DFT Study Research Articles

Investigation of the Dyeing Ability of Some Reactive Triazine Azo Dyes Containing Pyrazole Fragment.

The IR, 1H NMR, and DFT studies indicated that the prepared reactive disperse dyes predominately exist as hydrazone tautomers. The electronic absorption spectra in methanol were observed and compared to those computed using B3LYP/6-311G(d,p). The dyeing efficiency of the produced dispersed reactive dyes was examined on polyester, cotton, and polyester/cotton blended fabrics. The degree of exhaustion and the quick properties of the dyed samples in terms of perspiration, washing, scorch and light fastness were assessed. It was found that reactive disperse dyes under investigation have a higher affinity for dyeing polyester textiles than cotton textiles. Moreover, the reflectance and color strength of the synthesized dyes were measured and discussed.

Uncovering the potential of two-dimensional AlB2 monolayer as a negative electrode material for alkali metal ion batteries: A DFT study

The electrode's material properties have an important role in the efficient performance of metal ion batteries. The possibility of using the two-dimensional AlB2 monolayer as the negative electrode material of lithium, sodium, and potassium ions was explored by the first-principles calculation in this study. It turns out that the storage capacity of AlB2 for Li, Na, and K ions is superior to that of many reported negative electrodes, which are about 1102, 1102, and 413 mA h g−1, respectively. The migration barriers for Li, Na, and K ions in the monolayer of AlB2 are 0.428, 0.162, and 0.019 eV, respectively, indicating that the AlB2 monolayer can be charged and discharged rapidly. Therefore, AlB2 is promising as a potential anode material for alkali metal ion batteries.

Understanding the separation of trivalent lanthanides and actinides using multiple diglycolamide-containing ligands: a review

Abstract The complexation and separation behaviour of trivalent actinides and lanthanides with various multiple diglycolamide (DGA) group-containing ligands are compiled in the present review. The DGA arms are anchored on various scaffolds, viz., C- and N-pivot tripodal backbones, benzene-centred tripodal backbones, calix[4]arene, pillar[5]arene and azamacrocycle scaffolds. Dendrimers of different generations having DGA arms were also evaluated for the extraction and complexation studies of trivalent actinide and lanthanide ions. The extraction efficiency of the DGA units increases significantly when they are grouped together on a single backbone/scaffold. Furthermore, the selectivity was found to improve in many cases, particularly with respect to the UO2 2+ ion. This is very important for the development of suitable ligands for the extraction/separation of the actinide and lanthanide ions. Combined experimental, luminescence and DFT studies on the complexation of trivalent actinides and lanthanides with these DGA-based ligands are quite useful to understand their extraction and separation behaviour and this review article gives a critical analysis of the results available in the literature.

Coordination competency of a flexible polyfunctional tripodal framework: an insight on solution thermodynamics and DFT studies

Coordination competency of a flexible polyfunctional tripodal framework: an insight on solution thermodynamics and DFT studies

Elucidating the mechanistic sensing capability of novel tetragonal graphene quantum dot towards tobacco alkaloids: a DFT study

Elucidating the mechanistic sensing capability of novel tetragonal graphene quantum dot towards tobacco alkaloids: a DFT study

Potential application of C-MoS2 monolayer for identifying lung cancer biomarkers in exhaled breath: a DFT study

Potential application of C-MoS2 monolayer for identifying lung cancer biomarkers in exhaled breath: a DFT study

Effect of the Degree of Cluster TiCl4 on the Polymerization of Isoprene over Ziegler–Natta Catalysts: A DFT Study

Effect of the Degree of Cluster TiCl₄ on the Polymerization of Isoprene over Ziegler–Natta Catalysts: A DFT Study

Unveiling proton-responsive sites and reaction mechanisms in formic acid dehydrogenation catalyzed by Cp*Ir(III)-Pyridylpyrrole complexes: A DFT study

Transition metal catalysts based on proton-responsive ligands are crucial in the realm of chemical hydrogen storage. Nevertheless, the existence of multiple proton-responsive active sites on the ligand adds complexity to the mechanism, limiting our understanding of mechanistic preferences. In this study, density functional theory calculations are used to clarify the mechanistic preferences of iridium catalysts with multiple proton-responsive sites on the ligand for formic acid dehydrogenation. The calculated results show that, with the assistance of the α carbon atom (C2) of the pyrrole ligand site, the catalyst undergoes through an inner-sphere stepwise dehydrogenation mechanism. Moreover, the proton shuttle mechanism efficiently reduces the activation energy needed for H2 production, and solvent-assisted dehydrogenation shows lower energy barriers than substrate-assisted dehydrogenation. The reasons for mechanistic selectivity are further elucidated through Fukui function analysis, molecular plane parameter analysis, and the distortion-interaction model. These findings are anticipated to establish a theoretical foundation for the future design of high-performance catalysts for formic acid dehydrogenation.

Evaluating Terrestrol A as an Inhibitor Against SARS‐CoV‐2and Invasive Fungal Pathogens: A Comprehensive Computational Analysis

AbstractThe highly contagious SARS‐CoV‐2 virus, which initiated the COVID‐19 pandemic, has resulted in a significant loss of life worldwide. While vaccines and therapeutics have helped mitigate the impact of SARS‐CoV‐2, worries still persist regarding the emergence of Variants of Concern (VOCs). Additionally, the immunosuppressive effects of SARS‐CoV‐2 and steroid treatments increase susceptibility to complex fungal co–infections (e. g., aspergillosis and candidiasis), complicating treatment and escalating mortality rates. These circumstances highlight the urgent need for novel therapeutics. Thus, this study explores gentisyl alcohol and its derivatives as inhibitors of SARS‐CoV‐2 and fungal pathogens (Aspergillus fumigatus and Candida auris) via in‐silico methodologies. Initial multi–targeted docking simulations revealed that Terrestrol A(10) exhibited highly promising results, displaying the most favourable MolDock‐scores against all targets of interest, particularly against PDB ID 4K90 and 7CR5. The subsequent assessment of Terrestrol A(10) for their druglikeness, ADME, toxicity profiling, bioactivity, and PASS prediction also yielded highly favourable results. Structural dynamics analysis revealed stable yet slightly unfolding complexes, affirming their integrity. DFT studies also demonstrated favourable reactivity of Terrestrol A(10). This investigation identifies Terrestrol A(10) as a highly promising inhibitor against SARS‐CoV‐2 and fungal pathogens, laying the groundwork for in vitro and in vivo validation of its efficacy and clinical utility.

Breaking the Rules: On the Relative Stability of Some Methylencyclopropane and Methylcyclopropene Derivatives.

The structure of the spirocyclic product obtained by reacting catechol with 1,1-dichloro-2-(chloromethyl)cyclopropane is shown by NMR and X-ray analysis to be that of a 2-methylcyclopropene (MeCP), instead of the previously reported 2-methylenecyclopropane (MCP) one. The study of the equilibration between the two isomeric forms by experimental and computational means (including both Density Functional Theory - DFT - and Coupled Cluster with single, double, and perturbative triple excitations - CCSD(T) - calculations) revealed that, at variance with most of the alkylidenecyclopropane/alkylcyclopropene systems described to date, for the compounds of the present study the MeCP derivative is more stable by≈ 2.5-3.0 Kcal mol-1 than the MCP one. The extension of the DFT and CCSD(T) study to other spiro-MCP/MeCP pairs suggests that the origin of the unexpected shift of the equilibrium position can be tracked back to a combination of electronic and ring-strain effects. These findings lead to re-think a long-standing, and substantially undisputed belief in the area of unsaturated cyclopropane derivatives.

Electrocatalytic Reduction of CO2 to CO by Molecular Cobalt–Polypyridine Diamine Complexes

Cobalt complexes have previously been reported to exhibit high faradaic efficiency in reducing CO2 to CO. Herein, we synthesized capsule-like cobalt–polypyridine diamine complexes [Co(L1)](BF4)2 (1) and [Co(L2) (CH3CN)](BF4)2 (2) as catalysts for the electrocatalytic reduction of CO2. Under catalytic conditions, complexes 1 and 2 demonstrated the electrocatalytic reduction of CO2 to CO in the presence or absence of CH3OH as a proton source. Experimental and computational studies revealed that complexes 1 and 2 undergo two consecutive reversible one-electron reductions on the cobalt core, followed by the addition of CO2 to form a metallocarboxylate intermediate [CoII(L)–CO22−]0. This crucial reaction intermediate, which governs the catalytic cycle, was successfully detected using high resolution mass spectrometry (HRMS). In situ Fourier-transform infrared spectrometer (FTIR) analysis showed that methanol can enhance the rate of carbon–oxygen bond cleavage of the metallocarboxylate intermediate. DFT studies on [CoII(L)–CO22−]0 have suggested that the doubly reduced species attacks CO2 on the C atom through the dz2 orbital, while the interaction with CO2 is further stabilized by the π interaction between the metal dxz or dxz orbital with p orbitals on the O atoms. Further reductions generate a metal carbonyl intermediate [CoI(L)–CO]+, which ultimately releases CO.

DFT studies of the structural and electronic properties of PdGen (n= 1-11) clusters and adsorption capacity for some gas molecules

Abstract Density Functional Theory (DFT) calculations have been employed for the theoretical exploration of the geometric structures and electronic characteristics of PdGen (n = 1 - 11) clusters. An analysis of the second- order energy differences indicates that PdGe7 and PdGe10 clusters possess superior thermodynamic stability. PdGe10 showcases the highest chemical stability and the lowest chemical activity, attributed to its largest energy gap value (Eg). Vertical ionization potential (VIP) and vertical electron affinity (VEA) exhibit the decreasing and increasing trends, respectively, with the increase of the number n of Ge atoms. PdGe10 presents the highest electronegativity among these clusters. The study on the adsorption properties of PdGen (n=7,10) clusters with gases such as CO, NO, NO2, NH3, SO2 and H2S yields the adsorption structures, adsorption energies, Mulliken charge transfer, and changes in electronic properties. All the listed gas molecules chemically adsorb onto PdGe7. PdGe10 has a better adsorption performance for NO2, while its adsorption ability for CO is poorer. The potentiality of PdGen (n = 7, 10) clusters as gas sensors is also evaluated, which reveals that NO adsorption significantly affects the electronic properties, especially conductivity, of the systems. PdGe10 has an appropriate NO adsorption capacity and significant charge transfer, with the adsorption energy of -0.278 eV and the recovery time of about 10-9 seconds, indicating its fast response and hence good potentiality as the NO sensor. In contrast, PdGe7 has a higher adsorption capability towards NO with a lower adsorption energy of -1.16 eV, leading to difficulty in desorption and a longer recovery time of over 12 hours. Thus, PdGe10 would act as a potential gas sensing material.

Efficient Dye Extraction from Wastewater Using Indium-MOF-Immobilized Polyvinylidene Fluoride Membranes with Selective Filtration for Enhanced Remediation.

Industrial activities have led to releasing harmful substances into the environment, necessitating the elimination of these toxic compounds from wastewater. Organic dyes, commonly found in industrial effluents, pose a threat to ecosystems and human health. Conventional treatment methods often suffer from limitations such as high cost and poor efficiency. Metal-organic frameworks (MOFs) have emerged as promising materials for selective separation, including membrane filtration (MF). Mixed-matrix membranes (MMMs) combining MOFs with polymers offer improved filtration properties. In this study, MMMs were fabricated by incorporating synthesized In-MOF with a polyvinylidene fluoride (PVDF) polymer (In-MOF@PVDF MMMs) using the nonsolvent-induced phase separation process. The MMMs were evaluated for the MF of various organic dyes, achieving notable removal efficiencies. The membrane containing 20% In-MOF (M4) demonstrated exceptional performance, removing 99% of the methylene blue (MB) dye. Additionally, membrane M4 effectively filtered Azure A (AZA), Azure B (AZB), and toluidine blue O (TOLO) with a removal efficiency of 99%. However, for Rhodamine B (RHB) and methyl orange (MO), the removal efficiencies were slightly lower at 74 and 39%, respectively. Further, these membranes are utilized in selective dye filtration in the MB+/RHB+ and MB+/MO- systems, where the selectivity was found for MB. The isothermal and DFT studies revealed the membrane's behavior with dye mixtures, while water stability and regeneration studies confirmed its durability. Thus, these findings highlight the potential of In-MOF@PVDF MMMs for effective and selective dye removal in wastewater treatment applications.

Investigating the adsorption behavior of cyano radical on zigzag aluminum nitride and aluminum phosphide nanotubes: A DFT study

Investigating the adsorption behavior of cyano radical on zigzag aluminum nitride and aluminum phosphide nanotubes: A DFT study

DFT studies on structure, electronics, bonding nature, NBO analysis, thermodynamic properties, molecular docking, and MM-GBSA evaluation of 4-methyl-3-[2-(4-nitrophenyl)-1,3-dioxo-2,3-dihydro-1H-isoindole-5-amido]benzoic acid: a potent inhibitor of Graves’ disease

AbstractA calculation analysis on the molecular structure and energy of 4-methyl-3-[2-(4-nitrophenyl)-1,3-dioxo-2,3-dihydro-1H-isoindole-5-amido]benzoic acid (COD30) is carried out with the 6-311G (d,p) basis set by the DFT/RB3LYP method as an anti-graves' disease treatment. The calculated FT-IR spectrum is strongly correlated with the vibrational spectra reported in the literature. To evaluate the entire electron density and organic reactive sites of COD30, molecular electrostatic potential (MEP) and frontier molecular orbitals (FMO) were analyzed. The density of states analysis is used to determine the orbital molecular contributions (DOS and PDOS). In comparison to methimazole (MMI) and propylthiouracil, COD30 showed more encouraging docking results, and it also offered golden binding contacts in addition to an improvement in docking energy (PTU). The outcomes of bioactivity prediction and MD simulation indicate that COD30 could be further developed into an inhibitor of Graves' disease.

Development of a fluorescent scaffold by utilizing quercetin template for selective detection of Hg2+: Experimental and theoretical studies along with live cell imaging

Quercetin is an important antioxidant with high bioactivity and it has been used as SARS-CoV-2 inhibitor significantly. Quercetin, one of the most abundant flavonoids in nature, has been in the spot of numerous experimental and theoretical studies in the past decade due to its great biological and medicinal importance. But there have been limited instances of employing quercetin and its derivatives as a fluorescent framework for specific detection of various cations and anions in the chemosensing field. Therefore, we have developed a novel chemosensor based on quercetin coupled benzyl ethers (QBE) for selective detection of Hg2+ with “naked-eye” colorimetric and “turn-on” fluorometric response. Initially QBE itself exhibited very weak fluorescence with low quantum yield (Φ = 0.009) due to operating photoinduced electron transfer (PET) and inhibition of excited state intramolecular proton transfer (ESIPT) as well as intramolecular charge transfer (ICT) within the molecule. But in presence of Hg2+, QBE showed a sharp increase in fluorescence intensity by 18-fold at wavelength 444 nm with high quantum yield (Φ = 0.159) for the chelation-enhanced fluorescence (CHEF) with coordination of Hg2+, which hampers PET within the molecule. The strong binding affinity of QBE towards Hg2+ has been proved by lower detection limit at 8.47 µM and high binding constant value as 2 × 104 M−1. The binding mechanism has been verified by DFT study, Cyclic voltammograms and Jobs plot analysis. For the practical application, the binding selectivity of QBE with Hg2+ has been capitalized in physiological medium to detect intracellular Hg2+ levels in living plant tissue by using green gram seeds. Thus, employing QBE as a fluorescent chemosensor for the specific identification of Hg2+ will pave the way for a novel approach to simplifying the creation of various chemosensors based on quercetin backbone for the precise detection of various biologically significant analytes.

A Siderophore Mimicking Gelation Component for Capturing and Self-Separation of Fe(III) from an Aqueous Solution of Mixture of Metal Ions.

The carbohydrazide-based gelation component N2,N4,N6-(1,3,5-triazine-2,4,6-triyl)tris(benzene-1,3,5-tricarbohydrazide) (CBTC) was synthesized and characterized using various spectroscopic tools. CBTC and trimesic acid (TMA) get self-assembled to form metallogel with Fe3+, specifically through various noncovalent interactions in a DMSO and H2O mixture. The self-assembly shows remarkable specificity toward Fe(III) among different transition metal salts. It is pertinent to point out that the binding specificity for Fe3+ can also be found in nature in the form of siderophores, as they are mainly involved in scavenging iron selectively from the surroundings. DFT studies have been used to investigate the possible interaction between the different components of the iron metallogel. To determine the selectivity of CBTC for iron, CBTC, along with trimesic acid, is used to interact with other metal ions, including Fe(III) ions, in a single system. The gelation components CBTC and TMA selectively bind with iron(III), which leads to the formation of metallogel and gets separated as a discrete layer, leaving the other metal ions in the solution. Therefore, CBTC and TMA together show iron-scavenging properties. This selective scavenging property is explored through FE-SEM, XPS, PXRD, IR, and ICP-AES analysis. The FE-SEM analysis shows a flower-petal-like morphology for the Fe(III) metallogel. The resemblance in the CBTC-TMA-Fe metallogel and metallogel obtained from the mixture of different metal salts is established through FE-SEM images and XPS analysis. The release of iron from the metallogel is achieved with the help of ascorbic acid, which converts Fe3+ to Fe2+. In biological systems, iron also gets released similarly from siderophores. This is the first report where the synthesized gelation component CBTC molecule is capable of scavenging out iron in the form of metallogel and self-separating from the aqueous mixture in the presence of various other metal ions.

Ultrasound-assisted nano-GO/NiO mediated green synthesis, DFT studies and antiinflammatory activity of spiro indoles

An improved procedure has been developed for synthesizing derivatives of spiroindole in 84–87% yield by using catalytic amount of graphene oxide supported nickel oxide nanocomposite (GO/NiO NC) as a proficient heterogeneous catalyst under ultrasonic-irradiation. GO/NiO NC can be recycled and reused for three successive runs with slight reduction in its catalytic activity. Short reaction time, simple workup, and eco-friendly conditions are key features of the current protocol. Most importantly, the synthesized compounds, 4b, 4c, 5b, 5c, and 5d showed good anti-inflammatory potential by inhibiting protein denaturation at all the given concentrations. HOMO-LUMO studies indicate that the carbonitrile derivatives have the smallest energy gap which implies more chemical reactivity.

Superalkalis with Hydrogen as Central Electronegative Atom and their Possible Applications: Ab Initio and DFT Study.

Superalkalis are unusual species having ionization energies lower than that of the alkali metals. These species with various applications are of great importance in chemistry due to their low ionization energies and strong reducing property. A typical superalkali contains a central electronegative core decorated with excess metal ligands. In the quest for novel superalkalis, we have designed the superalkalis HLi2, HLiNa and HNa2 using hydrogen as central electronegative atom for the first time employing high level ab initio (CCSD(T), MP2) and density functional theory (ωB97X-D) methods. The superalkalis exhibit very low ionization energies, even lower than that of cesium. Stability of these species is verified from binding energy and dissociation energy values. The superalkalis are capable of reducing SO2, NO, CO2, CO and N2 molecules by forming stable ionic complexes and therefore can be used as catalysts for the reduction or activation of systems possessing very low electron affinities. The superalkalis form stable supersalts with tailored properties when interact with a superhalogen. They also show remarkably high non-linear optical responses, hence could have industrial applications. It is hoped that this work will enrich the superalkali family and spur further theoretical and experimental research in this direction.

Photocatalytic Synthesis of β-Keto Primary Chlorides by Selective Chlorocarbonylation of Olefins.

Functionalized primary alkyl chlorides are precursors to a plethora of scaffolds but their access from chemical feedstocks remains challenging. Herein, we report a concise dual Ni/photoredox catalytic protocol for regioselective chlorocarbonylation of unactivated alkenes that enables rapid access to β-keto primary chlorides. The catalytic process features an extensive substrate scope, scalability and functional group tolerance. The Ni/photocatalytic Cl⋅ generation and subsequent cross-coupling is implicated for the process based on the control experiments and DFT study. The synthetic utility of the protocol has been further corroborated through functionalization of complex substrates and modifications of the product.