Theoretical DFT Study Research Articles

From germolane to germylenes: a theoretical DFT study of thermal decomposition pathways and reactivity

This study addresses the often-overlooked chemistry of germanium compared to the extensively researched carbon and silicon. Using advanced DFT methods, we investigated the thermal decomposition of germolane (germacyclopentane). The suggested mechanisms include a 1,2-H shift and 1,1-H2 elimination to form a pentacyclic germylene (1λ2-germolane). The other pathway involves a stepwise [3 + 2] cycloreversion to form a diradical followed by ethene and germirane. Under M062X/def2-TZVP level of theory, the activation barriers in terms of Gibbs energy (ΔG ‡ 298) for the 1,2-H shift and 1,1-H2 elimination pathways were 240.9 and 236.3 kJ/mol, respectively. The reaction energies (ΔG° 298) for the initiative steps in the 1,2-H shift and 1,1-H2 elimination mechanisms were 102.9 and 96.2 kJ/mol, indicating a thermodynamic and kinetic competition between the two routes. Temperature dependence analysis from 300 to 1200 K reveals that the 1,1-H2 elimination dominates at higher temperatures and is expected to become spontaneous above 1000 K.

Crystal structure, Hirshfeld surface analysis, and DFT theoretical studies of an azobenzene derivative from powder X-ray diffraction

Crystal structure, Hirshfeld surface analysis, and DFT theoretical studies of an azobenzene derivative from powder X-ray diffraction

4-Diphenylaminobenzaldehyde-formulated isonicotinohydrazide for the rapid recognition of Cu2+ ions; Application of RGB tool, pharmaceutical samples, and DFT studies

High copper concentrations have been linked to several harmful illnesses in humans and negatively affect the kidneys and liver. The design and synthesis of simple and effective chemosensors for recognizing copper (Cu2+) ions are extremely significant. However, most of the colorimetric chemosensors have been developed using an intramolecular charge transfer binding mechanism based on donor-acceptor conjugation systems. This study aimed to fabricate a novel Schiff base colorimetric chemosensor, N'-(4-(diphenylamine) benzylidene) isonicotinohydrazide (DPBA-INH), with high sensitivity and selectivity towards copper ions in the semi-aqueous medium (DMSO: H2O, 7:3, v/v). The synthesized receptor DPBA-INH was distinguished using various spectroscopic methods, including NMR analysis, Fourier transform infrared spectroscopy, HRMS, and ultraviolet-visible (UV–vis) spectroscopy. When exposed to sunlight, the receptor DPBA-INH with Cu2+ ion complexation exhibited a color change from orange to pale yellow. A Job's plot and electrospray ionization mass spectra confirmed the presence of complexation at a stoichiometric binding proportion of the receptor to Cu2+ ions of 1:1. The receptor DPBA-INH interacts with Cu2+ ions in a 1:1 stoichiometric manner with a detection limit of 1.40 × 10−7 M. The experimental results were supported by a theoretical DFT study. Moreover, the receptor effectively measured Cu2+ ions in pharmaceutical samples and test strip analyses. Furthermore, the rapid colorimetric recognition of Cu2+ ions in a semi-aqueous medium was achieved using DPBA-INH, which was demonstrated to be an excellent receptor. Notably, DPBA-INH was employed to detect copper ions in real water samples.

Zeolites as Solid Solvents: Explaining the Chloromethane Hydrolysis over Metal-Exchanged Zeolite Y by DFT Calculations.

We report a theoretical DFT study of the reaction pathways for chloromethane hydrolysis over metal-exchanged zeolites (Li+, Na+, K+, and Mg2+). A cluster of 78 T atoms (T referring to Si or Al atoms), comprising the zeolite Y super cavity coupled with the sodalite cage and three hexagonal prism units (Si(78-x)Al x O129H54; x = 1 or 2), was used in the calculations. The study was carried out using the ONIOM method. The high layer was computed at M062X/6-31++G(d,p), whereas the low layer was computed at the PM6 level of theory. The energy profile was obtained by single-point calculations at the M062X/6-31++G(d,p) for the entire structure. The first step studied was the adsorption of chloromethane on the zeolite, which involves an ion-dipole interaction between the metal cation and the chlorine atom. Then, two mechanistic pathways were investigated: one via formation of an adsorbed methoxide and the other involving a direct, one-step, nucleophilic attack of the water molecule to the adsorbed chloromethane. In all systems studied, the direct mechanism showed a lower energy of activation than the route involving the methoxide intermediate. The same behavior was also observed for chloromethane methanolysis to afford dimethyl ether on the metal-exchanged zeolites. The theoretical results are in agreement with the experiments of chloromethane hydrolysis over metal-exchanged zeolite Y, explaining the formation of dimethyl ether upon chloromethane methanolysis on zeolites of low or no acidity. The transition state for the direct route resembles a SN2 process assisted by the surface, reinforcing the concept of zeolites as solid solvents, providing a polar nanoenvironment that favors and assists the formation of ionic transition states and intermediates.

Tuning the Structures of Amide‐Imine Conjugates for Sequential Optical Recognition of Mo(VI) and AsO2− Ions

AbstractTwo amide‐imine conjugates where amide is synthesized by reacting hydrazine with 4‐hydroxybenzoic acid and subsequently condensed with 2‐hydroxy naphthalene‐1‐carbaldehyde (m1) and 2‐hydroxy benzaldehyde (m2), selectively detects Mo(VI) at nano molar level via change in emission characteristics. The interactions have been authenticated from single crystal X‐ray structures of resulting Mo(VI) complexes (Mo1 and Mo2). Further, Mo1 selectively interacts with AsO2− via formation of H‐bond that facilitates its detection through change of emission characteristics. The binding constant of Mo1 for AsO2− is 1.02×105 M−1/2. The TCSPC studies support the interaction of Mo1 with AsO2−. The probe‐analyte interaction has also been established by different spectroscopic techniques like 1H NMR, ESI‐MS, FTIR and Jobs experiment. Theoretical DFT studies justifies the reason behind the interaction and support experimental spectroscopic findings. Notably, the sequential fluorescence recognition of Mo(VI) and AsO2− by m1 have been explored to construct a logic gate.

CO2 adsorption on a K-promoted MgO surface: A DFT theoretical study

The primary cause of global warming is the emission of greenhouse gases such as CO2. So reducing CO2 emissions is vital. This paper investigates the impact of the atom K as a promoter of MgO on the CO2 adsorption properties using the DFT theoretical computational method. By analyzing the adsorption energy, bader charge as well as the density of states and COHP, it was found that K-promoting the MgO (100) surface resulted in a redistribution of charge on the MgO surface and enhanced CO2 adsorption compared to the pure MgO surface. The presence of K atoms causes orbital hybridization among O (CO2) and Mg atoms, O (CO2) atoms and K atoms, and the surface O atoms and K atoms. These interactions lead to the formation of (MgO)Mg-O(CO2) and (CO2)O−K−O(MgO) chemical bonds. The adsorption energy of CO2 on the K-promoted MgO surface increased from -0.32 eV to -1.01 eV compared to the pure surface, enhancing the adsorption of CO2.

Toward highly ionic polyelectrolyte membrane: Synthesis, characterization, membrane performance and theoretical studies of PVDF-g-PAN/PAMPS hybrid membranes

Novel highly ionic polyvinylidene fluoride (PVDF) membranes grafted with an acrylonitrile monomer to yield the target (PVDF-g-PAN) via radical polymerization and then blended with the amphiphilic copolymer poly (2-acrylamido-2-methyl-1-Propane sulfonic acid (PAMPS) via physical interactions (PVDF-g-PAN)/(PAMPS), were designed and constructed. The new functional groups obtained (fluoride, nitrile, and sulfonic functions) were confirmed via FTIR analysis, and the prepared membranes were characterized using SEM, TGA, tensile strength, water contact angle, and mechanical stability instruments. The essential characteristics of the polyelectrolyte membranes, including the IEC, ionic conductivity, methanol permeability, thermal stability, and high mechanical qualities, were examined. It was discovered that, the oxidative stability of the modified membrane (P3) with a high concentration of conductive PAMPS affected the percentage of weight loss (5.25 %) at the end of 24 h. In addition, the water absorption capacity increased with increasing in the concentration of PAMPS. Similarly, the highly concentrated PAMPS modified membranes (P3) have an ionic exchange capacity and proton conductivity equal to IEC= 1.93 meq/g, which is greater than that of the Nafion membrane by 0.91 meq/g. Furthermore, appropriate DFT theoretical studies such as EHOMO, ELUMO, energy band gap and dipole moment (µ) were thoroughly examined and employed to validate the highly ionic system. It was found that, the energy band gap of PVDF-g-PAN/PAMPS was 5.19 eV, which is lower than that of the grafted polymer value (7.17 eV), confirming that the electrons are transferred readily from the HOMO level to the LUMO level. In addition, the dipole moment of the PVDF-g-PAN/PAMPS was 7.10 Debye, which is greater than the dipole moment value of the grafted polymer (2.07 Debye), indicating the highly ionic character of the hybrid polymer. Finally, the promising results obtained demonstrated favorable film-forming and structural properties, making it a promising option for polyelectrolyte membranes. It also has the added advantage of being cost-effective and can be applied in many electrochemical applications.

Investigating the corrosion inhibition of copper using DFT theoretical study with three organic molecules

A theoretical study of the inhibition efficiency of three organic heterocyclic molecules has been thoroughly probed using density functional theory B3LYP/6-31G(d) level. The calculated global quantities such as electrophilicity and nucleophilicity show that the three organic inhibitors are nucleophiles. The obtained values of charge transfer and energy of back-donation show that the 2-amino-4-(4-bromophenyl)thiophene-3-carbonitrile is the best inhibitor. Parr function indices have been calculated to determine the most preferred sites for the nucleophilic attacks towards the electrophilic transition metal surface of copper. The electrostatic surface potential has been mapped in order to explore the major regions of the molecules responsible of the inhibition. It is found that the zone surrounding the nitrogen atom and the -aromatic system of benzene are the one forming the protection layer. The theoretical results are in good commitment with the experimental results.

Enhancing the Crystallinity of Keto‐enamine‐Linked Covalent Organic Frameworks through an in situ Protection‐Deprotection Strategy

Abstractβ‐Keto‐enamine‐linked 2D covalent organic frameworks (COFs) have emerged as highly robust materials, showing significant potential for practical applications. However, the exclusive reliance on 1,3,5‐triformylphloroglucinol (Tp aldehyde) in the design of such COFs often results in the production of non‐porous amorphous polymers when combined with certain amine building blocks. Attempts to adjust the crystallinity and porosity by a modulator approach are inefficient because Tp aldehyde readily forms stable β‐keto‐enamine‐linked monomers/oligomers with various aromatic amines through an irreversible keto‐enol tautomerization process. Our research employed a unique protection‐deprotection strategy to enhance the crystallinity and porosity of β‐keto‐enamine‐linked squaramide‐based 2D COFs. Advanced solid‐state NMR studies, including 1D 13C CPMAS, 1H fast MAS, 15N CPMAS, 2D 13C−1H correlation, 1H−1H DQ‐SQ, and 14N−1H HMQC NMR were used to establish the atomic‐level connectivity within the resultant COFs. The TpOMe‐Sqm COFs synthesized utilizing this strategy have a surface area of 487 m2 g−1, significantly higher than similar COFs synthesized using Tp aldehyde. Furthermore, detailed time‐dependent PXRD, solid‐state 13C CPMAS NMR, and theoretical DFT studies shed more light on the crystallization and linkage conversion processes in these 2D COFs. Ultimately, we applied this protection‐deprotection method to construct novel keto‐enamine‐linked highly porous organic polymers with a surface area of 1018 m2 g−1.

Enhancing the Crystallinity of Keto-enamine-Linked Covalent Organic Frameworks through an in situ Protection-Deprotection Strategy.

β-Keto-enamine-linked 2D covalent organic frameworks (COFs) have emerged as highly robust materials, showing significant potential for practical applications. However, the exclusive reliance on 1,3,5-triformylphloroglucinol (Tp aldehyde) in the design of such COFs often results in the production of non-porous amorphous polymers when combined with certain amine building blocks. Attempts to adjust the crystallinity and porosity by a modulator approach are inefficient because Tp aldehyde readily forms stable β-keto-enamine-linked monomers/oligomers with various aromatic amines through an irreversible keto-enol tautomerization process. Our research employed a unique protection-deprotection strategy to enhance the crystallinity and porosity of β-keto-enamine-linked squaramide-based 2D COFs. Advanced solid-state NMR studies, including 1D 13 C CPMAS, 1 H fast MAS, 15 N CPMAS, 2D 13 C-1 H correlation, 1 H-1 H DQ-SQ, and 14 N-1 H HMQC NMR were used to establish the atomic-level connectivity within the resultant COFs. The TpOMe -Sqm COFs synthesized utilizing this strategy have a surface area of 487 m2 g-1 , significantly higher than similar COFs synthesized using Tp aldehyde. Furthermore, detailed time-dependent PXRD, solid-state 13 C CPMAS NMR, and theoretical DFT studies shed more light on the crystallization and linkage conversion processes in these 2D COFs. Ultimately, we applied this protection-deprotection method to construct novel keto-enamine-linked highly porous organic polymers with a surface area of 1018 m2 g-1 .

MgO-modified biochar by modifying hydroxyl and amino groups for selective phosphate removal: Insight into phosphate selectivity adsorption mechanism through experimental and theoretical

Metal oxides-modified biochars have been widely studied as promising adsorbents for removing phosphate from wastewater discharge. Yet, the low adsorption selectivity towards phosphate severely limits its potential in practical applications. In this study, MgO-modified biochar modified by hydroxyl and amino groups (OH/NH2@MBC) is developed for selective phosphorus recovery from wastewater. As major results, the OH/NH2@MBC exhibits favorable phosphate adsorption performance is superior to that of MBC resin in the presence of co-existing anions (NO3−, Cl−, HCO3− and SO42−) and natural organic matter (humic acid) even actual wastewater, suggesting its superior selectivity towards phosphate. The OH/NH2@MBC shows an excellent phosphate adsorption capacity (43.27 mg/g) and desorption ratio (82.34 %) after five cycles under the condition of anion coexistence (100 mg/L). The experimental and DFT theoretical study reveals that attaching hydroxyl and amino groups onto the MBC surface, which facilitates to inhibiting the side effects of anions (NO3−, Cl−, HCO3−, and SO42−) through Lewis acid-base sites, hydrogen bonds, and metal affinity, and preferentially select adsorption P, contributing greatly to improve phosphate adsorption selectivity. Importantly, the presence of amino and hydroxyl groups can reduce the Fermi level of OH/NH2@MgO(220) and OH/NH2@MgO(200) and improve the adsorption selection for HPO42−. This study provides an effective strategy for enhancing the adsorption selectivity of metal oxides-modified biochars towards phosphate through modifying functional groups.

S-Se oxidative addition to auranofin derivatives: a DFT study.

Oxidative addition of the S-Se bond to Au(I) complexes is discussed for a series of 26 auranofin (AF) derivatives. AF and its analogues are Au(I) complexes with recognized anticancer activity that act by binding and inhibiting the thioredoxin reductase (TrxR) enzyme. Generally, the oxidative addition to Au(I) is a sluggish reaction under mild conditions (i.e., a high activation barrier - ΔH‡), which is also verified here for AF, ΔH‡ = 33.0 kcal mol-1. However, we predicted that subtle changes in the AF ligands can make the process feasible under standard conditions. For instance, the exchange of -PEt3 by -P(Et2)(OEt), which is a weaker electron σ-donor, reduced the activation barrier to 17.1 kcal mol-1. Furthermore, substitution of the -SAtg ligand by -Cl- leads to a ΔH‡ value of 22.5 kcal mol-1. Overall, the reaction is driven by the nucleophilic attack of the S-Se bond on the Au(I) center, attributed mainly to the charge transfer (4p)Se → (6p)Au, which characterizes the addition step. At the transition state (TS) point, the (5d)Au → σ*(S-Se) charge transfer becomes relevant, facilitating the S-Se bond breakage and the oxidation step. In addition to the electron transfers, the strain energy to deform the linear Au(I) geometry to the tetracoordinated Au(III) arrangement in the TS structure plays a primary role in explaining the trends in the activation barriers. Finally, the activation barrier (ΔH‡) and reaction energy (ΔH°) were correlated for most of the complexes studied, which suggests that the reaction passes through a late or product-like TS and, therefore, the steric and electronic factors affecting ΔH‡ also act on ΔH°. Overall, the results presented here might open up a new field of investigation for interactions between AF derivatives and TrxR, which contributes to a full understanding of the biological mechanism of action of these species.

Using eugenol scaffold to explore the explosive sensing properties of Cd(II)-based coordination polymers: experimental studies and real sample analysis.

Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies. Consequently, the N,O-donor chelating ligand HL was coordinated with Cd2+, in the presence of bridging pseudohalides (thiocyanate, SCN-, and dicyanamide, N(CN)2-) to synthesize two luminescent coordination polymers (CPs 1 and 2): [Cd2(L)2(X)2]n (where HL = 4-allyl-2-(((2-(benzylamino)ethyl) imino)methyl)-6-methoxyphenol and Xs are bridging pseudohalides, i.e., SCN- and N(CN)2-) on a Cd-eugenol scaffold. The CPs depicted structural diversity, bulk-phase purity, thermal stability, and the presence of interlayer supramolecular C-H⋯π interactions together with C-H⋯S (for CP 1) and C-H⋯N (for CP 2) interactions. The CPs further exemplified themselves as selective and sensitive 'turn-off' probes towards trinitrophenol (TNP) (quenching efficiency: 82.02% and 83.86% for 1 and 2) among a pool of hazardous nitroaromatic compounds (NACs). Accordingly, 1 and 2 exhibited an ultralow limit of detection (LOD) of 0.29 and 0.15 μM, with high quenching constants (KSV) of 5.91 × 104 and 17.60 × 104 M-1, respectively. In addition, TNP sensing events were evidenced to be recyclable and exhibited fast response (∼31 s, 1, and ∼40 s, 2), which increased its real-world viability. Vapor phase TNP sensing was also accomplished upon drop-casted CP films. Experimental investigations and theoretical DFT study confirmed the cooperative occurrence of RET-IFE-PET-collisional quenching and non-covalent π⋯π stacking as key factors involved in the TNP sensing performance. The competency of 1 and 2 in the detection of TNP from several complex environmental matrices (CEMs), viz. matchstick powder, river and sewage water, and soil specimens, was also established with good recovery (∼66-86% and ∼68-93% for 1 and 2, respectively) and high KSV values (3.90-11.39 × 104 and 6.17-18.79 × 104 M-1 for 1 and 2, respectively).

Ba15Zr14Te42: a new complex ternary telluride structure with low thermal conductivity.

Heavier metal-based tellurides with complex structures are of great interest for thermoelectric (TE) applications. Herein, we report the synthesis of a new telluride Ba15Zr14Te42 using high-temperature reactions of elements. Our single-crystal X-ray diffraction study reveals that it crystallizes in the space group R3̄c of the trigonal crystal system and is isostructural to its Se analogue Ba15Zr14Se42 complex. The unit cell of the structure accommodates 426 atoms with cell dimensions of a = b = 13.2666(10) Å, c = 96.195(9) Å, and V = 14 662(3) Å3. This structure consists of 18 unique crystallographic atoms (3 × Ba, 8 × Zr, and 7 × Te). The bonding of Zr and Te atoms creates chains of ∞1[Zr14Te42]30-, which are separated by the Ba2+ cations. Although all the Zr atoms have a coordination number of 6, they form two types of coordination polyhedra by bonding with six Te atoms: slightly distorted octahedral and trigonal prisms of ZrTe6. We have synthesized polycrystalline Ba15Zr14Q42 (Q = Se/Te) samples, which were characterized by optical absorption studies to reveal direct bandgaps of <0.5 eV for the Te analogue and 1.3(1) eV for the Se analogue. The lattice thermal conductivity (klat) values of the samples are ultralow: ∼0.46 W mK-1 and ∼0.30 W mK-1 at 773 K for the Te and Se analogues, respectively. Temperature-dependent resistivity and thermopower studies were carried out for the Ba15Zr14Te42, which showed the p-type degenerate semiconducting nature of the sample at high temperatures. The theoretical DFT studies predict a bandgap of 0.14 eV for the Ba15Zr14Te42 phase.

Nonlinear optical and spectroscopic properties, thermal analysis, and hemolytic capacity evaluation of quinoline-1,3-benzodioxole chalcone.

This article describes the synthesis, characterization (1H NMR, 13C NMR, FT-IR, HRMS and XRD), UV-Vis absorption and fluorescence spectra, theoretical analysis, evaluation of nonlinear optical properties (NLO), thermal analysis and determination of the hemolytic capacity of the compound (E)-N-(4-(3-(benzo[d][1,3]dioxol-5-yl)acryloyl)phenyl)quinoline-3-carboxamide (5). Radiological findings showed that compound 5 crystallized in space group Pca21. Furthermore, theoretical DFT studies performed with the B3LYP and M062X functionals showed good agreement with the experimental results and provided valuable information on the molecular and electronic structure, reactivity, polarizability, and kinematic stability of the compound. Besides, compound 5 did not show any hemolytic effect on human erythrocytes and exhibited strong NLO properties. The TG and DTA thermograms of quinoline-chalcone (5) revealed a multi-step thermal decomposition process with a total mass loss of 83.2%, including water content loss. The DTA curves exhibited endothermic peaks corresponding to decomposition steps, melting point, and thermochemical transition. Additionally, exothermic peaks in the DTA thermograms align with significant mass loss, confirming the compound's melting point and water content, as validated by X-ray diffraction analysis. These results contribute to the advancement of research on compounds with NLO properties and offer a promising avenue for the development of substances potentially applicable to optical devices in the biomedical field.

Novel zinc-antimony alloy as anodes in alkaline batteries in the presence of sulfide ions additive: Practical and computational study

The charge-discharge and corrosion processes of alloyed zinc with antimony in alkaline electrolytes were studied without and with adding sulfide ions. The obtained results reveal that the density of corrosion current (Icorr.) decays gradually, while the efficiency value of inhibition rises as a result of increasing S2− ions concentration. The process of an anodic reaction is more impacted than that of a cathodic one by adding S2− ions to the electrolyte. In addition, the presence of S2− ions can reduce ZnO and Sb2O3 produced on each surface of the two studied electrodes. The results showed that inhibition efficiency is also increased by raising the solution temperature containing the tested alloy’s S2− ions (1 × 10−3 M). This observation reflects that the type of S2− ions adsorption on the surface is chemical, and the additive species' adsorption process follows the Langmuir model. The data of charge-discharge investigation revealed that the longest discharge times of the two studied electrodes were obtained when S2− ions were present in the highest concentration (1 × 10−3 M). However, alloy II displayed a longer time and a bigger potential difference than alloy I. This illustrates that the addition of K2S helps suppress hydrogen evolution. Therefore, the self-discharge can be diminished, and the discharge capacity increased. The alkaline battery’s over-potential catalytic reaction is remarkably reduced, and the battery’s cyclic stability is improved. These results confirm that the addition of S2− ions has significantly improved the studied alloy utilization as an anode in alkaline batteries. The DFT theoretical study revealed that S2− ion is possessed at low ΔEgap. This can contribute to the inhibition process through chemical adsorption.

Experimental and theoretical DFT study of hydrothermally synthesized MoS2-doped-TiO2 nanocomposites for photocatalytic application

Two-dimensional (2D) transition metal dichalcogenides (TMDCs) have shown considerable potential in photocatalytic applications. In the present research, the hydrothermal technique was used to prepare 2D MoS2, TiO2, and 2D layered structured with basic ration formulation as MoS2(1-x)TiO2x (X = 5 %, 10 %w/w) nanocomposites as an effective catalyst for degradation of aqueous methylene blue (M.B.) under controlled light radiations. The GGA-PBE computed approach was used to estimate the energy bandgap (Eg), electronic, and optical properties of 2D MoS2, TiO2, and MoS2(1-x)TiO2x (X = 5 %, 10 %) by density functional quantum computing simulation. The TiO2 nanospheres were efficiently decorated on the surface of layered of MoS2 and some of nanospheres mixed into layered matrix. Scanning Electron Microscopy (SEM) and X-ray diffraction (XRD) investigate the morphology and crystal phase structure of the samples. Experimental and theoretical results related the energy bandgap (Eg) of the 2D layered structure of MoS2, TiO2, and MoS2(1-x)TiO2x (5 %, 10 % w/w) shows a decrement trend 1.56, 2.4, 1.02, and 0.5 eV respectively with increasing doping percentages. The observed extra gamma active states of MoS2(1-x)TiO2x (X = 5 %, 10 % w/w) are found to be generated and contributed to the creation of conduction and valance bands as the result of the decremented of their energy bandgap. The optical conductance was increased from 2.5 to 9.8 Ω−1cm−1 with a bandgap decrement of 2.4–0.5 eV in the ultraviolet–visible spectrum region. Exploration of theoretical and experimental results of this work, the MoS2(1-x)TiO2x (5 %, 10 % w/w) show increment in absorbance from 1.4 × 105 to 4.5 × 105 cm−1 and 0.6 cm−1 to 1.25 cm−1 respectively. The most interesting result is at the peak of 650 nm wavelength, as it is considered a proficient photo-catalyst material due to the enhanced absorption surface area for exposure of light and decrement of the photo-generated charge recombination rate and increment of the charge transportation with the inclusion of TiO2. The breakdown of methylene blue within 15 min confirmed that the prepared MoS2(1-x)TiO2x nanocomposite was a stable, and cost-effective material for photocatalytic application.

Design, Synthesis, Anticancer Screening and Molecular Modelling Studies of Novel Thiazoles

AbstractA library of novel benzamide‐thiazolyl‐chalcone compounds was synthesized via Claisen‐Schmidt reaction and spectroscopically characterized using FT‐IR, 1H‐NMR, 13C‐NMR, LC–MS, and HR‐MS. The synthesized compounds were biologically evaluated using in vitro MTT assay against different cancer cell lines (MCF‐7, MDA‐AMB‐231, Caco‐2, A549, and H1299). Amongst all compounds screened, (E)‐N‐(5‐(3‐(4‐hydroxyphenyl)‐3‐oxoprop‐1‐en‐1‐yl)thiazol‐2‐yl)benzamide and (E)‐N‐(5‐(3‐(4‐methoxyphenyl)‐3‐oxoprop‐1‐en‐1‐yl)thiazol‐2‐yl)benzamide showed potent anti‐proliferation against breast (MCF‐7) and colon cancer cell lines reaching 88.56 % and 84.36 % with IC50 values of 44.00 μM and 58.88 μM, respectively. All synthesized compounds exhibited no significant cytotoxicity to normal cells. Structure‐activity relationship studies demonstrated the effect of electron‐donating and electron‐withdrawing groups on the anticancer activity of the molecules under investigation. This was also corroborated by theoretical DFT studies. Thus, these molecules may serve as potential lead candidates for further development of novel anticancer agents against breast and colon cancers.

Rare earth ion-infused α-MnO2 nano-rods for excellent EMI shielding efficiency: Experimental and theoretical insights

In this communication, for the first time rare earth elements like Gd3+ and Er3+ ions are impregnated into the α-MnO2tunneled structure involving the modified chemical synthesis route followed by hydrothermal technique. X-ray diffraction patterns and Raman spectroscopy confirm the proper phase formation without any impurity. A theoretical in-depth DFT study for the electronic bands and variation of density of states with the infusion of rare earth elements into the host structure confirms the experimental findings and depicts the suitability of the material for the EMI shielding application. The novel synthesis technique helps to achieve uniform nanorod formation with a high specific surface area. Doping-induced defects, high surface-to-volume ratio, Maxwell-Wagner–Siller interfacial polarization, etc. lead to achieving high dielectric response with moderate tangent loss at a frequency range of 40 Hz to 1 MHz. Temperature-dependent dielectric behavior indicates the paramagnetic to ferromagnetic transition at 120 °C and 70 °C for the Gd- and Er-doped α-MnO2 samples respectively. The electromagnetic interference (EMI) shielding effectiveness (SE) has achieved a maximum of −43 dB at 15.3 GHz and − 46 dB at 15.3 GHz for Gd- and Er-doped α-MnO2 thin layer of thickness ∼600 μm respectively. Higher dipolar polarization, loss tangent, conductive pathways, and defects inside the crystal lead to attaining a high EMI shielding efficiency. This result reveals >99.997% EMI SE against the hazardous electromagnetic waves in the microwave/GHz frequency region.

Network-supported and adaptable binding efficacy for flexible and multi-functionalized chitosan/phenolic carbaldehyde hydrogels

A thoughtful strategy has been intended to control the hydrogel networking to assess the binding efficacy of multifunctional hydrogel. The processing of two distinct network-supported hydrogels has portrayed to express the operating interactions involved during co-existence with solvents, small molecules, biomolecules, etc. Herein, chitosan has separately functionalized in semisynthetic approaches with 4-hydroxyisopthalaldehyde (ChDA) and 2-hydroxybenzene-1,3,5-tricarbaldehyde (ChTA) to construct different gel networks. The disposition of gel networks ChDA adapts more flexible chain or spine, whereas ChTA possesses restricted movements within gel networks. The gel networks of hydrogels have a significant role in their distinct physical activities. Their gel-bonding elucidations have performed to establish the variation in mechanical, swelling photophysical properties, etc. Remarkable self-fluorescence behaviors are used as a tool for binding study. Distinctive gel networks and their flexibility have investigated against self-fluorescence, UV–Vis, and FTIR against small molecule, Boron trifluoride and biomolecule, and Bovine serum albumin. Hydrogel/BF3 shows variation in fluorescence due to the disposition of gel networks. Hydrogel/BSA quenching of fluorescence at three different temperatures provides the binding constant and Stern-Volmer quenching constant. Theoretical DFT and docking studies successfully established the flexibility against binding study. The controlling of cross-linking or functionalization is very crucial for the development of hydrogel-mediated applications.