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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

SARs Investigation of α-, β-, γ-, δ-, ε-RuCl₂(Azpy)₂ Complexes as Antitumor Drugs

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Computational Chemistry 2016年第1期4卷 1-10页

作者： kafoumba bamba Ouattara Wawohinlin Patrice N’Guessan Kouakou Nobel Nahossé Ziao Laboratoire de Thermodynamique et de Pysico-Chimie du Milieu UFR-SFA Université Nangui Abrogoua Abidjan C&ocirc te d’Ivoire

Structure Activity-Relationships (SARs) of the five possible isomers of RuCl2(Azpy)2 were predicted thanks to DFT method. Azpy stands for 2-phenylazopyridine and the structure of the isomers α-RuCl2(Azpy)2, β-RuCl2(Azpy)2, γ-RuCl2(Azpy)2, δ-RuCl2(Azpy)2 and ε-RuCl2(Azpy)2 call respectively α-Cl, β-Cl, γ-Cl, δ-Cl and ε-Cl are defined according to chlorine atoms orientations. Hence, they are divided into two groups. In the first group comprising α-Cl, β-Cl and ε-Cl, both chlorine atoms are in cis position and Azpy ligands are intervertical. Whereas the two others isomers (γ-Cl and δ-Cl), they form the second group. Here, both chlorine are in trans position and Azpy are planar. The five synthesized isomers were investigated as potential antitumor agents. Then, regarding the DNA, its bases are stacked by pair. Therefore, complexes are assumed to insert and to stack on them through intercalative mode. So the electronic and geometric structures become more important to describe their SARs. Consequently, group 2 regarding γ-Cl and δ-Cl presents the best structure to allow intercalation between DNA base-pairs. Besides, the energy order of the lower unoccupied molecular orbital (LUMO) of the isomers is ELUMO(β-Cl) > ELUMO(α-Cl) > ELUMO(ε-Cl) > ELUMO(γ-Cl) > ELUMO(δ-Cl). The energy gap between LUMO and HOMO was also sorted as Δ(L-H)(β-Cl) > Δ(L-H)(α-Cl) > Δ(L-H)(ε-Cl) > Δ(L-H)(γ-Cl) > Δ(L-H)(δ-Cl). In addition, the total dipole moment was classified as μ(ε-Cl) > μ(β-Cl) > μ(α-Cl) > μ(γ-Cl) > μ(δ-Cl). Finally, net charge of the ligand Azpy was also classified as QL(δ-Cl) > QL(γ-Cl) > QL(ε-Cl) > QL(α-Cl) > QL(β-Cl). All those parameters show that δ-Cl isomer displays the highest activity as antitumor drug when intercalating between the DNA basepairs Cytosine-Guanine/Cytosine-Guanine (CG/CG).

关键词： Structure Activity-Relationship (SARs) Ru (II) Complexes Azpy DFT Lanl2dz DNA-Binding

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

Molecular Structure, Electronic Structure, Properties and Analyses of Five Azopyridine Ruthenium Complexes α-Cl, β-Cl, γ-Cl, δ-Cl and ε-Cl of RuCl<sub>2</sub>(4,6-Dimethyl-Phenylazopyridine)<sub>2</sub>as 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

Theoretical Study of Benzothiazole and Its Derivatives: Molecular Structure, Spectroscopic Properties, NBO, MEP and TD-DFT Analyses

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Journal of Materials Science and Chemical Engineering 2024年第3期12卷 31-50页

作者： Konaté Abdoulaye Bédé Affoué Lucie Ouattara Lamoussa Koné Soleymane bamba kafoumba Laboratory of Constitution and Reaction of Matter University Félix Houphou&#235t-Boigny Abidjan Ivory Coast Department of Marine Sciences University of San-Pedro San-Pedro Ivory Coast Laboratory of Thermodynamics and Physico-Chemistry of Environment University Nangui Abrogoua Abidjan Ivory Coast

Benzothiazole (BTH) and its derivatives are organic molecules with biologic actions. Because of their many applications, they are produced on a massive scale and used in a number of environmental compartments. Their discharge into water produces environmental problems, exposing our environment to public health problems. A solution that can contribute to their deterioration is becoming a necessity. For this reason, a conceptual analysis of the reactivity of benzothiazole and four of its compounds was undertaken in order to investigate certain aspects of their biodegradability. A theoretical investigations of the compounds studied were conducted in the gas and water phases with the most widely used density functional theory method, Becke-3-Parameter-Lee-Yang-Parr (B3LYP) with 6-31G+ (d, p) basis. Reactivity study calculated global indices of reactivity revealed that 2-SCH3_BTH is the most reactive. Dipole moment values analysis reveals that 2-NH2_BTH is the most soluble in water, while the lipophilicity shows that 2-NH2_BTH is the most hydrophilic compound. Thermodynamic parameters values reflect that reactions are respectively exothermic and spontaneous. By analyzing an Electrostatic Molecular Potential (EMP) map, researchers can pinpoint reactive sites on a molecule and anticipate its reactivity. This assessment is further enhanced by incorporating global and local reactivity descriptors. Additionally, an exploration of frontier molecular orbitals offers valuable insights into the molecule’s charge transfer characteristics. Moreover, a combined examination of internal and external molecular interactions unveils hyperconjugative interactions arising from charge delocalization, as elucidated through natural bond orbital (NBO) analysis.

关键词： Benzothiazole Reactivity DFT/B3LYP Stability TD-DFT

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

Protonation Sites in Benzimidazolyl-Chalcones Molecules: An ab Initio and DFT Investigation

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Computational Chemistry 2016年第3期4卷 65-72页

作者： Mamadou Guy-Richard Kone Sopi Thomas Affi Nahossé Ziao kafoumba bamba Edja Florentin Assanvo Laboratoire de Thermodynamique et de Physico-Chimie du Milieu UFR SFA Université Nangui Abrogoua Abidjan République de C&Ocirc te-d’Ivoire

In this work, we have focused our investigations on the protonation sites predilection in the benzimidazolyl- chalcones (BZC) derivatives. Particularly, we are interested in the study of geometrical and energetical parameters. BZC are well known for their particularly nematicidal activity. Ten (10) BZC derivatives coded BZC-1 to BZC-10, with various larvicidal concentrations, have been selected for this work. They all are different one from another by the phenyl ring which is substituted by electron modulators such as alkyl, hydroxyl, alkoxy, aminoalkyl, halogen and nitro or replaced by the furan. Quantum chemical methods, namely HF/6-311 + G(d,p) and MPW1PW91/6- 311 + G(d,p) theory levels have been used to determine the geometrical and energetical parameters by the protonation on each heteroatom of the BZC derivative. An accuracy results with relatively less time consuming has been obtained using Hartree-Fock (HF) and Density Functional Theory methods (DFT/MPW1PW91). The calculations results allow identifying the sp2 nitrogen as the preferential site of protonation in BZC derivative compounds.

关键词： Benzimidazolyl-Chalcone Quantum Chemistry Protonation Proton Affinity Gas Phase Basicity

Development of Predictive QSPR Model of the First Reduction Potential from a Series of Tetracyanoquinodimethane (TCNQ) Molecules by the DFT (Density Functional Theory) Method

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Computational Chemistry 2019年第4期7卷 121-142页

作者： Fatogoma Diarrassouba Mawa Koné kafoumba bamba Yafigui Traoré Mamadou Guy-Richard Koné Edja Florentin Assanvo Laboratoire de Thermodynamique et de Physico-chimie du Milieu UFR-SFA Université Nangui Abrogoua Abidjan Côte d’Ivoire Laboratoire de Chimie Organique et des Substances Naturelles UFR-SSMT Université Félix Houphouët Boigny Abidjan Côte d’Ivoire

In this work, which consisted to develop a predictive QSPR (Quantitative Structure-Property Relationship) model of the first reduction potential, we were particularly interested in a series of forty molecules. These molecules have constituted our database. Here, thirty molecules were used for the training set and ten molecules were used for the test set. For the calculation of the descriptors, all molecules have been firstly optimized with a frequency calculation at B3LYP/6-31G(d,p) theory level. Using statistical analysis methods, a predictive QSPR (Quantitative Structure-Property Relationship) model of the first reduction potential dependent on electronic affinity (EA) only have been developed. The statistical and validation parameters derived from this model have been determined and found interesting. These different parameters and the realized statistical tests have revealed that this model is suitable for predicting the first reduction potential of future TCNQ (tetracyanoquinodimethane) of this same family belonging to its applicability domain with a 95% confidence level.

关键词： Tetracyanoquinodimethane First Reduction Potential QSPR Statistical Analysis

Quantitative Structure Anti-Cancer Activity Relationship (QSAR) of a Series of Ruthenium Complex Azopyridine by the Density Functional Theory (DFT) Method

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Computational Molecular Bioscience 2017年第2期7卷 19-31页

作者： Kouakou Nobel N’guessan Mamadou Guy-Richard Koné kafoumba bamba Ouattara Wawohinlin Patrice Nahossé Ziao Laboratoire de Thermodynamique et de Physico-Chimie du Milieu UFR SFA Université Nangui Abrogoua Abidjan C&ocircte-d’Ivoire

A series of ruthenium azopyridine complexes have recently been investigated due to their potential cytotoxic activities against renal cancer (A498), lung cancer (H226), ovarian cancer (IGROV), breast cancer (MCF-7) and colon cancer (WIDR). Thus, in order to predict the cytotoxic potentials of these compounds, quantitative structure-activity relationship studies were carried out using the methods of quantum chemistry. Five Quantitative Structure Activity Relationship (QSAR) models were obtained from the determined quantum descriptors and the different activities. The models present the following statistical indicators: regression correlation coefficient R2 = 0.986 - 0.905, standard deviation S = 0.516 - 0.153, Fischer test F = 106.718 - 14.220, correlation coefficient of cross-validation = 0.985- 0.895 and = 0.010 - 0.001. The statistical characteristics of the established QSAR models satisfy the acceptance and external validation criteria, thereby accrediting their good performance. The models developed show that the variation of the free enthalpy of reaction , the dipole moment μ and the charge of the ligand in the complex Ql, are the explanatory and predictive quantum descriptors correlated with the values of the anti-cancer activity of the studied complexes. Moreover, the charge of the ligand is the priority descriptor for the prediction of the cytotoxicity of the compounds studied. Furthermore, QSAR models developed are statistically significant and predictive, and could be used for the design and synthesis of new anti-cancer molecules.

关键词： Ruthenium Azopyridine Complex Anti-Cancer QSAR DFT Method