{"title":"Magnetically recoverable nanocatalyst for the synthesis of pyranopyrazoles: CoFe2O4@SiO2-HClO4","authors":"Nikita Vinod Thakare, Anand Shankar Aswar, Nilesh Govindrao Salunkhe","doi":"10.5155/eurjchem.14.3.385-392.2457","DOIUrl":"https://doi.org/10.5155/eurjchem.14.3.385-392.2457","url":null,"abstract":"The multiheterocyclic ring system shows valuable pharmaceutical and biological activities. In the present study, a microwave-assisted three-component reaction between aryl aldehyde, malononitrile, and 5-methyl-2,4-dihydro-3H-pyrazole-3-one led to the synthesis of pyrano[2,3-c]pyrazoles has been described. The reaction was carried out under solvent-free conditions in the presence of a new magnetically recoverable nanocatalyst (CoFe2O4@SiO2-HClO4). The reported protocol offers several advantages such as being environmentally benign, being rapid, inexpensive, having high atom and step economy, and being facile. The simple method of catalyst preparation, easy magnetic recovery, and reusability of the catalyst for four runs are notable features of the nanocatalyst. Antibacterial activity of all synthesized compounds was tested against Escherichia coli and Staphylococcus aureus. All synthesized compounds showed promising biological activity and may be used as a potential antibacterial candidate in biological science.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136336316","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Green synthesis of silver nano-catalyst using ionic liquid and their photocatalytic application to the reduction of p-nitrophenol","authors":"Ravi Ranjan, Durga Gupta, Madhulata Shukla","doi":"10.5155/eurjchem.14.3.316-322.2436","DOIUrl":"https://doi.org/10.5155/eurjchem.14.3.316-322.2436","url":null,"abstract":"Ionic liquids (ILs) carrying special properties can act as electronic as well as steric stabilisers by preventing nanoparticle (NP) growth and NP aggregation. The effect of visible light on the catalytic properties of silver nanoparticles is a hot topic of extensive research nowadays. The present report demonstrates the current developments in the green synthesis of silver nanoparticles in ionic liquids and a detailed study of the room-temperature catalytic and photocatalytic reduction of p-nitrophenol (PNP) to p-aminophenol (AP). The Ag nanoparticles (AgNPs) functionalised by ionic liquids are prepared in the 40-140 nm range and are found to be spherical in shape. The photocatalytic properties of these nanocomposites for the reduction of PNP to AP were studied. Photocatalytic degradation of PNP was also analysed by these composite nanostructures. The plasmonic photocatalytic properties of the synthesised AgNPs revealed activity significantly higher than that of the room-temperature catalysis. Density functional theory calculations showed that strong interactions exist between nanoclusters and ILs. Natural bond orbital analysis showed that IL also activates the nanoparticles for further photocatalytic reduction by transferring electron transfer from the donor (IL) to the acceptor (Ag cluster) and activating the silver NPs for further catalytic reaction. Photocatalytic degradation of PNP (reduction of PNP to AP) using NP in the absence of light follows first-order kinetics, whereas in the presence of light it follows zero-order reaction kinetics.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136336309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Aphouet Aurelie Koffi, N'guadi Blaise Allou, Mougo Andre Tigori, Teminfolo Yaya Soro, Albert Trokourey, Paulin Marius Niamien
{"title":"Study of expired Fuclo 500 drug as an environmentally sustainable corrosion inhibitor","authors":"Aphouet Aurelie Koffi, N'guadi Blaise Allou, Mougo Andre Tigori, Teminfolo Yaya Soro, Albert Trokourey, Paulin Marius Niamien","doi":"10.5155/eurjchem.14.3.353-361.2443","DOIUrl":"https://doi.org/10.5155/eurjchem.14.3.353-361.2443","url":null,"abstract":"This work deals with aluminium corrosion inhibition by expired drugs containing flucloxacillin in 1 M hydrochloric acid medium, using the gravimetric method and density functional theory. Weight loss results showed that the inhibitory efficiency of this compound increases with concentration and decreases with increasing temperature. The study also indicates that this molecule is adsorbed according to the modified Langmuir model (Villamil model). Furthermore, the thermodynamic parameters of adsorption (∆Goads, ∆Hoads, ∆Soads) and activation (Ea*, ΔHa*, ΔSa*) show that the adsorption is mixed type (chemisorption and physisorption). In addition, density functional theory provides access to the quantum chemical parameters of the molecule such as the lowest vacant orbital energy (ELUMO), the highest occupied orbital energy (EHOMO), the absolute electronegativity (χ), the global hardness (η), the global softness (S), the fraction of transferred electrons (ΔN) as well as the electrophilicity index (ω) for finding correlation between the inhibitor structure and the experimental data.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136336656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriel Vitor de Lima Marques, Renata Barbosa de Oliveira
{"title":"From ancient Asian relics to contemporaneity: A review of historical and chemical aspects of Cannabis","authors":"Gabriel Vitor de Lima Marques, Renata Barbosa de Oliveira","doi":"10.5155/eurjchem.14.3.393-400.2442","DOIUrl":"https://doi.org/10.5155/eurjchem.14.3.393-400.2442","url":null,"abstract":"From the Himalayan mountains to the South American coast, Cannabis, a general term for plants of the genus Cannabis, with thousands of years of contact with humankind, shows its versatility as food tools such as hemp, religious and hedonistic input, and other purposes through the millennia, according to the populations in question. In this paper, a review of the context of the use of Cannabis and its place in world history is presented, from ancient Mesopotamian relics, traditional Chinese and Ayurvedic medicines, to the reasoning behind the isolation and structural elucidation of three phytocannabinoids and the spread of Cannabis throughout the world.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136341564","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohammad Ali Ebrahimzadeh, Seyedeh Roya Alizadeh, Zahra Hashemi
{"title":"Green synthesis of gold nanoparticles using Sambucus ebulus fruit extract, characterization, and antileishmanial, antibacterial, antioxidant, and photocatalytic activities","authors":"Mohammad Ali Ebrahimzadeh, Seyedeh Roya Alizadeh, Zahra Hashemi","doi":"10.5155/eurjchem.14.2.223-230.2403","DOIUrl":"https://doi.org/10.5155/eurjchem.14.2.223-230.2403","url":null,"abstract":"In this study, gold nanoparticles were synthesized using the fruit extract of Sambucus ebulus (S. ebulus) as a reducing, capping, and stabilizing agent. Biogenic synthesis of gold nanoparticles (Au nanoparticles) was accomplished using S. ebulus fruit extract in the presence of hydrogen tetrachloroaurate(III) trihydrate at a temperature of 65 °C and the solution stirred at 400 rpm. The characterization of the synthesized nanoparticles (SE-AuNPs) was performed using different analytical methods, such as scanning electron microscopy (FE-SEM), energy dispersion X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR), X-ray diffraction analysis (XRD), and UV-vis spectroscopy. A strong absorption peak at 565 nm confirmed the formation of the gold nanoparticle. On the basis of the electron microscopy results, AuNPs were mostly spherical with an average size of 116.2 nm. The cubic crystalline structure of the prepared nanoparticles was confirmed using the XRD pattern and the average crystallite size was obtained at 28.471 nm. FT-IR analysis confirmed the presence of functional groups in the plant extract for the synthesis of nanoparticles. SE-AuNPs showed good antibacterial activity against Gram-positive and Gram-negative bacteria tested and exhibited potent antileishmanial activity. Furthermore, SE-AuNPs showed excellent antioxidant activity that inhibited DPPH radicals with an IC50 value of 21.976 µg/mL. The prepared AuNPs acted to degrade methyl orange (MO), which was performed in sodium borohydride and visible light.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"163 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135967515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A corrected benzene nitration three-step mechanism derived by DFT calculation and MO theory","authors":"Hongchang Shi","doi":"10.5155/eurjchem.14.1.39-52.2340","DOIUrl":"https://doi.org/10.5155/eurjchem.14.1.39-52.2340","url":null,"abstract":"Density-functional theory (DFT) calculations at the LC-wHPBE/6-311++G(d,p) level found that the textbook three-step nitration mechanism of benzene in mixed acids was seriously wrong. Step 1 of generating nitronium ion (NO2+) is not spontaneous, the NO2+ is generated by Lewis collision, and needs to overcome a barrier Ea = 18 or 22 kcal/mol in mixed acid or in nitric acid. Obtaining the Ea of the Lewis collision by quantum chemical calculations is a highlight of the study. The reaction system (NO2+ + H2O) + HSO4⎺ or + NO3⎺ or + nH2O (n ≥ 1) can make NO2+ spontaneously change to HNO3 through a poly(≥3)-molecular acidification. Sulfuric acid can greatly reduce [H2O] and increase [NO2+]. Therefore, the nitration rate in mixed acid is much faster than that in nitric acid. Step 2, C6H6 + NO2+, is an electrophilic addition, follows the transition state theory, and needs to overcome a low barrier, ΔE* = 7 kcal/mol. The product of Step 2 is the σ-complex C6H6-NO2+. The essence of the electrophilic addition is the transfer of HOMO-1 electrons of C6H6 to LUMO of NO2+. Step 3 is a spontaneous Lewis acid-base neutralization without any barrier, and generates the target product nitrobenzene C6H5NO2. NO2+ and σ-complex are the two active intermediates in nitration. The benzene nitration rate control step is not Step 2 of generating σ-complex, but is Step 1 to generate NO2+. The DFT calculation obtains the barriers Ea and ΔE*, the reaction heats ΔHσ and ΔHp of each step of the nitration, resulting in the total nitration reaction heat ΔH = -35 kcal/mol. It is consistent with the experimental ΔH = -34 kcal/mol. Based on the results, a corrected benzene nitration three-step mechanism proposed.","PeriodicalId":11778,"journal":{"name":"European Journal of Chemistry","volume":"484 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135821796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}