KF/Al2O3 as an Efficient,Green, and Reusable Catalytic System for the Solvent-Free Synthesis of N-Alkyl Derivatives of Sulfonamides via Michael Reactions

KF/Al ₂ O ₃ efficiently catalyzes the microwave-assisted Michael addition of sulfonamides to α,β-unsaturated esters under solvent-free conditions to afford N-alkyl derivatives of sulfonamides as biologically interesting compounds in high yields and in short reaction times. In this reaction, N,N-dialkylsulfonamides are also produced, but in very low yields.     

Ab Initio Study of Structures,Metallotropic 1,2-Shifts and Prototropic 1,2-Shifts of Cyclopentadienyl(trimethyl)silane, -germane and -stannane

Molecular structures, metallotropic and prototropic shifts of cyclopentadienyl(trimethyl)silane ( 1 ), cyclopentadienyl(trimethyl)germane ( 2 ), and cyclopentadienyl(trimethyl)stannane ( 3 ) were investigated using ab initio molecular orbital and the Becke, Lee, Yang, and Parr density functional (B3LYP) methods. The results show that the most stable structure of compounds 1-3 has the (CH 3 ) 3 M fragment in the allylic position. The energy barrier of metallotropic shifts in compound 1 is higher than in 2 , and in compound 2 higher than in 3 , in good agreement with experimental data. The cyclopentadienyl rings in compounds 1-3 are found to be planar but this result contradicts the reported experimental data.     

Novel Schiff base’s complex as a green catalyst for the synthesis of diindolylmethanes under ultrasonics irradiation

A facile and convenient protocol was developed for the synthesis of diindolylmethanes in short reaction time and high yields using newly synthesized complex as an efficient recyclable heterogeneous catalyst. All synthesized compounds were characterized by IR, NMR spectra and elemental analysis.     

Adsorption of Cu(II) and Zn(II) ions from aqueous solutions onto fine powder of Typha latifolia L. root: kinetics and isotherm studies

Fine powder of Typha latifolia L. root was used for adsorption of copper and zinc ions from buffered and nonbuffered aqueous solutions. The adsorption reached equilibrium in 60 min. During this time, more than 90 % of the adsorption process was completed. The effect of initial pH, initial concentration of metal ion, and contact time was investigated in a batch system at room temperature. The optimum adsorption performance was observed at pH 5.00 and 4.25 for nonbuffered solutions of Cu(II) and Zn(II), respectively, while for buffered solutions it occurred at pH 6.00. The total metal uptake decreased on application of ammonium acetate buffer, from 37.35 to 17.00 mg g^?1 and 28.80 to 9.90 mg g^?1 for Cu(II) and Zn(II) solutions, respectively, with 100 mg L^?1 initial concentration. The pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich models were used to describe the adsorption kinetics. The experimental data followed the pseudo-second-order kinetic model. The biosorption equilibrium was well described by Langmuir and Freundlich isotherm models.     

Synthesis of 3-Pyrazolyl-4H-1,2,4-triazoles Using Fe3O4@SiO2@Tannic Acid Nanoparticles as an Efficient,Green, and Magnetically Separable Catalyst

Russian Journal of Organic Chemistry - Tannic acid‐functionalized silica‐coated Fe3O4 nanoparticles (Fe3O4@SiO2@tannic acid) were synthesized and characterized by transmission electron...     

Energy and exergy analysis of a novel turbo-compounding system for supercharging and mild hybridization of a gasoline engine

Journal of Thermal Analysis and Calorimetry - Number of hybrid vehicles has increased around the world significantly. Automotive industry is utilizing the hybridization of the powertrain system to...     

Photocatalytic ozonation for degradation of 2-sec-butyl-4,6-dinitrophenol (DNBP) using titanium dioxide: effect of operational parameters and wastewater treatment

The results of degradation efficiency of 2-sec-butyl-4,6-dinitrophenol (DNBP) in a batch system by various advanced oxidation processes revealed the order of TiO₂/UV/O₃ > TiO₂/O₃ > UV/O₃ > O₃ > UV/TiO₂. All processes followed pseudo-first order kinetics. The influence of operational parameters such as initial pH, initial concentration of DNBP, ozone and catalyst dosage on the TiO₂/UV/O₃ process, which was the most significant investigated method. The ozone dosage was found to have the noticeable impact on the process; however, initial pH and TiO₂ dosage were less effective. The mineralization of 40 mg/L of DNBP and petrochemical wastewater under the obtained optimal conditions was monitored by total organic carbon and chemical oxygen demand, respectively. The results demonstrated that the TiO₂/UV/O₃ process was a very effective method for degradation and mineralization of DNBP in aqueous solutions and industrial wastewater. The degradation intermediates were identified by GC–MS.     

A simple,rapid and effective protocol for synthesis of bis(pyrazolyl)methanes using nickel–guanidine complex immobilized on MCM-41

Research on Chemical Intermediates - In this paper, a rapid, easy and very efficient method for the synthesis of bis(pyrazolyl)methanes has been reported in the presence of nickel–guanidine...     

Ab initio calculation of the spin-rotation constant for 2Π diatomics: Test of the Van Vleck approximation

Ab initio calculations are carried out to determine γ^Π (true), the first-order contribution to the spin-rotation constant, γ^Π, for the X²Π ground states of OH, HF⁺, and HCl⁺ and their deuterated analogs. These calculations demonstrate that the contribution of this term to the experimentally determined value of γ^Π is small, as has been previously conjectured. Furthermore, it is found in the cases under study that the Van Vleck approximation to γ^Π (true) significantly overestimates its importance, and a more realistic approximation is presented.