Understanding the lithiation mechanisms of pyrenetetrone-based carbonyl compound as cathode material for lithium-ion battery: Insight from first principle density functional theory

The application of plain cycloalkanes and heterocyclic derivatives in the synthesis of valuable natural products and pharmacologically active intermediates has increased tremendously in recent times with much attention being paid to the lower cycloalkane members. The structural and molecular properties of higher seven-membered and nonaromatic heterocyclic derivatives are less known despite their stable nature and vast application; thus, an insight into their structural and electronic properties is still needed. Appropriate quantum chemical calculations utilizing the ab initio (MP2) method, meta-hybrid (M06-2X) functional, and long-range-separated functionals (ωB97XD) have been utilized in this work to investigate the structural reactivity, stability, and behavior of substituents on cycloheptane (CHP) and its derivatives: azepane, oxepane, thiepane, fluorocycloheptane (FCHP), bromocycloheptane (BrCHP), and chlorocycloheptane (ClCHP). Molecular global reactivity descriptors such as Fukui function, frontier molecular orbitals (FMOs), and molecular electrostatic potential were computed and compared with lower members. The results of two population methods CHELPG and Atomic Dipole Corrected Hirshfeld Charges (ADCH) were equally compared to scrutinize the charge distribution in the molecules. The susceptibility of intramolecular interactions between the substituents and cycloalkane ring is revealed by natural bond orbital analysis and intramolecular weak interactions by the independent gradient model (IGM). Other properties such as atomic density of states, intrinsic bond strength index (IBSI), and dipole moments are considered. It is acclaimed that the strain effect is a major determinant effect in the energy balance of cyclic molecules; thus, the ring strain energies and validation of spectroscopic specificities with reference to the X-ray crystallographic data are also considered.

Meta-Hybrid Density Functional Theory Prediction of the Reactivity, Stability, and IGM of Azepane, Oxepane, Thiepane, and Halogenated Cycloheptane

Ionic liquids (ILs) have lately piqued scientific attention due to their potential applications in green transition technologies such as catalysis, electrochemistry, and photovoltaic. The investigation of structural stability, reactivity, topological analysis, and thermodynamics of 4-methylpridine (4-picoline) based ILs is carried out using an advanced computational electronic structure theory technique based on first principle density functional theory (DFT). The ILs were modeled based on the interaction of 4-methylpridine (4-picoline) ion (cation) with borate, nitrate, phosphate, carbonate, and sulfate anions which have been chemically symbolized respectively as follows: [PMHP]+[HBO3]−, [PMHP]+[HNO3]−, [PMPH]+[HPO3]−, [PHMP]+[HCO3]−, and [PHMPM]+[HSO4]−. The energy difference between HOMO - LUMO of the studied compounds were found to show a general decreasing trend in the order: [PMHP][H2BO3] > [PMHP][NO3]> [PMPH][H2PO3]> [PHMP][HCO3]> [PHMPM][HSO4] with the borate ([PMHP][H2BO3]) and sulfate ([PHMPM][HSO4]) ILs having the relatively highest and least energy gap of 6.30 and 4.14 eV respectively. Strong interaction energies of 329.50 kca/mol, 114.41 kcal/mol, 107.12 kcal/mol, 98.19 kcal/mol and 87.86 kcal/mol involving the bonding, anti – bonding and lone pair orbitals associated with the pair of ILs were obtained as a trend: [PMHP][HSO4] > [PMHP][HCO3] > [PMPH][H2BO3] > [PHMP][NO3] > [PHMPM][H2PO3]. The intermolecular hydrogen bond (H-bond) analysis between the cation and anions ILs pairs obtained from quantum theory of atoms-in-molecules (QTAIM) reveals strong, weak, and electrostatic bonds. [PMPH]+[HSO4]− ILs pair was observed to possess the highest binding energy of -20.06 kcal/mol in the same way energy decomposition analysis (EDA) reveals a relatively strong orbital interaction in the [PMPH][HSO4] ILs due to the increase in electrostatic interaction of the four O-atoms in the sulfate anion, the analysis of the thermodynamic results indicates that the syntheses of the ILs are exothermic and spontaneous. 

Reactivity, stability, and thermodynamics of para-methylpyridinium-based ionic liquids: Insight from DFT, NCI, and QTAIM

This research work focuses on the synthesis, spectroscopic characterization, DFT studies, and in silico molecular docking of two azo compounds; (E)-6-((4,6-dichloro-1,3,5-triazin-2-yl)amino)-4-hydroxy-3-(phenyldiazenyl)naphthalen-2-yl hydrogen sulfite (compound A) and (E)-6-((4,6-dichloro-1,3,5-triazin-2-yl)amino)-3-((4-formylphenyl)diazenyl)-4-hydroxynaphthalen-2-yl hydrogen sulfite (compound D) to determine their application as chemotherapeutic drug for the treatment of the malignant glioblastoma multiforme (GBM). The experimental and theoretical vibrational wavenumbers of the synthesized compounds were compared and observed to be in good agreement. Density functional theory (DFT) at the B3LYP/6-311++G(d,p) level of theory was further utilized to investigate the frontier molecular orbitals, Fukui reactivity functions, excitation energies, and the natural bond orbital (NBO) analysis for the investigation of the bonding interactions of the studied compounds. The binding affinities of the studied compounds and the standard drug (temozolomide) against four different GBM proteins: 6bft, 6s79, 1Is5, and 1z2b was investigated using in silico molecular docking approach. Compound A displayed the highest relative binding affinities of -8.7 and -8.6 with 6s79 and 1Is5 proteins respectively compared to compound D with the binding affinity of -7.6. Both compounds A and D showed little to no interaction with 1z2b protein but their binding affinities with 6bft, 6s76 and 1Is5 proteins are relatively higher than those of the standard drug. Pharmacological studies also showed that both compounds exhibit good solubility in water resulting in good lipophilicity. With the obtained results, it is safe to say that the compounds and their derivatives could be considered as a potential chemotherapeutic drug for the treatment of glioblastoma or as a precursor for the synthesis of other pharmaceutical products. 

Reactive azo compounds as a potential chemotherapy drugs in the treatment of malignant glioblastoma (GBM): Experimental and theoretical studies

Antimicrobial activities of 1-phenyl-3-methyl-4-trichloroacetyl-pyrazolone: Experimental, DFT studies, and molecular docking investigation

Electronic structure investigation of the stability, reactivity, NBO analysis, thermodynamics, and the nature of the interactions in methyl-substituted imidazolium-based ionic liquids

Vibrational, electronic, spectroscopic properties, and NBO analysis of p-xylene, 3,6-difluoro-p-xylene, 3,6-dichloro-p-xylene and 3,6-dibromo-pxylene: DFT study

Synthesis, Spectroscopic, DFT Study, and Molecular Modeling of Thiophene-Carbonitrile Against Enoyl-ACP Reductase Receptor

We have obtained analytically the bound state solutions for the non-relativistic Schrodinger equation for the Eckart plus inversely quadratic Yukawa potential (EIQYP) using the parametric Nikiforov-Uvarov (NU) method. In order to validate our approximation, the bound state energies were computed and predicted for some selected diatomic molecules at different adjustable screening parameters from the available spectroscopic model parameters. The fact-finding obtained are in agreement with previously reported results available in literature. Furthermore, the graphs of the effective potential against inter-nuclear distance for low and high values of the screening parameters were reported. From our graphs, we observed that the approximation is best fit for very low values of the screening parameter α ≪ 1.

Evaluation of the bound state energies of some diatomic molecules from the approximate solutions of the Schrodinger equation with Eckart plus inversely quadratic Yukawa potential

Electronic structure theory study of the reactivity and structural molecular properties of halo-substituted (F, Cl, Br) and heteroatom (N, O, S) doped cyclobutane

Emmanuel I. Ubana

Papers

Electronic structure investigation of the stability, reactivity, NBO analysis, thermodynamics, and the nature of the interactions in methyl-substituted imidazolium-based ionic liquids

Vibrational, electronic, spectroscopic properties, and NBO analysis of p-xylene, 3,6-difluoro-p-xylene, 3,6-dichloro-p-xylene and 3,6-dibromo-pxylene: DFT study

Synthesis, Spectroscopic, DFT Study, and Molecular Modeling of Thiophene-Carbonitrile Against Enoyl-ACP Reductase Receptor

Evaluation of the bound state energies of some diatomic molecules from the approximate solutions of the Schrodinger equation with Eckart plus inversely quadratic Yukawa potential

Electronic structure theory study of the reactivity and structural molecular properties of halo-substituted (F, Cl, Br) and heteroatom (N, O, S) doped cyclobutane