DFT Study Research Articles

Structural modulation of methyl 4-(2,11-diisopropylbenzopentaphen-5-yl based chromophore with B12N12 nano cage for enhancing the NLO Properties: A DFT study

Currently, key electronic and nonlinear optics (NLO) properties of DPOB chromophore were explored through doping with B12N12 nanocage. Therefore, two complexes I and II were designed by doping nanocage on methoxy and carbonyl group of DPOB at minimum distance. The DFT/TD-DFT approaches at B3LYP-GD3/6-311G(d,p) functional were utilized to accomplished the NLO properties. A band gap: 3.109 and 2.707 eV in complexes I and II, respectively with higher value of softness and least hardness were investigated in doped material than their pure forms (DPOB and B12N12). The hyperpolarizability of studied compounds increases as: B12N12 < DPOB<Complex I<Complex II. Among all investigated compounds, complex II showed the maximum values of dipole moment (15.826 D), linear polarizability (7.04 × 102a.u.) and non-linear polarizability (βtot = 4.13 × 103 and γtot = 6.70 × 105a.u.). These findings illustrated that doping of inorganic nanocages over organic surfaces is an efficient strategy to improve the NLO properties.

Unveiling the role of oxygen in ammonia coal combustion: A DFT study on NOx emission mechanism

Ammonia-coal combustion mitigates CO2 emissions, yet nitrogen oxide emissions and char nitrogen oxidation mechanisms require further study. Our research employs density functional theory to explore coal char interactions with NO, NH3, and the impact of hydroxyls (–OH) and oxygen on reduction–oxidation processes. Findings indicate oxygen aids in forming hydroxyls on coal char, facilitating NO to NO2 conversion, lowering the activation energy for ammonia-coal oxidation to NO2. Oxygen also promotes char nitrogen oxidation to NO, reducing its activation energy. In NH3/coal/O2 systems, NH3 oxidation initiates NO formation. With the increase of the temperature, the reduction rate of NO by ammonia is always higher than the production rate of NO.

TM@MoSSe (TM = Ni, Fe) as novel electrocatalysts for reduction of CO2 to CO: A DFT study

It is crucial to develop highly efficient, selective and low-overpotential electrocatalysts for CO2 reduction. This paper proposes an efficient iron and nickel single-atom catalyst using Janus MoSSe as the substrate to reduce CO2 to CO by using DFT calculations. The adsorption of a single TM atom like Fe, Co, Ni, Ru, Rh, Pd, Os, Ir and Pt on Janus MoSSe monolayer results in a decrease in band gap, which may accelerate the catalytic CO2 reduction. The excellent catalytic activity of Fe@MoSSe and Ni@MoSSe is owing to the high d-band center and hence the strong TM-CO2 bonding. The asymmetric structure of Janus MoSSe creates the local built-in electric field, which further increases by about 8% or 0.8% after the adsorption of single Ni or Fe atom so as to afford the better electrocatalytic performances for reduction of CO2 to CO in both TM modified systems. So, this work proposes the catalysts Fe@MoSSe and Ni@MoSSe with good selectivity and activity for CO2 reduction by revealing their underlying mechanisms, and Janus MoSSe may be used as a potential substrate material for CO2 reduction catalysts.

Fulgide Derivatives as Photo-Switchable Coatings for Cathodes of Lithium Ion Batteries - A DFT Study.

Photo-switchable coatings for lithium ion batteries (LIB) can offer the possibility to control the diffusion processes from the electrode materials to the electrolyte and thus, for example, reducing the energy loss in the fully charged state. Fulgide derivatives, as known photo-switches, are investigated concerning their use as coating for vanadium pentoxide, a potential cathode material for LIB. With the help of Density Functional Theory calculations, two fulgide derivatives are characterized with respect to their photophysics, their aggregation behaviour on the cathode material and the ability to form self-assembled monolayers (SAM). Furthermore, the two states of the photo-switchable coating are tested with respect to lithium diffusion from the cathode material, passing the SAM and entering the electrolyte. We found a difference for the energy barriers depending on the state of the photo-switch, preferring its closed form. This behaviour can be used to prevent the loss of charge in batteries of portable devices.

Gas-Phase Reactivity of Actinides Monocations with NH3: ICP-MS Experiments Combined with a DFT Study.

The reactivity of actinide monocations (Th+, U+, Np+, Pu+, Am+, and Cm+) with NH3 gas was studied in the reaction cell of an inductively coupled plasma-mass spectrometer (ICP-MS). Only Th+, U+, Np+, and Cm+ react completely with NH3 to form AnNH+, contrary to Pu+ and Am+. Differences in reactivity are found between U+/Pu+, Pu+/Cm+, and Am+/Cm+, which could resolve isobaric interferences in ICP-MS. DFT calculations were performed across the first half of the actinide series. The calculated reaction energy between An+ and NH3 reproduces the experimental trends in reactivity with Th+ > Pa+ > U+ > Np+ > Ac+ > Cm+ > Pu+ > Am+. The reaction path involves the initial formation of an AnNH3+ adduct followed by N-H bond insertion with the formation of HAnNH2+ and H2AnNH+ intermediate species and subsequent H2 loss. The trend in reactivity across the actinides is largely due to the first energy barrier and formation of the HAnNH2+ intermediate species. This limiting step is energetically unfavorable for the Pu+ and Am+ cations. For these cations, the excitation energy required to achieve a reactive configuration with two non-f electrons available for bonding is too high.

Exploring the Electronic, Magnetic, Optical, and Thermoelectric Properties of Mn3Si2Te6 by Using the Strain Effect: A DFT Study

Exploring the Electronic, Magnetic, Optical, and Thermoelectric Properties of Mn3Si2Te6 by Using the Strain Effect: A DFT Study

Ajuga orientalis L. Extract as a Green Corrosion Inhibitor of Aluminum in an Acidic Solution: An Experimental and DFT Study

The inhibitory effect of A. orientalis L. extract (AO) on aluminum corrosion in a 1.0 M HCl solution was investigated utilizing weight loss, electrochemical polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). The results show that AO is a potent inhibitor in an acidic environment, and that the inhibition potency increases with concentration. Temperature investigations showed that, in an acidic medium, the efficiency decreased, increased, and then decreased as the temperature rose. Adsorption isotherms from Freundlich, Temkin, El Awady, and Redlich–Peterson (R-P) approximated the inhibitor’s adsorption properties. For the inhibitory behavior, a physical and chemical adsorption mechanism is proposed. The adsorption process’s thermodynamic parameters (Ea, ΔH*, and ΔS*) were determined and explained. The inhibitor, AO, was identified as a mixed-type (anodic and cathodic) inhibitor based on polarization studies. According to the SEM findings, the inhibitor partially covers the metal surface, providing it with a respectable level of protection. The weight loss, electrochemical polarization, EIS, scanning electron microscopy (SEM), and quantum chemical calculations show a strong agreement, indicating that the AO extract is a highly effective inhibitor of aluminum in an acidic solution.

DFT calculations of structural, chemical, electronic and thermodynamic properties of Rifampicin and Oxalic Acid

The thermodynamic properties of the compounds contribute to the theoretical analysis of the results of favorable energies that are subject to interaction. In this work, through the DFT study, the comparison of the functionals ωB97XD and B3LYP. Geometry optimization calculations and vibrational frequencies were performed for the individual ions and for the interactions. In all cases, all calculated vibrational frequencies are positive, confirming the optimized geometry obtained as a minimum on the potential energy surface. The calculations were carried out in solvent, considering the solvation effect in methanol using the IEFPCM (Integral Equation Formalism of the Polarizable Continuum Model) method. The present work aims to carry out a theoretical study, for in-depth investigations of structural, electronic and thermodynamic properties. In usability in the calculation of the thermodynamic properties, Rifampicin (RIF) and Oxalic Acid (OXA) and the interaction between RIF-OXA in the protonated form protonated RIF with charge +1 and deprotonated OXA with charge -1. In this context, the most favorable thermodynamic parameters in the interaction calculated RIF+-OXA- the values of ∆EZPVE+BSSE, ∆G298 and ∆H in kcal/mol more favorable are -19.62, -14.81 and -25,77.

Corrosion Inhibition of Copper by Pisum sativum Peel Extracts in NaCl Solution: Phytochemical Analysis and DFT Study

Corrosion Inhibition of Copper by Pisum sativum Peel Extracts in NaCl Solution: Phytochemical Analysis and DFT Study

Electron donor-acceptor complex enabled photocascade strategy for the synthesis of trans-dihydrofuro[3,2-c]chromen-4-one scaffolds via radical conjugate addition of pyridinium ylide.

A visible-light-induced photocascade strategy is disclosed for the synthesis of trans-dihydrofuro[3,2-c]chromen-4-one scaffolds. The photocascade consists of electron donor-acceptor (EDA) complex enabled formation of arylidene coumarinone, followed by 1,4-radical conjugate addition (1,4-RCA) of an in situ generated pyridinium ylide radical (PyYR) towards diastereoselective formation of the trans-dihydrofuro[3,2-c]chromen-4-one scaffold in good to excellent yield. Thorough mechanistic investigations comprising photophysical, spectroscopic, electrochemical and DFT studies provide further insights into the reaction mechanism.

Bio-templating approach and DFT study of ZrMo@KIT-6 catalyst for the conversion of deep fried oil into sustainable biodiesel production

In this study, highly porous ZrMo@KIT-6 heterogeneous catalyst was developed using Aloevera gel along with Pluronic as a mixed template. The catalytic activity was executed in biodiesel production from low valued deep fried oil to develop a sustainable energy approach. The physiochemical properties of the developed catalyst were assessed in depth using different analytical techniques including, TGA, XRD, BET, TPD-NH3, FESEM- EDX and XRD analyses. It was noted that the catalyst synthesized with Aloevera gel and Pluronic mixed template possessed improved texture, morphological properties and evenly distributed active centers with total acidity of 0.95 mmol/g and surface area of 741.46 m2/g. These experimental results were further endorsed by DFT analysis. Moreover, the designed catalystexhibited paramounted catalytic efficacy in transesterification reaction of deep fried oil into biodiesel, providing a phenomenal 97.7 % biodiesel yield under optimal reaction conditions. Apart from this, the designed catalyst sustained catalytic activity up to five times with biodiesel yield 87 %. Thus, the designed catalyst presents a novel fuel strategy which will bring both financial and environmental sustainability in the future.

DFT Study in An Asymmetric Organocatalytic Homologation: Mechanism, Origin of Stereoselectivity

DFT Study in An Asymmetric Organocatalytic Homologation: Mechanism, Origin of Stereoselectivity

Insight into Structural, Electronic, Elastic and Optical Properties of Thallium Based Perovskite TlXBr3 (X = Ti, Zr) via DFT Study for Reflective Coating

Insight into Structural, Electronic, Elastic and Optical Properties of Thallium Based Perovskite TlXBr3 (X = Ti, Zr) via DFT Study for Reflective Coating

Synthesis of Sulfonamide-Based Schiff Bases as Potent Anticancer Agents: Spectral Analyses, Biological Activity, Molecular Docking, ADME, DFT, and Pharmacophore Modelling Studies.

The current study focuses on the synthesis and characterization of six benzenesulfonamide-based Schiff base derivatives (7-12) with various electron-withdrawing and electron-donating substituents (-F, -CI, -Br, -CH3, and -OCH3) and the assessment of their antiproliferative activities against human lung (A549) and liver (HepG2) cancer cell lines using in vitro and in silico approaches. The structures of the synthesized compounds (7-12) were elucidated by elemental analysis and FT-IR, 1D (1H, 13C, APT, and DEPT-135), and 2D (HMQC and HMBC) NMR spectroscopies. The cytotoxic activities of the targeted compounds were determined at various concentrations against these cancer cell lines for 72 h, using the MTT method. The targeted molecules (7-12) demonstrated remarkable antiproliferative activities, with IC50 values ranging from 6.032-9.533 μM against the A549 cell line and 5.244-9.629 μM against the HepG2 cell line. These compounds showed activities at lower or very similar concentrations to cisplatin against the A549 cell line and at much lower concentrations than cisplatin against the HepG2 cell line. Among them, compounds 10 and 12 were found to be more effective against A549 and HepG2 cells, respectively, than cisplatin. These compounds were analyzed by interacting with the 1BNA, 4HJO, and 4ASD crystal structures in molecular docking studies.

Two Step One-Pot Synthesis of 7-Azaindole Linked 1,2,3-Triazole Hybrids: In-Vitro and In-Silico Antimicrobial Evaluation.

Herein, we report design, synthesis and characterization of a new library of 7-azaindole N-ethyl linked 1,2,3-triazoles containing ethylene as a spacer unit, and evaluation of all the synthesized compounds for their antimicrobial properties. Antibacterial potential was checked against two Gram positive (B. subtilis and S. aureus) and two Gram negative (E. coli and P. aeruginosa) bacterial strains while antifungal potential was assayed against two fungal strains (C. albicans and A. niger). All the tested compounds showed satisfactory antibacterial potency in comparison to reference drug ciprofloxacin with MIC values ranging from 0.0108 to 0.0432 μmol/mL. Interestingly, except two, all the target compounds showed better antifungal property as compared to the reference drug fluconazole with MIC values less than 0.0408 μmol/mL. One of the compounds exhibited two-fold better antifungal potential in comparison to fluconazole. Furthermore, in-silico ADMET and DFT studies reported drug likeness behavior and chemical reactivity parameters, respectively. The cytotoxicity results on substrate azide 3 and most potent 1,2,3-triazoles (5 d and 5 l) were found to be non-toxic.

Unleashing the synergistic potential of 2D-2D nanosheet based S-scheme heterojunction: Cooperative boosting of CO2 reduction to solar fuel and biomass valorization.

Harnessing inexhaustible solar energy for CO2 valorization is substantial step toward achieving carbon-neutral energy cycle. However, CO2 conversion often exhibits slow kinetics, necessitating the utilization of sacrificial agents making the process economically unfeasible. In the ongoing quest for sustainable and economically feasible CO2 valorization, herein the photoreduction of CO2 to CO coupled with biomass-based alcohol oxidation to fine chemicals is reported via Bi2WO6/g-C3N4 (BWO/g-CN) 2D-2D nanosheet based S-scheme heterojunction. Importantly, BWO/g-CN-60 exhibits highest photocatalytic activity with CO production rate of 6.87 mmol g-1 h-1, accompanied by >98% selectivity and selective oxidation of veratryl alcohol to veratraldehyde, with notable yield of 42% in 6 h under simulated solar light. The apparent quantum yield (AQY) of 14.3% is achieved for CO production at the wavelength of 420 nm. Additionally, the formed heterostructure results in enhanced charge separation and accelerated charge transfer kinetics as validated by PL, EIS, and photocurrent studies. EPR, 13CO2 labeling, DFT studies, and various controlled experiments provided deeper insight into the mechanism of underlying photo-redox process. Thus, the current study presents a sustainable paradigm for CO2 mitigation by converting it into solar fuel, while synergistically producing the fine chemicals through effectively harnessing the full potential of charge carriers.

Naphthalene Diimide and Bis-Heteroleptic Ru(II) Complex-Based Hybrid Molecule with 3-in-1 Functionalities.

Multipurpose applications of a newly developed homobimetallic Ru(II) complex, Ru-NDI[PF6]4, which incorporates 1,10-phenanthroline and triazole-pyridine ligands and linked via a (-CH2-)3 spacer to the reputed anion-π interacting NDI system, are described. Solution-state studies of the bimetallic complex, including EPR, PL, UV-vis, and NMR experiments, reveal two sequential one-electron transfers to the NDI unit, generating NDI⋅- and NDI2- in the presence of F- selectively. This process inhibits the primary electron transfer from Ru(II) to the NDI unit, thereby allowing the 3MLCT-based emission of the complex to be recovered, resulting in a corresponding ten-fold increase in luminescence intensity. DFT and TD-DFT computational studies further elucidate the experimentally observed absorption spectra of the complex. Secondly, CT-DNA binding studies with the complex are performed using various spectroscopic analyses such as UV-vis, PL, and CD. Comparative DNA binding studies employing EB and molecular docking reveal that the binding with CT-DNA occurs through both intercalative and groove binding modalities. Thirdly, the photocatalytic activities of the complex towards C-C, C-N, and C-O bond formation in organic cross-coupling reactions, including the amidation of α-keto acids to amines and the oxidation of alcohol to aldehydes, are also demonstrated.

Computation‐Guided Scope Exploration of a Conjugate Addition/Truce‐Smiles Cascade Reaction for Scaffold Diversification

Based on the successful application of a nitroaryl transfer cascade reaction in the total synthesis of various monoterpene indole alkaloids proceeding via fused bicyclic intermediate, we investigated analogous cascade reactions involving spiro, bridged, and alternatively fused bicyclic intermediates. Unfortunately, none of these was found to afford the desired nitroaryl transfer product. DFT studies of the original cascade process revealed that the Truce‐Smiles rearrangement is the rate‐determining step. In addition, we found that the subsequent SO2 extrusion is accompanied by retro‐Mannich ring opening, resulting in a stabilized enolate that only recyclizes after activation of the cyclic imine moiety. Computation of the reaction profiles of the proposed alternative cascade reactions showed that the barrier for the Truce‐Smiles rearrangement is unreasonably high for the bridged and alternatively fused systems, but only moderately higher for the five‐membered spiro system. Reasoning that even more electron‐deficient arenesulfonamides should have a lower barrier for the Truce‐Smiles rearrangement, we synthesized the corresponding 2,4‐dinitrobenzenesulfonamide precursor and found that it indeed smoothly undergoes the nitroaryl transfer cascade at room temperature. In this case, however, the cascade reaction produces a cyclic imine product, as the intermediate 2,4‐dinitrophenyl‐substituted enolate is insufficiently nucleophilic to undergo the Mannich cyclization.

Cyanide and chloroform detection through J-aggregates based aggregation induced emission probe with real sample applications

Isopthalamide based probe DPI has been synthesized by an easy two-step substitution reaction. Unique fluorescence properties of probe DPI were exploited for sensing of CNˉ and chloroform. Various spectroscopic techniques such as NMR, LC-MS, SEM, DLS, UV-Vis. and fluorescence spectroscopy in combination with DFT studies were used to confirm efficient detection of CN‾ through a non-covalent interaction of cyanide with probe. Furthermore, probe showed fluorescence emission at 360 nm which shifted significantly to 415 nm upon addition of water exhibiting unique AIE characteristics and formation of desired J-aggregates. Mechanistically, CN‾ and chloroform were selectively detected through fluorescence quenching with 9 nM and 0.2 % v/v limit of detection (LOD), respectively. Photoinduced electron transfer (PET) was proven to be involved as a sensing mechanism. Moreover, DPI exhibited interesting solvatochromism properties. DPI was proven to be a highly sensitive probe which showed solid-state and vapor phase on-field detection of CN‾. Similar sensing behavior of DPI probe towards CN‾ was seen in food and water samples.

First report on exploration of structural features of natural compounds (NPACT database) for anti-breast cancer activity (MCF-7): QSAR-based virtual screening, molecular docking, ADMET, MD simulation, and DFT studies.

The online version contains supplementary material available at 10.1007/s40203-024-00266-5.