On the performance of molecular tailoring approach for estimation of the intramolecular hydrogen bond energies of RAHB systems: a comparative study

Structural Chemistry - In the current research, the performance of molecular tailoring approach (MTA) for estimation of the intramolecular hydrogen bond (IMHB) energies of the simple...     

Synthesis of 4-aryl-7-methoxy-9-thia-[1,3,4a]triazafluorene-2-selones via a three-component condensation of 6-methoxybenzothiazol-2-ylamine,potassium selenocyanate and an acyl chloride

Abstract

A simple, one-pot synthesis of six 4-aryl-7-methoxy-9-thia-[1,3,4a]triazafluorene-2-selones has been achieved in moderate to good yields via a three-component condensation of 6-methoxybenzothiazol-2-ylamine, potassium selenocyanate and variously substituted benzoyl chlorides in acetone at room temperature.     

Synthesis,Crystal Structure and Comparative Study on the Removal of Cationic Dyes Using Different Amide and Amine Groups

Crystallography Reports - Two crystalline materials C18H16N3O3 (1) and C10H8N2⋅C8H7NO4 (2) have been synthesized under solvothermal conditions with different time and temperatures. The...     

The study of thiazole adsorption upon BC2N nanotube: DFT/TD-DFT investigation

Structural Chemistry - Herein, we evaluated the adsorption of thiazole over the surface of BC2N nanotube using PBE and M06-2X functionals and 6-311G** standard basis set. We considered one and two...     

A new method for probabilistic assessments in power systems,combining monte carlo and stochastic‐algebraic methods

This article discusses a new methodology, which combines two efficient methods known as Monte Carlo (MC) and Stochastic‐algebraic (SA) methods for stochastic analyses and probabilistic assessments in electric power systems. The main idea is to use the advantages of each former method to cover the blind spots of the other. This new method is more efficient and more accurate than SA method and also faster than MC method while is less dependent of the sampling process. In this article, the proposed method and two other ones are used to obtain the probability density function of different variables in a power system. Different examples are studied to show the effectiveness of the hybrid method. The results of the proposed method are compared to the ones obtained using the MC and SA methods. © 2014 Wiley Periodicals, Inc. Complexity 21: 100–110, 2015     

A Comparative Study of Anti-Candida Activity and Phenolic Contents of the Calluses from Lythrum salicaria L. in Different Treatments

In the study, anti-Candida activity and phenol contents of Lythrum salicaria L. calli and wild species have been evaluated. The seeds of L. salicaria (Lythraceae), collected from Lahidjan City in the north of Iran, were cultured in Murashige and Skoog medium (MSM) with a supplement, gibberellin, to germinate. Callus inductions were performed from segments of seedling on MSM containing different concentrations of plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D) and 6-benzylaminopurine (BAP). The activity of calluses extracts, wild plant, gallic acid, and 3,3′,4′-tri-O-methylellagic acid-4-O-β-d-glucopyranoside (TMEG) as the main phenolic compounds against Candida albicans was assessed using cup plate diffusion method. The total phenols contents of calli and wild plant extracts were analyzed using Folin–Ciocalteu reagent. The callus formation in MSM supplemented with various concentrations of 2,4-D and BAP were 0–100 %. Anti-Candida activity of callus extract which obtained from MSM supplemented with 2,4-D and BAP (1 mg?dm^?3) was similar to the wild plant extract. Minimum inhibitory concentration values of gallic acid and TMEG were obtained as 0.312 and 2.5 mg?cm^?3, respectively. Gallic acid equivalent values in all treatments were from 0 to 288 μg GAE mg^?1. Phenolic contents of plant aerial parts (331?±?3.7 μg GAE mg^?1) and the callus, which developed in MSM including 1 mg?dm^?3 of both 2,4-D and BAP, showed the same phenolic value and exhibited anti-Candida extract activity.     

Solid phase extraction of trace amounts of silver (I) using dithizone-immobilized alumina-coated magnetite nanoparticles prior to determination by flame atomic absorption spectrometry

A new, simple, fast and reliable solid-phase extraction (SPE) method has been developed to separation/preconcentration of trace amounts of silver ion from environmental water samples using dithizone/sodium dodecyl sulfate immobilized on alumina-coated magnetite nanoparticles (DTZ/SDS-ACMNPs) and its determination by flame atomic absorption spectrometry. The coating of alumina on Fe₃O₄ NPs not only avoids the dissolving of Fe₃O₄ NPs in acidic solution, but also extends their application without sacrificing their unique magnetization characteristics. This method avoided the time-consuming column-passing process of loading large volume samples in traditional SPE through the rapid isolation of DTZ/SDS-ACMNPs with an adscititious magnet. Optimal experimental conditions including amount of DTZ/SDS, pH value, standing time, sample volume, type, volume and concentration of eluent and co-existing ions have been studied and established. Under the optimal experimental conditions, the detection limit for Ag(I) with enrichment factors of 100 was found to be 0.52?ng?mL^?1 and its relative standard deviations (RSD) was 3.4% (n?=?10, C?=?5.0?µg?mL^?1). The linear range of calibration curve for Ag(I) was 2–5000?ng?mL^?1 with a correlation coefficient of 0.9991. The proposed method was successfully applied to the determination of target analyte in different water and wastewater samples. The validity of the method has been checked by applying it to study the recovery of silver ion in spiked water and wastewater samples.     

Application of β-cyclodextrin in polymeric solid phase for separation and determination of lead in different environmental matrices

Immobilization of β-cyclodextrin on Dowex resin as an insoluble polymeric matrix by covalent bond presents a new solid-phase medium for preconcentration of Pb (II) at trace level in environmental samples prior to its flame atomic absorption spectrometric determination. The method is based on the sorption of lead after passing on modified Dowex sorbent in a column. The effect of several parameters such as pH, flow rate of sample, eluent kind and volume was investigated. The sorption capacity of the matrix has been found to be 0.4996?mg?g^?1 of adsorbent with the preconcentration factor of 250 for Pb (II). Nitric acid (3 M) as an eluent was sufficient to obtain quantitative recovery (>95%) for Pb (II). The optimum flow rate was 10?ml?min ^?1. The calibration curve was linear in the range of (3–250?ng?mL^?1) with a correlation coefficient of 0.9995. The limit of detection (LOD) based on three times the standard deviation of the blank was 1.37?ng?mL^?1. The relative standard deviation (RSD) for determination of 10?ng?mL^?1 and 100?ngmL^?1 of Pb (II) was 3.00 % and 0.58 % (n?=?10), respectively. The method was successfully applied to determination of lead in some environmental samples such as tap water, river water, soil and rice.     

An efficient synthesis of functionalized tetrahydro-lH-indeno[2, 1-c]pyridine derivatives by a PPh3-promoted condensation reaction between acetylene esters and 1,3-dioxo-N-aryl-2,3- dihydro-1 H-indene-2-carboxamides

A reaction between 1,3-dioxo-N-aryl-2,3-dihydro-lH-indene-2-carboxamides, dialkyl acetylenedicar- boxylates, and triphenylphosphine or trimethylphosphite is described as a simple and efficient method for the synthesis of 5-hydroxy-4-aryl-2,5-dihydrofuran-2,3-dicarboxylate derivatives.