Overview of recent developments in carbon-based nanocomposites for supercapacitor applications.

Energy storage devices are recognized as environmentally friendly technologies. Supercapacitors, known for their high cycle stability, have been proposed as potential alternatives to fossil fuels. Recent studies have focused on selecting suitable electrode materials to achieve energy storage systems with high stability, high specific capacity, and biocompatibility.

Expression of concern: Schiff base Mn(iii) and Co(ii) complexes coated on Co nanoparticles: an efficient and recyclable magnetic nanocatalyst for HO oxidation of sulfides to sulfoxides.

Expression of concern for 'Schiff base Mn(iii) and Co(ii) complexes coated on Co nanoparticles: an efficient and recyclable magnetic nanocatalyst for HO oxidation of sulfides to sulfoxides' by Shokoufeh Ghahri Saremi , , 2018, , 3889-3898, https://doi.org/10.1039/C7RA11225D.

Expression of concern: Green synthesis of Pd nanoparticles supported on reduced graphene oxide, using the extract of fruit, and their use as recyclable and heterogeneous nanocatalysts for the degradation of dye pollutants in water.

Expression of concern for 'Green synthesis of Pd nanoparticles supported on reduced graphene oxide, using the extract of fruit, and their use as recyclable and heterogeneous nanocatalysts for the degradation of dye pollutants in water' by Saba Hemmati , , 2018, , 21020-21028, https://doi.org/10.1039/C8RA03404D.

Efficient phosphate removal utilizing N, Zn-doped carbon dots as an innovative nanoadsorbent.

The primary goal of this study is to examine PO adsorption from aqueous solutions using zinc-doped carbon dots (Zn-N-CDs) as a new adsorbent and cost-effective technique. Zn-N-CDs were produced through a hydrothermal process and subsequently identified using various techniques. The effect of reaction time, temperature, pH, ionic strength, adsorbent dosage, initial PO concentration, and anion competition (NO , Cl, HCO , and SO ) on PO adsorption using Zn-N-CDs were investigated.

A new MOF-based modified adsorbent for the efficient removal of Hg(ii) ions from aqueous media: isotherms and kinetics.

Herein, a new MOF-based modified adsorbent for the efficient removal of Hg(ii) ions from water media was successfully prepared. Initially, a MOF nanocomposite was synthesized and applied as an efficient adsorbent for the removal of the target heavy metal ion. Following the synthesis, the MOF-based modified adsorbent was identified and characterized by SEM, XRD and FT-IR analytical instruments.

Advancements in double decarboxylative coupling reactions of carboxylic acids.

The double decarboxylative coupling reaction between two (similar or different) molecules of carboxylic acids is an emerging area that has gained considerable attention as a new avenue for forging carbon-carbon bonds. Since this synthetic strategy only utilizes carboxylic acids as easily accessible, non-toxic and stable starting materials, and extrudes carbon dioxide (CO) as the only waste by-product, it can be considered as an environmentally benign alternative to traditional coupling reactions which mainly rely on the use of toxic organic halides or organometallic reagents. The aim of this review is to highlight the recent advances and developments in this exciting new field that may serve as inspiration for future research to mature it.

Copper supported modified magnetic carrageenan as a bio-based catalyst for the synthesis of novel scaffolds bearing the 1,2,3-triazole unit through the click reaction.

The ongoing work delineates the design of a novel library of 1,2,3-triazole-attached phenylacetamides through molecular hybridization of propargyl and phenylacetamide derivatives. Copper-supported modified magnetic carrageenan serves as a green heterogeneous catalyst, ensuring high yield, efficient reaction times, high atom economy, utilization of an environmentally friendly catalyst from a natural source, and a straightforward workup procedure. The successful synthesis of the catalyst is confirmed and evaluated using various analytical techniques, while the synthetic compounds are characterized through H NMR and C NMR.

Design, synthesis, antimicrobial, antibiofilm evaluation and /-isomerization of novel 6-((arylamino)methylene)benzo[] phenazin-5(6)-ones induced by organic solvent.

New 6-((arylamino)methylene)benzo[]phenazin-5(6)-one derivatives were synthesized, and good-to-high yields were achieved through one-pot, four-component condensation of 2-hydroxy-1,4-naphthoquinone, 1,2-phenylenediamine, aromatic amines and triethyl orthoformate using formic acid as catalyst under solvent-free conditions at 90 °C. The structure of these new compounds was confirmed using FT-IR and H-NMR as well as MS spectroscopy. Investigation of spectroscopy data indicated that the synthesized compounds exist in the keto-enamine tautomeric form and undergo /-isomerization around the C[double bond, length as m-dash]C bond in DMSO- at room temperature.

Synthesis of a Au/Au NPs-PPy/l-CYs/ZIF-8 nanocomposite electrode for voltammetric determination of insulin in human blood.

In this work, a modified electrode named Au/Au NPs-PPy/l-CYs/ZIF-8 was designed and built and simultaneously doped into electropolymerized polypyrrole (PPy) film using cyclic voltammetry (CV). Scanning Electron Microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and CV were used to characterize the composite films. The PPy-(ZIF-8) modified Au electrode was used to determine insulin using Square-Wave Voltammetry (SWV).

Recent advances in the application of magnetic nanocatalysts in multicomponent reactions.

Recently, the preparation and applications of magnetic nanostructures have attracted increasing attention in nanocatalysis studies, and magnetic nanoparticle (MNP) functionalized catalysts have been applied in important reactions such as Suzuki-Miyaura and Heck couplings. The modified nanocomposites demonstrate significant catalytic efficiency and excellent benefits in the context of catalyst recovery methods. This review discusses the recent modified magnetic nanocomposites in the field of catalytic applications along with the synthetic processes that are usually employed.

Direct sulfonamidation of (hetero)aromatic C-H bonds with sulfonyl azides: a novel and efficient route to -(hetero)aryl sulfonamides.

-Aryl sulfonamides belong to a highly important class of organosulfur compounds which are found in a number of FDA-approved drugs such as dofetilide, dronedarone, ibutilide, sotalol, sulfadiazine, sulfamethizole, vemurafenib, and many more. There is therefore continuing interest in the development of novel and convenient protocols for the preparation of these pharmaceutically important compounds. Recently, direct sulfonamidation of (hetero)aromatic C-H bonds with easily available sulfonyl azides has emerged as an attractive and powerful strategy to access -(hetero)aryl sulfonamides where non-toxic nitrogen gas forms as the sole by-product.

Electrochemical study of 4-chloroaniline in a water/acetonitrile mixture. A new method for the synthesis of 4-chloro-2-(phenylsulfonyl)aniline and -(4-chlorophenyl)benzenesulfonamide.

The electrochemical oxidation of 4-chloroaniline as a model compound in a water/acetonitrile mixture was investigated by cyclic voltammetry and differential pulse voltammetry. It was established that one-electron oxidation of 4-chloroaniline followed by disproportionation reaction affords unstable (4-iminocyclohexa-2,5-dien-1-ylidene)chloronium. In water/acetonitrile mixtures and in the absence of nucleophiles, the most likely reaction on produced chloronium is hydrolysis and -quinoneimine formation.

Development and evaluation of a pH-responsive and water-soluble drug delivery system based on smart polymer coating of graphene nanosheets: an study.

The objective of this study is to develop a controlled and water-soluble delivery system for doxorubicin (DOX) based on the coating of graphene (G) with a smart polymer. A combination of polyethyleneimine (PEI) and G-DOX is investigated by performing density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Several parameters have been employed to evaluate the effect of PEI on the adsorption and release mechanisms of DOX.

Recent developments in electrochemical sensors for detecting hydrazine with different modified electrodes.

The detection of hydrazine (HZ) is an important application in analytical chemistry. There have been recent advancements in using electrochemical detection for HZ. Electrochemical detection for HZ offers many advantages, , high sensitivity, selectivity, speed, low investment and running cost, and low laboriousness.

Correction: Oxidative carboxylation of olefins with CO: environmentally benign access to five-membered cyclic carbonates.

[This corrects the article DOI: 10.1039/C9RA10755J.].

Oxidative carboxylation of olefins with CO: environmentally benign access to five-membered cyclic carbonates.

The purpose of this focus review is to provide a comprehensive overview of the direct synthesis of five-membered cyclic carbonates oxidative carboxylation of the corresponding olefins and carbon dioxide with particular attention on the mechanistic features of the reactions. The review is divided into two main sections. The first section is a discussion of the single-step reactions, while the second consists of an overview of one-pot, two-step sequential reactions.

Immobilized TiO nanoparticles on carbon nanotubes: an efficient heterogeneous catalyst for the synthesis of chromeno[]pyridine derivatives under ultrasonic irradiation.

A new protocol for the synthesis of chromeno[]pyridine derivatives is described a three-component reaction of 4-aminocoumarin, aromatic aldehydes and malononitrile catalyzed by TiO nanoparticles immobilized on carbon nanotubes (TiO-CNTs) as an efficient heterogeneous catalyst under ultrasonic irradiation in water. The sustainable and economic benefits of the protocol are the high yields of products, short reaction time, simple work-up procedure, and use of a non-toxic and reusable catalyst.

A walk around the application of nanocatalysts for cross-dehydrogenative coupling of C-H bonds.

Cross-dehydrogenative coupling reactions between two unmodified C-H bonds are one of the most attractive and fundamental strategies for the construction of C-C bonds. As these reactions avoid pre-functionalization and de-functionalization of the substrates, they are cleaner, safer, and faster than traditional cross-coupling reactions. After the introduction of the modern area of cross-dehydrogenative coupling in 2003, many efforts have been devoted to the development of more efficient and selective catalytic systems for these appealing reactions.

Palladium nanoparticles decorated into a biguanidine modified-KIT-5 mesoporous structure: a recoverable nanocatalyst for ultrasound-assisted Suzuki-Miyaura cross-coupling.

In the current research work, a new KIT-5-biguanidine-Pd(0) catalyst was prepared and applied to ultrasound-assisted Suzuki-Miyaura cross-coupling reactions using ultrasound waves at ambient temperature. The ultrasound-assisted method is a green and efficient method for C-C coupling. Many parameters of the Suzuki coupling reaction were examined, such as the irradiation time, the types of organic and inorganic bases, the types of aprotic and protic solvents, and the dosage (mol%) of catalyst.

Recent advances in direct trifluoromethylation of olefinic C-H bonds.

The aim of this review is to provide a comprehensive overview of the direct trifluoromethylation of olefinic C-H bonds with special attention on the mechanistic aspects of the reactions. The review is divided into two major sections. The first focuses exclusively on trifluoromethylation of terminal alkenes, while the second will cover trifluoromethylation of internal alkenes.

Methods for direct C(sp)-H bonds azidation.

Direct functionalization of C-H bonds has attracted great attention in recent years from the perspectives of atom and step economy. In this context, a variety of processes have been developed for the construction of synthetically and biologically important organic azides through the oxidative C-H bonds azidation. In this review, we have summarized recent progress in the direct azidation of C(sp)-H bonds.

Cross-dehydrogenative coupling reactions between arenes (C-H) and carboxylic acids (O-H): a straightforward and environmentally benign access to -aryl esters.

Transition-metal catalyzed cross-dehydrogenative-coupling reactions encompass highly versatile and atom economical methods for the construction of various carbon-carbon and carbon-heteroatom bonds by combining two C(X)-H (X = heteroatom) bonds. Along this line, direct acyloxylation of C-H bonds with carboxylic acids has emerged as a powerful and green approach for the synthesis of structurally diverse esters. In this focus-review we will describe recent progress in direct esterification of aromatic C-H bonds with special emphasis on the mechanistic features of the reactions.

Sensitive detection of methylated DNA and methyltransferase activity based on the lighting up of FAM-labeled DNA quenched fluorescence by gold nanoparticles.

DNA methylation of cytosine bases, which is catalyzed by methyltransferase enzymes, involve biochemical processes that contribute to gene expression and gene regulation in cells. Detection of abnormal patterns of both methylated DNA and methyltransferase enzyme activity at early stages could be considered as promising targets for early cancer diagnosis. In the present study, a novel and facile method is introduced for the sensitive detection of the M.