Pub Date : 2023-01-01DOI: 10.31489/2959-0663/3-23-14
A. Kurmanova, F. Abilkanova, I. Pustolaikina, Sergey N. Nikolskiy
A theoretical study of proton transfer dynamics in complexes of some substituted benzoic acids with 3,6-di-tert-butyl-2-hydroxyphenoxyl (DTBPO) radical is presented. To elucidate the transfer mechanism, reaction pathways for various complexes of benzoic acid derivatives with DTBPO were modeled. The calculations were performed by the DFT method at the UB3LYP/6-31G+(d, p) level of theory using QST3, IRC proce-dures, in vacuum and toluene medium (PCM solvation model). Geometric and kinetic parameters of com-plexes with o-, p-, and m-isomers of nitrobenzoic and chlorobenzoic acids were calculated. Theoretically es-timated activation barrier of 29-30 kJ/mol turned out to be approximately 30 % higher than the previously ob-tained experimental data. It was noted that in the case of o-isomers of aromatic acids the coplanarity of the transition state structure is violated, in contrast to the initial state. This leads to a change in the proton transfer mechanism. The dynamics of charge distribution, dipole moment and electrostatic potential in the studied complexes were analyzed. Based on the calculated data, it was shown that the studied intermolecular proton exchange process occurs throughout Hydrogen Atom Transfer (HAT), and not throughout Proton-Coupled Electron Transfer (PCET) mechanism.
{"title":"DFT Study of Intermolecular Proton Exchange with Some Derivatives of Benzoic Acids","authors":"A. Kurmanova, F. Abilkanova, I. Pustolaikina, Sergey N. Nikolskiy","doi":"10.31489/2959-0663/3-23-14","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-14","url":null,"abstract":"A theoretical study of proton transfer dynamics in complexes of some substituted benzoic acids with 3,6-di-tert-butyl-2-hydroxyphenoxyl (DTBPO) radical is presented. To elucidate the transfer mechanism, reaction pathways for various complexes of benzoic acid derivatives with DTBPO were modeled. The calculations were performed by the DFT method at the UB3LYP/6-31G+(d, p) level of theory using QST3, IRC proce-dures, in vacuum and toluene medium (PCM solvation model). Geometric and kinetic parameters of com-plexes with o-, p-, and m-isomers of nitrobenzoic and chlorobenzoic acids were calculated. Theoretically es-timated activation barrier of 29-30 kJ/mol turned out to be approximately 30 % higher than the previously ob-tained experimental data. It was noted that in the case of o-isomers of aromatic acids the coplanarity of the transition state structure is violated, in contrast to the initial state. This leads to a change in the proton transfer mechanism. The dynamics of charge distribution, dipole moment and electrostatic potential in the studied complexes were analyzed. Based on the calculated data, it was shown that the studied intermolecular proton exchange process occurs throughout Hydrogen Atom Transfer (HAT), and not throughout Proton-Coupled Electron Transfer (PCET) mechanism.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"230 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89033110","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 : 2023-01-01DOI: 10.31489/2959-0663/1-23-8
Venkatesh B. Gopula, Mohsin K. Pathan
The Biginelli reaction is one the useful multicomponent reactions and a very appropriate reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones derivatives. These 3,4-dihydropyrimidin-2(1H)-ones have biological and pharmacological properties which makes them a very important class of medicinal chemistry. Although they are an important class of medicinal chemistry, the syntheses of these compounds have been catalyzed by large number of strong Bronsted acids and Lewis acids under thermal conditions. Small organic molecules, organocatalysts, have been used as catalysts for the Biginelli reaction in a small number as compared to Bronsted acids and Lewis acid. Benzoic acid, which is a small organic molecule, although an acid, has never been tested for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Benzoic acid is an inexpensive, non-toxic molecule, it has been successfully tested here as a catalyst for the one-pot three component synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives via Biginelli reaction between β-keto ester, a variety of aromatic aldehydes and urea or thiourea under thermal conditions using 20 mol% benzoic acid in acetonitrile solvent refluxed for 12 h to give good to high yields. This synthetic method includes inexpensive, non-toxic, easily available benzoic acid as a catalyst and is carried out in a simple operational procedure.
{"title":"Simple and Efficient Method for One Pot Multicomponent Synthesis of 3,4-Dihydropyrimidin-2-(1H)-One Derivatives Catalyzed by Organocatalyst: Benzoic Acid","authors":"Venkatesh B. Gopula, Mohsin K. Pathan","doi":"10.31489/2959-0663/1-23-8","DOIUrl":"https://doi.org/10.31489/2959-0663/1-23-8","url":null,"abstract":"The Biginelli reaction is one the useful multicomponent reactions and a very appropriate reaction for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones derivatives. These 3,4-dihydropyrimidin-2(1H)-ones have biological and pharmacological properties which makes them a very important class of medicinal chemistry. Although they are an important class of medicinal chemistry, the syntheses of these compounds have been catalyzed by large number of strong Bronsted acids and Lewis acids under thermal conditions. Small organic molecules, organocatalysts, have been used as catalysts for the Biginelli reaction in a small number as compared to Bronsted acids and Lewis acid. Benzoic acid, which is a small organic molecule, although an acid, has never been tested for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones. Benzoic acid is an inexpensive, non-toxic molecule, it has been successfully tested here as a catalyst for the one-pot three component synthesis of 3,4-dihydropyrimidin-2-(1H)-one derivatives via Biginelli reaction between β-keto ester, a variety of aromatic aldehydes and urea or thiourea under thermal conditions using 20 mol% benzoic acid in acetonitrile solvent refluxed for 12 h to give good to high yields. This synthetic method includes inexpensive, non-toxic, easily available benzoic acid as a catalyst and is carried out in a simple operational procedure.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"206 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81581056","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":"Digital Water Marking and its Application in Various Media Types","authors":"K. Sivaraman, G. Kavitha","doi":"10.29333/EJAC/2018256","DOIUrl":"https://doi.org/10.29333/EJAC/2018256","url":null,"abstract":"","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"42 1","pages":"952-957"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75421311","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":"Remote Power Monitoring, Computing and Controlling through GSM Network","authors":"G. Michael, R. Kavitha","doi":"10.29333/EJAC/2018243","DOIUrl":"https://doi.org/10.29333/EJAC/2018243","url":null,"abstract":"","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"136 1","pages":"877-884"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76380941","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}
In communication systems corruption of data and hacking of data is unavoidable. These are the major problems we are facing in communication system. This project presents an enhanced multiple error detection and correction scheme based on the Redundant Residue Number System (RRNS). RRNS is often used in parallel processing environments because of its ability to increase the robustness of information passing between the processors. The proposed multiple error correction scheme utilizes the Chinese Remainder Theorem (CRT) together with a novel algorithm that significantly simplifies the error correcting process for integers. This enhanced scheme is compared with the existing method and this enhanced scheme is used in the CDMA application.
{"title":"Error Detection and Correction Using Chinese Remainder Theorem in CDMA","authors":"K. Subbulakshmi.","doi":"10.29333/EJAC/2018242","DOIUrl":"https://doi.org/10.29333/EJAC/2018242","url":null,"abstract":"In communication systems corruption of data and hacking of data is unavoidable. These are the major problems we are facing in communication system. This project presents an enhanced multiple error detection and correction scheme based on the Redundant Residue Number System (RRNS). RRNS is often used in parallel processing environments because of its ability to increase the robustness of information passing between the processors. The proposed multiple error correction scheme utilizes the Chinese Remainder Theorem (CRT) together with a novel algorithm that significantly simplifies the error correcting process for integers. This enhanced scheme is compared with the existing method and this enhanced scheme is used in the CDMA application.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"204 1","pages":"871-876"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77879169","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}
Event-driven information and A* search have garnered improbable interest from both steganographers and system administrators in the last several years. In fact, few futurists would disagree with the visualization of neural networks, which embodies the confirmed principles of theory. Jayet, our new heuristic for heterogeneous theory, is the solution to all of these problems.
{"title":"A Methodology for the Construction of Public-Private Key Pairs","authors":"Kaliyamurthie K.P, R. Udayakumar","doi":"10.29333/EJAC/2018262","DOIUrl":"https://doi.org/10.29333/EJAC/2018262","url":null,"abstract":"Event-driven information and A* search have garnered improbable interest from both steganographers and system administrators in the last several years. In fact, few futurists would disagree with the visualization of neural networks, which embodies the confirmed principles of theory. Jayet, our new heuristic for heterogeneous theory, is the solution to all of these problems.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"26 1","pages":"992-998"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84134179","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":"Security Using Big Data","authors":"D. Jeyapriya, S. Theivasigamani","doi":"10.29333/EJAC/2018248","DOIUrl":"https://doi.org/10.29333/EJAC/2018248","url":null,"abstract":"","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"10 1","pages":"913-917"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78598507","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}
Rasterization must work [9]. Given the current status of electronic modalities, electrical engineers particularly desire the simsulation of erasure coding, which embodies the essential principles of operating systems. Our focus in this paper is not on whether the well-known psychoacoustic algorithm for the understanding of IPv6 [7] is Turing complete, but rather on presenting an analysis of systems (OilyDab) [9].
{"title":"Architecting Thin Clients Using Scalable Archetypes","authors":"Kaliyamurthie K.P, R. Udayakumar","doi":"10.29333/EJAC/2018261","DOIUrl":"https://doi.org/10.29333/EJAC/2018261","url":null,"abstract":"Rasterization must work [9]. Given the current status of electronic modalities, electrical engineers particularly desire the simsulation of erasure coding, which embodies the essential principles of operating systems. Our focus in this paper is not on whether the well-known psychoacoustic algorithm for the understanding of IPv6 [7] is Turing complete, but rather on presenting an analysis of systems (OilyDab) [9].","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"44 1","pages":"985-991"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73843909","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}
The highest security issue that is faced in current scenario in MANET is infrastructure centralization. The task routing and forwarding is achieved to the max only when the there is excellent cooperation among the participating nodes. By selfish act of few nodes, the process of forwarding is interrupted for reasons like saving the battery power. Malicious activities like Denial of Service (DoS) raise a security threat to MANET. Research and analysis of various security attacks is the focal point of this project. In this system DSR Protocol is extended with a feature of “node friendship“, which creates smooth cooperation in an adhoc environment. Based on the above work the concept of grey hole attack can be detected and eliminated.
{"title":"Detection of Malicious Attacks in Mobile Ad Hoc Networks (MANET)","authors":"G. Michael, R. Kavitha","doi":"10.29333/EJAC/2018244","DOIUrl":"https://doi.org/10.29333/EJAC/2018244","url":null,"abstract":"The highest security issue that is faced in current scenario in MANET is infrastructure centralization. The task routing and forwarding is achieved to the max only when the there is excellent cooperation among the participating nodes. By selfish act of few nodes, the process of forwarding is interrupted for reasons like saving the battery power. Malicious activities like Denial of Service (DoS) raise a security threat to MANET. Research and analysis of various security attacks is the focal point of this project. In this system DSR Protocol is extended with a feature of “node friendship“, which creates smooth cooperation in an adhoc environment. Based on the above work the concept of grey hole attack can be detected and eliminated.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"6 1","pages":"885-894"},"PeriodicalIF":0.0,"publicationDate":"2019-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74955606","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}
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