially the Mellin transform of Jacquet's Whittaker function. In the proof, the full multiple Dirichlet series is produced by applying the Lipschitz summation formula several times and by an integral which collapses the sum over SL(n−1,Z) in the Fourier expansion of the cusp form.     

Intramolecular phenylborane complexes with monobasic bidentate Schiff bases

A series of intramolecular complexes with Schiff base ligands having N∩S and N∩O donor systems were synthesized in an open vessel under microwave irradiation (MWI) using a domestic microwave oven. The reaction time has been brought down from hours to seconds with improved yield as compared with the conventional heating. The complexes have been characterized on the basis of elemental analysis, conductance measurements and spectroscopic analysis. Based on the IR, ¹H NMR, ¹¹B NMR and ¹³C NMR spectroscopic studies, a tetrahedral geometry has been proposed for the resulting complexes. The compounds have been screened in vitro against bacteria and fungi to test their antimicrobial property and in vivo in male albino rats to test their antifertility property. The testicular sperm density, motility and density of cauda epididymal spermatozoa along with biochemical parameters of reproductive organs have been examined and discussed. Copyright © 2007 John Wiley & Sons, Ltd.