Pub Date : 2021-06-07DOI: 10.1515/9783110682045-009
O. Oloba-Whenu, Idris O. Junaid, C. Isanbor
{"title":"9 A computational study of the SNAr reaction of 2-ethoxy-3,5-dinitropyridine and 2-methoxy-3, 5-dinitropyridine with piperidine","authors":"O. Oloba-Whenu, Idris O. Junaid, C. Isanbor","doi":"10.1515/9783110682045-009","DOIUrl":"https://doi.org/10.1515/9783110682045-009","url":null,"abstract":"","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"97 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74888399","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 : 2021-06-07DOI: 10.1515/9783110682045-005
Ibrahim Olasegun Abdulsalami, B. Semire, I. Bello
{"title":"5 Theoretical examination of efficiency of anthocyanidins as sensitizers in dye-sensitized solar cells","authors":"Ibrahim Olasegun Abdulsalami, B. Semire, I. Bello","doi":"10.1515/9783110682045-005","DOIUrl":"https://doi.org/10.1515/9783110682045-005","url":null,"abstract":"","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"65 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83530729","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 fatty acid derivatives, prepared from renewable natural oils, can be used as highly promising and potential substitutes for petrochemicals. The study of process improvement and stereochemical mechanism for preparing these derivatives would be beneficial for their industrial production. Conjugated linoleic acid (CLA) containing 9cis-11trans (9c, 11t) and 10trans-12cis (10t, 12c) isomers was prepared from Salicornia herbacea seed oil. Maleic anhydride cycloadduct of CLA (MAC) was prepared by an improved process, and it was characterized by FTIR, 1H and 13C NMR, etc. A new method to calculate conformers-ratio of CLA or MAC was also developed. Furthermore, the stereochemical mechanism for the improved preparation of MAC was proposed primarily by the calculation method above. The following observations were made: 1) The yield of MAC could reach as high as 96.7% under mild reaction conditions and with an easy and efficient product separation; 2) The trans-trans CLA in the s-cis conformation acted as a predominant reactant to Diels-Alder [4 + 2] cycloaddition of maleic anhydride, which was the main reaction occurred simultaneously with catalytic configurational isomerizations of CLA in one step; 3) From all studied CLA conformers, the most stable conformation was the s-trans conformation of trans-trans CLA, while the s-cis conformation of trans-trans CLA had the most favorable structural parameters for cyclohexenyl ring formation; 4) Four MAC conformers derived from 9c, 11t- and 10t, 12c-CLA, were obtained as final main products that were determined to be cis-cycloadducts; 5) The endo/exo ratios of the cis- cycloadducts derived from 9c, 11t- and 10t, 12c-CLA, were 2.14:1 and 1.99:1, respectively; and 6) The results obtained from the calculation method above were in excellent accordance with those from our experiments.
{"title":"A Proposed Stereochemical Mechanism for the Improved Preparation of Maleic Anhydride Cycloadduct of CLA","authors":"Jieyu He, Jia‐Ling Liao, Junyan Qu","doi":"10.4236/cc.2021.93009","DOIUrl":"https://doi.org/10.4236/cc.2021.93009","url":null,"abstract":"The fatty acid derivatives, prepared from renewable natural oils, can be used as highly promising and potential substitutes for petrochemicals. The study of process improvement and stereochemical mechanism for preparing these derivatives would be beneficial for their industrial production. Conjugated linoleic acid (CLA) containing 9cis-11trans (9c, 11t) and 10trans-12cis (10t, 12c) isomers was prepared from Salicornia herbacea seed oil. Maleic anhydride cycloadduct of CLA (MAC) was prepared by an improved process, and it was characterized by FTIR, 1H and 13C NMR, etc. A new method to calculate conformers-ratio of CLA or MAC was also developed. Furthermore, the stereochemical mechanism for the improved preparation of MAC was proposed primarily by the calculation method above. The following observations were made: 1) The yield of MAC could reach as high as 96.7% under mild reaction conditions and with an easy and efficient product separation; 2) The trans-trans CLA in the s-cis conformation acted as a predominant reactant to Diels-Alder [4 + 2] cycloaddition of maleic anhydride, which was the main reaction occurred simultaneously with catalytic configurational isomerizations of CLA in one step; 3) From all studied CLA conformers, the most stable conformation was the s-trans conformation of trans-trans CLA, while the s-cis conformation of trans-trans CLA had the most favorable structural parameters for cyclohexenyl ring formation; 4) Four MAC conformers derived from 9c, 11t- and 10t, 12c-CLA, were obtained as final main products that were determined to be cis-cycloadducts; 5) The endo/exo ratios of the cis- cycloadducts derived from 9c, 11t- and 10t, 12c-CLA, were 2.14:1 and 1.99:1, respectively; and 6) The results obtained from the calculation method above were in excellent accordance with those from our experiments.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"65 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88564393","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 demand and pursuit of chemical entities with UV filtration and antioxidant properties for enhanced photoprotection have been driven in recent times by acute exposure of humans to solar ultraviolet radiations. The structural, electronic, antioxidant and UV absorption properties of drometrizole (PBT) and designed ortho-substituted derivatives are reported via DFT and TD-DFT in the gas and aqueous phases. DFT and TD-DFT computations were performed at the M062x-D3Zero/6-311++G(d,p)//B97-3c and PBE0-D3(BJ)/def2-TZVP levels of theory respectively. Reaction enthalpies related to hydrogen atom transfer (HAT), single-electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) mechanisms were computed and compared with those of phenol. Results show that the presence of -NH2 substituent reduces the O-H bond dissociation enthalpy and ionization potential, while that of -CN increases the proton affinity. The HAT and SPLET mechanisms are the most plausible in the gas and aqueous phases respectively. The molecule with the -NH2 substituent (PBT1) was identified to be the compound with the highest antioxidant activity. The UV spectra of the studied compounds are characterized by two bands in the 280 - 400 nm regions. Results from this study provide a better comprehension antioxidant mechanism of drometrizole and present a new perspective for the design of electron-donor antioxidant molecules with enhanced antioxidant-photoprotective efficiencies for applications in commercial sunscreens.
{"title":"Investigation of the Antioxidant and UV Absorption Properties of 2-(2’-hydroxy-5’-methylphenyl)-benzotriazole and Its Ortho-Substituted Derivatives via DFT/TD-DFT","authors":"Numbonui Stanley Tasheh, A. Fouegue, J. Ghogomu","doi":"10.4236/cc.2021.93010","DOIUrl":"https://doi.org/10.4236/cc.2021.93010","url":null,"abstract":"The demand and pursuit of chemical entities with UV filtration and antioxidant properties for enhanced photoprotection have been driven in recent times by acute exposure of humans to solar ultraviolet radiations. The structural, electronic, antioxidant and UV absorption properties of drometrizole (PBT) and designed ortho-substituted derivatives are reported via DFT and TD-DFT in the gas and aqueous phases. DFT and TD-DFT computations were performed at the M062x-D3Zero/6-311++G(d,p)//B97-3c and PBE0-D3(BJ)/def2-TZVP levels of theory respectively. Reaction enthalpies related to hydrogen atom transfer (HAT), single-electron transfer followed by proton transfer (SET-PT), and sequential proton loss electron transfer (SPLET) mechanisms were computed and compared with those of phenol. Results show that the presence of -NH2 substituent reduces the O-H bond dissociation enthalpy and ionization potential, while that of -CN increases the proton affinity. The HAT and SPLET mechanisms are the most plausible in the gas and aqueous phases respectively. The molecule with the -NH2 substituent (PBT1) was identified to be the compound with the highest antioxidant activity. The UV spectra of the studied compounds are characterized by two bands in the 280 - 400 nm regions. Results from this study provide a better comprehension antioxidant mechanism of drometrizole and present a new perspective for the design of electron-donor antioxidant molecules with enhanced antioxidant-photoprotective efficiencies for applications in commercial sunscreens.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"69 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83607778","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}
Malaria is a life-threatening disease responsible for half a million death annually, and with nearly half of the world’s population at risk. The rapid drop in observed cases of malaria in the last two decades has been due to a combination of preventive and therapeutic remedies. However, the absence of a vaccine, new antimalarial chemotherapies and increased parasitic resistance have led to a plateau of infections and renewed research interest in target human and Plasmodium (the malaria parasite) receptors and new drugs. In this study, the impact of mutation on the affinity on antimalarial drugs with the bifunctional enzyme complex, dihydrofolate reductase (DHFR) is explored. In addition, homology modeling is used to build the three-dimensional models of the enzymes Plasmodium telomerase reverse-transcriptase (pf-TERT) and Plasmodium dihydropteroate synthetase (pf-DHPS) to determine their affinity with antimalarial drugs. The interaction energies and stable complexes formed between these enzymes and antimalarial drugs (chloroquine, artemisinin, primaquine, pyrimethamine, sulfadoxine and pentamidine) were modelled using AutoDock vina. Our data indicate that pf-TERT and pf-DHPS form stable complexes with the antimalarial ligands with affinity ranging from .0 to .9 kcal/mol. The affinity with crystal structures of DHFR receptors was higher ranging from .0 to .0 kcal/mol. The affinity to DHFR also decreases with the mutation a confirmation of the source of resistance. The highest affinity interaction for all the receptors modeled is observed with Artemisinin a benchmark antimalarial drug. This can be attributed to the size, shape and dipolar surface of the ligand. The observed complexes are stabilized by strategic active site polar and non-polar contacts.
{"title":"Computational Study of the Interactions between Antimalarial Chemotherapies with Folate Pathway Receptors and Telomerase Reverse Transcriptase","authors":"Djogang Lucie Karelle, Forlemu Neville, Emadak Alphonse, Njabon Njankwa Eric, I. Patouossa, Nenwa Justin","doi":"10.4236/cc.2021.93011","DOIUrl":"https://doi.org/10.4236/cc.2021.93011","url":null,"abstract":"Malaria is a life-threatening disease responsible for half a million death annually, and with nearly half of the world’s population at risk. The rapid drop in observed cases of malaria in the last two decades has been due to a combination of preventive and therapeutic remedies. However, the absence of a vaccine, new antimalarial chemotherapies and increased parasitic resistance have led to a plateau of infections and renewed research interest in target human and Plasmodium (the malaria parasite) receptors and new drugs. In this study, the impact of mutation on the affinity on antimalarial drugs with the bifunctional enzyme complex, dihydrofolate reductase (DHFR) is explored. In addition, homology modeling is used to build the three-dimensional models of the enzymes Plasmodium telomerase reverse-transcriptase (pf-TERT) and Plasmodium dihydropteroate synthetase (pf-DHPS) to determine their affinity with antimalarial drugs. The interaction energies and stable complexes formed between these enzymes and antimalarial drugs (chloroquine, artemisinin, primaquine, pyrimethamine, sulfadoxine and pentamidine) were modelled using AutoDock vina. Our data indicate that pf-TERT and pf-DHPS form stable complexes with the antimalarial ligands with affinity ranging from .0 to .9 kcal/mol. The affinity with crystal structures of DHFR receptors was higher ranging from .0 to .0 kcal/mol. The affinity to DHFR also decreases with the mutation a confirmation of the source of resistance. The highest affinity interaction for all the receptors modeled is observed with Artemisinin a benchmark antimalarial drug. This can be attributed to the size, shape and dipolar surface of the ligand. The observed complexes are stabilized by strategic active site polar and non-polar contacts.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"319 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77133508","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}
Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.
{"title":"DFT Study of Dimerization Sites in Imidazo[1,2-a]pyridinyl-chalcone Series","authors":"B. Konaté, S. T. Affi, N. Ziao","doi":"10.4236/cc.2021.91001","DOIUrl":"https://doi.org/10.4236/cc.2021.91001","url":null,"abstract":"Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"114 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80758948","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}
A quantum chemical screening of two imidazole-based chalcone ligands: 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter referred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion-corrected density functional theory (DFT-D3) and time-dependent DFT (TD-DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorganization energies. The light extraction efficiency of the HL1-Pt complex was deduced to be particularly impressive, thus suitable for the manufacture of hole transport layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us to validate the greater stability in moisture (towards oxidation), of HL2 complexes compared to their HL1 counterparts. metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.
{"title":"A Quantum Chemical Screening of Two Imidazole-Chalcone Hybrid Ligands and Their Pd, Pt and Zn Complexes for Charge Transport and Nonlinear Optical (NLO) Properties: A DFT Study","authors":"F. Bine, Numbonui Stanley Tasheh, J. Ghogomu","doi":"10.4236/cc.2021.94012","DOIUrl":"https://doi.org/10.4236/cc.2021.94012","url":null,"abstract":"A quantum chemical screening of two imidazole-based chalcone ligands: 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-(phenylallyl)]phenol and 2-[1-(3-(1H-imidazol-1-yl)propylimino)-3-4-nitrophenylallyl]phenol (hereinafter referred to as HL1 and HL2 respectively) and their Pd, Pt and Zn chelates for charge transport and nonlinear optical (NLO) properties, is reported via dispersion-corrected density functional theory (DFT-D3) and time-dependent DFT (TD-DFT) methods. From our results, Pd and Pt complexes have been observed to show excellent hole-transport properties, owing to their very small reorganization energies. The light extraction efficiency of the HL1-Pt complex was deduced to be particularly impressive, thus suitable for the manufacture of hole transport layer in violet light emitting diodes (LEDs). Moreover, redox potentials and chemical stability studies have enabled us to validate the greater stability in moisture (towards oxidation), of HL2 complexes compared to their HL1 counterparts. metal charge transfer electronic transitions identified in the resulting complexes with the exception of the zinc complexes.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"6 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73293856","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 efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. Dispersion-corrected DFT (DFT-D3) and time-dependent DFT (TD-DFT) calculations were performed at PBE0/def2-TZVP//PBEh-3c and CAM-B3LYP/def2- TZVP levels of theory, respectively. Conceptual DFT, the quantum theory of atoms-in-molecules (QTAIM) and local energy decomposition (LED) analyses have been performed. The LED analysis was performed at the coupled-cluster singles and doubles with perturbative triples (CCSD(T))/def2-SVP level of theory. Frontier molecular orbital energy gaps calculated using the TD-DFT method are found to lie in the range 3.574 - 4.444 eV, indicative of good adsorption and corrosion inhibition efficacies of the investigated molecules. The interactions between aluminium and the inhibitor molecules studied are found to be energetically favorable, owing to negative computed interaction energy values. Furthermore, QTAIM analysis revealed metal-carbon, metal-oxygen and metal-nitrogen interactions in the inhibitor-aluminium complexes, which are predominantly electrostatic in character, according to LED analysis results. Calculated proton affinities (PAs) have revealed the anticorrosion potentials of the investigated inhibitors in acidic medium, with a noticeable dependency on temperature within the range 273.15 - 343.15 K.
{"title":"Corrosion Inhibition of Aluminium in Gas and Acid Media by Some Chalcone-Based N-(3-Aminopropyl)Imidazoles: TD-DFT-Based FMO, Conceptual DFT, QTAIM and EDA Studies","authors":"F. Bine, Stanley Numbonui Tasheh, N. K. Nkungli","doi":"10.4236/cc.2021.91003","DOIUrl":"https://doi.org/10.4236/cc.2021.91003","url":null,"abstract":"The efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. Dispersion-corrected DFT (DFT-D3) and time-dependent DFT (TD-DFT) calculations were performed at PBE0/def2-TZVP//PBEh-3c and CAM-B3LYP/def2- TZVP levels of theory, respectively. Conceptual DFT, the quantum theory of atoms-in-molecules (QTAIM) and local energy decomposition (LED) analyses have been performed. The LED analysis was performed at the coupled-cluster singles and doubles with perturbative triples (CCSD(T))/def2-SVP level of theory. Frontier molecular orbital energy gaps calculated using the TD-DFT method are found to lie in the range 3.574 - 4.444 eV, indicative of good adsorption and corrosion inhibition efficacies of the investigated molecules. The interactions between aluminium and the inhibitor molecules studied are found to be energetically favorable, owing to negative computed interaction energy values. Furthermore, QTAIM analysis revealed metal-carbon, metal-oxygen and metal-nitrogen interactions in the inhibitor-aluminium complexes, which are predominantly electrostatic in character, according to LED analysis results. Calculated proton affinities (PAs) have revealed the anticorrosion potentials of the investigated inhibitors in acidic medium, with a noticeable dependency on temperature within the range 273.15 - 343.15 K.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"93 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80454160","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 : 2020-12-01DOI: 10.1142/s0219633620500352
J. Tao, Xiaofeng Wang, K. Zhang
In order to compare the influence of binders on the oily exudation of cyclotrimethylenetrinitramine (RDX) based aluminized explosives, polyvinyl acetate (EVA) and copolymer of vinylidene fluoride and perfluoropropylene (F2603) were selected as binders, which are most commonly used in the press-packed explosives. Herein, the binding energies of wax with the components of RDX-based aluminized explosives containing EVA and F2603 were predicted. Then, the migration models of wax in EVA and F2603 were constructed respectively, and the migration rate of wax in two binders was also calculated. Finally, experimental verification was carried out for wax migration in the two aluminized explosives. The results show that the binding energies of wax with other components of RDX-based composite explosive are all positive, which indicates that the physical compatibility of RDX-based aluminized explosives containing EVA and F2603 is excellent. In addition, wax interacts with the other components of RDX-based explosives mainly via Van der Waals force. However, the binding strength of wax with RDX crystals and binders decreases with the increase of temperature. The type of binders has a great influence on the migration rate of wax, and the oily exudation rate of wax in F2603 is about 4 times than that in EVA both at 298 K and 344 K. Meanwhile, the polymer configuration greatly changes the migration rate of wax. The calculated results are in good agreement with the experimental results.
{"title":"Comparative study on the oily exudation of aluminized explosives containing EVA and F2603","authors":"J. Tao, Xiaofeng Wang, K. Zhang","doi":"10.1142/s0219633620500352","DOIUrl":"https://doi.org/10.1142/s0219633620500352","url":null,"abstract":"In order to compare the influence of binders on the oily exudation of cyclotrimethylenetrinitramine (RDX) based aluminized explosives, polyvinyl acetate (EVA) and copolymer of vinylidene fluoride and perfluoropropylene (F2603) were selected as binders, which are most commonly used in the press-packed explosives. Herein, the binding energies of wax with the components of RDX-based aluminized explosives containing EVA and F2603 were predicted. Then, the migration models of wax in EVA and F2603 were constructed respectively, and the migration rate of wax in two binders was also calculated. Finally, experimental verification was carried out for wax migration in the two aluminized explosives. The results show that the binding energies of wax with other components of RDX-based composite explosive are all positive, which indicates that the physical compatibility of RDX-based aluminized explosives containing EVA and F2603 is excellent. In addition, wax interacts with the other components of RDX-based explosives mainly via Van der Waals force. However, the binding strength of wax with RDX crystals and binders decreases with the increase of temperature. The type of binders has a great influence on the migration rate of wax, and the oily exudation rate of wax in F2603 is about 4 times than that in EVA both at 298 K and 344 K. Meanwhile, the polymer configuration greatly changes the migration rate of wax. The calculated results are in good agreement with the experimental results.","PeriodicalId":49976,"journal":{"name":"Journal of Theoretical & Computational Chemistry","volume":"19 1","pages":"2050035"},"PeriodicalIF":2.4,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46613155","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 : 2020-11-01DOI: 10.1142/s0219633620500285
Gururaj Somadi, S. Sivan
Humanity is facing a grieve danger of coronavirus disease-19 caused by severe acute respiratory syndrome novel coronavirus-2 (SARS nCov-2) There is an urgent need of therapeutics that can help in overcoming this global pandemic Identifying novel therapeutic target and screening already approved drug is a faster approach in this situation Spike glycoprotein (Sgp) of SARS nCoV-2 is potentials target where in researchers have targeted receptor binding domain (RBD) of S1 domain The S2 domain of Sgp also plays a pivotal role in viral entry, but the mechanism is less understood We analyzed the structure of Sgp S2 domain in pre-fusion state and Heptad repeat region in its post-fusion state available from protein data bank Sgp shows three major regions in S2 domain, the fusion peptide (FP), heptad repeat 1 (HR1) and central helical (CH) region The HR1 region undergoes structural changes by flipping approximately 180∘ and coil up to form a rod like structure during fusion process implying its role in viral entry into the host cell This structural change in S2 domain helices is crucial step, if this process is hindered by targeting the HR1 and CH region then the progression of virus can be stopped Possible binding cavity was identified near the HR1 and CH region in S2 domain and docking-based virtual screening of FDA approved drugs was performed Promising candidates like Troxerutin, Thymopentin and Daclatasvir can be used as therapeutics provided an immediate in-vitro and clinical studies are carried out by research groups Analysis of three-dimensional structure of SARS nCov-2 Spike glycoprotein (Sgp) S2 domain in pre-fusion and post-fusion sate indicate structural changes in S2 domain is vital for viral fusion and entry into host cell Most favorable drug binding site was identified in S2 domain and dock based virtual screening was carried out to obtain hit molecules from a database of already approved FDA drugs [ABSTRACT FROM AUTHOR] Copyright of Journal of Theoretical & Computational Chemistry is the property of World Scientific Publishing Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission However, users may print, download, or email articles for individual use This abstract may be abridged No warranty is given about the accuracy of the copy Users should refer to the original published version of the material for the full abstract (Copyright applies to all Abstracts )
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