One‐Step Pyro‐Synthesis of a Nanostructured Mn3O4/C Electrode with Long Cycle Stability for Rechargeable Lithium‐Ion Batteries

A nanostructured Mn₃O₄/C electrode was prepared by a one‐step polyol‐assisted pyro‐synthesis without any post‐heat treatments. The as‐prepared Mn₃O₄/C revealed nanostructured morphology comprised of secondary aggregates formed from carbon‐coated primary particles of average diameters ranging between 20 and 40 nm, as evidenced from the electron microscopy studies. The N₂ adsorption studies reveal a hierarchical porous feature in the nanostructured electrode. The nanostructured morphology appears to be related to the present rapid combustion strategy. The nanostructured porous Mn₃O₄/C electrode demonstrated impressive electrode properties with reversible capacities of 666 mAh g^?1 at a current density of 33 mA g^?1, good capacity retentions (1141 mAh g^?1 with 100 % Coulombic efficiencies at the 100^th cycle), and rate capabilities (307 and 202 mAh g^?1 at 528 and 1056 mA g^?1, respectively) when tested as an anode for lithium‐ion battery applications.     

New heteroleptic palladium(II) dithiocarbamates: synthesis,characterization, packing and anticancer activity against five different cancer cell lines

Two new heteroleptic palladium(II) complexes have been synthesized by reacting equimolar quantities of palladium(II) chloride, sodium 4‐(2‐methoxyphenyl)piperazine‐1‐carbodithioate and diphenyl‐p‐tolylphosphine ( 1 ) or tri‐p‐tolylphosphine ( 2 ). Complexes 1 and 2 have been characterized using elemental analysis, Fourier transform infrared spectroscopy, multinuclear NMR (¹H, ¹³C and ³¹P) spectroscopy and single‐crystal X‐ray analysis. The latter technique confirms a pseudo square‐planar geometry in which two adjacent positions are occupied by bidentate dithiocarbamate while chloro and substituted triphenylphosphine are present at the remaining two positions. The anticancer activity of both complexes against five different cancer cell lines (LU – human lung carcinoma, established at UIC, Department of Surgical Oncology; MCF7 – human breast adenocarcinoma, ATCC number HTB‐22?; MDA‐MB‐231 – human breast adenocarcinoma, ATCC number HTB‐26?; Hepa‐1c1c7 – mouse liver hepatoma, ATCC number CRL‐2026?; PC‐3 – human prostate adenocarcinoma, ATCC number CRL‐1435?) was determined by MTT assay, revealing 2 has higher activity than 1 . A drug–calf thymus DNA binding study with UV–visible spectroscopy reveals a higher DNA binding affinity of 2 (3.511 × 10⁴ M^?1) than 1 (4.213 × 10³ M^?1). Density functional theory studies confirm the relatively more stable nature of 2 than 1 . Copyright © 2016 John Wiley & Sons, Ltd.     

Development of a capillary electrophoresis method for the enantioselective estimation of primaquine in pharmaceutical formulations

A capillary electrophoresis (CE) method has been developed that allows the separation and estimation of primaquine enantiomers using hydroxypropyl-gamma-cyclodextrin (HP-gamma -CD) as a chiral selector. The influence of chemical and instrumental parameters on the separation, such as type and concentration of CD, buffer concentration, buffer pH, applied voltage, capillary temperature, and injection time, were investigated. Good separation of the racemic mixture of primaquine was achieved using a fused-silica capillary (52.5 cm effective length x 50 microm id) and a background electrolyte composed of tris-phosphate buffer solution (50 mM, pH 2.5) containing 15 mM HP-gamma-CD as a chiral selector. The recommended applied voltage, capillary temperature, and injection time were 15 kV, 25 degrees C, and 6 s, respectively. Within-day and interday reproducibility of peak area and migration time gave relative standard deviation values ranging from 1.05-3.30%. Good recoveries (range of 96.8-104.9%) were obtained from the determination of placebos that were spiked with 0.25-1.00 mg/L primaquine. The proposed CE method was successfully applied to the assay of primaquine diphosphate in pharmaceutical formulations (tablets).     

In vitro anticancer activity and biologically relevant metabolization of organometallic ruthenium complexes with carbohydrate-based ligands

The synthesis and in vitro anticancer activity of dihalogenido(eta6-p-cymene)(3,5,6-bicyclophosphite-alpha-D-glucofuranoside)ruthenium(II) complexes are described. The compounds were characterized by NMR spectroscopy and ESI mass spectrometry, and the molecular structures of dichlorido-, dibromido- and diiodido(eta6-p-cymene)(3,5,6-bicyclophosphite-1,2-O-isopropylidene-alpha-D-glucofuranoside)ruthenium(II) were determined by X-ray diffraction analysis. The complexes were shown to undergo aquation of the first halido ligand in aqueous solution, followed by hydrolysis of a P--O bond of the phosphite ligand, and finally formation of dinuclear species. The hydrolysis mechanism was confirmed by DFT calculations. The aquation of the complexes was markedly suppressed in 100 mM NaCl solution, and notably only very slow hydrolysis of the P--O bond was observed. The complexes showed affinity towards albumin and transferrin and monoadduct formation with 9-ethylguanine. In vitro studies revealed that the 3,5,6-bicyclophosphite-1,2-O-cyclohexylidene-alpha-D-glucofuranoside complex is the most cytotoxic compound in human cancer cell lines (IC50 values from 30 to 300 microM depending on the cell line).     

Uptake of Tm(III) ions onto polyurethane foam from H2O - ethanol mixture containing 1-(2-pyridylazo)-2-naphthol (PAN)

Summary The sorption of microquantities of Tm(III) ions on washed polyurethane foam (PUF) from a mixture of aqueous solution and ethanol containing PAN was examined. The maximum sorption of 3.18^. 10^-6M solution of Tm(III) ions was observed at pH 8 with 30-minute equilibration time. The optimum ratio of aqueous-ethanol phase for the sorption of Tm(III) ions was found to be 3:1 v/v, respectively. The sorption rate of metal ions on PUF is followed a first order kinetics and obeyed the equation for an intra particle diffusion process. The equilibrium concentration data of Tm(III) ions could be described satisfactorily by several adsorption isotherms. The Freundlich adsorption isotherm constants 1/nand K_Fare 0.66±0.02 and (5.7±0.3)^. 10^-3mol^. g^-1, respectively. The Langmuir isotherm constants for monolayer coverage (Q) and binding strength of sorption (b) are (2.5±0.7)^. 10^-5mol^. g^-1and (1.6±0.1)^. 10⁴l^. mol^-1, respectively. The sorption capacity derived from Dubinin-Radushkevich (D-R) isotherm is (1.7±0.2)^. 10^-4mol^. g^-1and the sorption free energy (E) is 9.8±0.2 kJ^. mol^-1indicating chemisorption phenomena. The thermodynamic parameters indicate that the sorption of Tm(III) ions onto PUF is endothermic, entropy driven and spontaneous in nature.     

A theoretical investigation of intermolecular interaction of a phthalimide based “on–off” sensor with different halide ions: tuning its efficiency and electro-optical properties

The interaction between chemosensor, N-(2-methyl-1,3-dioxo-indan-5-yl)-benzamide (1) and different halide ions (F ^? , Cl^? and Br^?) has been investigated using density functional theory (DFT). A clear insight of the sensor anion binding process has been presented. Our calculations revealed that the observed colorimetric and fluorescent signals are induced due to the ground state deprotonation of the sensor molecule caused by F^? which has two times higher binding affinity than other halide ions (Cl^? and Br^?). Derivatives of system 1 have been made to find a better sensor with higher binding affinity and longer wavelength of absorption. All the derivatives are better sensors than the parent 1 except 4-methyl-N-(2-methyl-1,3-dioxo-indan-5-yl)-benzamide (2). Among these derivatives, trimethyl-[4-(2-methyl-1,3-dioxo-indan-5-ylcarbamoyl)-phenyl]-ammonium (8) and (5-benzoylamino-1,3-dioxo-indan-2-yl)-trimethyl-ammonium (9) showed a change to higher binding energies of about 58 Kcal/mol and longer absorption wavelengths of 53 nm after deprotonation process than the parent system 1 which is highly demanded in selective chemical sensing. Systems 8, 9 and their deprotonated zwitterionic forms (8z and 9z) have also been studied for their nonlinear optical responses. Systems 8, 9 showed significantly good first hyperpolarizability (β) of 84 × 10^?30 and 40 × 10^?30 esu, respectively. These β values increase in zwitterionic states up to 216 × 10^?30 and 109 × 10^?30 esu, respectively after deprotonation with F^?, representing a new signal of deprotonation.     

Structural,dielectric and electrical properties of zinc doped nickel nanoferrites prepared by simplified sol–gel method

Zinc doped nickel ferrite nanoparticles having the general formula Ni_1−xZn_xFe₂O₄ (x = 0.1, 0.2, 0.3, 0.4, 0.5) were prepared with simplified sol–gel method. The structural and dielectric properties of these samples sintered at 750 ± 5 °C were studied. X-ray diffraction patterns confirm the single phase spinel structure for prepared samples. The scanning electron microscope images indicated that the particle size of the samples lies in the nanometer regime. The dielectric constant (ε_r) and dielectric loss tangent (tan δ) of nanocrystalline nickel ferrites were investigated as a function of frequency and Zn concentration. The dependence of ε_r and tan δ on the frequency of the alternating applied electric field is in accordance with the Maxwell–Wagner model. The prepared samples have a lowest dielectric constant compared to the already reported samples of the same composition to the best of our knowledge. The effect of Zn doping on the dielectric properties of nickel ferrites is explained on the basis of cations distribution in the crystal structure.