The rapid development of high-capacity anodes for non-lithium ion batteries (NLIBs) has attracted significant attention in the scientific community towards removing fossil fuels. Herein, first-principles calculations based on density functional theory (DFT) were utilized to look into the applicability of the hexagonal boron oxide (B3O3) monolayer as an anode material for non-lithium ion (K+, Ca2+, and Al3+) batteries. The K+, Ca2+, and Al3+ ions are preferentially adsorbed on the large hollow site of B3O3 monolayer with binding energies of -53.77, -170.55, and -620.85 kcal mol-1, respectively. It was found the adsorption energies generally decrease by increasing the metal ion concentration. The theoretical storage capacities were predicted to be 790.33, 1185.50, and 1778.25 mAh g−1 for K+, Ca2+, and Al3+ ions, respectively. Furthermore, the diffusion energy barrier of a single metal ion was very low (0.22/0.39, 0.12/0.35, and 0.17/0.05 eV for K+, Ca2+, and Al3+ ions, respectively). The findings suggested that the B3O3 monolayer can be used in designing high-performance boron-containing nanostructures for NLIBs.

“Atoms in Molecules” formalism has been exploited to highlight the non-covalent interactions present within the molecular frameworks of a series of compounds structurally analogous to 2-(2-Hydroxyphenyl)benzothiazole and to critically assess the energetics of the interaction lines towards the conformational preference as well as the global stabilization of the said structures. Moreover, for a comprehensive scrutiny of the regulatory role of the aromatic stabilization of the rings present within the frameworks in governing the preferred conformation as well as to study its modulations in the presence of the non-covalent communications; Nucleus independent chemical shift (NICS) descriptor has also been employed. The hydrogen bonds associated with the Closed conformations of the concerned structures are distinguished by closed shell synergy with a credible degree of covalency and the corresponding energetics is found to have no discernible dependence on the substitutions in the aromatic nuclei. On the other hand, the Open conformations are found to have either an H····H or an N····H interaction lines; topologically identified as closed-shell interaction. For the systems with an N12 substitution (vide Scheme 1), the difference between the energies of the Closed and the Open conformations is found to significantly decrease which has been attributed to the enhanced stability of the N12 and the Hd atoms in the Open conformations, corroborated by a marginal increase in the aromaticity of the allied Open conformations as compared to the Closed conformations.

Novel heteroleptic complex [Co(SSC)(OA)(H2O)2] was synthesized with salicylaldehyde semicarbazone (SSC) and Oxalic acid (OA). The complex was characterized by FT-IR, UV, and Mass spectrometry. Molecular properties were computed at the B3LYP method with LANL2DZ basis set in the gas phase. Bond length, bond angles, and dihedral angles were calculated. The Nonlinear optical (NLO) value is 8542.135X10-33 esu helps in finding the potential of Co (III) as a good NLO candidate whereas charge delocalization. The stability of the compound was deliberated using natural bond orbital (NBO) analysis. Molecular electrostatic potential (MEP), HOMO-LUMO energy gap 2.54671 eV supports the possibility of charge transfer in the complex. The Quantum Theory of Atoms in Molecules (QTAIM) framework and Reduced Density Gradient (RDG) analysis support hydrogen bonding interactions between SSC and OA molecules. In-vitro studies for the complex measure its antibacterial activity and support the distinguished activity of the Co (III) complex.

Carbon-based metal-free catalysts are becoming increasingly attractive for the low cost and environmental friendliness. With one more valence electron than C, N doping has been extensively studied for the preparation feasibility. While the main group element B is comparable to transition metals in many reactions for co-existence of lone pair electrons and vacant orbitals. The synergistic effect of co-doping B and N has been explored both experimentally and theoretically. However, the in-depth understanding of the structure–property relationships of B, N co-doping in carbon materials remains to be uncovered. Herein, through extensive density functional theory (DFT) calculations, the doping sites (meta vs ortho) and number of N atoms around B on the synergetic promotion for O2 activation was investigated. Our results reveal that ortho-N captured more electrons from B compared with meta-N. Moreover, O2 activation effect is directly related to the energy level of empty sp3 orbital of B. Subsequently, O2 dissociation and CO oxidation were used as probe reactions to evaluate the catalytic performance of all B, N co-doped graphene structures. It is found that the introduced N atoms, especially meta-N creates another electrophilic center to accommodate the dissociated O atom, thus O2 dissociation process was promoted kinetically. Besides, CO oxidation proceeds easily on meta- and meta, ortho-N co-doped structures, while the strong interaction between O2 and ortho-N doped substrates hampers the reaction, which perfectly obeys the Sabatier Principle. This work not only uncovers the synergetic effect of BN co-doping in carbon-based materials, but also shed new light on developing metal-free catalysts.

The minimum image locus method first introduced by Theodorou and Suter (1985) allows us to extend the effective ranges of radial distribution functions obtained from molecular simulations at no extra cost. In this paper, we present a few extensions of the minimum image locus method to improve the accuracy and applicability of the original formulation, followed by performance evaluation with sufficient statistical accuracy to provide guidelines for use in real-world problems. Our results on liquid water and molten lithium fluoride indicate that the effective ranges of radial distribution functions can be safely increased by ≃ 25% for a simple cubic lattice, while the gain is much lower for body centered cubic and face centered cubic lattices. Therefore, as far as the radial distribution functions are concerned, the use of a simple cubic lattice is recommended for modeling homogeneously disordered systems.

Photosensitizers can impact on the efficiency of dye-sensitized solar cells (DYSCs) by adjusting their electromechanical and optical attributes, and because of this they are considered important. Thus, they should satisfy certain requirements in order for DYSCs to operate efficiently. In the present research, a photosensitizer, Flavan-3-ol was proposed and graphene quantum dots doped with the nitrogen atom (N-GQDs) were used to modify its attributes. The electronic, optical and geometric attributes of this photosensitizer was probed using DFT as well as time-dependent DFT. In order to validate the basis set and the density functional used in the present study, we used the available data on the parent Flavan-3-ol. There was a substantial narrowing in the energy gap of Flavan-3-ol after hybridization. As a result, there was a shift in the absorption of Flavan-3-ol, i.e., it changed from the UV region to the visible region, thus matching the solar spectrum. Moreover, a light-harvesting efficiency near unity was achieved after an increase in the intensity of absorption intensity, which is capable of increasing the generation of current. We adjusted the newly-designed dye nanocomposites’ energy levels were closely aligned with reduction potential and the conduction band, which indicated the possibility of injecting and regenerating electrons. Based on the attributes of the materials, it can be confirmed that they meet the requirements and can be used in DYSCs.

A series of NN/NN bridged furazan energetic materials were designed. Physicochemical properties of the designed compounds were calculated based on the structures which were optimized by density functional theory (DFT) method at B3LYP/6-311G (d, p) level. The results indicate that the solid-phase heats of formation of the designed compounds were high which range from 1066.3 kJ mol−1(compound D4) to 2476.5 kJ mol−1 (compound C5). The N3 energetic was the most effective group to improve the heat of formation of the designed compounds while energetic group C(NO2)3 was the most effective unit to increases the density, heat of detonation, detonation velocity and detonation pressure. Finally, compounds C1, C2, C7 and F1 were screened as candidates of high energy density materials based on calculated detonation properties and sensitivities.

We give a first principles approach for the structural, electronic and magnetic properties of LiCoBO3 and CoBO3 in the monoclinic lattices. Along [0 0 1] direction, based on density functional theory approach and using Full Potential Linear Augmented Plane Wave (FP-LAPW) method, Polarized spin and spin–orbit coupling are included in calculations, and major spin was set up. The calculations were carried out using generalized gradient approximation (GGA) + an on-site Coulomb self-interaction correction potential (GGA + U). The magnetic and orbital moments are estimated. The U value was considered to be equal to 6 eV for Co atom. The average equilibrium voltage over a full cycle, of the LiCoBO3 battery is estimated from our FP-LAPW calculations. The capacity of a cell and energy density of LiCoBO3 were calculated. The compound LiCoBO3 is a semiconductor with average intercalation voltage 4.01 V. The voltage difference help promote electrochemical performance, which opens a window for Li-ion battery marketing application.

Civil-used proton exchange membrane fuel cell (PEMFC) may be the potential candidate for the construction of the global new energy system including the use of hydrogen energy. Nevertheless, the cathode oxygen reduction reaction (ORR) occurs sluggishly, reining the conversion efficiency of it, which hinders the further commercialization of PEMFC. Currently, the replacement of undesirable Pt catalysts by more stable and economical catalytic materials is the main topic in the field of ORR. Herein, ferromagnetic metal-based endohedral metallofullerenes (EMFs) electrocatalyst with single-atomic shell decoration (M4@MN4C60, M = Fe, Co, Ni) are theoretically constructed and evaluated by the density functional theory method. The encapsulation energy calculation reveals that the synthesis of all EMFs requires additional external energy supply, which can explain why few successfully experimental synesis of EMFs have been reported. Among all studied catalysts, the CoN4C60 stands out with the highest ORR performance comparable to Pt, and the Fe- and Ni- based EMFs shows considerable activity enhancement after the cluster encapsulation. The electronic structure calculation reveals that the encapsulated Fe4 cluster leads to an electron accumulation around the Fe atom in active center, thereby weakening the *OH binding and enhance the ORR performance.

Utilizing the Molecular Electron Density Theory, to survey the [2+3] cycloaddition processes between 4-methyl-Benzonitrile-N-oxide (1) and 9α-hydroxyparthenolide (2), reaction, activation energies and the reactivity indices are determined. An examination of conceptual DFT indices, 9α-hydroxyparthenolide (2) will provide in this reaction as an eletrophile, whereas 4-methyl-Benzonitrile-N-oxide (1) will share as a nucleophile. The reaction and activation energies clearly demonstrate that this cyclization is regio- chemo and stereospecific, which is in perfect agreement with the outcomes of the experiment. The mechanism of this [2+3] cycloaddition follows two steps mechanism, as indicated by ELF analysis.

High-coverage CO adsorption on seven surfaces of Fe3C catalyst has been systematically studied by density functional theory and thermodynamics. Results show that CO molecules prefer to bind on surface iron atoms of Fe3C catalyst, and the saturation coverage ranges from 0.5 to 0.833 monolayers (ML) on different surfaces. The equilibrium phase diagrams of CO adsorption on different Fe3C surfaces at different CO coverage are plotted, and the stable CO concentration on each surface of Fe3C at any CO partial pressure and temperature could be easily identified. CO adsorption/activation on Fe3C catalyst via an acceptance-donation mechanism can be explained by the projected density of states (PDOS) and charge density difference plots. Interestingly, stabilities of the Fe3C surfaces can be modified by adsorbed CO, and eventually the morphologies of Fe3C nanoparticle can also be changed. Our results provide essential information for selective synthesis of Fe3C catalyst with specific structures experimentally.

Upon the adsorption and sensing of C2H2 and C2H4, we purpose pristine WTe2 monolayer as a promising candidate and uncover the enhanced mechanism of Ni-doping towards such two gas species in this work, using the density functional theory (DFT) method. Results show that pristine WTe2 monolayer performs physisorption upon C2H2 and C2H4 molecules with adsorption energies of −0.57 and −0.63 eV, and the small changes in its bandgap indicate the unsuitability for gas sensing use. The Ni-doping is energy-favorable with formation energy of −0.15 eV by substituting a Te atom on the WTe2 surface, and C2H2 and C2H4 adsorptions are both determined as chemisorption with adsorption energies of −1.40 and −1.22 eV. The electron redistributions are dramatically promoted in the Ni-WTe2/gas systems, and the obvious decrease of bandgap in Ni-WTe2 monolayer after C2H2 and C2H4 adsorptions, about 25.6% and 12.6%, suggests the strong potential for its exploration as a resistance-type gas sensor with sensing response of −97.8% and −85.4%. The analysis of recovery property reveals the reusability of Ni-WTe2 monolayer after several seconds exposure under UV light at 398 K. These findings give a deep insight into the WTe2-based gas sensor upon the typical gases in the transformer oil.

The intramolecular Diels–Alder cycloaddition between cyclobutadiene and butadiene, which involves post-transition-state bifurcation (PTSB), has been investigated using the ring-polymer molecular dynamics (RPMD), classical MD and quasi-classical trajectory (QCT) simulations, and supervised machine-learning (ML) technique. The branching fraction of this reaction strongly depends on the simulation temperature. While QCT, classical MD and RPMD simulations performed at room temperature, starting from the ambimodal transition state (TS), showed the similar dynamics, QCT overestimated the minor branching fraction at low temperature. The supervised machine-learning analysis revealed that the initial coordinates and momenta for low frequency modes at the ambimodal TS contribute to the branching dynamics. The classical MD and RPMD methods follow similar conditions to quantum Boltzmann distributions, whereas the artificially localized phase distribution, considering that the zero-point energy is wedged into the classical particles. As a result, the QCT method can provide inadequate bifurcation dynamics, such as the overestimation of the minor product.

The Avigan antiviral drug adsorption by an oxidized form of a graphene flake; so called Ovalene, was investigated using density functional theory calculations to provide molecular insights into the sensing functions of targeted drug delivery issues. The features and stabilized models of Ovalene and Avigan and their three interacting Avigan@Ovalene complexes were obtained. Inter-molecular and intra-molecular communications were found among the models, in which the intra-molecular communications inside Avigan were observed as a preventive factor for formations of strong complexes. Hence, the complex with a weaker intra-molecular interaction was placed at the highest adsorption strength level and that one with a stronger intra-molecular interaction was placed at the lowest level. Based on the results, Ovalene was found as an expected Avigan drug carrier with suitable recovery time and conductance rate to provide a sensing function. Consequently, Avigan@Ovalene complexes were proposed for further investigations regarding the targeted drug delivery issues.

Halogenation of organic compounds is an important functionalization process for further chemical transformation and the benzylic hydrogen is reactive towards the photochemically generated Br atom. This work reports the free energy profile of the several steps of the reaction of the Br atom with toluene leading to benzyl bromide, (dibromomethyl)benzene, and (tribromomethyl)benzene using reliable theoretical B2GP-PLYP method. A detailed microkinetic analysis of the reaction rate and product distribution was also performed. Our analysis points out that polar solvent increases the reaction rate in relation to apolar one. Substitution on the aromatic ring cannot be explained by the electrophilic mechanism in an apolar medium. The reactivity of different benzylic substrates was evaluated, and we have found that the cyano electron-withdrawing group in the aromatic ring retards the reaction, while the ortho-methoxy group, and oxygen and nitrogen atoms bonded to the benzylic carbon, enhance the reaction rate.

Due to its thermochemical stability, CH4 is generally difficult to be dissociated. In this paper, the role of Sc atom in the results of the C-H bond activation operation was investigated using the DFT-D (M06-2X) method to understand the reaction process. It was discovered that the double low-spin state Sc atom easily react with CH4, whereas the high-spin ground state Sc is inert. The mechanism of the supported ScAl2O2- activated CH4 and the free Sc reaction system are extremely similar. The major channel is the low-spin state, displaying the incidence of spin flipping has an orbital drill-through effect. In the ScAl2O2- reaction, the Al2O2- anion can efficiently support Sc atom and thereby activate CH4 while also imparting its high reactivity to the supported Sc. In the future, it will be possible to examine the role of the Sc atom in the catalytic activation process of ScAl2O3- on CH4.

Although Chlorpyrifos which is also called chlorpyrifos ethyl an organophosphate insecticide, acaricide and miticide has been reported to have been primarily use in the control of foliage and soil -borne insect pests. Excess release of the insecticide to the environment can cause acute health effects which include stinging eyes, rashes, blisters, blindness, dizziness and even death. Therefore, in the recent era, finding a nanostructure that can best detect and sense the presence of Chlorpyrifos Insecticide (CPI) in the environment is of scientific interest. Herein, theoretical modelling using Al12Se12 and its metal decorated Ag, Au and Cu were investigated using DFT/def2tzvp/PBE0-gd3bj level of theory. From this study, the Cl site of Chlorpyrifos Insecticide (CPI) was observed to have better adsorption performance compared to the O site. From the electronic properties, the Al12Se12 surface decorated with Ag for trapping Chlorpyrifos Insecticide (CPI) at the Cl site has the lowest energy gap of 0.0625 eV while that which interacted with Cu decorated at the S atom has the highest energy gap of 3.2553 eV. This shows that adsorption of Chlorpyrifos Insecticide (CPI) on Al12Se12 surface decorated with Ag at Cl site makes it more reactive and ready for more chemical interactions in the environment than that when interacted at S atom. All the objective presented herein showed that adsorption of CPI on the nanostructure at Chlorine site had better adsorption characteristics compared to the O site.

The [3 + 2] cycloaddition (32CA) reaction of benzonitrile oxide BNO with 5-methylenehydantoin (MH) has been studied with the MEDT perspective at the DFT/B3LYP/6–31 + g(d,p) level of theory. Topological analysis of the ELF shows zwitterionic character of this 32CA reaction and the non-polar character is revealed form the global electron density transfer (GEDT) calculations at the TSs, consistent with the calculated high relative free energies between 27.6 and 39.1 kcal mol−1. The energetically predicted regioselectivity and atropisomerism induced facial selectivity towards anti isomer is in complete agreement with the experimental outcome. The activation energy in this 32CA reaction is associated with the creation of non-bonding electron density at N2 nitrogen and pseudoradical center at C3 and the formation of new CC and CO covalent bonds were not observed at the TSs which was in conformity with the calculated total electron density and the positive Laplacian of electron density at the bond critical points observed at the interatomic bonding regions of the TSs.

The electronic, magnetic, and optical characteristics of hexaazabipyH2 molecule (HA) and the 3d transition metal complexes for hexaazabipyH2 (TMHA) are investigated utilizing DFT and TD-DFT calculations. The stability of the investigated complexes is confirmed by the binding energy, molecular dynamic, and vibrational frequencies. The calculated HOMO-LUMO gap values show that the HA and TMHA are semiconductors. The magnetic moment (µ) for the investigated complexes is estimated, and the greatest µ value (3.76 µB) is recorded for the CrHA complex. The existence of the TM atom influences the UV–Vis spectrum of HA, where a redshift has occurred for the TMHA complexes except the ZnHA. The MnHA complex has a high light harvesting efficiency value of 0.403. The HA and TMHA complexes have refractive indices in the range of 2.311 to 3.323. Our results show that the HA as well TMHA complexes might be promising materials for solar cells and optoelectronics applications.

This study developed a new prediction model for hole injection barriers. Based on the electronegativity equalized model (EEM), the vacuum level shift in the adjacent layers was further considered in this model. In addition, the variation in ΦITO, which is dependent on the doping concentration of Sn, was considered as one of the determinants for predicting the hole injection barrier (HIB) between ITO and the organic layer. Further, the effect of p-dopants on the HTL energy level was also introduced in this model. The predicted HIBs of various anode/organic junctions were quantitatively and qualitatively consistent with UPS experiments. We believe that the developed EEM model can aid in determining the appropriate HTL/HIL organic materials without tremendous effort and time costs.