Electrophilicity-based Charge Transfer Research Articles

Understanding the interactions between anticancer active molecules Cp2TiCl2 and Cp2VCl2 and E@Al12 (E = C, Si) clusters using density functional theory calculations

This work investigated the interaction between E@Al12 (E = C, Si) clusters and titanocene dichloride (TDC) and vanadocene dichloride (VDC) anticancer drugs using BP86. Corrected interaction energy values of the complexes were computed. Interaction effect on the frontier orbital energy values of the pure nano-cluster and drugs were illustrated. Also, electrophilicity-based charge transfer (ECT) was indicated charge flow from anticancer drug to nano-cluster. Cl⋅⋅⋅Al weak non-covalent interactions in the studied systems were explored with Independent gradient model analysis based on Hirshfeld partition of molecular density (IGMH) and Non-covalent interaction (NCI). QTAIM analysis was considered to exploring of bond critical point of Al…Cl.

Synthesis, spectroscopic, crystal structure and Hirshfeld surface analysis and DFT calculations of (E)-N-(2,6-dichlorophenyl)-1-(5-nitro-2-(piperidin-1-yl)phenyl) methanamine

In this study, experimental methods X-ray single crystal analysis, UV-vis spectroscopy and FT-IR spectroscopy, and theoretical methods Density Functional Theory (DFT) were used to study the structure of the new Schiff base (E)-N-(2,6-dichlorophenyl)-1-(5-nitro-2-(piperidin-1-yl)phenyl) methanamine. Theoretical calculations of the title compound and FT-IR harmonic vibration frequencies were carried out using B3LYP methods with the 6-31G(d,p) basis set. The optical properties have been studied by DFT calculation and the experimental UV-Vis spectrum presents its contribution to the HOMO-LUMO boundary. The molecular electrostatic potential map (MEP-ESP), analysis of frontier molecular orbitals (FMO), and determination of thermodynamic properties for the title compound were conducted using identical levels of theory. Besides, the structural state and crystal packing of the title compound were analyzed using molecular structure, Hirshfeld surfaces, interactions energies, energy frameworks and electrophilicity-based charge transfer (ECT) with DNA bases.

Effects of Au6 and Au20 Adsorption Sites of Cyromazine-Au Complexes by Raman Spectroscopy and Density Functional Theory.

Cyromazine, when used as an insect growth regulator and low-toxicity insecticide, may degrade into melamine and pose a potential threat to the environment and soil health, which has thus attracted extensive research on eliminating such a harmful effect. In this paper, density functional theory (DFT)/LC-BLYP/6-311G(d,p) is used to optimize the geometric structure and analyze the vibration of cyromazine. The DFT/LC-BLYP/def2-SVP is used for the cyromazine-Au complex optimization and vibration analysis. The molecular electrostatic potential (MEP), frontier molecular orbitals (FMOs), vibration frequency, electrophilicity-based charge transfer (ECT) descriptor, binding energy (BE), polarizability, normal Raman spectroscopy (NRS), and surface-enhanced Raman spectroscopy (SERS) of cyromazine adsorbing on Au6 and Au20 are calculated. The study of the chemical enhancement mechanism of SERS of cyromazine at different adsorption sites of Au6 or Au20 confirms the existence of a charge transfer between cyclopromazine and Au6 and Au20, which can adsorb and form stable cyromazine-Au complexes. The results show that N2, H13, and N4 are the adsorption sites of Au6 and Au20. The Raman spectra of the cyromazine-Au complex can be selectively enhanced with a factor up to 9.07. Compared with those of cyromazine-Au6, the Raman spectra of cyromazine-Au20 are enhanced more significantly.

Synthesis and characterization of tetradentate benzophenone derivative Schiff base and properties in different lyotropic media

A new Schiff base ligand of 6,6′-(1Z,1′Z)-(butane-1,4-diylbis(azanylyidene))bis (phenylmethanylylidene))bis(3-octyloxy) phenol) was synthesized and characterized using XRD and different spectroscopic analyses (FTIR, 1H NMR, 13C NMR, and UV–Vis.) DFT/B3LYP/6-31G(d,p) level of theory was applied successfully to the present compound. Theoretically calculated parameters of the synthesized compound were compared with the experimentally obtained results. The optimized structure has been investigated using the same level of theory for various studies, including frontier molecular orbital analysis, molecular electrostatic potential, chemical reactivity indexes, natural bond orbital analysis, electrostatic potential, and the electrophilicity-based charge transfer with DNA bases.

Electrophilicity-based charge transfer for developing aquatic-quantitative structure toxicity relationships (Aqua-QSTR)

Electrophilicity-based charge transfer for developing aquatic-quantitative structure toxicity relationships (Aqua-QSTR)

Investigating the New Schiff Base (E)-2-(((2-bromo-3-methylphenyl)imino)methyl)-4-methoxyphenol Using Synthesis, XRD, DFT, FTIR spectroscopy, Hirshfeld,

In this research, the title compound was synthesized and characterized using spectroscopic analyses like FTIR and XRD. The compoundand#39;s structure was optimized using Density Functional Theory (DFT) at B3LYP method with 6-311++G(d,p) basis set. The experimental parameters obtained by XRD were found to agree well with the theoretically calculated parameters. The title compound was studied using several methods, including FMOs, MEP, Hirshfeld surface analysis, 2D fingerprint plots, net charges, Electrophilicity-based Charge Transfer (ECT), Natural Bond Orbital analysis and global chemical reactivity descriptors.

Synthesis, crystal structure, theoretical chemical activitiy, electrophilicity-based charge transfer (ECT) with DNA bases and molecular docking studies of 2-amino-4-(2,4-dimethoxyphenyl)-5,6-dihydrobenzo[H]quinoline-3-carbonitrile

In this study, the title compound is synthesized and characterized by X-ray diffraction method, FT-IR, UV–Vis, TGA and NMR spectroscopy. The crystal packing is mainly controlled by N–H…N, C–H…N hydrogen bonds and C–H…π interactions. Hirshfeld surface analysis reveals the presence of intermolecular interactions in the crystal. All theoretical computations (NBO, FMOs, MEP, FF, ECT) are calculated by Density Functional Theory (DFT) at B3LYP level by using 6–311G(d,p) basis set. The stability of the molecule arising from hyperconjugative interactions, charge delocalization was analyzed by using natural bond orbital analysis (NBO). Also, the interactions between the title molecule and DNA bases are investigated by using the ECT (electrophilicity-based charge transfer) method. Calculations show that the title molecule interacts with the guanine more than other DNA bases. Furthermore, the interactions states between the guanine DNA (PDB:4ENM) and the studied molecule is determined by molecular docking study.

Synthesis, spectral characterization, DFT and in silico ADME studies of the novel pyrido[1,2-a]benzimidazoles and pyrazolo[3,4-b]pyridines

The chemical behavior of 3-substituted-6,8-dimethylchromones 1-3 was studied towards two selected nucleophiles namely 1H-benzimidazol-2-ylacetonitrile (R1) and 5-amino-2,4-dihydro-3H-pyrazol-3-one (R2). A diversity of pyrido[1,2-a] benzimidazoles and pyrazolo[3,4-b]pyridines was efficiently synthesized through different transformation reactions; depending on the functional group present at C-3 position of the chromone moiety. The two nucleophiles reacted with acrylonitrile 1 through γ-pyrone ring opening at C-2 position followed by recyclization, while compounds 2 and 3 reacted with the two nucleophiles through addition onto the exocyclic double bonds followed by cycloaddition onto the nitrile functions. All theoretical computations were calculated by using Density Functional Theory (DFT) B3LYP method with the help of 6-311G(d,p) basis set. In theoretical studies, the global chemical activity descriptors (FMOs, electron affinity, ionization potential, hardness, softness, etc.) and MEP were calculated to predict the important information related with the stability and reactivity of the prepared molecules. Compound 7 which obtained through ring opening and recyclization of compound 1 by reagent R2 is the more stable product. Fukui functions (FFs) for the starting substrates 1-3 were determined by using the same level of theory. With the aid of local based descriptors in the form of condensed Fukui functions, the sites available for nucleophilic attack for compound 1 were C10 then at C8, and for compounds 2 and 3 were C14 then at C26. The electrons transfer occurs from the nucleophilic reagents (R1 and R2) to the starting substrates 1-3 as deduced from electrophilicity-based charge transfer study (ECT > 0). To explain the nonlinear optical (NLO) properties of the synthesized compounds, the dipole moment, polarizability, and first hyperpolarizability values (in the range 0.84 × 10−30 - 3.85 × 10−30 esu) have been calculated and compared with urea as a reference material. In addition, the 1H NMR chemical shifts of prepared compounds were simulated by GIAO manner and compared with experimental chemical shifts results. The “drug-likeness” and ADME appeared in good agreement with the Lipinski, Ghose and Veber rules, indicating the ability of the prepared compounds to be predictively orally active and bioavailable.

DFT quantum chemical calculations (Fukui functions, NLO, TDOS, OPDOS, DNA/ECT) on 4-(dec-2yn-1-yloxy)phthalonitrile

In this study, structural and electronic properties of 4-(dec-2yn-1-yloxy)phthalonitrile were analyzed theoretically. The optimized structure in the gas phase of the title compound was achieved by density functional theory (DFT) method with the B3LYP hybrid functional using 6-31G (d,p) basis set. Then, IR, 1H-NMR, 13C-NMR spectroscopic properties of the title molecule were calculated and compared with the corresponding experimentally ones. Besides these, the molecular electrostatic potential (MEP) surface, frontier molecular orbitals (FMO), chemical activity, Fukui function analysis, nonlinear optical properties (NLO) in different solvent environments, total (TDOS), partial (PDOS) and overlap population density of state (OPDOS) diagrams were offered. Finally, the interactions between the title molecule with adenine, cytosine, thymine and guanine which are DNA bases were investigated by using the electrophilicity-based charge transfer (ECT) method and charge transfer (ΔN). According to NLO calculations, the value of the first hyperpolarizability of the title compound in the gas phase was found nearly twenty two times more than that of urea.

The new dimeric copper(II) complex from anticancer drug cytosine arabinoside

In this study, the new copper(II) based cytosine arabinoside (ara-C) analog was synthesized and characterized by analytical and spectroscopic methods. Especially the data obtained from FT-IR spectroscopy showed that ara-C coordinated with copper(II) ions through –C=O and -Nring groups and formed a complex compound in a tetrahedral structure. The proposed structure of this dimeric copper(II) complex was defined as [Cu2(ara-C)2Cl4]. Also, the ability of both compounds to bind to double helix fish sperm DNA (dsDNA) and the damage to the HeLa cell line was investigated. All theoretical chemical activity analyses (hardness and softness parameters, Fukui functions, net charges) of the ara-C and [Cu2(ara-C)2Cl4] molecules were performed with DFT with mixed basis set including LANL2DZ for Cu atom and 6-311G(d,p) for carbon, oxygen, nitrogen, chlorine and hydrogen atoms with B3LYP functional was applied. The stability of the molecule arising from hyperconjugative interactions, charge delocalization was analyzed by using natural bond orbital analysis (NBO) for optimized structure of [Cu2(ara-C)2Cl4]. Also, the interactions between the studied molecules (ara-C and [Cu2(ara-C)2Cl4] with DNA bases such as adenine, cytosine, guanine, and thymine were investigated by using the ECT (electrophilicity-based charge transfer) method. Furthermore, the best binding sites of the DNA (PDB:1BNA) protein to the ligands (ara-C and [Cu2(ara-C)2Cl4] were examined and the binding energies and interaction states were determined by molecular docking study.

Interaction of cisplatin anticancer drug with C20 bowl: DFT investigation

This study investigated the cisplatin (anticancer drug) interaction with C20 bowl and C20H10(Bowl) molecule including hydrogen-saturated with using mPW1PW91 functional. The stability of the various isomers of drug interaction with C20 bowl was investigated. The interaction energy values were estimated in these systems. Changes in the structural parameters and the frontier orbital energy and HOMO-LUMO gap values were evaluated. Charge transfer between fragments were shown with electrophilicity-based charge transfer (ECT). The Octanol–water partition coefficient (log P) and molecular volume (Vm) of these drug precursor molecules were studied. Also, Pt-C bond characterizations were illustrated using QTAIM analysis. The results showed that C20 bowl can be a promising nanocarrier for cisplatin anticancer drug.

Synthesis, structural, spectroscopic, intermolecular interactions, kinetic stability, charge transfer method with DNA bases and electronic properties of (E)-3-(2-ethoxyphenyl)-5-(3-(2-methoxyphenyl)-4methylthiazol-2(3H)-ylidene)-2-thioxothiazolidin-4-one: Computational and experimental approach

In the current paper, the new molecule (E)-3-(2-Ethoxyphenyl) -5-(3-(2methoxyphenyl) -4 methylthiazol-2(3H) -ylidene) -2-thioxothiazolidin-4-one (EMTh2) was synthesized and characterized using FT-IR, UV-vis, NMR, and X-ray diffraction experimental techniques. The experimental structure was determined from single-crystal X-ray diffraction data at low temperature (173 K). The compound crystallizes in the monoclinic system and space group P21/c with cell parameters: a=11.1100(5) Å, b=13.0597(6) Å, c=15.2343(7) Å, β=103.480(5)°, Z=4. R= 0.0512 was the final value for 4372 observed reflections. The two thiazol rings are coplanar, while the ethoxyphenyl and methoxy phenyl rings are essentially perpendicular to these rings with dihedral angle values of 107.2° for C4-N2-C8-C13 and 101.7° for C3-1-C15-C20. All theoretical calculations are performed using DFT with B3LYP functional and 6-31G(d,p) basis set. Both theoretical and experimental molecular structures were investigated and compared to one another. Furthermore, Hirshfeld surface analysis was performed to display surface contours and 2D-fingerprint plots were used to obtain contributions of the most important intermolecular interactions. The theoretical UV-vis spectrum was computed in chloroform as a solvent using the TD-DFT method. 1H and 13C-NMR chemical shifts were calculated using the GIAO approximation and the results were compared to the experimental ones. In addition, natural bond orbital (NBO), global reactivity parameters, MPA and NPA atomic charges, molecular electrostatic potential, Fukui functions were estimated using the same level of theory. The interactions between the investigated molecule and DNA bases (mainly adenine, cytosine, guanine, and thymine) were explored using the electrophilicity-based charge transfer method.

Synthesis, Structural Investigation, Hirshfeld Surface Analysis, and Biological Evaluation of N-(3-Cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide.

In this study, a novel heterocyclic amide derivative, N-(3-cyanothiophen-2-yl)-2-(thiophen-2-yl)acetamide (I), was obtained by reacting 2-aminothiophene-3-carbonitrile with activated 2-(thiophen-2-yl)acetic acid in a N-acylation reaction and characterized by elemental analyses, FT-IR, 1H and 13C NMR spectroscopic studies, and single crystal X-ray crystallography. The crystal packing of I is stabilized by C–H···N and N–H···N hydrogen bonds. In addition, I was investigated computationally using the density functional theory (DFT) method with the B3LYP exchange and correlation functions in conjunction with the 6311++G(d,p) basis set in the gas phase. Fukui function (FF) analysis was also carried out. Electrophilicity-based charge transfer (ECT) method and charge transfer (ΔN) were computed to examine the interactions between I and DNA bases (such as guanine, thymine, adenine, and cytosine). The most important contributions to the Hirshfeld surface are H···H (21%), C···H (20%), S···H (19%), N···H (14%), and O···H (12%). An ABTS antioxidant assay was used to evaluate the in vitro antioxidant activity of I. The compound exhibited moderate antioxidant activity. The antimicrobial activity of the title molecule was investigated under aseptic conditions, using the microdilution method, against Gram-positive and Gram-negative bacterial strains, and it also demonstrated significant activity against yeasts (Candida glabrata ATCC 90030, Candida krusei ATCC 34135). The findings revealed that the molecule possesses significant antioxidant and antimicrobial properties.

Synthesis, X-ray diffraction, spectroscopic (FT-IR, UV-Vis, 1H-NMR, 13C-NMR and TGA), DFT and molecular docking studies of (E)-3-(((3-chloro-4-(4-chlorphenoxy) phenyl) imino) methyl) benzene-1,2-diol

The title compound has been synthesized and characterized by FT-IR, UV-Vis, TGA, 1H-NMR and 13C-NMR spectroscopic techniques. Solid state of title structure has been determined by XRD. The molecular properties of title compound have performed by Density functional theory (DFT) using B3LYP/6-31G(d,p) method. Also, the interactions between the title molecule with DNA bases have been calculated by using the electrophilicity-based charge transfer (ECT) method for investigating the charge transfer. Finally, molecular docking study has also performed to investigate the binding pattern of the title compound with PDB ID: 2QDJ inhibitor targets and showed good insights on the possible interactions.

Exploring intermolecular interactions in some halogen substituted formyl coumarins and their DFT studies

The present manuscript describes an in-depth analysis of various interactions present in the crystal structure of formyl coumarins using Crystal explorer 17.0. Element based interactions were quantified by the decomposition of generated 3D surfaces into 2D fingerprint regions. DFT methods were used to explore electrostatic parameters, global and local reactivity descriptors. Electrophilicity based charge transfer (ECT) analysis was done to explore the probability of charge transfer between formyl coumarins and DNA base pairs. The reactivity and selectivity of different formyl coumarins have been accessed using Fukui functions in their reduced form. Non-bonding orbital (NBO) analysis revealed the presence of various hyperconjugative interactions and their stabilization energy in formyl coumarins. Non-linear optical properties are presented in terms of first order hyperpolarizibility (β0), where maximum β0 is observed for C4 (1.64 × 10-30esu.) which is found to be 2 times greater than that of p-nitroaniline. Molecular electrostatic potential (MEP) plots are mapped in terms of electron density.

Chemisorption of C2H2 on C20 bowl: A computational investigation

In this investigation, the chemisorption of C2H2 gas on the C20 bowl was studied at the LC-wPBE/6-311G(d,p) level of theory. Various models of chemisorption of C2H2 gas on the C20 bowl were considered. The illustration of chemisorption was performed using the energy decomposition analysis (EDA). Variations in the frontier orbitals energies and structural parameters were also considered. The electrophilicity-based charge transfer (ECT) was used to illustrate charge transfer between fragments. Thermochemical parameters of this process were revealed.

Hydrogen adsorption and storage on palladium-functionalized C20 bowl and C20H10 bowl molecule including hydrogen saturation

This study investigated hydrogen molecule adsorbing on palladium-functionalized C20 bowl and its H-saturated form (C20H10 bowl) using the B3LYP-D3 model. Moreover, this study examined the stability of different isomers of hydrogen adsorption. The values of adsorption energy were calculated in the investigated systems. This study demonstrated changes in the dipole moment and structural parameters. Additionally, this study indicated the differences in the frontier orbital energy and HOMO—LUMO gap values. Electrophilicity-based charge transfer showed charge transfer between fragments. Furthermore, this study also computed the hydrogen molecule's recovery duration in the investigated systems. In addition, the present study showed the field emission features of the examined system.

Computational investigation of interaction between titanocene dichloride and nanoclusters (B12N12, B12P12, Al12N12 and Al12P12)

This study investigated the interactions between B12N12, B12P12, Al12N12 and Al12P12 nanoclusters and titanocene dichloride anticancer drug complex using B3P86 functional. The bonding interaction between the nano-clusters and anticancer drug were examined through energy decomposition analysis (EDA). A good quadratic equation between interaction energy and molar volume (Vm) were provided. Charge transfer between fragments were illustrated with electrophilicity-based charge transfer (ECT). According to calculations, the values of heat of formation of the studied systems were negative (exothermic), which shows that these molecules are thermodynamically stable. The relationship between molar refractivity (MR) and Vm presented linear correlation.

The interaction between carboplatin anticancer drug and B12N12 nano-cluster: A computational investigation

This study investigated the interaction between B12N12 nano-cluster and carboplatin complex using B3P86 functional. Two interaction modes between B12N12 nano-cluster and carboplatin complex were considered. The bonding interaction between the B12N12 nano-cluster and carboplatin complex was examined through energy decomposition analysis (EDA). Also, Shubin Liu’s energy decomposition analysis (EDA-SBL) is used to study the source of energy differences between various isomers of B12N12 ... carboplatin complex. Charge transfer between fragments were illustrated with electrophilicity-based charge transfer (ECT) and extended charge decomposition analysis (ECDA). The quantum theory of atoms in molecules (QTAIM) analysis was applied to assess the Pt-B and Pt-N bonds within B12N12 ... carboplatin complex.

Chemical Reactivity and Skin Sensitization Studies on a Series of Chloro- and Fluoropyrroles—A Computational Approach

Global density functional descriptors analysis on a series of chloro- and fluoropyrroles provide vital data concerning their overall biochemical activities. In this study, a comprehensive investigation is presented for a series of chloro- and fluoropyrroles using DFT-based descriptors to elucidate physicochemical properties and their relevance to reactivity, charge transfer, site selectivity, and toxicity. Electrophilicity-based charge transfer (ECT) descriptor reveals the fact that chloro- and fluoropyrroles act as electron donors during their interaction with DNA bases. The local descriptor, namely, multiphilic descriptor conveys the activeness of specific sites in chloro- and fluoropyrroles. Further, Toxicity Prediction Komputer Assisted Technology (TOPKAT) studies on carcinogenicity bioassays using four rodent models provide the interesting fact that chloro- and fluoropyrroles exhibit a strong skin sensitization effect in these species.