Sensing of Phosphates by Using Luminescent EuIII and TbIII Complexes: Application to the Microalgal Cell Chlorella vulgaris

Phenanthroline‐based chiral ligands L¹ and L² as well as the corresponding Eu^III and Tb^III complexes were synthesized and characterized. The coordination compounds show red and green emission, which was explored for the sensing of a series of anions such as F^?, Cl^?, Br^?, I^?, NO₃^?, NO₂^?, HPO₄^2?, HSO₄^?, CH₃COO^?, and HCO₃^?. Among the anions, HPO₄^2? exhibited a strong response in the emission property of both europium(III) and terbium(III) complexes. The complexes showed interactions with the nucleoside phosphates adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP). Owing to this recognition, these complexes have been applied as staining agents in the microalgal cell Chlorella vulgaris. The stained microalgal cells were monitored through fluorescence microscopy and scanning electron microscopy. Initially, the complexes bind to the outer cell wall and then enter the cell wall through holes in which they probably bind to phospholipids. This leads to a quenching of the luminescence properties.     

Plasmon‐Enhanced Photocurrent Generation from Click‐Chemically Modified Graphene

The visible‐light response of Au nanoparticles (AuNPs) assembled on rGO through different molecular bridges was investigated by transient photocurrent generation. We prepared rGO with two self‐assembled monolayers (SAMs), one linear and the other with aromatic triazoles through a click cycloaddition reaction. A fivefold photocurrent enhancement was observed for triazole linkers over the aminopropyltrimethoxysilane (APTMS) linker. Cyclic voltammetry (CV) and impedance measurements also suggest fast electron transfer on account of the low resistance offered by the click‐modified rGO surface whereby introduction of triazoles offers the efficient bridge between the donor AuNPs and acceptor rGO.     

para-Selective Arylation of Arenes: A Direct Route to Biaryls by Norbornene Relay Palladation

Biaryl compounds are extremely important structural motifs in natural products, biologically active components and pharmaceuticals. Selective synthesis of biaryls by distinguishing the subtle reactivity difference of distal arene C−H bonds are significantly challenging. Herein, we describe para-selective C−H arylation, which is acheived by a unique combination of a meta-directing group and norbornene as a transient mediator. Upon direct meta-C−H palladation, one-bond relay palladation occurs in presence of norbornene and subsequently para-C−H arylation is achieved for sulfonates, phosphonates and phenols bearing 2,6-disubstitution patterns. The protocol is amenable to electron-deficient aryl iodides. Multisubstituted arenes and phenols are obtained by postsynthetic modification of the products. The protocol allows the synthesis of hexa-substituted benzene by sequential selective distal C−H functionalization.     

N-donor stabilized complexes of nickel(II) diphenyldithiophosphates: single-crystal X-ray,HSA and computational analysis

Transition Metal Chemistry - Nickel(II) complexes with octahedral coordination stabilized by N-donor ligands corresponds to [{(ArO)2PS2}2Ni·L2] [Ar = 4-(C2H5)C6H4 (3), and...     

One-pot green synthesis of novel 5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine derivatives with eco-friendly biodegradable eggshell powder as efficacious catalyst

Research on Chemical Intermediates - An eco-friendly and efficient green protocol is developed for the synthesis of sixteen pyrazolo-phthalazine derivatives (5a–p) by using...     

The integrable Boussinesq equation and it’s breather,lump and soliton solutions

The fourth-order nonlinear Boussinesq water wave equation, which explains the propagation of long waves in shallow water, is explored in this article. We used the Lie symmetry approach to analyze the Lie symmetries and vector fields. Then, by using similarity variables, we obtained the symmetry reductions and soliton wave solutions. In addition, the Kudryashov method and its modification are used to explore the bright and singular solitons while the Hirota bilinear method is effectively used to obtain a form of breather and lump wave solutions. The physical explanation of the extracted solutions was shown with the free choice of different parameters by depicting some 2-D, 3-D, and their corresponding contour plots.

     

Efficient synthesis of indolizines and new imidazo[1,2-a]pyridines via the expected cyclization of aromatic cycloimmonium ylides with electron deficient alkynes and ethyl cyanoformate

Aromatic cycloimmonium ylides underwent smooth cyclization with electron deficient alkynes in presence of anhydrous K₂CO₃ in DMF solvent at room temperature to afford substituted indolizines. Ylides have also undergone expected cyclization with ethyl cyanoformate to produce imidazo[1,2-a]pyridines. The structures of these newly synthesized compounds have been confirmed by spectroscopic techniques and X-ray diffraction studies.     

Dielectric behaviour of La substituted BPZT ceramics

Here, we report dielectric behaviour of lanthanum substituted Ba_0.80Pb_0.20Ti_0.90Zr_0.10O₃ (BPZT) ceramics. The material series with compositional formula Ba_0.80−xLa_xPb_0.20Ti_0.90Zr_0.10O₃ (BLPZT) with x varying from 0 to 0.01 in the steps of 0.0025 was chosen for investigations. The material was synthesized by solid state reaction method. Reacted powder compacted in form of circular discs were sintered at 1325 °C. All the samples were subjected to X-ray diffraction (XRD) analysis and found to be single phase. Dielectric behaviour was studied as a function of frequency and temperature and Curie temperature (T_c) was determined. T_c was found to decrease with increasing x. The details are discussed and presented in this paper.     

Metformin and glitazones: does similarity in biomolecular mechanism originate from tautomerism in these drugs?

This theoretical study attempts to find out similarity between metformin and glitazone class of antidiabetic drugs. It was found that some tautomeric forms of both metformin and thiazolidinedione ring of glitazones have similar molecular electrostatic potential (MESP) surface and may bind to a common complementary surface. Complexation and docking studies were also carried out in order to support this hypothesis. Copyright © 2007 John Wiley & Sons, Ltd.     

Investigations into a free radical-mediated 1,2-imino migration

The radical reactions of a series of bromides 9a-c and selenides 12-15 have been investigated to determine the factors that are important for a successful radical-mediated 1,2-imino migration.