RETRACTED: Synthesis of efficient cobalt–metal organic framework as reusable nanocatalyst in the synthesis of new 1,4-dihydropyridine derivatives with antioxidant activity

Abstract

Efficient cobalt–metal organic framework (Co-MOF) was prepared via a controllable microwave-assisted reverse micelle synthesis route. The products were characterized by SEM image, N2 adsorption/desorption isotherm, FTIR spectrum, and TG analysis. Results showed that the products have small particle size distribution, homogenous morphology, significant surface area, and high thermal stability. The physicochemical properties of the final products were remarkable compared with other MOF samples. The newly synthesized nanostructures were used as recyclable catalysts in the synthesis of 1,4-dihydropyridine derivatives. After the confirmation of related structures, the antioxidant activity of derivatives based on the DPPH method was evaluated and the relationship between structures and antioxidant activity was observed. In addition to recyclability, the catalytic activity of Co-MOF studied in this research has remarkable effects on the synthesis of 1,4 dihydropyridine derivatives.

Research primary processing of live of silk cocoons in a solar installation

“…The uncertainty in experimental efficiency of the solar collector was ±3% Dried silk cocoons in the solar dryer was reeled in the reeling machine and compared with dried cocoons in the conventional electrical oven dryer used at silk reeling centres. In the electrical dryers, air temperature reduced in the steps from 95 C to 55 C [15,16]. Drying time in the dryer was about 10 h. There was no marked difference in the physical appearance of the silk obtained from the dried cocoon cocoons in both dryers.…”

A device for detecting current asymmetry in a three-phase alternating current system

“…Synchronous and asynchronous motors have low reverse sequence resistance. Even small reverse sequence voltages in the TPSS can cause significant reverse sequence currents in engines, which, superimposed on the direct sequence currents, cause current overload of individual phases of the engine and, consequently, additional heating of the stator and rotor which leads to accelerated aging of the insulation and a decrease in the available power of the engine [21,22];  There are additional losses of active power and electrical energy due to the flow of reverse and zero sequence currents in the elements of the TPSS up to 1 kV [4];  Due to voltage losses from the reverse and zero sequence currents, additional voltage deviations in individual phases of the TPSS up to 1 kV appear, which are not eliminated by conventional (three-phase) voltage regulation means [23,24].…”

Sulfonated Cobalt Metal–Organic Framework Embedded Mixed Matrix Membrane towards Fuel-Cell Applications

“…A sCo-MOF was synthesized with a few post-treatment modifications of other sulfonated MOFs’ literature. , Briefly, a mixture of 5-sulfoisophthalic acid (1.34 g, 5 mmol) and cobalt­(II) chloride hexahydrate (1.19 g, 5 mmol) was dissolved in 90 mL of DMF and 5 mL of an acetic acid solution. The homogeneous mixture was vigorously stirred and held at 125 °C for 24 h. After the reaction, the mixture was cooled to room temperature, and then the product was repeatedly rinsed with DMF and obtained by centrifugation (3000 rpm for 20 min).…”