Volume 17, Issue 1, March - December 2024
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Monthly Archives: January 2024
Cu(im)2-derived Cu@N–C catalyst for one-pot synthesis of 2-substituted indoles via domino Sonogashira coupling-cyclization reactions
Mono-cyclopentyl substituted [1,3,4]thiadiazole thione tautomer: study of the spectroscopic, geometric, thermal, and biological properties
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Analysis of Photocatalytic Degradation of Phenol by Zinc Oxide Using Response Surface Methodology
Phenol and phenolic compounds pose a serious threat to the ecosystem, human health, and water resources. Photocatalytic degradation is the most suitable technique for removing organic pollutants from wastewater, and ZnO is an effective photocatalyst. This study evaluated both the photocatalytic degradation of phenol and the measurement of TOC using a ZnO photocatalyst, demonstrating the feasibility of employing RSM.
Abstract
In this study, the photocatalytic degradation of phenol, which is commonly found in industrial wastewater at high rates, was investigated using a zinc oxide (ZnO) catalyst. It is thought that our findings will contribute to the removal of phenol in industrial wastewater. The experimental study was conducted in a batch-type air-fed cylindrical photocatalytic reactor, and a central composite design (CCD) was chosen and analyzed using response surface methodology (RSM). The study aimed to explore the effects of initial phenol concentration, catalyst concentration, airflow rate, and degradation time on the photocatalytic degradation of phenol and the removal efficiency of total organic carbon (TOC). A quadratic regression model was developed to establish the relationship between phenol degradation, TOC removal effectiveness, and the four factors mentioned. The validity of the model was assessed through an analysis of variance (ANOVA). A good agreement was observed between the model results and the experimental data. As a result of the experiments carried out under optimized conditions, the degradation percentage of phenol was found to be 77.15 %, and the degradation percentage of TOC was 59.87 %. Additionally, pseudo-first-order kinetics were used in the photocatalytic degradation of phenol.
Tuning the Sign and Magnitude of Complexation‐Induced pKa Shifts in Cucurbit[7]uril Host‐Guest Complexes by Molecular Engineering
![Tuning the Sign and Magnitude of Complexation-Induced pKa Shifts in Cucurbit[7]uril Host-Guest Complexes by Molecular Engineering](https://onlinelibrary.wiley.com/cms/asset/996e14d8-8246-4c88-adf5-ba51f89b20c1/ijch202300143-toc-0001-m.png)
Abstract
Cucurbiturils are popular macrocyclic receptors that bind complementary guest molecules with high affinity in aqueous environments. They are recognized for their ability to selectively bind positively charged guest molecules, including ionizable ammonium cations which frequently display much higher affinity than their neutral counterparts. This selectivity for the protonated species is translated into an increase in the basicity of encapsulated guests (i. e. into complexation-induced positive pK a shifts). However, despite being very rare, negative pK a shifts can be observed for specific guests. Following a previous work from our group reporting slightly negative pK a shifts for flavylium and chalcone dyes featuring N-diethylamino substituents (ΔpK a=− 0.2), herein we report a systematic study on the complexation of N-dialkylaminochalcones with CB7. The results show that the pK a shifts of these host-guest complexes can be rationally tuned by the nature of the N-dialkylamino groups and as well by target substitutions on the skeleton of the dye, allowing the design of a CB7 1 : 1 host-guest complex with a ΔpK a=− 0.6.
Interaction of N2, O2 and H2 Molecules with Superalkalis
N2 (blue), O2 (red) and H2 (grey) interact differently with superalkali clusters. Their interaction varies from strong covalent to weak van der Waals interaction leading to the possibility of reduction or adsorption of these small molecules.
Abstract
Superalkalis (SAs) are exotic clusters having lower ionization energy than alkali atoms, which makes them strong reducing agents. In the quest for the reduction of diatomic molecules (X2) such as N2, O2, and H2 using Møller-Plesset perturbation theory (MP2), we have studied their interaction with typical superalkalis such as FLi2, OLi3, and NLi4 and calculated various parameters of the resulting SA−X2 complexes. We noticed that the SA−O2 complex and its isomers possess strong ionic interaction, which leads to the reduction of O2 to O2 − anion. On the contrary, there are both ionic and covalent interactions in SA−N2 complexes such that the lowest energy isomers are covalently bonded with no charge transfer from SA. Further, the interaction between SA and H2 leads to weakly bound complexes, which results in the adsorption of H2 molecules. The nature of interaction is found to be closely related to the electron affinity of diatomic molecules. These findings might be useful in the study of the activation, reduction, and adsorption of small molecules, which can be further explored for their possible applications.
Green Synthesis of Copper Nanoparticles Using Sargassum spp. for Electrochemical Reduction of CO2
CuNPs were synthesized using a cost-effective and environmentally friendly extract applying Sargassum spp. as versatile reducing agent. In this study, CuNPs with nanoflower morphology were synthesized. The experimental characterizations (XRD, SEM, and TEM,) recommend that the green synthesis method has promising effect for the synthesis of CuNPs, stable and homogeneously dispersed onto biochar. The CuNPs-CSKPH is promising electrocatalyst for the electrochemical reduction of CO2.
Abstract
This study presents a green method of producing copper nanoparticles (CuNPs) using aqueous extracts from Sargassum spp. as reducing, stabilizing, and capping agents. The CuNPs created using this algae-based method are not hazardous, they are eco-friendly, and less toxic than their chemically synthesized counterparts. The XRD characterization of the CuNPs revealed the presence of Cu and CuO, with a crystallite size ranging from 13 to 17 nm. Following this, the CuNPs were supported onto a carbon substrate, also derived from Sargassum spp. (biochar CSKPH). The CuNPs in biochar (CuNPs-CSKPH) did not appear in the XRD diffractograms, but the SEM-EDS results showed that they accounted for 36 % of the copper weight. The voltamperometric study of CuNps-CSKPH in acid media validated the presence of Cu and the amount was determined to be 2.58 μg. The catalytic activity of CuNPs-CSKPH was analyzed for the electrochemical reduction of CO2. The use of Sargassum spp. has great potential to tackle two environmental problems simultaneously, by using it as raw material for the synthesis of activated biochar as support, as well as the synthesis of CuNPs, and secondly, by using it as a sustainable material for the electrochemical conversion of CO2.
Nanomaterials Connected to Bioreceptors to Introduce Efficient Biosensing Strategy for Diagnosis of the TORCH Infections: A Critical Review
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Investigations on the thermo physical properties of the binary mixtures of 2-methyl-pentanediol-2,4 with n-alkanols at various temperatures (hexylene glycol with 1-octanol, 1-nonanol, 1-decanol)
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(Self-)assembled news: recent highlights from the supramolecular chemistry literature (Quarter 4, 2023)
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