Orbital Analysis Research Articles

Enhanced Thermoelectric Properties in Na-Doped PbTe via Pb Vacancies and Trace Eu Doping.

Enhancing the thermoelectric performance of Na-doped PbTe is challenging due to the low solubility of Na, a problem that remains insufficiently explored from a theoretical perspective, particularly regarding the role of Pb vacancies. In this study, we utilize crystal orbital Hamilton population and electron localization function analyses to investigate the impact of Pb vacancies on Na solubility in PbTe. Our findings indicate that Pb vacancies strengthen Na-Te bonding and improve electron localization around Te atoms, which reduces the formation of Te vacancies and facilitates a higher dissolution of Na. Furthermore, we examine the effects of trace Eu doping in Pb0.95Na0.04Te, which optimizes band convergence, leading to a power factor of ∼27 μW cm-1 K-2 at 823 K and a significant reduction in lattice thermal conductivity to ∼0.42 W m-1 K-1. The synergistic effects of these modifications result in a peak zT of ∼2.3 at 823 K and an average zT of ∼1.2 across the temperature range of 323 to 823 K. These insights highlight Pb vacancies and trace Eu doping as promising strategies for advancing high-performance thermoelectric materials, thus contributing to the broader field of thermoelectric research and material development.

Electronic Spectroscopy of the Halogenated Criegee Intermediate, ClCHOO: Experiment and Theory.

A chlorine-substituted Criegee intermediate, ClCHOO, is photolytically generated using a diiodo precursor, detected by VUV photoionization at 118 nm, and spectroscopically characterized via ultraviolet-visible (UV-vis)-induced depletion of m/z = 80 under jet cooled conditions. UV-vis excitation resonant with a π* ← π transition yields a significant ground state depletion, indicating a strong electronic transition and rapid photodissociation. The broad absorption spectrum peaks at 350 nm and is attributed to contributions from both syn (∼70%) and anti (∼30%) conformers of ClCHOO based on spectral simulations using a nuclear ensemble method. Electronic structure theory shows significant differences in the vertical excitation energies of the two conformers (330 and 371 nm, respectively) as well as their relative stabilities in the ground and excited electronic states associated with the π* ← π transition. Natural bond orbital analysis reveals significant and nonintuitive nonbonding contributions to the relative stabilities of the syn and anti conformers.

Controlled tuning of HOMO and LUMO levels in supramolecular nano-Saturn complexes.

Optoelectronics usually deals with the fabrication of devices that can interconvert light and electrical energy using semiconductors. The modification of electronic properties is crucial in the field of optoelectronics. The tuning of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) and their energy gaps is of paramount interest in this domain. Herein, three nano-Saturn supramolecular complex systems are designed, i.e., Al12N12@S-belt, Mg12O12@S-belt, and B12P12@S-belt, using S-belt as the host and Al12N12, Mg12O12, and B12P12 nanocages as guests. The high interaction energies ranging from -22.03 to -63.64 kcal mol-1 for the complexes demonstrate the stability of these host-guest complexes. Frontier molecular orbital (FMO) analysis shows that the HOMO of the complexes originates from the HOMO of the host, and the LUMO of the complexes originate entirely from the LUMO of the guests. The partial density of states (PDOS) analysis is in corroboration with FMO, which provides graphical illustration of the origin of HOMO and LUMO levels and the energy gaps. The shift in the electron density upon complexation is demonstrated by the natural bond orbital (NBO) charge analysis. For the Al12N12@S-belt and B12P12@S-belt complexes, the direction of electron density shift is towards the guest species, as indicated by the overall negative charge on encapsulated Al12N12 and B12P12. For the Mg12O12@S-belt complex, the overall NBO charge is positive, elaborating the direction of overall shift of electronic density towards the S-belt. Electron density difference (EDD) analysis verifies and corroborates with these findings. Noncovalent interaction index (NCI) and quantum theory of atoms in molecules (QTAIM) analyses signify that the complexes are stabilized via van der Waals interactions. Absorption analysis explains that all the complexes absorb in the ultraviolet (UV) region. Overall, this study explains the formation of stable host-guest supramolecular nano-Saturn complexes along with the controlled tuning of HOMO and LUMO levels over the host and guests, respectively.

Tailored Silica‐Based Sensors (SBA‐Pr‐Ald‐MA) for Efficient Detection of Iron (III) Ions: A Comprehensive Theoretical and Experimental Viewpoint

ABSTRACTThe synthesis and characterization of SBA‐Pr‐Ald‐MA as a modified mesoporous silica material made from SBA‐15 are presented in this work. Meldrum's acid (MA), 2‐chloroquinoline‐3‐carbaldehyde, and 3‐(chloropropyl)‐trimethoxysilane were used to functionalize the SBA‐15. The detection limit of 7.80 × 10−8 M for SBA‐Pr‐Ald‐MA demonstrated its exceptional selectivity toward Fe3+ ions. Density functional theory (DFT) calculations were conducted using B3LYP/6‐311g(d,p)/LANL2DZ to investigate the molecular electrostatic potential (MEP), geometry optimization, molecular orbital analysis, quantum chemical descriptors, and photoinduced electron transfer (PET). Geometry optimization and the MEP diagram verified the mechanism of the interaction obtained from experimental results. PET analysis indicated that the electrons transition to the LUMO of the Pr‐Ald‐MA + Fe3+ complex, leading to maximum fluorescence quenching efficiency. Future research could explore the sensor's application in real‐world environmental monitoring systems and extend its application to detect other hazardous metal ions.

Combined Experimental and Computational Investigations of 4‐Amino‐2‐Chloro‐6,7‐Dimethoxyquinazoline as Potential Anti‐Alzheimer Agent

ABSTRACTAlzheimer's disease (AD) is a neurodegenerative condition that leads to the deterioration of brain cells, resulting in memory loss, thinking, and executive skills. In this work, 4‐amino‐2‐chloro‐6,7‐dimethoxyquinazoline (ACDQ) has been studied using the 6–311++G(d,p) B3LYP functional of the density functional theory (DFT) approach utilizing a basis set. Geometry optimization and fundamental vibrational frequencies are calculated using the above method. The spectroscopic investigations such as FT‐IR, FT‐Raman, and UV–Vis spectra are performed on the selected compound. The time‐dependent DFT calculations are performed in the gas and water phases to determine electronic properties and energy gap using the same basis set. Charge density distributions have been used to illustrate the energy gap between the highest occupied and lowest unoccupied molecular orbitals. Mulliken population analysis is performed to determine the atomic charges of ACDQ. From the natural bond orbital analysis, it is observed that there is a significant electron delocalization in ACDQ due to the presence of intramolecular interactions. To evaluate ACDQ's anti‐Alzheimer potential, a molecular docking simulation is used to assess its structural stability and biological activity against proteins associated with Alzheimer's disease. Our docking study revealed that, ACDQ has a strong interaction with 4EY7 protein with binding energy of −8.1 kcal mol−1. Additionally, metrics such as the root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the radius of gyration are considered (Rg) were computed using molecular dynamics simulations to evaluate the stability of the protein–ligand interaction. Studies on the ADMET prediction of ACDQ have also been carried out. The findings of the current study support the potential of ACDQ as an effective lead therapeutic for Alzheimer's disease.

Bioavailability and molecular recognition between secondary metabolites of Euphorbia hirta L. and 5-lipoxygenase using fragment molecular orbital method and pair interaction energy decomposition analysis

Is presented the bioavailability analysis for seven secondary metabolites from Euphorbia hirta L. (Euphorbiaceae). The bioactivity score, the molecular similarity analysis for each secondary metabolite, and the molecular docking 5-LOX/metabolite complex are also presented. For the similarity analysis, it is referenced the structure of allosteric LOX-5 inhibitor 3-acetyl-11-keto-beta-boswellic acid (AKBA). The fragment molecular orbital method (FMO) and pair interaction energy decomposition analysis (PIEDA) were applied to evaluate the interaction energy between secondary metabolites and the 5-LOX active site. Log P values of all the secondary metabolites studied were found to be higher than 5, contrary to what was expected with Lipinski’s rules of five. The reference LOX-5 ligand has a high electrostatic potential similarity with most secondary metabolites studied, with values from 0.667 to 0.730. Both AKBA and metabolites ligands were wedged between the two domains of LOX-5, and the main residues contact were LEU-66, ARG-68, VAL-110, HIS-130, ILE-126, GLN, 129, and LYS-133. The PIEDA analysis showed that stabilization in the 5-LOX active site is mainly dominated by hydrophobic interactions, with values up to -35 Kcal/mol. Due to the low presence of terminal-OH groups, electrostatic origin, and charge transfer interaction energies are also important but have values of less than 20 Kcal/mol.

Development and application of a LC-HRMS method for simultaneous determination of ten illicit antifungal drugs in herbal bacteriostatic products.

The widespread use of sub-therapeutic antibiotics may lead to treatment failures, increased resistance to antibiotics, and even the encouragement of the formation of superbugs. Fraudulent herbal medicines that actually contain unlabeled active ingredients are a global problem. Therefore, streamlined and accurate analytical techniques that can identify and quantify a variety of antimicrobials in suspected illegal products are required. In the present work, we developed a sensitive, robust, and accurate method that involves multi-step extraction, EMR-lipid-based pass-through cleanup, and UHPLC-Q/HRMS with an orbital ion trap instrument analysis for the simultaneous detection of ten illicit antifungal drugs (flucytosine, fluconazole, ketoconazole, naftifine hydrochloride, griseofulvin, bifonazole, econazole nitrate, elubiol, clotrimazole, and miconazole nitrate) in herbal disinfection products. This validated method was then applied to 210 authentic samples, resulting in 25% of the samples being positive for the drugs. The results suggested the need to strengthen controls in this field to detect illicit antifungal drugs in herbal bacteriostatic products, which represents a potential health risk for the consumer. On a global scale, more and more frequent routine monitoring is being carried out in this area. This study provides valuable insights into large-scale complex sample chemical profiling, and the method developed appears to be promising and applicable for high-throughput routine multiple antibiotic analysis in a complex sample matrix.

Examining Magnetic Properties and Multiferroicity in the Isostructural Cu2TSiS4 (T = Mn and Fe) System Based on the DFT Approach and the Orbital Interaction Analysis.

In the experiment, despite their structural and electronic similarities, Cu2MnSiS4 exhibits AFM ordering characterized by a propagation vector k = (1/2, 0, 1/2), while Cu2FeSiS4 has a different type of AFM ordering with a propagation vector k = (1/2, 1/2, 1/2). To unravel how these differences arise, we investigated magnetic properties of Cu2TSiS4 (T = Mn and Fe) based on the DFT calculation and an orbital interaction analysis. We suggest that the Cu+ ion plays an important role in exhibiting different magnetic structures for the isostructural and pseudoisoelectronic Cu2TSiS4 (T = Mn and Fe) compounds. In detail, participation of Cu+ ions into spin exchange interaction J5, which is a spin exchange interaction along the b-direction, is critical for exhibiting AFM coupling of J5, and the strength of this effect should be responsible for exhibiting different magnetic structures of Cu2MnSiS4 and Cu2FeSiS4. We also explored the ferroelectric polarization of the Cu2TSiS4 (T = Mn and Fe) system on the basis of DFT + U and DFT + U + SOC calculation. Our result reveals that the ferroelectric polarization of the Cu2TSiS4 (T = Mn and Fe) system is mainly governed by its geometric structure rather than its magnetic order and the spin-orbit coupling effect.

Natural Flavonoids as Primary Amoebic Meningoencephalitis Inhibitor: Virtual Screening, Molecular Docking, MD Simulation, MMPBSA, Density Functional Theory, Principal Component, and Gibbs Free Energy Landscape Analyses

ABSTRACTFlavonoids have been showing diversified bioactivities. Primary amoebic meningoencephalitis is a brain inflammation caused by Naegleria fowleri brain eating amoeba. In this manuscript, we selected 93 flavonoids by extensive literature survey and 83 flavonoids passed drug likeness parameter. Selected flavonoids were molecular docked against primary amoebic meningoencephalitis N. fowleri CYP51 receptor considering voriconazole as standard. Beta naphthoflavone, abyssinone I, and abyssinone III showed maximum docking scores of −10.9 kcal/mol, −10.7 kcal/mol, and −10.6 kcal/mol, respectively, whereas voriconazole showed docking scores of −7.6 kcal/mol. Molecular dynamic simulation data showed that RMSD values attained almost a static value during the simulation, and all nearest interacting amino acid residues were fluctuated within limit. Molecular Mechanics Poisson‐Boltzmann Surface Area (MMPBSA) data of beta naphthoflavone abyssinone I, abyssinone III, and voriconazole showed free binding energies of −82.755 kJ/mol, −1924.193 kJ/mol, −1890.335 kJ/mol, and −540.141 kJ/mol, respectively. Frontier molecular orbital (FMO) analysis showed that abyssinone III was the chemically reactive molecule and beta naphthoflavone showed maximum electrophilicity. Molecular electrostatic potential (MEP) analysis portrayed possible nucleophilic‐electrophilic attack areas of the structures. PCA and free energy landscape (FEL) analysis data confirmed the stable conformations between flavonoids and receptor. Abyssinone I and III showed nontoxic behavior. These data confirmed that if we repurpose these flavonoids against primary amoebic meningoencephalitis, it will be beneficial for mankind.

Effect of a single water molecule on the conformational preferences of a capped Pro–Gly dipeptide in the gas phase

Herein, we have investigated the effect of microhydration on the secondary structure of a capped dipeptide Boc-DPro-Gly-NHBn-OMe (Boc = tert-butyloxycarbonyl, Bn = Benzyl), i.e., Pro–Gly (PG) with a single H2O molecule using gas-phase laser spectroscopy combined with quantum chemistry calculations. Observation of a single conformer of the monohydrated peptide has been confirmed from IR-UV hole-burning spectroscopy. Both gas-phase experimental and theoretical IR spectroscopy results confirm that the H2O molecule is inserted selectively into the relatively weak C7 hydrogen bond (γ-turn) between the Pro C=O and NHBn N–H groups of the peptide, while the other C7 hydrogen bond (γ-turn) between the Gly N–H and Boc C=O groups remains unaffected. Hence, the single H2O molecule in the PG⋯(H2O)1 complex significantly distorts the peptide backbone without appreciable modification of the overall secondary structural motif (γ–γ) of the isolated PG monomer. The nature and strength of the intra- and inter-molecular hydrogen bonds present in the assigned conformer of the PG⋯(H2O)1 complex has also been examined by natural bond orbital and non-covalent interaction analyses. The present investigation on the monohydrated peptide demonstrates that several H2O molecules may be required for switching the secondary structure of PG from the double γ-turn to a β-turn that is favorable in the condensed phase.

Declined S1 but Constant T1 Energy: Thermally Activated Delayed Fluorescence with Triplet Blocking Effect.

Thermally activated delayed fluorescence (TADF) molecules have been widely investigated in organic light emitting diodes (OLED), organic lasing, etc. Small singlet-triplet energy gap (ΔEST) and high radiative rate constants (kF) are highly desired to utilize triplet excitons efficiently and are beneficial to reduce efficiency roll-off of devices of OLED devices. The prevalent TADF molecules are via donor-acceptor molecular design, for which the decreasing of the ΔEST is often at the expense of reducing the kF. Herein, we demonstrated a new ΔEST modulation approach to construct TADF with high kF, based on triplet blocking effect, i.e., the extension of π-conjugation of a triplet constrainer (IB) leads to a gradually red-shifted S1 but a constant T1 energy and therefore reduced ΔEST controlled from monomer (IB), monomer-linker (IB-BF2), to dimer of IB-BF2-IB. The natural transition orbital analysis indicates that S1 state is delocalized while T1 state is localized as confirmed by time resolved electron paramagnetic resonance spectroscopy. Therefore, the ΔEST is reduced from 0.60 eV, 0.46 eV to 0.25 eV, while keeping faster radiation rate (around 108 s-1) than that of conventional donor-acceptor molecules (106∼107 s-1). As a result, the emission mechanisms are regulated from fluorescence for IB, phosphorescence/TADF dual emissions for IB-BF2 to TADF for IB-BF2-IB. This paper proposed a new approach of ΔEST modulation and a new type of TADF molecule with high radiation rate, which is crucial for fundamental photophysics as well as material science.

Declined S1 but Constant T1 Energy: Thermally Activated Delayed Fluorescence with Triplet Blocking Effect

AbstractThermally activated delayed fluorescence (TADF) molecules have been widely investigated in organic light emitting diodes (OLED), organic lasing, etc. Small singlet‐triplet energy gap (ΔEST) and high radiative rate constants (kF) are highly desired to utilize triplet excitons efficiently and are beneficial to reduce efficiency roll‐off of devices of OLED devices. The prevalent TADF molecules are via donor‐acceptor molecular design, for which the decreasing of the ΔEST is often at the expense of reducing the kF. Herein, we demonstrated a new ΔEST modulation approach to construct TADF with high kF, based on triplet blocking effect, i.e., the extension of π‐conjugation of a triplet constrainer (IB) leads to a gradually red‐shifted S1 but a constant T1 energy and therefore reduced ΔEST controlled from monomer (IB), monomer‐linker (IB‐BF2), to dimer of IB‐BF2‐IB. The natural transition orbital analysis indicates that S1 state is delocalized while T1 state is localized as confirmed by time resolved electron paramagnetic resonance spectroscopy. Therefore, the ΔEST is reduced from 0.60 eV, 0.46 eV to 0.25 eV, while keeping faster radiation rate (around 108 s−1) than that of conventional donor‐acceptor molecules (106∼107 s−1). As a result, the emission mechanisms are regulated from fluorescence for IB, phosphorescence/TADF dual emissions for IB‐BF2 to TADF for IB‐BF2‐IB. This paper proposed a new approach of ΔEST modulation and a new type of TADF molecule with high radiation rate, which is crucial for fundamental photophysics as well as material science.

Bioassay-guided separation of antioxidants in Blaps rynchopetera Fairmaire and their theoretical mechanism

Blaps rynchopetera Fairmaire is a medicinal insect with a wide range of biological activities. Some of its activities, including anti-cancer and anti-inflammatory activities, are closely related to antioxidant capacity. In this study, a method was established to investigate components and theoretical mechanism of antioxidant from B. rynchopetera. As a result, two antioxidants were obtained by bioassay-guided separation and identified as 4-(2-hydroxyethyl)-1,2-benzenediol and 4-ethylbenzol-1,3-diol. Their EC50 were 20.20 ± 0.30 μM and 22.90 ± 1.30 μM for ABTS·+ scavenging, and 153.00 ± 2.00 μM and 301.00 ± 3.00 μM for DPPH· scavenging, respectively. The thermodynamic investigation indicated that the 2-OH of 4-(2-hydroxyethyl)-1,2-benzenediol and the 1-OH of 4-ethylbenzol-1,3-diol were more susceptible to be attacked by free radicals. They tended to exert antioxidant effects via the sequential proton loss electron transfer mechanism in polar media, whereas the hydrogen atom transfer mechanism was more likely to occur in non-polar media. In addition, frontier molecular orbital theory and energy barrier analysis suggested that 4-(2-hydroxyethyl)-1,2-benzenediol was more likely to react with DPPH·. These results confirmed that 4-(2-hydroxyethyl)-1,2-benzenediol had better antioxidant potential.

Synthesis, quantum chemical insights, vibrational spectral elucidation, insecticide likeness and docking analysis of the insecticide active novel molecule 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole

Oxadiazole derivatives containing pyridine moiety were biologically active molecules that have been widely applied in recent years in research on pesticides, particularly insecticides. In this work, a newly synthesized 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole compound was characterized using spectroscopic techniques. The quantum chemical computations based on density functional theory were employed to investigate the molecular configuration of title compound. The modes of vibrations of the compound were identified through potential energy distribution, and the results were consistent with the experimental infrared and Raman data. Natural bond orbital assessment evaluated the significant donor-acceptor interactions within the molecule. The frontier molecular orbital analysis was performed to obtain global reactivity parameters. The molecular electrostatic potential was used to visualize the chemical reactivity and charge distribution of the molecule. From the nuclear magnetic resonance spectra, the carbon atoms bonded with nitrogen and oxygen atoms show the up-shielded peaks. The chemical implication of molecule was explained using electron localization function and localized orbital locator analysis. Moreover, the molecular docking studies performed for the newly synthesized compound revealed an efficient interaction with the acetylcholine receptor and exhibited better binding affinity than commercialized insecticides. Whilst, the physicochemical properties were assessed using the insectiPAD webtool to comprehend the insecticidal properties of title compound. Finally, the quantitative structure activity relationship study of 2-(4-nitrophenyl)-(3,5-difluoro-pyridine-6-yl)-1,3,4-oxadiazole showed higher activity (pLC50 = −1.43) against Mythimna separata, as compared to commercial insecticide avermectin (pLC50 = −1.47). These results provided that title compound could be used as a template for future insecticide investigations.

A DFT analysis of the antioxidant capacity of scopolin and scopoletin.

Scopolin and scopoletin belong to the class of coumarins and have experimentally proven natural antioxidants. Natural antioxidants are crucial in mitigating the impact of oxidants in the human body through radical scavenging. Even though scopolin and scopoletin are proven antioxidants by experimental results, their antioxidant mechanisms still remained unexplained. In this study, Density functional theory (DFT) calculations were used to study the radical scavenging mechanisms of both scopolin and scopoletin using kinetic and thermodynamics parameters. The global parameters indicated that both scopolin and scopoletin have antioxidant properties. The band gap energy revealed that scopoletin (4.18eV) has strong antioxidant activity compared to scopolin (4.31eV). These studies found that hydrogen atom transfer (HAT) is the primary mechanism for CH3OO• radical scavenging at the C-H bond in scopolin (91.98kcal.mol-1) and the O-H bond in scopoletin (77.05kcal.mol-1) due to their lowest bond dissociation energies. The calculated activation energy ( ) for the radical scavenging reaction, reconfirmed scopoletin ( =11.19kcal.mol-1) performed as a better antioxidant compared to scopolin ( =20.91kcal.mol-1). In this study, the results of DFT calculations confirmed that scopoletin exhibits a higher antioxidant capacity, and HAT mechanism is the most effective radical scavenging mechanism. The antioxidant activity of scopolin and scopoletin was determined by DFT at the B3LYP/6-31G(d) level of theory. Global parameter calculations and frontier molecular orbital analysis were conducted to assess these compounds' capacity for scavenging radicals. Hydrogen atom transfer (HAT), sequential electron transfer proton transfer (SETPT), and sequential proton loss electron transfer (SPLET) mechanisms were the three main mechanisms that were taken into consideration. The potential energy surface (PES) verified the most appropriate processes shown by the enthalpy calculations.

Optical materials enhancing the chemical reactivity characteristics of N-benzyloxycarbonyl-L-phenylalanine: Spectroscopic, electronic properties, natural bond orbital, stability, electron-hole, Topology and molecular docking analyses

In the field of organic chemistry, the exploration of heterocyclic compounds is considered as vital, with roots in medicinal chemistry and the synthesis of organic composites. The optimized structural configuration with the geometrical values was obtained and related to the experimental data. The theoretical computational methods were carried out using a versatile basis set, B3LYP/6–311++G(d,p). The spectroscopic insights of N-Benzyloxycarbonyl-l-Phenylalanine (NBCLP) were performed, and the simulated assigned vibrational wavenumbers (PED contributions) were compared with the experimental information. Further, employing the optimized structure of FMO's molecular orbitals, energy parameters were attained for the various solvents. The detailed theoretical interpretations were assessed on the UV–Vis absorption spectra (TD-DFT/M062X) for different solvents, and their respective values were related to the experimental value. The electronic properties of the FMO's orbitals match the experimental UV–Vis absorption energy value. The reactivity regions (nucleophilic and electrophilic) were obtained using the MEP map, and the corresponding lone pair/donor-acceptor transitions along with the higher stabilization energies were discussed using NBO analysis. Moreover, using the Multiwave function analyzer interface, electron-hole analysis for the excited states, along with parameters such as excitation energy, charge transfer length, H, t, and Δr indices for the above-mentioned solvents, and topological analysis, viz., ELF, LOL, and RDG, were discussed for the header composite. To enhance the biological behavior, molecular docking-in silico analysis was accomplished, suitable protein receptors were attained, and the results show the measure of binding energy in the ligand-protein interactions. Consequently, the present investigations imply that NBCLP may be designated as a potent and satisfying medication for the ailment of tuberculosis.

Biocompatible Triboelectric Nanogenerators for Self-Powered Microelectronics: Design, Performance, and Real-Time Applications.

In the present study, we demonstrated a cost-effective chia seed-based triboelectric nanogenerator (C-TENG), leveraging the triboelectric properties of chia seeds. The C-TENGs are fabricated with a simple architecture, establishing adaptability, cost effectiveness, and versatility as an ecofriendly harvester of mechanical energy. The C-TENG exhibits open- circuit voltage and short-circuit currents on the order of 501.8 V and 24.5 μA, respectively. Load matching reveals the maximum power density output at a load resistance of 5 MΩ, reaching 290 mW/m2. The cycle test over 3400 cycles confirms the C-TENG's stability. Furthermore, its capability to charge capacitors with different capacitances highlights its potential as a biomechanical energy harvester. The prototype device for evaluating the real-time applications demonstrated the C-TENG's, ability to illuminate LEDs, power a calculator, capture kinetic energy during walking, and transducer as an electronic switch. This investigation pioneered the exploration of chia seeds in TENGs, presenting a sustainable and efficient solution for self-powered microelectronic devices. The electron affinity of materials has been analyzed through inter- and intramolecular charge distribution using density functional theory. The direction of charge transfer was estimated through frontier molecular orbital analysis supported by the experimental findings of triboelectrification via contact separation from the molecule to polytetrafluoroethylene (PTFE).

Diverse Cyclization Pathways Between Nitriles with Active α-Methylene Group and Ambiphilic 2-Pyridylselenyl Reagents Enabled by Reversible Covalent Bonding.

Herein, we describe a novel coupling between ambiphilic 2-pyridylselenyl reagents and nitriles featuring an active α-methylene group. Depending on the solvent employed, this reaction can yield two distinct types of cationic pyridinium-fused selenium-containing heterocycles, 1,3-selenazolium or 1,2,4-selenadiazolium salts, in high yields. This is in contrast to what we observed before for other nitriles. Notably, the formation of selenadiazolium is reversible, gradually converting into the more thermodynamically stable selenazolium product in solution. Our findings reveal, for the first time, the reversible nature of 1,3-dipolar cyclization between the CN triple bond and 2-pyridylselenyl reagents. Nitrile substitution experiments in the adducts confirmed the dynamic nature of this cyclization, indicating potential applications in dynamic covalent chemistry. DFT calculations revealed the mechanistic pathways for new cyclizations, suggesting a concerted [3 + 2] cycloaddition for the formation of selenadiazolium rings and a stepwise mechanism involving a ketenimine intermediate for the formation of selenazolium rings. Natural bond orbital analysis confirmed the involvement of σ-hole interactions and lone pair to σ* electron donation in these processes. Additionally, theoretical investigations of σ-hole interactions were performed, focusing on the selenium-centered contacts within the new compounds.

Exploring optical, electronic and NLO properties: Growth and characterization of rubidium hydrogen (+)- tartrate crystals

Rubidium, a highly reactive alkali metal, is used in several research areas, such as electronics for its light-emitting properties, and in making glass, ceramics, and in biomedical studies. Single crystals of Rubidium Hydrogen (+)-Tartrate (RHT) suitable for the X-ray analysis were obtained from water solution. The crystal structure of the RHT crystal was determined using single crystal XRD, revealing an orthorhombic system with a non-centrosymmetric space group, P212121. The lattice parameters were a = 7.9233 Å, b = 10.9883 Å, and c = 7.6527 Å, with a unit cell volume of 666.272 ų. The structural vibrations of the RHT compound were analysed using FT-IR and FT-Raman spectroscopy, while NMR provided further insights into its molecular structure. Theoretical investigations at the DFT/RB3LYP/LANL2DZ level were conducted to explore the molecular structure, vibrational spectra, and bonding interactions within the RHT compound's molecular system. Natural Bond Orbital (NBO) analysis of the RHT compound revealed significant charge transfer interactions and stabilization energies, particularly highlighting strong electron donor-acceptor correlations that contribute to the molecule's overall stability. The UV–Vis and HOMO-LUMO calculations were performed in the gas phase. Optical conductivity studies have been performed. The broad spectral curve in the photoluminescence spectrum reflects the optical effects and showed a significant intense peak at 281.22 nm and a moderately intense peak at 395.9 nm. First order hyperpolarizability studies reveals that nonlinear optical efficiency is 1.06 times better than urea and 58.19 times than KDP. Furthermore, Third Harmonic Generation (THG) studies using the Z-scan technique were also conducted to investigate the nonlinear properties.

A new chalcone derivative: Synthesis, crystal structure, Hirshfeld surface, quantum chemical investigations, Druggability and human Cathepsin D inhibitory activity

This paper presents the synthesis of a novel chalcone derivative, and its molecular structure has been determined by NMR and single-crystal X-ray diffraction analysis. The molecules are connected via OH⋅⋅⋅O, CH⋅⋅⋅O, and CH⋅⋅⋅S hydrogen bonds along with CH⋅⋅⋅π and π⋅⋅⋅π interactions. Hirshfeld surface studies have been conducted to comprehensively quantify the patterns of intermolecular interactions. DFT calculations provided insights into the nature of the molecule, including frontier molecular orbital, ADCH charge, Molecular Electrostatic Potential and Natural Bond Orbitals analysis using the optimized structure by B3LYP/6–311 G (d, p) level. The calculated HOMO-LUMO gap (3.23 eV) indicates decent softness and reactivity of the target molecule. The molecular docking studies reveal that the target compound exhibits a high binding affinity with Human Cathepsin D (CatD), with a docking score of -7.58 kcal/mol. The assessment of drug-likeness properties and ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiles further support its potential as a potent CatD inhibitor candidate for medication development.