Pub Date : 2024-01-13DOI: 10.53555/ejac.v19i1.1029
Vandana Gupta, Lokesh Verma
{"title":"\"The Role Of Neurotransmitters In Haloperidol-Induced Catalepsy: A Comprehensive Review Of The Current Understanding”","authors":"Vandana Gupta, Lokesh Verma","doi":"10.53555/ejac.v19i1.1029","DOIUrl":"https://doi.org/10.53555/ejac.v19i1.1029","url":null,"abstract":"","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"23 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140509215","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 : 2023-09-30DOI: 10.31489/2959-0663/3-23-15
Dinara A. Birimzhanova, Irina S. Irgibaeva, Nikolay N. Barashkov
Decreasing fluorescence efficiency in the solid-state is general and is mainly attributed to the intermolecular vibronic interactions, which induce the nonradiative deactivation process. Whereas the isolated dye molecules are virtually non-luminescent in dilute solutions, they become highly emissive upon solution thickening or aggregation in poor solvents or in the solid-state show an increase of luminescence intensity, the phenomenon of the aggregation-induced emission (AIE phenomenon). The development of efficient luminescent materials is a topic of great current interest. Theoretical calculation shows that the dye molecules' aggregation-induced emission characteristics result from intermolecular interactions. Utilizing such features, the molecules can be employed as fluorescent probes for the detection of the ethanol content in aqueous solutions. Quantum-chemical calculations using the method of density functional theory the computations of structure and electronic spectra of aggregated forms of 5-(4’-dimethylaminobenzylidene)barbituric acid and the Gaussian 98 program packages have been performed. The unusual spectral behavior of 5-(4’-dimethylamino-benzylidene)barbituric acid was investigated theoretically by the DFT method and its time-dependent variant TDDFT. Carried out calculations using Zindo, as well as ab initio calculations, confirm the appearance of a new band during aggregation and its shift to the red region when the number of molecules increases.
{"title":"Quantum-Chemical Study of Aggregation of 5-(4'-Dimethylaminobenzylidene)Barbituric Acid","authors":"Dinara A. Birimzhanova, Irina S. Irgibaeva, Nikolay N. Barashkov","doi":"10.31489/2959-0663/3-23-15","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-15","url":null,"abstract":"Decreasing fluorescence efficiency in the solid-state is general and is mainly attributed to the intermolecular vibronic interactions, which induce the nonradiative deactivation process. Whereas the isolated dye molecules are virtually non-luminescent in dilute solutions, they become highly emissive upon solution thickening or aggregation in poor solvents or in the solid-state show an increase of luminescence intensity, the phenomenon of the aggregation-induced emission (AIE phenomenon). The development of efficient luminescent materials is a topic of great current interest. Theoretical calculation shows that the dye molecules' aggregation-induced emission characteristics result from intermolecular interactions. Utilizing such features, the molecules can be employed as fluorescent probes for the detection of the ethanol content in aqueous solutions. Quantum-chemical calculations using the method of density functional theory the computations of structure and electronic spectra of aggregated forms of 5-(4’-dimethylaminobenzylidene)barbituric acid and the Gaussian 98 program packages have been performed. The unusual spectral behavior of 5-(4’-dimethylamino-benzylidene)barbituric acid was investigated theoretically by the DFT method and its time-dependent variant TDDFT. Carried out calculations using Zindo, as well as ab initio calculations, confirm the appearance of a new band during aggregation and its shift to the red region when the number of molecules increases.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"21 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":"136249292","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 : 2023-09-30DOI: 10.31489/2959-0663/3-23-0
Hans S. Ågren, Rashid R. Valiev, Irina S. Irgibaeva
{"title":"Special Issue Foreword from Guest Editors","authors":"Hans S. Ågren, Rashid R. Valiev, Irina S. Irgibaeva","doi":"10.31489/2959-0663/3-23-0","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-0","url":null,"abstract":"","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"21 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":"136341547","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 : 2023-08-02DOI: 10.31489/2959-0663/3-23-12
I. Uvarova, A. Aldongarov, Zhadyra Y. Baitassova
The direction of organic electronics research is attracting more and more interest from the scientific community. One of the indicators of such interest is the appearance of commercially available products with screens based on organic compounds. Therefore, conducting experimental and theoretical research in this area is an urgent task. Pentacoordination neutral complexes of silicon are poorly studied from the point of view of application in organic electronics, as well as six-coordination analogues. We present data on the calculation of reorganization energies, intermolecular transfer integrals, transfer rates and charge mobility for the optimized structures of pentacoordinated silicon complexes Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2. We have applied Marcus-Hush model for calculation of charge mobilities. The Si(DPP)(CH3)2 structure contains one diphenylpyridine (DPP = 2,6-diphenylperidine) ligand. The Si(bzimpy)(CH3)2 structure contains one benzimidazole (bzimpy = 2,6-bis(benzimidazole-2'-il)pyridine) ligand. Computational data were obtained using the B3LYP hybrid functional and the basis set 6-31G*. All calculations were performed using Gaussian09 program package. The charge mobility data obtained for Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2 pentacordinated silicon complexes were compared with their six-coordinate counterparts Si(DPP)2 and Si(bzimpy)2 for which experimental data on charge mobilities become available last years. Comparison with six-coordination analogues of complexes showed that penta-coordination complexes Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2 have much higher mobility of electrons, while Si(bzimpy)(CH3)2 also has higher hole mobility. We suppose this could be related to different symmetry of the pentacoordinated and hexacoordinted complexes. It is shown that the mobility of holes is much higher in the complex Si(bzimpy)(CH3)2 than in Si(DPP)(CH3)2.
{"title":"Theoretical Study of Charge Mobility Poperties of Complexes Si(DPP)(CH3)2 and Si(Bzimpy)(CH3)2","authors":"I. Uvarova, A. Aldongarov, Zhadyra Y. Baitassova","doi":"10.31489/2959-0663/3-23-12","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-12","url":null,"abstract":"The direction of organic electronics research is attracting more and more interest from the scientific community. One of the indicators of such interest is the appearance of commercially available products with screens based on organic compounds. Therefore, conducting experimental and theoretical research in this area is an urgent task. Pentacoordination neutral complexes of silicon are poorly studied from the point of view of application in organic electronics, as well as six-coordination analogues. We present data on the calculation of reorganization energies, intermolecular transfer integrals, transfer rates and charge mobility for the optimized structures of pentacoordinated silicon complexes Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2. We have applied Marcus-Hush model for calculation of charge mobilities. The Si(DPP)(CH3)2 structure contains one diphenylpyridine (DPP = 2,6-diphenylperidine) ligand. The Si(bzimpy)(CH3)2 structure contains one benzimidazole (bzimpy = 2,6-bis(benzimidazole-2'-il)pyridine) ligand. Computational data were obtained using the B3LYP hybrid functional and the basis set 6-31G*. All calculations were performed using Gaussian09 program package. The charge mobility data obtained for Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2 pentacordinated silicon complexes were compared with their six-coordinate counterparts Si(DPP)2 and Si(bzimpy)2 for which experimental data on charge mobilities become available last years. Comparison with six-coordination analogues of complexes showed that penta-coordination complexes Si(DPP)(CH3)2 and Si(bzimpy)(CH3)2 have much higher mobility of electrons, while Si(bzimpy)(CH3)2 also has higher hole mobility. We suppose this could be related to different symmetry of the pentacoordinated and hexacoordinted complexes. It is shown that the mobility of holes is much higher in the complex Si(bzimpy)(CH3)2 than in Si(DPP)(CH3)2.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84363177","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 : 2023-08-01DOI: 10.31489/2959-0663/3-23-9
G. K. Obiyenwa, Semire Banjo, A. Oyebamiji, Ibrahim A. Olasegun, D. F. Latona, M. D. Adeoye, O. A. Odunola
Great attention is being shifted to Dye-sensitized solar cells because of their structural and electronic tunability, high performance, and low cost compared to conservative photovoltaic devices. In this work, B3LYP/6-31G** level of theory was used to study the molecular architecture of the donor-π-acceptor (D-π-A) type. This architecture contains a series of dyes with the 2-cyano-2-pyran-4-ylidene-acetic acid (PLTP-dye) and 2-cyanoprop-2-enoic acid (CLTP-dye) units as acceptors; donor groups and thiophene-based π-linkers. The molecular and electronic properties, light harvesting efficiency, open circuit voltage (VOC), injection force (ΔGinject), regeneration force (ΔGregen) and excitation state lifetime ( ) were calculated. CLTP-dyes showed lower band gap, chemical hardness (η), chemical potential (μ), higher electrophilicity (ω) and electron denoting power (ω-) than the corresponding PLTP-dyes. The ω- demonstrated that PLTP-1, PLTP-2 and PLTP-3, CLTP-1, CLTP-2 and CLTP-3 should readily push electrons to the π-linker, which can lead to high intra-molecular charge transfer and photocurrent for the dyes. The Voc and ΔGinject parameters favoured the CLTP-dyes over corresponding PLTP-dyes, and also dyes with the N,N-diphenylaniline donor have higher Voc, ΔGinject values and longer wavelengths (λmax) than the dyes with carbazole unit (N,N-diphenylaniline dyes > Carbazole dyes) in accordance with the calculated ω-, although all the dyes have good regeneration and injection abilities.
{"title":"TD-DFT and DFT Investigation on Electrons Transporting Efficiency of 2-Cyano-2-Pyran-4-Ylidene-Acetic Acid and 2-Cyanoprop-2-Enoic Acid as Acceptors for Thiophene-Based π-Linkers Dye-Sensitized Solar Cells","authors":"G. K. Obiyenwa, Semire Banjo, A. Oyebamiji, Ibrahim A. Olasegun, D. F. Latona, M. D. Adeoye, O. A. Odunola","doi":"10.31489/2959-0663/3-23-9","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-9","url":null,"abstract":"Great attention is being shifted to Dye-sensitized solar cells because of their structural and electronic tunability, high performance, and low cost compared to conservative photovoltaic devices. In this work, B3LYP/6-31G** level of theory was used to study the molecular architecture of the donor-π-acceptor (D-π-A) type. This architecture contains a series of dyes with the 2-cyano-2-pyran-4-ylidene-acetic acid (PLTP-dye) and 2-cyanoprop-2-enoic acid (CLTP-dye) units as acceptors; donor groups and thiophene-based π-linkers. The molecular and electronic properties, light harvesting efficiency, open circuit voltage (VOC), injection force (ΔGinject), regeneration force (ΔGregen) and excitation state lifetime ( ) were calculated. CLTP-dyes showed lower band gap, chemical hardness (η), chemical potential (μ), higher electrophilicity (ω) and electron denoting power (ω-) than the corresponding PLTP-dyes. The ω- demonstrated that PLTP-1, PLTP-2 and PLTP-3, CLTP-1, CLTP-2 and CLTP-3 should readily push electrons to the π-linker, which can lead to high intra-molecular charge transfer and photocurrent for the dyes. The Voc and ΔGinject parameters favoured the CLTP-dyes over corresponding PLTP-dyes, and also dyes with the N,N-diphenylaniline donor have higher Voc, ΔGinject values and longer wavelengths (λmax) than the dyes with carbazole unit (N,N-diphenylaniline dyes > Carbazole dyes) in accordance with the calculated ω-, although all the dyes have good regeneration and injection abilities.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86137271","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 : 2023-08-01DOI: 10.31489/2959-0663/3-23-6
B. Minaev
Chemistry as a science about spin and electric charge of micro particles which provide driving forces of atomic interactions and molecular structure transformations fits pretty well to the modern Quantum Information Science (QIS) requirements. Today’s computers operate only electric current signals in the semiconductor networks but the electron-spin properties are not exploited in a large extend. Spintronics provides spin-polarized currents and manipulates magnetic spin interactions; it uses mostly solid state chemistry of heavy elements. But a rich organic chemistry of solvents and fin films offers a great potential for molecular electronics and quantum computing. Photo-excited organic complexes of the “chromophore–radical” type provide good promise for many technological applications in molecular spintronics and electronics, including QIS technology. The doublet state photo excitation of stable organic radical being delocalized onto the linked anthracene molecule within picoseconds and subsequently evolved into a quartet state for big radicals (a pure high spin state) of the mixed radical-triplet character presents a sensible spin-optical interface for qubit in quantum computing. This high-spin state is coherently addressable with EPR microwaves even at room temperature, with the optical read-out induced by intersystem crossing (ISC) to emissive triplet state. Such integration of radical luminescence and high-spin states EPR provides the organic materials involvement into emerging QIS technologies
{"title":"Spin Catalysis in Photochemical Reactions and Its Applications to Quantum Information Nanotechnology","authors":"B. Minaev","doi":"10.31489/2959-0663/3-23-6","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-6","url":null,"abstract":"Chemistry as a science about spin and electric charge of micro particles which provide driving forces of atomic interactions and molecular structure transformations fits pretty well to the modern Quantum Information Science (QIS) requirements. Today’s computers operate only electric current signals in the semiconductor networks but the electron-spin properties are not exploited in a large extend. Spintronics provides spin-polarized currents and manipulates magnetic spin interactions; it uses mostly solid state chemistry of heavy elements. But a rich organic chemistry of solvents and fin films offers a great potential for molecular electronics and quantum computing. Photo-excited organic complexes of the “chromophore–radical” type provide good promise for many technological applications in molecular spintronics and electronics, including QIS technology. The doublet state photo excitation of stable organic radical being delocalized onto the linked anthracene molecule within picoseconds and subsequently evolved into a quartet state for big radicals (a pure high spin state) of the mixed radical-triplet character presents a sensible spin-optical interface for qubit in quantum computing. This high-spin state is coherently addressable with EPR microwaves even at room temperature, with the optical read-out induced by intersystem crossing (ISC) to emissive triplet state. Such integration of radical luminescence and high-spin states EPR provides the organic materials involvement into emerging QIS technologies","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85655696","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 : 2023-08-01DOI: 10.31489/2959-0663/3-23-7
V. Minaeva, Nataliya N. Karaush-Karmazin, Olexandr O. Panchenko, Maryana V. Chernyk, J. Simokaitiene, D. Volyniuk, J. Gražulevičius, B. Minaev, O. Reshetnyak
The IR absorption spectra of the recently synthesized series of benzoyl-containing thianthrene derivatives were studied in the context of their structural identification. Geometry optimizitation of the ground singlet state by density functional theory (DFT) calculations with the gradient and Hessian search were performed for thianthrene molecule in the framework of the C2v symmetry restriction. The excited singlet and triplet states of thianthrene were found to be distorted along the b3u vibrational mode of the D2h point group, as well as the ground state, which leads to the non-planar batterfly-like structure (C2v). But the excited states require additional symmetry reduction; they are closer to planarity but have no symmetry elements. Optimized ground states structure for the thianthrene-benzoyle molecule and its four derivatives with fluoro-substituents and different substitution positions were analysed through complete assignment of all their vibrational modes and comparison with experimental infrared absorption spectra. A good agreement between experimental data and DFT calculated IR spectra provides additional structural support to results of the X-ray diffraction analysis of all synthesized compounds. The Hirshfeld surfaces analysis of the crystalline 3-fluorobenzoyl-thianthrene (T3F) was performed in order to analyze intermolecular interactions in T3F crystal. It indicates the presence of weak CH…F, CH…S and CH…O intermolecular contacts, stabilizing the crystal structure of T3F. The CH…O interactions appear in the IR spectrum of T3F crystal as two vibrational modes with frequencies 3084 and 3078 cm–1. The intermolecular interactions CH…F and CH…S do not affect the IR spectrum of T3F.
{"title":"Structure and Spectral Properties of Thianthrene and Its Benzoyl-Containing Derivatives","authors":"V. Minaeva, Nataliya N. Karaush-Karmazin, Olexandr O. Panchenko, Maryana V. Chernyk, J. Simokaitiene, D. Volyniuk, J. Gražulevičius, B. Minaev, O. Reshetnyak","doi":"10.31489/2959-0663/3-23-7","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-7","url":null,"abstract":"The IR absorption spectra of the recently synthesized series of benzoyl-containing thianthrene derivatives were studied in the context of their structural identification. Geometry optimizitation of the ground singlet state by density functional theory (DFT) calculations with the gradient and Hessian search were performed for thianthrene molecule in the framework of the C2v symmetry restriction. The excited singlet and triplet states of thianthrene were found to be distorted along the b3u vibrational mode of the D2h point group, as well as the ground state, which leads to the non-planar batterfly-like structure (C2v). But the excited states require additional symmetry reduction; they are closer to planarity but have no symmetry elements. Optimized ground states structure for the thianthrene-benzoyle molecule and its four derivatives with fluoro-substituents and different substitution positions were analysed through complete assignment of all their vibrational modes and comparison with experimental infrared absorption spectra. A good agreement between experimental data and DFT calculated IR spectra provides additional structural support to results of the X-ray diffraction analysis of all synthesized compounds. The Hirshfeld surfaces analysis of the crystalline 3-fluorobenzoyl-thianthrene (T3F) was performed in order to analyze intermolecular interactions in T3F crystal. It indicates the presence of weak CH…F, CH…S and CH…O intermolecular contacts, stabilizing the crystal structure of T3F. The CH…O interactions appear in the IR spectrum of T3F crystal as two vibrational modes with frequencies 3084 and 3078 cm–1. The intermolecular interactions CH…F and CH…S do not affect the IR spectrum of T3F.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87834615","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 : 2023-07-31DOI: 10.31489/2959-0663/3-23-17
N. K. Ibrayev, E. Seliverstova
The S,N-doped carbon quantum dots based on citric acid and L-cysteine were synthesized. The sizes of the synthesized carbon dots vary from 4 to 10 nm. The absorption spectrum exhibits a band with a maximum at 360 nm, as well as a shoulder at about 240–250 nm. The fluorescence band of the studied carbon dots is located in the region of 370–600 nm with a maximum at ~430 nm. The properties of the long-lived luminescence of carbon quantum dots solutions were studied. It was established that the decay of triplet states occurs as a result of a radiative phosphorescent transition and triplet–triplet annihilation. The synthesized carbon quantum dots are reviled to be the singlet oxygen sensitizers, as evidenced by the observed luminescence of molecular oxygen upon excitation of solutions in the absorption band of the carbon quantum dots. It was shown that when O23 ( )g was added to the solution, the process of singlet–triplet annihilation develops, the efficiency of which depends on the concentrations ratio of triplet carbon quantum dots and singlet O2(1∆g) molecules. In the presence of plasmonic Ag nanoparticles, the phosphorescence of singlet oxygen is enhanced
{"title":"Interaction of the Excited Electronic States of Carbon Quantum Dots and Molecular Oxygen","authors":"N. K. Ibrayev, E. Seliverstova","doi":"10.31489/2959-0663/3-23-17","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-17","url":null,"abstract":"The S,N-doped carbon quantum dots based on citric acid and L-cysteine were synthesized. The sizes of the synthesized carbon dots vary from 4 to 10 nm. The absorption spectrum exhibits a band with a maximum at 360 nm, as well as a shoulder at about 240–250 nm. The fluorescence band of the studied carbon dots is located in the region of 370–600 nm with a maximum at ~430 nm. The properties of the long-lived luminescence of carbon quantum dots solutions were studied. It was established that the decay of triplet states occurs as a result of a radiative phosphorescent transition and triplet–triplet annihilation. The synthesized carbon quantum dots are reviled to be the singlet oxygen sensitizers, as evidenced by the observed luminescence of molecular oxygen upon excitation of solutions in the absorption band of the carbon quantum dots. It was shown that when O23 ( )g was added to the solution, the process of singlet–triplet annihilation develops, the efficiency of which depends on the concentrations ratio of triplet carbon quantum dots and singlet O2(1∆g) molecules. In the presence of plasmonic Ag nanoparticles, the phosphorescence of singlet oxygen is enhanced","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73256441","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 : 2023-07-31DOI: 10.31489/2959-0663/3-23-16
M. Kucherenko, T. M. Chmereva
A quantum theory of electronic energy transfer in a layered nanostructure with molecular J-aggregates of polymethine dyes was proposed. An expression for the exciton-plasmon bond energy depending on various parameters of the system was given. The rate of non-radiative Fὄrster resonance energy transfer (FRET) from surface plasmon polaritons (SPPs) of a metal substrate to Frenkel excitons of J-aggregates was determined and dispersion dependences for hybrid states were obtained. It was established that the energy transfer rate can reach values of 1012–1013 s–1, and the value of the Rabi splitting is up to 100 MeV. The kinetics of the process under strong exciton-plasmon interaction was investigated. The time dependence of the energy exchange between the system components had the form of damped oscillations depending on the relaxation parameters, the Rabi frequency, and the response to resonance. In addition, the exciton FRET between two parallel monolayers of J-aggregates of polymethine dyes separated by a nanometer-thick metal film was investigated. It was found that the presence of the metal layer increases the FRET rate. The spin evolution of a pair of two triplet (T) molecules localized in the nano-cell region under the over-barrier jumps regime in a magnetic field was studied. The influence of the parameters of the two-dimensional potential on the frequency of inter-dimensional motions and the population of triplets was considered. The spin dynamics of molecular T-T pairs in the magnetic field of a ferromagnetic globular nanoparticle under free surface diffusion of a spin-carrying molecule was investigated.
{"title":"Quantum Kinetics of the Electronic Energy Transformation in Molecular Nanostructures","authors":"M. Kucherenko, T. M. Chmereva","doi":"10.31489/2959-0663/3-23-16","DOIUrl":"https://doi.org/10.31489/2959-0663/3-23-16","url":null,"abstract":"A quantum theory of electronic energy transfer in a layered nanostructure with molecular J-aggregates of polymethine dyes was proposed. An expression for the exciton-plasmon bond energy depending on various parameters of the system was given. The rate of non-radiative Fὄrster resonance energy transfer (FRET) from surface plasmon polaritons (SPPs) of a metal substrate to Frenkel excitons of J-aggregates was determined and dispersion dependences for hybrid states were obtained. It was established that the energy transfer rate can reach values of 1012–1013 s–1, and the value of the Rabi splitting is up to 100 MeV. The kinetics of the process under strong exciton-plasmon interaction was investigated. The time dependence of the energy exchange between the system components had the form of damped oscillations depending on the relaxation parameters, the Rabi frequency, and the response to resonance. In addition, the exciton FRET between two parallel monolayers of J-aggregates of polymethine dyes separated by a nanometer-thick metal film was investigated. It was found that the presence of the metal layer increases the FRET rate. The spin evolution of a pair of two triplet (T) molecules localized in the nano-cell region under the over-barrier jumps regime in a magnetic field was studied. The influence of the parameters of the two-dimensional potential on the frequency of inter-dimensional motions and the population of triplets was considered. The spin dynamics of molecular T-T pairs in the magnetic field of a ferromagnetic globular nanoparticle under free surface diffusion of a spin-carrying molecule was investigated.","PeriodicalId":11690,"journal":{"name":"Eurasian Journal of Analytical Chemistry","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91281458","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 : 2023-06-30DOI: 10.31489/2959-0663/2-23-15
S. Tyanakh, M. Baikenov, Fengyun Ma, V. Fomin, G. Baikenova, Anuar S. Ashimhanov, Raikhan S. Seitzhan
The optimal conditions of catalytic hydrogenation of oil sludge (Atasu-Alashankou) and the change in the kinematic viscosity of the fraction to 350℃ from the studied factors using the method of probabilisticdeterministic planning were experimentally determined. During the hydrogenation process of oil sludge, the maximum total yield of light fractions reached 62.1 %, and the kinematic viscosity decreased from 2.2 to 1.2 mm2/s. It was established the initial hydrogen pressure and the amount of added nanocatalyst microsilicate with cobalt (catalyst 1) have the greatest influence on the yield of the middle fraction from oil sludge under experimental conditions. It was shown that catalyst 1 increases the yield of diesel fraction components during the hydrogenation process of oil sludge. For the first time, we established the individual and group chemical composition of the fraction up to 350℃ before and after processing. The use of nanocatalyst 1 in amounts of 1.2–1.5 % led to an increase in the yield of the fraction up to 350℃ and diesel fraction components. This is due to the yield of paraffinic hydrocarbons increasing from 57.6 (initial fraction) to 80.7 %, as well as a decrease in aromatic hydrocarbons from 14.1 to 12.9 % and polycyclic aromatic hydrocarbons from 9.56 to 4.3 %.
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