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Theoretical Investigation of Ru(II) Complexes as Photosensitizer for Photodynamic Therapy

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Computational Molecular Bioscience 2022年第2期12卷 109-121页

作者： Bamba Kafoumba Ouattara Lamoussa Massapihanhoro Pierre Ouattara Ouattara Wawohinlin Patrice Diarrassouba Fatogoma N’guessan Kouakou Nobel Ehouman Ahissan Donatien Ziao Nahossé laboratoire de thermodynamique et physico-chimie du milieu Université Nangui Abrogoua Abidjan Cote d’Ivoire

This work was undertaken to see how Ru II complexes can be suitable for photodynamic therapy through theoretical prediction. For that, four Ru II complexes, α-RuCl2(Azpy)2, , and were used in unrestricted state by providing with no more energy than 2.68 eV. The unrestricted state allows the complex molecule to display each of its electrons in one orbital. All the calculations such as optimization, frequency and TD-DFT calculations were performed at WB97XD/Lanl2dz level. It resulted from this investigation that Ru II complexes are active for both mechanisms suitable for photodynamic therapy in presence or absence of 3O2. Moreover, this reaction was assumed to take place only with Guanine DNA base as demonstrated in literature. Therefore, Guanine is admitted as the base most reacting with ruthenium complexes for photodynamic therapy. This work confirms our prediction regarding metallic complexes that are assumed to be photosensitized in condition that an electron must be isolated to favor the excitation. Nevertheless, Ru II complexes are found suitable for superficial therapy while Ru III must be active for deep therapy.

关键词： TD-DFT Ru(II) Photo-Dynamic Therapy (PDT) (Un)restricted Model

Molecular Structure, Electronic Structure, Properties and Analyses of Five Azopyridine Ruthenium Complexes α-Cl, β-Cl, γ-Cl, δ-Cl and ε-Cl of RuCl2(4,6-Dimethyl-Phenylazopyridine)2as Potential Cancer Drugs: DFT and TD-DFT Investigations

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Computational Chemistry 2018年第3期6卷 27-46页

作者： Nobel Kouakou N’Guessan Kafoumba Bamba Ouattara Wawohinlin Patrice NahosséZiao laboratoire de thermodynamique et physico-chimie du milieu UniversitéNangui AbrogouaAbidjanC&ocirc te d’Ivoire

Ground state geometries, natural bond orbital (NBO), analysis of frontier molecular orbitals (FMOs), analysis and spectral (RMN and UV-Visible) properties of five azopyridine ruthenium (II) complexes α-Cl, β-Cl, γ-Cl, δ-Cl and ε-Cl of RuCl2(Dazpy)2 have been theoretically studied by the density Functional Theory (DFT) and Time-dependent density Functional Theory (TD-DFT) methods using two basis sets: Lanl2DZ and a generic basis set in gas or in chloroform solvent. Dazpy stands for 4,6-dimethyl-phenylazopyridine. Optimized geometry shows that, except β-Cl, all the other four isomers α-Cl, γ-Cl, δ-Cl and ε-Cl are C2 symmetrical. Otherwise, a good agreement was found between experimental and the calculated geometry and NMR data. Moreover, Lanl2DZ effective core potential basis set provides good chemical shifts and geometric properties. Furthermore, the prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoc-cupied Molecular Orbital or LUMO) shows that the most active isomer suita-ble for electronic reactions is admitted to be δ-Cl. Besides, the NBO analysis indicates that the Ru-N is formed by the electron delocalization of lone pair atomic orbital of N2 and Npy to Ru. Also, the strongest interactions between LP(N) with LP*(Ru) and LP(Cl) with LP*(Ru) stabilize the molecular struc-ture. In addition, NBO shows that the five d orbitals of Ru in the complex are organized so that there is no order of priority from one complex to another. Therefore, the transition LP(Ru) → π*(N1 = N2) corresponding to Metal to Li-gand Charge Transfer (MLCT) is in reality no more than d → π*. Besides, TDDFT prediction in chloroform solvent reveals that all the five isomerics complexes absorb in the visible region as well as efficient photosensitizers. What’s more, δ-RuCl2(dazpy)2 can potentially act as the excellent sensitizer with a large band of absorption in visible region and a small excited energy. This study can help design and find out the abili

关键词： Azopyridine DFT NBO Pseudo-Potential Ru(II) Complexes

Cathodic Using of ZrB₂-αSiC and TiB₂-αSiC for PEM Electrolysis and Water Electrolysis at Low Temperature

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American Journal of Analytical Chemistry 2016年第1期7卷 1-11页

作者： Kafoumba Bamba Nahossé Ziao laboratoire de thermodynamique et de physico-chimie du milieu UFR-SFA Université Nangui Abrogoua Abidjan Cote d’Ivoire

39 mol% SiC of ceramic pellets ZrB2-αSiC and TiB2-αSiC were synthesized by the reactive hot pressure RHP process at 1850°C under 40 Mpa in vacuum. The XR diffraction displays the absence of other reagents apart from ZrB2, SiC and TiB2 confirming the purity of the pellets. The cathodic exploitation of both of them through electrochemical study shows that TiB2-αSiC is the most active for Hydrogen Evolution Reaction (HER) and Hydrogen Oxidation Reaction (HOR) in 0.5 M of H2SO4 solution at room temperature. Moreover, the kinetic exploitation shows that for both pellets the system is controlled by mass transport when they are used as HER. However, in the case of HOR, the system is controlled by the electron transfer.

关键词： Ceramic Pellets HER HOR Polarization Koutecky-Levich Plots

Quantum Chemical Characterization of Hydrogen Bonding Sites in Three 4-(4-Halo-Phenyl)-6-(Furan-2-yl) Pyrimidin-2-Amine derivatives

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Computational Chemistry 2017年第3期5卷 91-102页

作者： Yafigui Traore Kafoumba Bamba Nahossé Ziao Sopi Thomas Affi Mamadou Guy-Richard Kone laboratoire de thermodynamique et de physico-chimie du milieu UFR SFA Université NanguiAbrogoua Abidjan C&ocirc te-d’Ivoire

Hydrogen bonding (HB) sites in three pyrimidine compounds derivatives (DP), namely 4-(4-fluorophenyl)-6-(furan-2-yl) pyrimidin-2-amine (DP-1), 4-(4-chlorophenyl)-6-(furan-2-yl) pyrimidin-2-amine (DP-2) and 4-(4-bromophenyl)-6-(furan-2-yl) pyrimidin-2-amine (DP-3), have been investigated by quantum chemistry methods, especially at HF/6-311+G(d,p) and B3PW91/6-311+G(d,p) levels. Hydrogenfluori deserved as probe for hydrogen bonding complexes. Molecular electrostatic potential maps, geometricparameters of HB complexes, as well as energetic parameters of the complexation reactions have been computed. Finally, one out of two nitrogen atoms of pyrimidine nucleus has been identified as the major hydrogen bonding site in the three pyrimidine derivatives, with respective percentages of around 83.0% and 93.2% at HF/6-311+G(d,p) and B3PW91/6-311+G(d,p) levels.

关键词： Analgesic Hydrogen Bonding Pyrimidine derivatives Quantum Chemistry

Theoretical and Electrochemical Characterization of δ-RuCl₂(Nazpy)₂: Application to Oxidation of D-Glucose

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American Journal of Analytical Chemistry 2016年第1期7卷 57-66页

作者： Wawohinlin Patrice Ouattara Kafoumba Bamba Nahossé Ziao Kouakou Nobel N’guessan laboratoire de thermodynamique et de physico-chimie du milieu UFR-SFA Université Nangui-Abrogoua Abidjan Cote d’Ivoire

The heterogenized δ-RuCl2(Nazpy)2 deposited on carbon toray (CT) was studied for the first time as electrochemical catalyst. Before, it was characterized by visible-ultraviolet spectra and theoretically by TDDFT method at B3LYP/Lanl2DZ level. It displayed an MLCT t2geg → π* transition where t2geg due to the structure of Nazpy that considerably reduces energy between d AOs of Ru represents the HOMO of the complex and π* is identified as the LUMO. Electrochemistry study shows two redox ranges in both negative and positive sides of the potential. The positive side that corresponds to the couple RuIV/RuIII of catalyst appears to be active for oxidation of D-glucose in carbonate buffer with a high turnover. Therefore, Keto-2-gluconic and gluconic acids were the two main products obtained with respectively 80% and 17.6% of selectivity. Moreover, a small amount of tartaric and glycol acids coming from the c-c bond cleavage due to non-protection of the anomeric carbon of D-glucose were also observed.

关键词： DFT Calculation HOMO-LUMO Analysis NBO Electrochemistry Ruthenium Complex D-Glucose

ONIOM Method Characterization of Hydrogen Bonding Sites of Mycolactone A/B, a Buruli Ulcer Toxin

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Computational Chemistry 2017年第3期5卷 103-112页

作者： Kadjo Franç ois Kassi Mamadou Guy-Richard Koné Sopi Thomas Affi Nahossé Ziao laboratoire de thermodynamique et de physico-chimie du milieu UFR SFA Université Nangui Abrogoua Abidjan C&ocirc te-d’Ivoire

Mycolactone molecules are responsible of Buruli ulcer disease. In this work, we are interested in the geometric, energetic and spectroscopic characterization of the hydrogen bonding interactions in mycolactone A/B, using quantum chemical method, especially ONIOM(HF/6-311+G(d,p):AM1) and ONIOM (B3LYP/6-311+G(d,p):AM1) levels. ONIOM two layers method has been used because mycolactones compounds are very large, taking into account diffuse and polarization functions are important whenever the matter is intermolecular interactions. Geometric, energetic and spectroscopic parameters of hydrogen bonding reaction on each of the nine oxygen heteroatoms of mycolactone A/B have revealed that the O5sp2 heteroatom is far away the hydrogen bonding site. The identification of such a site constitutes a tool for working out a methodology for the annihilation of the destruction effects of mycolactones.

关键词： Hydrogen Bonding Mycobacterium ulcerans Mycolactone ONIOM Quantum Chemistry

NBO Population Analysis and Electronic Calculation of Four Azopyridine Ruthenium Complexes by DFT Method

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Computational Chemistry 2017年第1期5卷 51-64页

作者： N’Guessan Kouakou Nobel Kafoumba Bamba Ouattara Wawohinlin Patrice Nahossé Ziao laboratoire de thermodynamique et de physico-chimie du milieu UFR-SFA Université Nangui Abrogoua Abidjan C&ocirc te d’Ivoire

The molecular structure, the Natural Bond orbital (NBO) and the Time dependent-DFT of both isomers cis or γ-Cl and trans or δ-Cl of RuCl2(L)2, where L stands respectively for 2-phenylazopyridine (Azpy), 2,4-dimethyl-6-[phenylazo]pyridine (Dazpy), 2-[(3,5-dimethylphenyl)azopyridine] (Mazpy) and 2-pyridylazonaphtol (Nazpy) were calculated with DFT method at B3LYP/LANL2DZ level. The prediction of the frontier orbitals (Highest Occupied Molecular Orbital or HOMO and Lowest Unoccupied Molecular Orbital or LUMO) shows that the most active complexes suitable for electronic reactions are admitted to be the trans isomers. Moreover, δ-RuCl2 (Azpy)2 is discovered to react more actively as photo-sensitizer since its energy gap is the minimum. Besides, electronic structures of all complexes through NBO calculation indicate that Ru-N bonds are made of delocalization of occupancies from lone pair orbital of N atoms to the ruthenium. Moreover, Ru was assumed to have almost the same charge regardless the structure of the azopyridine ligands in the complex indicating that the ligands provide only a steric effect that is responsible for the ruthenium’s selectivity. Concerning the transition state, NBO analysis also highlights that the transition LP(Ru) π*(N1-N2) does correspond to t2g?π*(L). This transition is assumed to correspond to Metal to Ligand Charge Transfer (MLCT) that is responsible for the photo-sensitiveness of the metallic complex. Besides, TDDFT calculation of complexes showed that δ-RuCl2(Nazpy)2 displays the largest band during the absorption. For that reason, it is admitted to be the best photosensitizer due to a large system of conjugation provided by Nazpy ligand.

关键词： Natural Bond Orbital (NBO) HOMO LUMO Azopyridine Ligand MLCT LLCT

DFT Study of Dimerization Sites in Imidazo[1,2-a]pyridinyl-chalcone Series

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Computational Chemistry 2021年第1期9卷 1-17页

作者： Bibata Konate Sopi Thomas Affi Nahossé Ziao laboratoire de thermodynamique et de physico-chimie du milieu Université Nangui Abrogoua Abidjan C&#244te d’Ivoire

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.

关键词： Chemical Reactivity Conceptual DFT Imidazopyridinyl-Chalcone Nematicidal Activity Quantum Chemistry

Quantum Chemistry Prediction of Molecular Lipophilicity Using Semi-Empirical AM1 and Ab InitioHF/6-311++G Levels

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Computational Chemistry 2017年第1期5卷 38-50页

作者： Ouanlo Ouattara Nahossé Ziao laboratoire de thermodynamique et de physico-chimie du milieu UFR-SFA Université Nangui Abrogoua Abidjan C&ocirc te d’Ivoire

Reliable prediction of lipophilicity in organic compounds involves molecular descriptors determination. In this work, the lipophilicity of a set of twenty-three molecules has been determined using up to eleven quantum various descriptors calculated by means of quantum chemistry methods. According to Quantitative Structure Property Relationship (QSPR) methods, a first set of fourteen molecules was used as training set whereas a second set of nine molecules was used as test set. Calculations made at AM1 and HF/6-311++G theories levels have led to establish a QSPR relation able to predict molecular lipophilicity with over 95% confidence.

关键词： Molecular Lipophilicity Molecular descriptors Quantum Chemistry Statistical Analysis