The study effect of microwave radiation on the catalytic properties of transition metal ferrites synthesized by ceramic and sol-gel methods, in the oxidation reaction of carbon monoxide into dioxide. The aim of this work is to study the effect of microwave radiation on the production of cobalt, copper, nickel and manganese ferrites by sol-gel combustion technology using various organic reagents and to study their catalytic activity in the oxidative conversion of carbon monoxide into dioxide. Microwave treatment was carried out on a setup based on an EM-G5593V microwave oven (Panasonic) with a magnetron power varying from 300 to 800 W with an operating frequency of 2450 MHz. X-ray phase analysis of the products was carried out on a Bruker D 2Phazer automatic diffractometer. The measurement of the specific surface area of the samples was determined by low-temperature nitrogen adsorption by the multipoint BET method on a SORBI-MS instrument (ZAO META, Russia). IR spectra were recorded using FT-IR LUMOS Bruker spectrometers. The micrographs of samples were analyzed on the Sigma VP (Carl Zeiss Jena) equipment. It was determined that the most active catalysts for the oxidation of carbon monoxide to dioxide are ferrites obtained by the sol-gel combustion method using microwave radiation to "ignite" the gel. The use of microwave radiation in the preparation of ferrites by the sol-gel method with combustion can, in a very short time, measured in seconds, initiate a self-propagating exothermic combustion reaction in the entire volume of the sample. The catalytic activity in the oxidative conversion of carbon monoxide obtained by this method of ferrites comparable to the activity of ferrites obtained by the sol-gel method with traditional combustion.
{"title":"Microwave Sol-Gel Synthesis of Co, Ni, Cu, Mn Ferrites and İnvestigation of Their Activity in the Oxidation Reaction of Carbon Monoxide","authors":"Zulfugarova Sima Mamed, Azimova Gunel Ramiz, Aleskerova Zuleyxa Fikret, Ismailov Etibar Humbat, Litvishkov Yuriy Nikolayevich, Tagiyev Dilqam Babir","doi":"10.2174/2213335609666220303105233","DOIUrl":"https://doi.org/10.2174/2213335609666220303105233","url":null,"abstract":"\u0000\u0000The study effect of microwave radiation on the catalytic properties of transition metal ferrites synthesized by ceramic and sol-gel methods, in the oxidation reaction of carbon monoxide into dioxide.\u0000\u0000\u0000\u0000The aim of this work is to study the effect of microwave radiation on the production of cobalt, copper, nickel and manganese ferrites by sol-gel combustion technology using various organic reagents and to study their catalytic activity in the oxidative conversion of carbon monoxide into dioxide.\u0000\u0000\u0000\u0000Microwave treatment was carried out on a setup based on an EM-G5593V microwave oven (Panasonic) with a magnetron power varying from 300 to 800 W with an operating frequency of 2450 MHz. X-ray phase analysis of the products was carried out on a Bruker D 2Phazer automatic diffractometer. The measurement of the specific surface area of the samples was determined by low-temperature nitrogen adsorption by the multipoint BET method on a SORBI-MS instrument (ZAO META, Russia). IR spectra were recorded using FT-IR LUMOS Bruker spectrometers. The micrographs of samples were analyzed on the Sigma VP (Carl Zeiss Jena) equipment.\u0000\u0000\u0000\u0000It was determined that the most active catalysts for the oxidation of carbon monoxide to dioxide are ferrites obtained by the sol-gel combustion method using microwave radiation to \"ignite\" the gel.\u0000\u0000\u0000\u0000The use of microwave radiation in the preparation of ferrites by the sol-gel method with combustion can, in a very short time, measured in seconds, initiate a self-propagating exothermic combustion reaction in the entire volume of the sample. The catalytic activity in the oxidative conversion of carbon monoxide obtained by this method of ferrites comparable to the activity of ferrites obtained by the sol-gel method with traditional combustion.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46855512","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}
Pub Date : 2022-01-18DOI: 10.2174/2213335609666220118102344
Kaushik N. Kundaliya, N. Patel, D. I. Brahmbhatt
The 1,2,3-triazole, pyrazole and coumarin based derivatives have received much attention due to their wide coverage of biological properties. The present work describes the microwave synthesis of novel triazolyl pyrazolyl pyrazoline substituted coumarins. Structure of all the newly synthesized compounds are characterized by spectral analysis and screened for their in vitro antimicrobial activity by Broth dilution method. In synthetic method , the targets were prepared by reaction of various 3-{3-[3-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl]acryloyl} coumarins (coumarin chalcones) (3a-d) with hydrazine hydrate or aryl hydrazine(5a-c) in the presence of acetic/propionic acid under microwave irradiation. The structures of all the synthesized compounds were established by IR, 1H-NMR, 13C-APT and selected mass spectral data. The target compounds were also screen for their in vitro antimicrobial efficiency against representative panel of pathogenic strains specifically Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Fungi (Candida albicans, Aspergillus niger). In conclusion ,the target compounds were obtained by Microwave Irradiation (MWI) technique in good yield with short reaction time. Among all the synthesized compounds ,4c,4h,6a,6h and 6l were found to have significant activity against bacterial and fungal strains.
{"title":"Microwave Assisted Synthesis of Novel Triazolyl Pyrazolyl Pyrazoline Substituted Coumarins and their Antimicrobial Activity","authors":"Kaushik N. Kundaliya, N. Patel, D. I. Brahmbhatt","doi":"10.2174/2213335609666220118102344","DOIUrl":"https://doi.org/10.2174/2213335609666220118102344","url":null,"abstract":"\u0000\u0000The 1,2,3-triazole, pyrazole and coumarin based derivatives have received much attention due to their wide coverage of biological properties. The present work describes the microwave synthesis of novel triazolyl pyrazolyl pyrazoline substituted coumarins. Structure of all the newly synthesized compounds are characterized by spectral analysis and screened for their in vitro antimicrobial activity by Broth dilution method.\u0000\u0000\u0000\u0000In synthetic method , the targets were prepared by reaction of various 3-{3-[3-(5-methyl-1-aryl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-4-yl]acryloyl} coumarins (coumarin chalcones) (3a-d) with hydrazine hydrate or aryl hydrazine(5a-c) in the presence of acetic/propionic acid under microwave irradiation.\u0000\u0000\u0000\u0000The structures of all the synthesized compounds were established by IR, 1H-NMR, 13C-APT and selected mass spectral data. The target compounds were also screen for their in vitro antimicrobial efficiency against representative panel of pathogenic strains specifically Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis), Gram-negative bacteria (Escherichia coli, Salmonella typhi) and Fungi (Candida albicans, Aspergillus niger).\u0000\u0000\u0000\u0000In conclusion ,the target compounds were obtained by Microwave Irradiation (MWI) technique in good yield with short reaction time. Among all the synthesized compounds ,4c,4h,6a,6h and 6l were found to have significant activity against bacterial and fungal strains.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2022-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47339790","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}
Pub Date : 2021-10-06DOI: 10.2174/2213335608666211006121803
Yogesh B. Wagh, D. Dalal
Microwave-assisted domino cyclization reactions have attracted great interest for researchers to synthesize complex compounds in shorter times with increase yields. The domino reactions were used in various synthetic approaches and many drug deliveries in medicinal chemistry with microwave assisted approach. Microwave irradiation has been applied for the various domino reactions. The research related to microwave assisted domino cyclization was reviewed and the important methodologies are collected from 2011-2021. Only those methodologies that involve microwave-assisted domino cyclization reactions during synthesis in a related manner have been reviewed. Along with some recent syntheses that are microwave-assisted regarding new heterocyclic moieties are summarized. Microwave-assisted domino cyclization reactions can be employed to quickly explore and increase molecular diversity in synthetic chemistry. We hope that this review will be helpful to find out complex molecule synthesis by microwave-assisted domino cyclization reactions. This review aimed to explain the applications of microwaves for the domino reactions from 2011-2021. In this respect, the microwave mediated methods help researchers to make helpful studies.
{"title":"Microwave-Assisted Domino Cyclization Reactions","authors":"Yogesh B. Wagh, D. Dalal","doi":"10.2174/2213335608666211006121803","DOIUrl":"https://doi.org/10.2174/2213335608666211006121803","url":null,"abstract":"\u0000\u0000Microwave-assisted domino cyclization reactions have attracted great interest for researchers to synthesize complex compounds in shorter times with increase yields. The domino reactions were used in various synthetic approaches and many drug deliveries in medicinal chemistry with microwave assisted approach. \u0000\u0000\u0000\u0000\u0000Microwave irradiation has been applied for the various domino reactions. The research related to microwave assisted domino cyclization was reviewed and the important methodologies are collected from 2011-2021.\u0000\u0000\u0000\u0000\u0000Only those methodologies that involve microwave-assisted domino cyclization reactions during synthesis in a related manner have been reviewed. Along with some recent syntheses that are microwave-assisted regarding new heterocyclic moieties are summarized.\u0000\u0000\u0000\u0000\u0000 Microwave-assisted domino cyclization reactions can be employed to quickly explore and increase molecular diversity in synthetic chemistry. We hope that this review will be helpful to find out complex molecule synthesis by microwave-assisted domino cyclization reactions. This review aimed to explain the applications of microwaves for the domino reactions from 2011-2021. In this respect, the microwave mediated methods help researchers to make helpful studies.\u0000\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42771772","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}
Pub Date : 2021-09-23DOI: 10.2174/2213335608666210923144201
B. Banik, B. Sahoo, B. R. Kumar, Krishna Chandra Panda
The synthesis of heterocyclic compounds via carbon-nitrogen (C-N) bond formation reaction is considered as an emerged and efficient protocol in the field of synthetic chemistry. The C–N bond-forming reactions can proceed through condensation, coupling, ring-opening, cyclization or ring closure process etc. The reactivity pattern of these reactions mainly depends upon the reaction conditions as well as the type of catalysts and reacting substances that are associated with the synthesis of heterocyclic compounds containing the C-N system including pyrazole, imidazole, pyridine, pyrimidine, thiazole, tetrazole, isoxazole, benzothiazine and benzimidazole etc. Further, the technique of microwave-induced synthesis becomes an alternative strategy for the sustainable production of structurally diverse organic compounds. This method provides a cleaner reaction, faster reaction rate, atom economy and energy-efficient. So, the utilization of microwave radiation in organic synthesis becomes resource-friendly and eco-friendly processes. It follows the green chemistry approach by using safer solvents, renewable starting materials and green catalysts. The unique feature of this method is to generate various types of bioactive or medicinal agents.
{"title":"Microwave Induced Green chemistry approach towards synthesis of heterocyclic compounds via C-N Bond Forming Reactions","authors":"B. Banik, B. Sahoo, B. R. Kumar, Krishna Chandra Panda","doi":"10.2174/2213335608666210923144201","DOIUrl":"https://doi.org/10.2174/2213335608666210923144201","url":null,"abstract":"\u0000\u0000The synthesis of heterocyclic compounds via carbon-nitrogen (C-N) bond formation reaction is considered as an emerged and efficient protocol in the field of synthetic chemistry. The C–N bond-forming reactions can proceed through condensation, coupling, ring-opening, cyclization or ring closure process etc. The reactivity pattern of these reactions mainly depends upon the reaction conditions as well as the type of catalysts and reacting substances that are associated with the synthesis of heterocyclic compounds containing the C-N system including pyrazole, imidazole, pyridine, pyrimidine, thiazole, tetrazole, isoxazole, benzothiazine and benzimidazole etc. Further, the technique of microwave-induced synthesis becomes an alternative strategy for the sustainable production of structurally diverse organic compounds. This method provides a cleaner reaction, faster reaction rate, atom economy and energy-efficient. So, the utilization of microwave radiation in organic synthesis becomes resource-friendly and eco-friendly processes. It follows the green chemistry approach by using safer solvents, renewable starting materials and green catalysts. The unique feature of this method is to generate various types of bioactive or medicinal agents.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47898092","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}
Pub Date : 2021-09-22DOI: 10.2174/2213335608666210922155503
Kantharaju Kamanna, Yamanappagouda Amaregouda
Organocatalysis defines small organic molecules exclusively containing carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous atom to speed-up the chemical reactions. Researcher demonstrated large area of applications in various organic transformations catalyzed by the organocatalysts, due to their less moisture sensitivity and air, easy abundance, less polluting, not interfere with the final product and inexpensive. This highlights high demand and direct benefits in the pharmaceutical intermediate and fine chemical manufacture compared to other conventional transition metal and enzyme catalysts. This review article intends to compile literature reported application of the microwave accelerated organocatalyzed carbon-carbon and carbon–heteroatom bond formation reactions reported in the literature.
{"title":"Microwave-assisted organo-catalyzed C-C and C-X (heteroatom) bond-forming reactions-An overview","authors":"Kantharaju Kamanna, Yamanappagouda Amaregouda","doi":"10.2174/2213335608666210922155503","DOIUrl":"https://doi.org/10.2174/2213335608666210922155503","url":null,"abstract":"\u0000\u0000Organocatalysis defines small organic molecules exclusively containing carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorous atom to speed-up the chemical reactions. Researcher demonstrated large area of applications in various organic transformations catalyzed by the organocatalysts, due to their less moisture sensitivity and air, easy abundance, less polluting, not interfere with the final product and inexpensive. This highlights high demand and direct benefits in the pharmaceutical intermediate and fine chemical manufacture compared to other conventional transition metal and enzyme catalysts. This review article intends to compile literature reported application of the microwave accelerated organocatalyzed carbon-carbon and carbon–heteroatom bond formation reactions reported in the literature.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43144721","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}
Pub Date : 2021-09-17DOI: 10.2174/2213335608666210917121004
Moumita Saha, Asish R. Das
C-C or C-heteroatom bond formation from direct C-H bond activation of several heteroarenes containing suitable directing groups has now emerged as an efficient and straightforward strategy for the design of complex heterocyclic molecules as well as their late-stage functionalization. The most common problem of several C-H bond activation reactions is high temperature, long reaction time and unwanted side reactions where recent examples of MW assisted C-H bond activation showed the requirements of low temperature and short completion time and thus proved its efficacy in terms of heating effect and conversion rate of conventional heating methods. The schemes discussed in the present review depict the reaction conditions along with a look into the mechanism involved to render a deep understanding of the catalytic role of palladium-catalysis. In some examples, the optimization procedure of the corresponding strategy has been illustrated through tables, i.e., choice of catalyst, solvent screening, loading of the catalyst and percentage yield with different substrates. Each of the described illustrations has been analyzed considering a wide variety of reactants, reaction conditions, and transition metals employed as the catalyst. This review definitely allows to introduce the synthetic chemists in understanding the challenges associated with the previous methods as well as their drawbacks and future opportunities in choosing substrates, catalyst and reaction conditions. This review would be alluring to a wider range of synthetic chemists in academia and industrial R&D sectors working with heterocyclic chemistry. In this short perspective, an outline of recent eloquent examples of a variety of palladium-catalyzed C-H bond activation involving bio-oriented heterocycles achieved in the past ten years is nicely presented and the pros and cons of each strategy are highlighted so that the researchers could get enough scope for further designing and modification of developed protocols.
{"title":"Microwave-assisted Palladium-catalyzed C-H bond Functionalizations Towards the Synthesis of Bio-inspired Heterocycles","authors":"Moumita Saha, Asish R. Das","doi":"10.2174/2213335608666210917121004","DOIUrl":"https://doi.org/10.2174/2213335608666210917121004","url":null,"abstract":"\u0000\u0000C-C or C-heteroatom bond formation from direct C-H bond activation of several heteroarenes containing suitable directing groups has now emerged as an efficient and straightforward strategy for the design of complex heterocyclic molecules as well as their late-stage functionalization. The most common problem of several C-H bond activation reactions is high temperature, long reaction time and unwanted side reactions where recent examples of MW assisted C-H bond activation showed the requirements of low temperature and short completion time and thus proved its efficacy in terms of heating effect and conversion rate of conventional heating methods. The schemes discussed in the present review depict the reaction conditions along with a look into the mechanism involved to render a deep understanding of the catalytic role of palladium-catalysis. In some examples, the optimization procedure of the corresponding strategy has been illustrated through tables, i.e., choice of catalyst, solvent screening, loading of the catalyst and percentage yield with different substrates. Each of the described illustrations has been analyzed considering a wide variety of reactants, reaction conditions, and transition metals employed as the catalyst. This review definitely allows to introduce the synthetic chemists in understanding the challenges associated with the previous methods as well as their drawbacks and future opportunities in choosing substrates, catalyst and reaction conditions. This review would be alluring to a wider range of synthetic chemists in academia and industrial R&D sectors working with heterocyclic chemistry. In this short perspective, an outline of recent eloquent examples of a variety of palladium-catalyzed C-H bond activation involving bio-oriented heterocycles achieved in the past ten years is nicely presented and the pros and cons of each strategy are highlighted so that the researchers could get enough scope for further designing and modification of developed protocols.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45066720","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}
Pub Date : 2021-09-08DOI: 10.2174/2213335608666210908123730
Timothy Kovach, S. Boyd, Anthony Garcia, A. Fleischer, Katerine Vega, Regina Hilfiker, Joel Shertok, M. Mehan, Surendra K. Gupta, G. Takacs
Polybenzimidazole (PBI) is used in high temperature proton exchange membrane fuel cells (HT-PEMFCs) and redox flow batteries, where proton transfer occurs with the nitrogen-containing groups in PBI, and in aerospace applications exposed to oxygen and radiation. The objective is to investigate VUV photo-oxidation of PBI for the first time in order to incorporate polar functional groups on the surface to potentially enhance proton conductivity in HT-PEMFCs. A low-pressure microwave discharge of Ar generated 104.8 and 106.7 nm vacuum UV (VUV) radiation to treat PBI with VUV photo-oxidation. Analysis was done with X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), water contact angle (WCA) and Thermal Gravimetric Analysis (TGA) to detect changes in chemistry, surface roughness, hydrophilicity, and adhesion, respectively. XPS showed: an increase in the O concentration up to a saturation level of 15 ± 1 at %; a decrease of the C concentration by about the same amount; and little change in the N concentration. With increasing treatment time, there were significant decreases in the concentrations of C-C sp2, C-C sp3 and C=N groups, and increases in the concentration of C=O, O-C=O, O-(C=O)-O, C-N, and N-C=O containing moieties. The water contact angle decreased from 83° for pristine PBI down to 43°, making the surface more hydrophilic, primarily due to the oxidation, since AFM detected no significant changes in surface roughness. TGA analysis showed an improvement of water adhesion to the treated surface. Microwave generated VUV photo-oxidation is an effective technique for oxidizing the surface of PBI and increasing hydrophilicity.
{"title":"Surface Modification of Polybenzimidazole (PBI) with Microwave Generated Vacuum Ultraviolet (VUV) Photo-oxidation","authors":"Timothy Kovach, S. Boyd, Anthony Garcia, A. Fleischer, Katerine Vega, Regina Hilfiker, Joel Shertok, M. Mehan, Surendra K. Gupta, G. Takacs","doi":"10.2174/2213335608666210908123730","DOIUrl":"https://doi.org/10.2174/2213335608666210908123730","url":null,"abstract":"\u0000\u0000Polybenzimidazole (PBI) is used in high temperature proton exchange membrane fuel cells (HT-PEMFCs) and redox flow batteries, where proton transfer occurs with the nitrogen-containing groups in PBI, and in aerospace applications exposed to oxygen and radiation. \u0000\u0000\u0000\u0000\u0000The objective is to investigate VUV photo-oxidation of PBI for the first time in order to incorporate polar functional groups on the surface to potentially enhance proton conductivity in HT-PEMFCs. \u0000\u0000\u0000\u0000\u0000 A low-pressure microwave discharge of Ar generated 104.8 and 106.7 nm vacuum UV (VUV) radiation to treat PBI with VUV photo-oxidation. Analysis was done with X-ray Photoelectron Spectroscopy (XPS), Atomic Force Microscopy (AFM), water contact angle (WCA) and Thermal Gravimetric Analysis (TGA) to detect changes in chemistry, surface roughness, hydrophilicity, and adhesion, respectively. \u0000\u0000\u0000\u0000\u0000 XPS showed: an increase in the O concentration up to a saturation level of 15 ± 1 at %; a decrease of the C concentration by about the same amount; and little change in the N concentration. With increasing treatment time, there were significant decreases in the concentrations of C-C sp2, C-C sp3 and C=N groups, and increases in the concentration of C=O, O-C=O, O-(C=O)-O, C-N, and N-C=O containing moieties. The water contact angle decreased from 83° for pristine PBI down to 43°, making the surface more hydrophilic, primarily due to the oxidation, since AFM detected no significant changes in surface roughness. TGA analysis showed an improvement of water adhesion to the treated surface. \u0000\u0000\u0000\u0000\u0000 Microwave generated VUV photo-oxidation is an effective technique for oxidizing the surface of PBI and increasing hydrophilicity.\u0000\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41284117","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}
Pub Date : 2021-08-23DOI: 10.2174/2213335608666210823093626
Bijeta Mitra, P. Ghosh
In recent times, microwave assisted chemistry have gained enormous attraction in organic synthesis owing to its versatile advantages such as avoidance of harsh reaction condition, increase of yield, eliminates of by product, shorter reaction time and removal of wastages. Besides, water as a reaction medium further includes more benefit as it eliminates all the drawbacks of toxic solvent which may cause injuries for our mother earth. Furthermore C-C and C-heteroatom bond formation reactions are very significant as most of the drug as well as bioactive compounds contain heterocycles or C-hetero bond which is a key tool of chemistry. This article demonstrates the advancement on the topic of the microwave assisted C-C and C-heteroatom bond formation reactions in aqueous medium.
{"title":"Microwave-assisted C-C and C-heteroatom bond formations in aqueous medium","authors":"Bijeta Mitra, P. Ghosh","doi":"10.2174/2213335608666210823093626","DOIUrl":"https://doi.org/10.2174/2213335608666210823093626","url":null,"abstract":"\u0000\u0000In recent times, microwave assisted chemistry have gained enormous attraction in organic synthesis owing to its versatile advantages such as avoidance of harsh reaction condition, increase of yield, eliminates of by product, shorter reaction time and removal of wastages. Besides, water as a reaction medium further includes more benefit as it eliminates all the drawbacks of toxic solvent which may cause injuries for our mother earth. Furthermore C-C and C-heteroatom bond formation reactions are very significant as most of the drug as well as bioactive compounds contain heterocycles or C-hetero bond which is a key tool of chemistry. This article demonstrates the advancement on the topic of the microwave assisted C-C and C-heteroatom bond formation reactions in aqueous medium.\u0000","PeriodicalId":43539,"journal":{"name":"Current Microwave Chemistry","volume":null,"pages":null},"PeriodicalIF":0.8,"publicationDate":"2021-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45727600","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：