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...     

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.     

Synthetic application of lithiation reactions—xiv : Novel synthesis of 7,8-dimethoxy phenanthridine

The difficultly accessible 7,8-dimethoxy phenanthridine has been synthesised by organolithiation reaction in simple steps and in good yield.     

Studies on acoustic behavior of praseodymium soaps

The CMC and various acoustic parameters of praseodymium soaps in 1-pentanol have been determined by ultrasonic velocity measurements. The results show that the ultrasonic velocity, specific acoustic impedance, apparent molal compressibility, and molar sound velocity increase while adiabatic compressibility and intermolecular free length decrease with increasing concentration and chain length of soap.