Conformational effect of silica-supported poly(octadecyl acrylate) on molecular-shape selectivity of polycyclic aromatic hydrocarbons in RP-HPLC.

Poly(octadecyl acrylate) with a terminal reactive group was synthesized by radical telomerization in various solvents. The polymers were grafted onto porous silica for use in RP-HPLC, and the molecular recognition ability was investigated along with the selectivity for the structural isomers of polycyclic aromatic hydrocarbons. The mechanism of selectivity was also investigated with differential scanning calorimetry and NMR spectroscopic observations.     

Meglumine sulfate catalyzed solvent-free one-pot synthesis of coumarins under microwave and thermal conditions

A convenient method has been developed for the Pechmann reaction of phenols and β-keto esters catalyzed by meglumine sulfate. Solvent-free conditions, inexpensive catalyst, short reaction times, high yield, and ease of purification of the products are the advantages of this protocol. This novel catalytic system is expected to contribute to the development of more benign Pechmann condensation reactions of phenols with β-keto esters.     

A pseudospectral method for nonlinear Duffing equation involving both integral and non‐integral forcing terms

The Legendre pseudospectral method is developed for the numerical solution of nonlinear Duffing equation involving both integral and non‐integral forcing terms. By using differentiation matrix, the problem is reduced to the solution of a system of algebraic equations. The method is general, easy to implement, and yields very accurate results. Numerical experiments are presented to demonstrate the accuracy and the efficiency of the proposed computational procedure. Copyright © 2014 John Wiley & Sons, Ltd.     

Efficient 2,4,6‐trichloro‐1,3,5‐triazine‐catalyzed synthesis of 2‐arylbenzothiazoles and bisbenzothiazoles by condensation of 2‐aminithiophenol with aldehydes under mild conditions

2,4,6‐Trichloro‐1,3,5‐triazine efficiently catalyzed the condensation reactions between 2‐aminothiophenol and aromatic aldehydes to afford 2‐arylbenzothiazolles in good‐to‐excellent yields. Simple and mild reaction conditions, the use of a cheap catalyst and easy work up, and isolation are notable features of this method. J. Heterocyclic Chem., (2011).     

Ion Pairing,H‐bonding,and π‐π Interactions in Cobalt(II) Compound Containing Guanidinium Counter Ion

A novel proton transfer compound, (GH)₂(phendc), ( 1 ), was synthesized from the reaction of 1,10‐phenanthroline‐2,9‐dicarboxylic acid, phendcH₂, and guanidine hydrochloride, (GH)(Cl), (G: guanidine). The characterization was performed using IR, ¹H and ¹³C NMR spectroscopy. The cobalt(II) compounds were synthesized using proton transfer compounds containing guanidinium counter ion. These proton transfer compounds are (GH)₂(phendc), and (GH)₂(pydc) (pydcH₂: 2,6‐pyridinedicarboxylic acid). The chemical formulae and space groups are (GH)₂[Co(phendc)₂]·4H₂O, (2) , and (GH)₂[Co(H₂O)₆][Co(pydc)₂]₂, P2₁/n (3) . Non‐covalent interactions such as ionpairing, hydrogen bonding and π‐π stacking are discussed.     

Retrievable magnetic copper ferrite nanoparticles: an efficient catalyst for air oxidative cyclization of bisnaphthols

Herein, a green and efficient heterogeneous and photocatalytic system for the oxidation of bisnaphthols in acetonitrile under light-emitting diode will be presented. In this reaction, aerial oxygen and H₂O₂ have been used as oxidant in the presence of copper ferrite nanoparticles and N-hydroxyphthalimide as an organic co-catalyst. Copper ferrite nanoparticles were magnetically separated, the efficiency of which remained nearly unchanged up to five cycles. Magnetic copper ferrite nanoparticles were synthesized by sol–gel method and characterized by XRD, FT-IR, SEM, TEM, VSM and DRS analysis. In this project, both sets of diastereomers were formed.

Graphical abstract

Catalytic system for the oxidation of bisnaphthols.

     

Synthesis, structure, and magnetic properties of the layered copper(II) oxide Na2Cu2TeO6

A new quaternary layered transition-metal oxide, Na2Cu2TeO6, has been synthesized under air using stoichiometric (with respect to the cationic elements) mixtures of Na2CO3, CuO, and TeO2. Na2Cu2TeO6 crystallizes in the monoclinic space group C2/m with a = 5.7059(6) A, b = 8.6751(9) A, c = 5.9380(6) A, beta = 113.740(2) degrees, V = 269.05(5) A3, and Z = 2, as determined by single-crystal X-ray diffraction. The structure is composed of infinity(2)[Cu2TeO6] layers with the Na atoms located in the octahedral voids between the layers. Na2Cu2TeO6 is a green nonmetallic compound, in agreement with the electronic structure calculation and electrical resistance measurement. The magnetic susceptibility shows Curie-Weiss behavior between 300 and 600 K with an effective moment of 1.85(2) muB/Cu(II) and theta(c) = -87(6) K. A broad maximum at 160 K is interpreted as arising from short-range one-dimensional antiferromagnetic correlations. With the aid of the technique of magnetic dimers, the short-range order was analyzed in terms of an alternating chain model, with the surprising result that the stronger intrachain coupling involves a super-superexchange pathway with a Cu-Cu separation of >5 A. The J2/J1 ratio within the alternating chain refined to 0.10(1), and the spin gap is estimated to be 127 K.     

Investigation of Fermions in Non-commutative Space by Considering Kratzer Potential

The two-dimensional Dirac equation for a fermion moving under Kratzer potential in the presence of an external magnetic field is analytically being solved for the energy eigenvalues and eigenfunctions. Subsequently, we have obtained the Wigner function corresponding to the eigenfunctions.     

Sequential one‐pot multicomponent synthesis of bis‐aminothiazols and evaluation of their antibacterial and antioxidant activities

A series of novel bis‐thiazoles were synthesized through a one‐pot semi‐five‐component reaction of the prepared α‐bisbromo ketones, aldehydes, and thiosemicarbazide in the presence of p‐TsOH under reflux condition. Products were obtained in reasonable yields via an efficient, convenient, and simple setup. The inhibitory activity on bacterial growth of the products was studied against Gram‐negative (Escherichia coli and Pseudomonas aeruginosa) and Gram‐positive bacterial strains (Micrococcus luteus, Staphylococcus aureus) at different concentrations (25, 50, 100, and 200 μg/mL at 600 nm). Most of the products showed inhibitory activity at the concentration of 200 μg/mL. In addition, bis‐thiazoles showeed high to moderate antioxidant activity using the diphenylpicrylhydrazyl (DPPH) method. Bis‐thiazoles 6i and 6j showed higher antioxidant activity than vitamin C and vitamin E.