Ultrasound assisted one-pot, three-components synthesis of pyrimido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines: A new access via phenylsulfone synthon

A simple, facile, efficient and three-components procedure for the synthesis of pyrimido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines utilizing phenylsulfone synthon, under ultrasonic irradiation was developed.     

Application of computer algebra to Jones polynomials

In this paper we apply computer algebra (Maple) techniques to calculate Jones polynomial of graphs of K(2,q)-Torus knots. For this purpose, a computer program was developed. When a positive integer q is given, the program calculate Jones polynomial of graph of K(2,q)-Torus knots.     

Novel metal complexes containing 6-methylpyridine-2-carboxylic acid as potent α-glucosidase inhibitor: synthesis,crystal structures,DFT calculations,and molecular docking

Molecular Diversity - The World Health Organization (WHO) report shows that diabetes mellitus (DM) will be one of the ten deadly diseases in the near future. The best way to prevent DM is to...     

Gold nanoparticle included graphene oxide modified electrode: Picomole detection of metal ions in seawater by stripping voltammetry

We obtained a gold nanomaterial/graphene oxide-modified glassy carbon electrode and characterized it using transmission electron microscope, scanning electron microscope, cyclic voltammetry (CV), and X-ray photoelectron spectroscopy techniques. A response of the electrode using square wave anodic stripping voltammetry for Pb²⁺, Cu²⁺, and Hg²⁺ was found linear in the range from 1 × 10^–7 to 1 × 10^–11 M. The detection limits of Pb²⁺, Cu²⁺ and Hg²⁺ were 0.14, 0.5 and 1.2 pM, respectively. The method was applied to the simultaneous determination of Pb²⁺, Cu²⁺ and Hg²⁺ in seawater samples from a coastal region of Anatolia, and the results corresponded well with the values obtained by inductively coupled plasma-optical emission spectroscopy.     

Radical-scavenging activity of glutathione,chitin derivatives and their combination

Since chitosan and its amino-, cinnamo- or cinnamo-amino- derivatives are acid-soluble, the effect of acetic acid on hyaluronan (HA) macromolecules degraded by Cu(II) ions and ascorbate was examined to produce reactive oxygen species (ROS). Further, the effects of glutathione (GSH), chitosan and its derivatives, added individually or in combination, on the quenching of ROS and ABTS^˙+ cation radical were examined using rotational viscometry and ABTS assay, respectively. The results of the rotational viscometry indicated a rapid degradation of HA by ROS after the addition of acetic acid. Chitosan and its derivatives moderately decreased the rate of HA degradation, while GSH decreased the rate of HA degradation more significantly. Moreover, GSH enhanced the protection of HA macromolecules against their degradation in the presence of chitosan or its derivatives. The results of the ABTS assay confirmed the results of the rotational viscometry. The GSH in the combination with chitosan and its derivatives reduced ABTS^˙+ more intensively than when added individually.     

Organoactinides promote the dimerization of aldehydes: scope, kinetics, thermodynamics, and calculation studies

Surprising catalytic activities have been found for the actinide complexes Cp*(2)ThMe(2) (1), Th(NEtMe)(4) (2), and Me(2)SiCp'(2)Th(C(4)H(9))(2) (3) toward oxygenated substrates. During the catalytic dimerization of benzaldehydes to their corresponding esters, complexes 1 and 2 gave 65 and 85% yield in 48 h, respectively, while the geometry-constrained complex 3 gave 96% yield in 24 h. Exploring the effect of substituents on benzaldehyde, it has been found that, in general, electron-withdrawing groups facilitate the reaction. Kinetic study with complexes 1 and 3 reveals that the rate of the reaction is first order in catalyst and substrate, which suggests the rate equation "rate = k[catalyst](1)[aldehyde](1)". The activation energy of the reaction was found to be 7.16 ± 0.40 and 3.47 ± 0.40 kcal/mol for complexes 1 and 3 respectively, which clearly indicates the advantage of the geometry-constrained complex. Astonishing are the reactivity of the organoactinide complexes with oxygen-containing substrates, and especially the reactivity of complex 3, toward the dimerization of substrates like p-methoxybenzaldehyde, m/p-nitrobenzaldehyde, and furanaldehyde and the reactivity toward the polymerization of terephthalaldehyde. Density functional theory mechanistic study reveals that the catalytic cycle proceeds via an initially four-centered transition state (+6 kcal/mol), followed by the rate-determining six-centered transition state (+13.5 kcal/mol), to yield thermodynamically stable products.     

Reactivity of ionic liquids with kaolinite: melt intersalation of ethyl pyridinium chloride in an urea-kaolinite pre-intercalate

This paper reports a new route for the intercalation of an ionic liquid, namely 1-ethyl pyridinium chloride, into the interlamellar spaces of kaolinite. The intercalation was achieved using a kaolinite-urea intercalate as a starting material. The results of the XRD, FTIR, and TGA analyses confirmed the intercalation of ethyl pyridinium in the interlamellar spaces of kaolinite. 13C CP/MAS spectra indicated the complete displacement of urea by ethyl pyridinium. 29Si and 27Al NMR spectra of the starting materials and the products are also discussed as well as the results of the elemental analysis of the produced nanohybrid material.     

On Modules Over Group Rings

Let M be a right module over a ring R and let G be a group. The set MG of all formal finite sums of the form ∑? _g?∈?G m _g g where m _g ?∈?M becomes a right module over the group ring RG under addition and scalar multiplication similar to the addition and multiplication of a group ring. In this paper, we study basic properties of the RG-module MG, and characterize module properties of (MG) _RG in terms of properties of M _R and G. Particularly, we prove the module-theoretic versions of several well-known results on group rings, including Maschke’s Theorem and the classical characterizations of right self-injective group rings and of von Neumann regular group rings.