Synthesis of tetraaryl-p-benzoquinones by Suzuki-Miyaura cross-coupling reactions of tetrabromo-p-benzoquinone

Suzuki-Miyaura cross-coupling reactions of tetrabromo-p-benzoquinone provide a convenient approach to tetraaryl-p-benzoquinones.     

Synthesis,characterization, DNA binding and nuclease activity of binuclear copper(II) complexes of cuminaldehyde thiosemicarbazones

Binuclear copper(II) complexes of thiosemicarbazones derived from cuminaldehyde (p-isopropyl benzaldehyde) and substituted thiosemicarbazides NH₂NHC(S)NHR, where R = H, Me, Et or Ph have been synthesized and characterized. The ESR indicates that the dissociation of dimeric complex into mononuclear [Cu(L)Cl(DMSO)₃] units in polar solvents like DMSO, where L = monoanionic thiosemicarbazone. The molecular ion peak in the LC-MS coincides with the formula weight of the complexes. The absorption titration studies revealed that each of these complexes is an avid binder to calf thymus-DNA. The apparent binding constants are in the order of 10⁷–10⁸ M⁻¹. The nucleolytic cleavage activities of the ligands and their complexes were assayed on pUC18 plasmid DNA using gel electrophoresis in the presence and absence of H₂O₂. The ligands showed increased nuclease activity when administered as copper complexes. All these copper(II) complexes behave as an efficient chemical nucleases with hydrogen peroxide activation. These studies revealed that the complexes exhibit both oxidative and hydrolytic chemistry in DNA cleavage.     

Pauli Half Spinning and Elliptic Curve Based Information Confidentiality Mechanism

International Journal of Theoretical Physics - The use of digital contents has increased tremendously in this modern era. In fact, people spend more time on internet than ever which urged the...     

Multinuclear (Sn/Pd) complexes with disodium 2,2′-(dithiocarboxyazanediyl)diacetate hydrate; Synthesis,characterization and biological activities

Bimetallic chlorodi-/triorganotin(IV) derivatives of general formulas R₂(H₂O)SnLCSSSn(Cl)R₂ (R=Me: 1; Ph: 2) and R₃Sn(Na)LCSSSnR₃·H₂O (R=Bu: 3; Ph: 4) were prepared by reaction of iminodiacetic acid disodium salt hydrate (Na₂LH) with CS₂ and R₂SnCl₂/R₃SnCl in methanol. The reaction between Na₂LH, CS₂, and PdCl₂ produced [Na₂LCSS]₂Pd·2H₂O (5) which was treated with R₃SnCl to synthesize the heterobimetallic derivatives [R₃Sn(Na)LCSS]₂Pd·2H₂O (R=Me: 6; Ph: 7). The complexes were characterized by microanalysis, spectroscopic, and thermogravimetric analyses. Elemental analysis data, mass fragmentation, and thermal degradation patterns supported the molecular composition of the complexes. FT-IR data indicated monodentate binding of carboxylate while a chelating coordination mode of the dithiocarboxylate was verified in the solid state. A five-coordinate tin(IV) was demonstrated in the solid state. In solution, a tetrahedral/trigonal bipyramidal configuration around Sn(IV) and a square planar geometry of Pd(II) was indicated by multinuclear NMR (¹H and ¹³C) and UV-visible studies. The Pd(II) derivatives showed interaction with salmon sperm-DNA and caused an inhibition of alkaline phosphatase (ALPs). The antibacterial/antifungal potential of the coordination products varied with the nature of incorporated metal and a substitution pattern at tin(IV); the palladium metallation decreased the antimicrobial activities. The triorganotin(IV) products exhibited more powerful action against bacteria/fungi as compared to their diorganotin(IV) counterparts. The complexes displayed sufficiently lower hemolytic effects in vitro as compared to triton X-100 and slightly higher than PBS.     

Computational studies on optoelectronic and charge transfer properties of some perylene‐based donor‐π‐acceptor systems for dye sensitized solar cell applications

We report DFT studies on some perylene‐based dyes for their electron transfer properties in solar cell applications. The study involves modeling of different donor‐π‐acceptor type sensitizers, with perylene as the donor, furan/pyrrole/thiophene as the π‐bridge and cyanoacrylic group as the acceptor. The effect of different π‐bridges and various substituents on the perylene donor was evaluated in terms of opto‐electronic and photovoltaic parameters such as HOMO‐LUMO energy gap, λ_max, light harvesting efficiency(LHE), electron injection efficiency (Ø_inject), excited state dye potential (E^dye*), reorganization energy(λ), and free energy of dye regeneration (). The effect of various substituents on the dye–I₂ interaction and hence recombination process was also evaluated. We found that the furan‐based dimethylamine derivative exhibits a better balance of the various optical and photovoltaic properties. Finally, we evaluated the overall opto‐electronic and transport parameters of the TiO₂‐dye assembly after anchoring the dyes on the model TiO₂ cluster assembly.     

Structural,compositional and hardness properties of hydrogenated amorphous carbon nitride thin films synthesized by dense plasma focus device

The hydrogenated amorphous carbon nitride (a‐CN_x:H) thin films were synthesized on the SS‐304 substrates using a dense plasma focus device. The a‐CN_x:H thin films were synthesized using CH₄/N₂ admixture gas and 20 focus deposition shots on substrates placed at different distances from the anode top. X‐ray photoelectron spectroscopy and Raman analysis confirmed different C–N bonding in the a‐CN_x:H thin films. A decrease in the N/C ratio as well as the sp³/sp² ratio with an increase in the substrate distance has been observed. The higher amount of C–N formation for the film synthesized at 10 cm is observed which decreases with increasing distance. The X‐ray photoelectron spectroscopy and Raman analysis affirmed the C ≡ N presence in all the thin films synthesized at different distances. The morphology of the synthesized a‐CN_x:H thin films showed nanoparticles and nanoparticle clusters formation at the surface. The hardness results showed comparatively lower hardness of the a‐CN_x:H thin films due to the presence of C ≡ N. The C–N formation with lower amount of C ≡ N and a higher N/C ratio as well as a higher sp³/sp² ratio for the films synthesized at 10 cm show reasonably higher hardness. Copyright © 2016 John Wiley & Sons, Ltd.     

A review on <Superscript>90</Superscript>Y-labeled compounds and biomolecules

The field of therapeutic nuclear medicine is emerging rapidly as choice of treatment in oncology and other cellular malignancies. The growth of this branch of nuclear medicine is greatly facilitated by the introduction of a number of new radiopharmaceuticals and radionuclides. ⁹⁰Y-radiopharmaceuticals have confirmed their worth in medical and clinical areas in a very short span of time. The ⁹⁰Y is a radioisotope widely used for therapeutic purposes and considerable perfection has been made to understand the chemistry of ⁹⁰Y-labeled radiopharmaceuticals. The development of these radiopharmaceuticals can be made favorable by using appropriate buffer, incubation period, optimal pH, specific activity and reaction temperature. In this review, we have discussed the preparation of range of ⁹⁰Y transporting biological molecules such as antibodies radiolabeled peptides, antigens and microsphere with their clinical applications.     

Super face d-antimagic labeling for disjoint union of toroidal fullerenes

The discovery of the fullerene molecules and related forms of carbon such as nanotubes has generated an explosion of activity in chemistry, physics, and materials science. Classical fullerene is an all-carbon molecule in which the atoms are arranged on a pseudospherical framework made up entirely of pentagons and hexagons. A toroidal fullerene (toroidal polyhex) is a cubic bipartite graph embedded on the torus such that each face is a hexagon. In this paper we examine the existence of entire labeling, where face-weights of all 6-sided faces of disjoint union of toroidal fullerenes form an arithmetic progression with common difference \(\hbox {d}\in \{1,2,3\}\).     

Effect of Temperature on Cd2+ Sorption by Mixed Oxides of Iron and Silicon

The current study focuses on the synthesis and sorption properties of two mixed oxides of iron and silicon prepared by physical mixing (M₁) and sequential precipitation methods (M₂). Both the mixed oxides were synthesized from equimolar ratios of Fe(OH)₃ and SiO₂ and characterized for surface area, EDX, XRD and PZC. The surface area, micropore volume and average pore width of the oxide M₁ were higher as compared to the oxide M₂. However, potentiometric titrations revealed that mixed oxide synthesized by this method had a very high capacity towards Cd²⁺ ions as compared to the mixed oxide M₁. Sorption of Cd²⁺ ions at pH 5 on mixed oxide, M₂ was found to increase with temperature in the range 288 to 318 K. Langmuir equation was found applicable to the sorption data with R²>0.99. Entropy (ΔS^?), enthalpy (ΔH^?) and free energy changes (ΔG^?) were calculated which revealed the process to be endothermic and spontaneous in nature.