Simple synthesis of the novel Cu-MOF catalysts for the selective alcohol oxidation and the oxidative cross-coupling of amines and alcohols

A novel porous metal–organic framework {Cu₂(bbda)_0.5(Hbbda)_1.5(OAc)_1.5.8H₂O} (UoB-5) was synthesized under ultrasound irradiation by employing a new Schiff base ligand H₂bbda (4,4′(1,4-phenylene bis (azanylylidene)) bis (methanylylidene))dibenzoic acid) and was fully characterized. The microporous nature of UoB-5 was confirmed by gas-sorption measurements. This framework acted as a highly effective heterogeneous catalyst for the alcohol oxidation reaction with tert-butyl hydroperoxide (t-BuOOH) as an oxidant. The presence of coordinatively unsaturated metal sites in UoB-5 could be the reason for high performance in this reaction. Furthermore, using the long linker with the free -NC group and uncoordinated -N atom on the wall of the pores created UoB-5 an excellent candidate for the catalytic activities without activation of the framework. It was confirmed with the heterogeneous catalytic experiments on the one-pot tandem synthesis of imines from benzyl alcohols and anilines. Eventually, the new Cu-MOF (UoB-5) could be an alternative catalyst as a more economically favorable and environmentally friendly in the catalysis field.     

Erratum to: “Microstructural Study of Nylon-6/Gelatin Composite Nanofibers”

Russian Journal of Applied Chemistry - Page 1646, Figure 8 should be replaced by the following:     

Template synthesis of a rare 14-membered macrocyclic complex using cadmium(II) ion as a collector

Journal of Inclusion Phenomena and Macrocyclic Chemistry - In this work, a new macrocyclic cadmium complex, [Cd(ACE)I]2[CdI4] (1); ACE: 1,3,6,10,12,15-hexaazatricyclo[13.3.1.16,10]eicosane, was...     

Design and development of novel Co‐MOF nanostructures as an excellent catalyst for alcohol oxidation and Henry reaction,with a potential antibacterial activity

The novel metal–organic framework Co₂(bdda)_1.5(OAc)₁·5H₂O (UoB‐3) was synthesized via a simple method at room temperature. UoB‐3 was characterized by the different methods, including X‐ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT‐IR), N₂‐adsorption/desorption and elemental analysis. The catalytic ability of UoB‐3 was detected to be excellent for primary and secondary alcohols oxidation reaction with high yields under solvent‐free conditions. Moreover, UoB‐3 was highly active for Henry reaction of different aldehydes with nitromethane in water as a green solvent. The nanocatalyst can be recycled for five consecutive cycles without losing its activity and structural rigidity. The antibacterial activity of UoB‐3 nanostructures towards Gram‐negative bacteria, Escherichia coli and Gram‐positive bacteria, Bacillus cereus was also evaluated by using an inhibition zone test. These nanostructures exhibited strong antibacterial effect against both of them. The purpose of this study was the developing metal–organic framework materials with the enhanced activity in various fields.     

基于等效单元概念的梁结构损伤定位方法

研究目的是为梁结构提供一种基于等效单元概念的新损伤定位方法. 区分刚度损伤和质量损伤两种情况, 分别对连续梁和简支梁给出了具体的损伤定位方法. 利 用的具体指标是支座反力和跨中位移. 文中的新方法都可以得到以小区间表示的损伤位置结 果, 有效性得到了数值模拟算例和模型实验的验证.     

Screen-printed electrodes modified with HRP-zirconium alcoxide film for the development of a biosensor for acetaminophen detection

The development of a biosensor based on the immobilization of horseradish peroxidase (HRP) within a zirconium alkoxide-polyetilenimine film onto screen-printed electrodes (SPE) for acetaminophen detection and acetaminophen quantification in pharmaceutical products is described. The biosensor operation mode is based on monitoring the amperometric signal produced by the electrochemical reduction of the enzymatically generated electroactive oxidized species of acetaminophen in the presence of hydrogen peroxide. The enzyme immobilization is performed by retention in a polyethylenimine-zirconium alcoxide porous gel film, a technique that offers good entrapping and a protective environment for the biocomponent due to the hydration properties of the immobilization layer. SPEs have the advantage of being easily mass-produced at low costs with superior characteristics in comparison with classical electrode materials. In this configuration, zirconium alkoxide demonstrates its electrocatalytic activity. The biosensor allows the quantification of acetaminophen with a limit of detection of 6.21×10^?8 M and a linear range between 4.35×10^?7 M and 4.98×10^?6 M. Finally, the biosensor is applied to the quantitative analysis of acetaminophen in Perdolan® tablets.

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Numerical study of coal particle ignition in air and oxy-atmosphere

The ignition and combustion of coal particles are investigated numerically under conventional and oxy-fuel atmospheres. Devolatilization is computed using the chemical percolation devolatilization (CPD) model. The CPD model is coupled with a Lagrangian particle tracking method in the framework of a multiphysics, multiscale Navier–Stokes solver. Combustion in the gas phase is described using finite rate chemistry. The numerical results for ignition are compared with available experimental data and a remarkably good agreement is observed. The effect on flame ignition of the different phases characterizing the release of volatile gases is assessed. These different phases manifest themselves in two distinct peaks in the devolatilization rate and it is observed that ignition can occur during the first volatile release or on the onset of the second, depending on the particle size and gas temperature. It is found that an increase of ignition delay time in oxy-atmosphere compared to the air case is related to the depletion of radicals that react with the abundant carbon dioxide of the oxy-atmosphere, while the increased heat capacity of the mixture does not play a role.     

Copper‐Catalyzed Synthesis of Alkynyl Hydrazones from Alkynes and Hydrazonyl Chlorides

A novel ligand‐free synthesis of alkynyl hydrazones via coupling reaction of hydrazonyl chlorides and terminal alkynes, catalyzed by CuI led to excellent yields.     

Synthesis of Long‐Circulating,Backbone Degradable HPMA Copolymer–Doxorubicin Conjugates and Evaluation of Molecular‐Weight‐Dependent Antitumor Efficacy

Backbone degradable, linear, multiblock N‐(2‐hydroxypropyl)methacrylamide (HPMA) copolymer–doxorubicin (DOX) conjugates are synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization followed by chain extension via thiol‐ene click reaction. The examination of molecular‐weight‐dependent antitumor activity toward human ovarian A2780/AD carcinoma in nude mice reveals enhanced activity of multiblock, second‐generation, higher molecular weight conjugates when compared with traditional HPMA copolymer–DOX conjugates. The examination of body weight changes during treatment indicates the absence of non‐specific adverse effects.

     

High-performance numerical algorithms and software for subspace-based linear multivariable system identification

Basic algorithmic and numerical issues involved in subspace-based linear multivariable discrete-time system identification are described. A new identification toolbox—SLIDENT—has been developed and incorporated in the freely available Subroutine Library in Control Theory (SLICOT). Reliability, efficiency, and ability to solve industrial identification problems received a special consideration. Two algorithmic subspace-based approaches (MOESP and N4SID) and their combination, and both standard and fast techniques for data compression are provided. Structure exploiting algorithms and dedicated linear algebra tools enhance the computational efficiency and reliability. Extensive comparisons with the available computational tools based on subspace techniques show the better efficiency of the SLIDENT toolbox, at comparable numerical accuracy, and its capabilities to solve identification problems with many thousands of samples and hundreds of parameters.