HOMO-LUMO Analysis Research Articles

Vibrational frequency Analysis, DFT and in Vitro Fungicidal Activity Studies of Biphenyl-4-Carboxylic Acid, 2,4-Difluorobiphenyl and 4-Acetylbiphenyl- A Comparative Study

Comparative spectroscopic investigation of Biphenyl-4-carboxylic acid (BCA), 4-Acetylbiphenyl (ACB) and 2,4-difluorobiphenyl (DFB) are obtained by using Density Functional Theory (DFT) with B3LYP functional at 6-311++G(d, p) basis set. The vibrational assignments have been proposed with aid of the results of Normal Coordinate Analysis (NCA). The effects of carboxyl, acetyl and fluoro substituents on the vibrational frequencies of biphenyl have been investigated and compared. The molecular stability and bond strength was investigated by applying the Natural Bond Orbital (NBO) analysis. The other molecular properties like Mulliken charge analysis, HOMO-LUMO analysis and Molecular Electrostatic Potential (MESP) of the title compounds have been reported. In vitro analysis have been performed with two fungal pathogens Aspergillus niger and Candida albicans using well diffusion method. BCA compound exhibited excellent activity against the Aspergillus niger with zone of inhibition values in the range of 22 and 25 mm in 40 and 80 µl with 10 mg/ml. Molecular docking studies of the most active compound are carried out, and results showed reasonable binding modes in the fungicide active site of phytase protein Fophys and Succinate dehydrogenase (SDH) proteins. A preliminary Structure-Activity Relationship study of the biphenyl derivatives has led to the recognition of some important structural requirements for antifungal activity. Furthermore the fungicide-likeness analysis of BCA, DFB and ACB compounds have been developed to predict its fungicide activity by using fungiPAD webtool.

Nanorod-like Structure of ZnO Nanoparticles and Zn8O8 Clusters Using 4-Dimethylamino Benzaldehyde Liquid to Study the Physicochemical and Antimicrobial Properties of Pathogenic Bacteria

To study their physicochemical and antimicrobial properties, zinc oxide nanoparticles were synthesized using a simple chemical route and 4-dimethylaminobenzaldehyde (4DB) as an organic additive. ZnO nanoparticles were characterized with XRD analysis, which confirmed the presence of a hexagonal wurtzite structure with different crystalline sizes. The SEM morphology of the synthesized nanoparticles confirmed the presence of nanorods in both modifications of ZnO nanoparticles. EDS analysis proved the chemical composition of the synthesized samples via different chemical approaches. In addition, the optical absorption results indicated that the use of 4DB increased the band gap energy of the synthesized nanoparticles. The synthesized Zn8O8 and Zn8O8:4DB clusters were subjected to HOMO-LUMO analysis, and their ionization energy (I), electron affinity (A), global hardness (η), chemical potential (σ), global electrophilicity index (ω), dipole moment (μ), polarizability (αtot), first-order hyperpolarizability (βtot), and other thermodynamic properties were determined. Furthermore, the antimicrobial properties of the ZnO nanoparticles were studied against G+ (S. aureus and B. subtilis) and G- (K. pneumoniae and E. coli) bacteria in a nutrient agar according to guidelines of the Clinical and Laboratory Standards Institute (CLSI).

High drug carrying efficiency of boron-doped Triazine based covalent organic framework toward anti-cancer tegafur; a theoretical perspective

The therapeutic potential of Triazines-based six-membered ring covalent organic framework (COF) and respective boron doped derivative toward anticancer drug i.e., Tegafur (TG) is evaluated using the first principles DFT calculations. The geometric, energetic, and electronic properties of TG@Triazine and TG@TriazineB2 are computed to explore and compare the efficacy of selected COFs as drug carrier systems. The strength of the adsorption of tegafur onto the triazine-COFs is illustrated through the counterpoise corrected adsorption energies (Ecp). The computed Ecp of TG@Triazine and TG@TriazineB2 are −21.81 and −25.57 kcal/mol, which illustrate the physisorption of the drug on adsorbent. The nature of interactions i.e., physisorption between tegafur and Triazine COFs is further illustrated via the noncovalent interaction index (NCI) plot and quantum theory of atom in molecules (QTAIM), which illustrated that the weak dispersion forces are present between the drug and COF adsorbents. In comparison, the adsorption strength is significantly high in boronated triazineB2 COF. The electronic properties, including HOMO-LUMO analysis and NBO charge transfer analysis, reveal the significant variation in the electronic behavior of triazine COF, upon doping with boron, the Eg (HOMO-LUMO gap) of pristine Triazine (4.15 eV) reduced to 0.49 eV in TriazineB2 analogue. This significant decrease in the Eg of Triazine on boron doping illustrates the shifting of the semiconducting behavior of pristine Triazine to the metallic nature of TriazineB2, thus the electron transportation becomes double the magnitude (0.018 |e|) on interaction with tegafur drug as compared to 0.07 |e| in TG@Triazine. Finally, the recovery time is computed to illustrate the time taken by the drug in detaching at the active site. With this study, it is confirmed that the triazine-COF can be a significant drug carrier, however, the doping of boron further enhances the therapeutic potential of the adsorbent.

Investigation of Propyphenazone Molecule by Quantum Chemical Methods

Computational chemistry approaches were used to manage the phenazone molecule. The phenazone molecule was optimized at the 3-21G (d) level. The structural parameters were investigated. IR and NMR techniques, which are spectroscopic approaches, were used to determine the structure. The highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy, hardness (η), softness (σ), chemical potential (μ), electronegativity (χ), electrophilicity index (ω), nucleophilicity index (ε), the electron accepting power (ω+), electron-donating power (ω-), and polarizability of the propyphenazone molecule were investigated.
 NMR spectra for 1H and 13C, as well as UV-Vis spectra, were obtained. HOMO-LUMO and molecular electrostatic potential (MEP) analyses were carried out. The theoretical calculations for the molecular structure and spectroscopy were done using the Gaussian 09 software with HF and 3-211G (d) basis set calculations. The GaussSum 3 software was used to compute the density of state (DOS).

Synthesis, Molecular Docking, Dynamics, Quantum-Chemical Computation, and Antimicrobial Activity Studies of Some New Benzimidazole-Thiadiazole Hybrids.

In this study, some new compounds, which are 2-aminothiadiazole derivatives linked by a phenyl bridge to the 2-position of the benzimidazole ring, were designed and synthesized as antimicrobial agents. The structures of the compounds were elucidated by 1H and 13C NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. The antifungal activities of the synthesized compounds were tested on Candida albicans, Candida krusei, Candida glabrata, and Candida parapsilosis. Compound 5f is more active against C. albicans and C. glabrata than standard fluconazole and varicanazole. Compounds were also evaluated for their counteracting activity against Gram-positive Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, and Pseudomonas aeruginosa and Gram-negative Enterococcus faecalis, Bacillus subtilis, and Staphylococcus aureus. Compounds 5c and 5h had minimum inhibitory concentrations against E. faecalis close to that of the standard azithromycin. Molecular docking studies were performed against Candida species' 14-α demethylase enzyme. 5f was the most active compound against Candida species, which gave the highest docking interaction energy. The stabilities of compounds 5c and 5f with CYP51 were tested using 100 ns molecular dynamics simulations. According to the theoretical ADME calculations, the profiles of the compounds are suitable in terms of limiting rules. HOMO-LUMO analysis showed that 5h is chemically more reactive (represented with the lower ΔE = 3.432 eV) than the other molecules, which is compatible with the highest antibacterial activity result.

Efficiency of C = Se as hydrogen bond acceptor in controlling regioselective amination of 5,7-dinitroquinazoline-4-selenone: Quantum mechanical, AIM and docking analysis by density functional method

Herein, we explored the theoretical aspect of reaction between 5,7-dinitroquinazoline-4-selenone and methylamine by employing density functional theory (DFT) calculations. The energetic parameters confirmed that the reaction progressed via. concerted mechanism with the single step process instead of two step process via intermediate formation. Further, role of Se = C bond as non-conventional H-bond acceptor is reported in reaction controlling factors that monitors the regioselectivity of the present proposed reaction. Despite of substantial steric hindrance at ortho-position of 5,7-dinitroquinazoline-4-selenones, the regioselective amination resulted into ortho-substituted product (P2) rather than para-substituted product (P1) attributed to non-conventional NH---Se = C intramolecular hydrogen bonding. The topological properties of the electron density distributions have been studied by using quantum theory of atoms in molecules (QTAIM). The presence of non-conventional hydrogen bond acceptor–donor interactions (NH---Se = C) in ortho-positioned amination is achieved by electron density ρ(r) and Laplacian of electron density ∇2ρ(r) in QTAIM analysis and supported the results of DFT studies hybrid with B3LYP/6-31G(d,p) basis set. Due to the lack of intramolecular hydrogen bonding interactions (NH---Se = C), the para-positioned amination on 5,7-dinitroquinazoline-4-selenone is founded to be less feasible. Further, the DFT technique has been used to investigate frontier molecular orbital (FMO) analysis and global reactive parameters using the aforesaid level of theory and basis set. HOMO-LUMO analysis revealed that ortho-substituted product (P2) has a wider energy gap (3.0684 eV) than para-substituted product (P1) (2.6402 eV) suggesting more stability of P2. The presence of hydrogen bonding interactions is further confirmed by the change in electrostatic potential regions in ortho-substituted product (P2) as compared to reactants in molecular electrostatic potential surface (MEPS) studies. Both para-substituted product (P1) and ortho-substituted product (P2) have been docked into the protein 5FCT's active site to predict favored binding location, activity and affinity by using docking studies.

In-silico and in-detail experimental interaction studies of new antitumor Zn(II) complex with CT-DNA and serum albumin

In this study, a novel Zn(II) complex with the formula [Zn(pyrr-ac)2] (pyrr-ac: pyrrolidineacetate) was synthesized and characterized through molar conductivity, elemental analysis, 1H Nuclear Magnetic Resonance (1H NMR), UV-Visible spectroscopy, and Fourier transform infrared (FT-IR) methods. B3LYP level of DFT method along with aug-cc-pVTZ-PP/6-311G(d,p) basis set was utilized to perform the geometry optimization and HOMO-LUMO analysis. In addition, MEP, NLO and NBO computations were also performed at the same level of theory. In vitro antitumor activity of the mentioned complex on leukemia cell line, K562, was investigated using the MTT assay which surprisingly revealed the effective antitumor activity of the studied zinc complex. Interaction of this compound with biological macromolecules viz., CT-DNA and BSA was studied via different spectroscopic methods. The results of fluorescence experiment displayed that the metal complex binds to both macromolecules through hydrogen bond (H-bond) and van der Waals (vdW) forces. UV-Vis tests indicated a decline in the absorption spectra of CT-DNA/BSA in the presence of the compound. The interaction was further corroborated for CT-DNA via gel electrophoresis, CD spectroscopy and viscosity experiments and for BSA using CD spectroscopy. Furthermore, molecular docking simulation was done to evaluate the nature of interaction between the aforementioned zinc complex and CT-DNA/BSA. These results were in agreement with experimental findings and demonstrated that the main interaction is hydrogen bonding. The above type of investigations may provide a pathway through which zinc complexes join the anticancer category. The in-silico and in-vitro results confirm that the newly made [Zn(pyrr-ac)2] complex interacts with CT-DNA than BSA. Communicated by Ramaswamy H. Sarma

Investigating the third-order NLO properties of 4-[(Z)-(6-nitro-1,3-benzothiazol-2-yl)diazinyl]naphthalen-1-ol for nonlinear applications using the Z-scan technique and quantum chemical computations

The structural and optical characteristics of azo dye 4-[(Z)-(6-Nitro-1,3-benzothiazol-2-yl) diazinyl] naphthalen-1-ol were examined using UV-visible, FT-IR, and FT-Raman experimental spectroscopic techniques. The B3LYP method is employed to optimize the geometrical structure of the compound. NBO, as well as HOMO-LUMO analysis, is helpful to get an insight into the charge transfer interactions occurring in the molecule. Due to the presence of benzothiazole a significant bathochromic shift is observed in the absorption maxima in the polar solvent. The charge of individual atoms can be calculated using NPA analysis. The open and closed aperture Z-scan technique obtains the compound's third-order nonlinear optical properties. The positive sign of nonlinear refraction confirms the self-focussing behavior of the azo dye. The calculated second-order hyperpolarizability (γ) using DFT shows good agreement with the experimental result obtained from Z-scan. From the results of the Z-scan, this compound is a budding candidate for future optoelectronic and photonic devices.

Aluminium carbide nano-sheet as a promising adsorbent for removal of carbendazim

• Adsorbent efficacy of aluminium carbide nano-sheet (AlC 3 NS) for CB was evaluated for the first time. • CB interacted with the Al atoms of AlC 3 NS via -C=O group and the adsorption energy was approximately −30.14 kcal/mol. • The HOMO-LUMO analysis was conducted for investigating the charge transfer process. The widespread use of carbendazim (CB) as a pesticide molecule to control pests and to protect crops has worsened the problems associated with pollution. The excessive use of CB can cause atmospheric pollution through the contamination of soil as well as water sources. Within the current work, the adsorbent efficacy of aluminium carbide nano-sheet (AlC 3 NS) for CB was evaluated for the first time. We evaluated some of the important properties of CB, AlC 3 NS, and complex of CB-AlC 3 NS for investigating the effectiveness of AlC 3 NS as an adsorbent system. CB interacted with the Al atoms of AlC 3 NS via -C=O group and the adsorption energy was approximately −30.14 kcal/mol. The HOMO-LUMO analysis was conducted for investigating the charge transfer process, which was further supported by NBO analysis. The results demonstrated the possibility of using the AlC 3 NS as an efficient adsorbent system for the CB for the treatment of different kinds of wastewater.

Theoretical structural analysis (FT-IR, FT-R), solvent effect on electronic parameters NLO, FMO, NBO, MEP, UV (IEFPCM model), Fukui function evaluation with pharmacological analysis on methyl nicotinate

Theoretical investigation on FT-IR and FT-Raman has been done using vibrational spectroscopy with DFT method along with 6-311++G(d,p) as a basis level. The elemental modes of oscillations were allocated and analyzed theoretically. In gas and solvents water, DMSO, ethanol and methanol, NLO prospects were calculated, orbital HOMO-LUMO analysis, MEP studies were performed by DFT method, IEFPCM model. With the help of TD-SCF method, IEFPCM model, UV–Vis spectra have been explored. To understand electron delocalization due to hyper conjugation has been performed by the method NBO. Reactive sites were identified using Fukui functions. Pauli exchange repulsion effect was used to analyze ELF and LOL studies using multiwave function. NCI study was carried out to find bonding and anti-bonding interaction. Mechanism SwissADME was applied to get drug likeness properties.

The synthesis and photoelectrical performances of perylenediimide-based devices as an interface layer in metal-organic-semiconductors

The symmetric and asymmetric perylenediimide (PDI)-based organic ligands Ph-PDI-Ph (1), Pyr-PDI-Pyr (2), and Pyr-PDI-Ph (3) were synthesized. Au/(Pyr-PDI-Ph)/p-Si (D1), and Au/(Ph-PDI-Ph)/p-Si (D2) devices were fabricated using thermal evaporation and their photodiode performances were examined under the irradiation of 100 mW.cm−2 at −2 V. In addition to the analysis of photodiode performances, the electrical properties depending on temperature and frequency of these structures were calculated using three different methods, which are the thermionic emission, Norde function, and Cheung&Cheung function. Furthermore, the molecular geometry, electronic absorption spectra, HOMO-LUMO and MEP surface analysis of the molecules mentioned were computed using the DFT/B3LYP method with 6-31 G (d,p) basis set and DFT calculations supported both the non-planar structures or propeller structures and compatibility of the theoretical results with the experimental data. The results supported that the fabricated D1 and D2 devices can form a basis for practical applications in optoelectronic device applications, especially photodiodes and photodetectors.

Macrophage-Targeted Punicalagin Nanoengineering to Alleviate Methotrexate-Induced Neutropenia: A Molecular Docking, DFT, and MD Simulation Analysis.

Punicalagin is the most bioactive pomegranate polyphenol with high antioxidant and free-radical scavenging activity and can potentially cure different ailments related to the cardiovascular system. The current research work was envisioned to predict the targeting efficiency of punicalagin (PG) nanoparticles to the macrophages, more specifically to bone marrow macrophages. For this, we selected mannose-decorated PLGA-punicalagin nanoparticles (Mn-PLGA-PG), and before formulating this nanocarrier in laboratory settings, we predicted the targeting efficiency of this nanocarrier by in silico analysis. The analysis proceeded with macrophage mannose receptors to be acquainted with the binding affinity and punicalagin-based nanocarrier interactions with this receptor. In silico docking studies of macrophage mannose receptors and punicalagin showed binding interactions on its surface. PG interacted with hydrogen bonds to the charged residue ASP668 and GLY666 and polar residue GLN760 of the Mn receptor. Mannose with a docking score of −5.811 Kcal/mol interacted with four hydrogen bonds and the mannose receptor of macrophage, and in PLGA, it showed a −4.334 Kcal/mol docking score. Further, the analysis proceeded with density functional theory analysis (DFT) and HOMO–LUMO analysis, followed by an extensive 100 ns molecular dynamics simulation to analyse the trajectories showing the slightest deviation and fluctuation. While analysing the ligand and protein interaction, a wonderful interaction was found among the atoms of the ligand and protein residues. This computational study confirms that this nanocarrier could be a promising lead molecule to regulate the incidence of drug-induced neutropenia. Furthermore, experimental validation is required before this can be stated with complete confidence or before human use.

Spectroscopic investigation (IR and NMR) and HOMO-LUMO analysis of aromatic imines using theoretical approach

In this work, the theoretical studies on the structure, FT-IR, NMR, and UV–Vis spectroscopy of (E)-N-benzylidenebenzenamine (A1) and (E)-N-(2, 4′-dichlorobenzylidene) propan-1-amine (A2) are presented. The optimized structure of the molecules, NMR and UV–Vis spectra analysis were determined by the Density Functional Theory (DFT) method using B3LYP/6-311G (d, p) basis set. For FT-IR analysis, both the HF and DFT methods were used in order to determine their accuracy and reliability in theoretical calculations. The computed result of DFT calculations in comparison with the experimental results showed that the DFT method gives a more accurate prediction. The infrared (IR) spectra for the imine molecules have been recorded in the region of 500–4000 cm−1. The gauge-independent atomic orbital (GIAO) method has been used to evaluate the 13C and 1H nuclear magnetic resonance (NMR) chemical shifts of the molecules. The computed results of NMR spectra of the molecules was found to be in good agreement with the experimental data. The UV–Vis spectra of the molecules were computed to determine the HOMO-LUMO energies in order to gain insight into their electronic properties. Mulliken population analysis on atomic charges of the molecules was also calculated using the HF (Hartree-Fock) and B3LYP method. All the computed results indicated that the B3LYP method provides satisfactory results and, therefore, can be employed to support experimental data. It also demonstrated a reliable approach towards characterization of molecules in chemical science.

Exploring flexibility, intermolecular interactions and ADMET profiles of anti-influenza agent isorhapontigenin: A quantum chemical and molecular docking study

Isorhapontigenin (IRPG) drug emerges as promising efficient inhibitor for H1N1 and H3N2 subtypes which belong to influenza A virus; reported with IC50 value of 35.62 and 63.50 μM respectively. When experimental data are compared to the predicted geometrical parameters and vibrational assignments (FT-IR and FT-Raman), the findings indicated a strong correlation. The absorption bands of π→π∗ transitions are revealed through UV-Vis electronic properties; this confirms that the IRPG molecule shows strong bands. Through NBO and HOMO-LUMO analysis, the kinetic stability and chemical reactivity of the IRPG molecule were investigated. By using an MEP map, the IRPG's electrophilic and nucleophilic site selectivity was assessed. In a molecular docking investigation, the IRPG molecule shows a stronger inhibition constant and binding affinity for the H1N1 and H3N2 influenza virus. The IRPG molecule thus reveals good biological actions in nature and can be used as a potential therapeutic drug candidate for H1N1 and H3N2 virus A influenza.

A zinc(II) metal–organic complex based on 2-(2-aminophenyl)-1H-benzimidazole ligand: Exhibiting high adsorption capacity for aromatic hazardous dyes and catecholase mimicking activity

A dual functional metal–organic complex (MOC) {[Zn(L1)(Cl)2]·DMF} (1), ( L1 = 2-(2-aminophenylbenzimidazole) was synthesized by a solvothermal method and characterized by various analytical techniques. Crystals of 1 were harvested by a solvent evaporation method, and single-crystal X-ray diffraction (SCXRD) analysis revealed that 1 adopted a distorted tetrahedral geometry around the central metal ion. The topological simplification of 1 ascertained the simple hcb net. The bulk-phase purity of as-synthesized 1 was confirmed by the decent match of powder X-ray diffraction (PXRD) patterns with the simulated patterns. The band gap and chemical reactivity potential of 1 were confirmed by HOMO-LUMO analysis. Complex 1 showed the efficient adsorption of cationic methylene blue (MB) and anionic methyl orange (MO) dyes from wastewater with good uptake. At room temperature and at neutral pH, complex 1 exhibited the highest removal efficiencies (90% and 80%) and adsorption capacities (qe = 116.22 mg/g and 102.62 mg/g) for MB and MO dyes, respectively. The plausible mechanism of cationic and anionic dyes removal is based on insight from structural information and existance of array of non-covalent interactions in complex 1. Additionally, complex 1 was also evaluated for catecholase-like activity in ethanol for the oxidation of 3,5-DTBC to 3,5-DTBQ. Complex 1 showed good catecholase-like activity with potential catechol conversion results, kcat = 0.98⨯102 h−1, KM = 0.0506 M, and Vmax = 0.0485⨯10-3 M min−1.

Structural, Vibrational and Electro-Optical Properties on Perchlorate Salt of 4-Methoxyaniline Studied through Experimental and Theoretical Methods

Single crystals of hydrogen bonded 4-methoxyanilinium perchlorate (4MAPC) have been grown and the corresponding structure has been confirmed by Single crystal XRD analysis. The charge transfer on the nitrogen site of 4-methoxyaniline has been confirmed from elongated carbon and nitrogen bond distances. The Quantum chemical calculations of 4-methoxyanilinium perchlorate have been studied at HF and DFT methods with 6-311++G(d,p) level of theory to get the optimized geometry, FT-IR/FT-Raman spectra, charge distributions and the microscopic NLO efficiency of the title compound. The HOMO-LUMO analysis indicates that the electron delocalization and the energy gap between the HOMO-LUMO of the 4MAPC indicates the charge transfer within the molecule. The energy gap values between the molecular orbitals are 4.7358 eV (DFT)/6.8044(HF) eV, which makes the compound more reactive. The Population analysis has been studied and discussed. The Hirshfeld surface analysis suggests that the most significant contribution to the crystal packing is by O…H contacts (29%). The microscopic NLO parameters of 4MAPC have been calculated and the relative second order hyperpolarizability (γ) of the compound has found to be 47 times greater than that of standard Urea. .

Ab-initio simulation of the interaction of gold nanoclusters with glycine

Nanomaterial-Biomolecules complexes have several important applications in biological processes and bionanoscience. In this regard, the adsorption of the simplest amino acid (glycine) on the gold nanocluster has been studied to understand the interaction of amino acid with Au nanocluster. Small nanoclusters (neutral and cationic) of five, eight, thirteen, fifteen, and eighteen atoms have been utilized for this study. UV-Vis spectroscopy, Reduced Density Gradient (RDG), HOMO-LUMO analysis has been performed for nanoclusters and their glycine adsorbed complexes which provides information about the charge transfer binding mechanism, and establish the nature of interaction in glycine-gold nanocluster complexes. It is observed that the neutral and cationic Au nanoclusters show the highest adsorption energy for clusters of five, thirteen, and fifteen atoms. When the HOMO-LUMO energy gap of the cationic form of Au nanoclusters and glycine adsorbed Au nanoclusters are studied, it is observed that the HOMO-LUMO energy gap is decreased monotonically as cluster size increases in all cases (namely the lowest energy structure, first higher energy structure, and second higher energy structure). The results from the current work will be applicable as nanocluster sensors for glycine detection.

Theoretical study on S/Fe-doped hexagonal boron nitride (h-BN) sheet: Electronic and optical properties

Limited by the wide band gap of h-BN, the application of h-BN in photocatalysis is extremely challenging. In this paper, a strategy of co-doping monolayer h-BN with sulphur and iron was proposed to enhance the stability and catalytic activity of photocatalysts. Firstly, based on density functional theory (DFT), several models of monolayer h-BN nanosheets with iron decoration was created and optimized. Secondly, the structural, electronic, and optical properties were investigated in this paper, and the calculations proves that the introduction of impurity energy levels mainly composed of Fe 3d orbitals is the key to solving the wide bandgap of boron nitride. The HOMO-LUMO analysis shows S atoms participate in the redistribution of electrons, which inhibits the recombination of electron-hole pairs. This work verified the higher photocatalytic ability and wider light absorption range of monolayer h-BN co-doped with sulfur and iron. This paper has pointed a promising path for the modification of h-BN in the direction of photocatalysis.

A DFT investigation on theranostic potential of alkaline earth metal doped phosphorenes for ifosfamide anti-cancer drug

Cancer is one of the leading causes of human mortality and a theranostics strategy is essential for its effective treatment. Density function theory (DFT) simulations were executed to examine the drug delivery, photothermal potential, and photoimaging guided cancer diagnostic potential of pristine and alkaline earth metal (M=Be, Mg, and Ca) doped phosphorenes (M-PH). The topological, electronic, and thermodynamic descriptors of M@PH and Ifosfamide (IFO) loaded systems (IFO@M-PH) were calculated. The oxygen atoms of IFO coordinated with the doped M-PH carrier. The adsorption process was exothermic and hence spontaneous. A higher adsorption energy was found for IFO@M-PH systems compared to undoped system. The polarity of the drug-carrying system is increased after doping which is favorable for effective in vivo drug flow. The HOMO-LUMO and natural bond orbital (NBO) analyses revealed that doping facilitated the charge transfer from drug to phosphorene. The quantum theory of atoms in molecules (QTAIM) and non-covalent interaction (NCI) studies show the presence of weak non-covalent interactions among the drug and substrate, supporting the effective drug release. The excited-state calculations for drug loaded complexes show the shifting of λmax from 434 nm to Near-Infrared (NIR) region. This supported IFO@M-PH as a potential candidate for photothermal therapy and photoimaging guided cancer diagnostic.

Synthesis, spectral analysis, DFT calculations, biological potential and molecular docking studies of indole appended pyrazolo-triazine.

A series of novel 5-(3,5-disubstituted-1H-indol-2-yl)-2,3-dimethyl-1-phenyl-2,6-dihydro-1H-pyrazolo[4,3-e][1,2,4]triazines (3a-l) were synthesized in single step from 3,5-disubstituted indole-2-carbohydrazide and 4-aminoantipyrine under acidic conditions with excellent yields. The various spectroscopic methods were used to prove the formation of all these products. The compounds 3a, 3b, 3e, 3f, 3i and 3j exhibited excellent antibacterial and antifungal activities with an MIC value of 3.125µg/ml against the tested pathogens and anti-tuberculosis inhibitory potential against M. tuberculosis which is equivalent to standard drug. The antidiabetic activity of the compounds 3a and 3b showed the maximum potential as glucosidase inhibitors with IC50 = 47.21μg/ml and IC50 = 48.36μg/ml, respectively. The physicochemical characteristics like ADMET, drug-likeness and bioactivity scores for these molecules were also disclosed. To comprehend the electronic behavior of compound 3a, density functional theory estimations at the DFT/B3LYP level via 6-31G++ (d, p) have been carried out to replicate the structure and geometry. The first-order hyperpolarizability calculation was used to calculate the nonlinear visual feature of compound 3a. The charge transfer interface among the structure is elucidated by the estimated HOMO-LUMO analysis. Further, molecular docking studies were carried out for synthesized compounds with human maltase-glucoamylase (PDB: 2QMJ).