LUMO Research Articles

A Facile One-Step Self-Assembly Strategy for Novel Carbon Dots Supramolecular Crystals with Ultralong Phosphorescence Controlled by NH4.

A new methodological design is proposed for carbon dots (CDs)-based crystallization-induced phosphorescence (CIP) materials via one-step self-assembled packaging controlled by NH4 +. O-phenylenediamine (o-PD) as a nitrogen/carbon source and the ammonium salts as oxidants are used to obtain CDs supramolecular crystals with a well-defined staircase-like morphology, pink fluorescence and ultralong green room-temperature phosphorescence (RTP) (733.56ms) that is the first highest value for CDs-based CIP materials using pure nitrogen/carbon source by one-step packaging. Wherein, NH4 + and o-PD-derived oxidative polymers are prerequisites for self-assembled crystallization so as to receive the ultralong RTP. Density functional theory calculation indicates that NH4 + tends to anchor to the dimer on the surface state of CDs and guides CDs to cross-arrange in an X-type stacking mode, leading to the spatially separated frontier orbitals and the through-space charge transfer (TSCT) excited state in turn. Such a self-assembled mode contributes to both the small singlet-triplet energy gap (ΔEST) and the fast inter-system crossing (ISC) process that is directly related to ultralong RTP. This work not only proposes a new strategy to prepare CDs-based CIP materials in one step but also reveals the potential for the self-assembled behavior controlled by NH4 +.

Tin doping modulates electron-hole recombination in Dion-Jacobson phase 2D hybrid perovskite

To obtain less-toxic and optimal-band-gap perovskite materials, tin (Sn)-lead (Pb) hybrid technology comes into the sight of researchers. The Sn–Pb ratio primarily affects the electronic band structure, conductivity, and carrier transport, which are essential for optoelectronic performance. While most reports are about 3D materials, there has been little coverage of 2D Sn–Pb perovskites which exhibiting improved stability. In this paper, the e-h recombination dynamics in Dion-Jacobson Phase 2D Sn–Pb perovskites are studied using time-dependent ab initio nonadiabatic molecular dynamics (NAMD) simulation. It is found that Sn doping plays a significant role in narrowing the band-gap of 2D perovskites and localizing the charge distribution. Only a small amount of Sn doping can minimize NA coupling and shorten decoherence time of frontier orbitals simultaneously, then leading to longer charge recombination time. NAMD simulations reveal the optimal Sn ratio (25 mol%) and provide an effective way to design high-performance 2D perovskite materials.

Ultrasound-assisted ring opening of epoxides in HFIP: THF: Synthesis, characterization, computational studies and molecular docking of novel 2‑hydroxy dithiocarbamates

Under the influence of ultrasonic irradiation, pyridazinone, triazinone, or phthalimide containing 2‑hydroxy dithiocarbamates, a biologically relevant novel organo-sulfur compound, was synthesized. Detailed characterization, computational, and molecular docking studies are being investigated. Molecular interactions were studied using 3D Hirshfeld surfaces and corresponding 2D fingerprint plots. Theoretical (DFT) studies on the molecular structure, HOMO, LUMO, and quantum chemical descriptors were performed at the B3LYP/6–311++G(d,p) level of theory. At the same time, the interaction energy was computed using the B3LYP/6–31G(d,p) level of theory. The FMO study revealed that molecules 4a and 4p in the gas phase have 3.545 eV and 3.263 eV HOMO-LUMO energy gaps, respectively, and they are hence kinetically stable. Quantum chemical calculations confirm the electrophilic character of compounds 4a and 4p, as the molecule is stable and highly electrophilic. The interactions of 2‑hydroxy dithiocarbamate derivatives (4a-4t) with the ligand-binding site of the target COX-2 (cyclooxygenase-2) enzyme were investigated using in-silico molecular docking experiments. Compared to the standard medicine celecoxib, the results showed that most synthesized derivatives had better glide scores and interaction. The docking study of all the synthesized compounds revealed that compounds 4a, 4e, and 4o interact well with the COX-2 enzyme as anti-inflammatory drugs. Molecular dynamic simulation was utilized to validate the docking study and explore the stable binding site and interaction of compound 4o, which is the most potent. The findings indicated that compound 4o exhibited better stability and interaction when compared to the reference drug.

Diverse Coordination Modes and Bidirectional Noninnocence of Pyridyl-β-diketonate on Ruthenium Platforms as a Function of Coligands.

The article demonstrated diverse binding modes of deprotonated 1,3-di(2-pyridinyl)-1,3-propanedione (HL) (κ2-[O,O]-, κ2-[N,O]-, and μ-bis-κ2-[N,O]-) on selective ruthenium platforms: Ru(acac)2 (dimeric [1]ClO4), Ru(bpy)2 (monomeric [2]ClO4), Ru(pap)2 (isomeric monomeric [3]ClO4/[4]ClO4, dimeric [5](ClO4)3), and Ru(PPh3)2(CO) (monomeric 6, isomeric dimeric [7]ClO4/[8]ClO4) (acac = acetylacetonate, bpy = 2,2'-bipyridine, pap = 2-phenylazopyridine). Structural authentication of the complexes revealed (i) diverse binding mode of L- including its unprecedented bridging mode in [8]ClO4, (ii) varying degrees of nonplanarity of L-, and (iii) development of 1D polymeric chains or dimeric/tetrameric forms via intermolecular π-π interactions. The preferential binding feature of L- in the complexes could also be corroborated by their calculated relative energies. The analysis of the multiredox steps of the complexes suggested severe mixing of metal-ligand frontier orbitals, which in effect pinpointed the involvement of L- in both the oxidative and reductive processes along the redox chain, suggesting its bidirectional noninnocence under the present coordination situations. Though α-diketone or β-diketiminate was reported to activate O2 on the selective Ru(acac)2 platform, the inability of analogous β-diketonate-derived [1]ClO4 could be attributed to its calculated greater HOMO-LUMO energy gap, which disfavored electron exchange at the metal(RuIII)-ligand(L-) interface to introduce the required unpaired spin at the ligand backbone toward the 3O2 activation event.

Highly Efficient Hybrid White Organic Light‐Emitting Diodes with External Quantum Efficiency Exceeding 30% by Integrating Electron‐Trapping Sensitized Structure and Gradient‐Doping System

AbstractIn this work, efficient two‐color (blue and yellow) hybrid white organic light‐emitting diodes (WOLEDs) with high efficiencies are constructed by introducing iridium(III) bis(4,6‐(difluorophenyl) pyridinato‐N,C2’)picolinate (FIrpic) as electron sensitizer. Experimental results demonstrate that FIrpic with the deep lowest unoccupied molecular orbital (LUMO) level enables preferential electron trapping to collect excessive electrons, thus realizing carrier's balance and high recombination probability. The obtained cool WOLED exhibits the maximum external quantum efficiency (EQE), current efficiency (ηc), and power efficiency (ηp) of 31.05%, 76.36 cd A−1 and 69.92 lm W−1, respectively. Moreover, by gradient doping FIrpic into yellow EML, the generated forward built‐in electric field originating from gradient electrons distribution reduces carriers transport resistance and improves the transport of holes; the diffusion effect of gradient electrons distribution promotes electrons’ transport, thus enhancing the utilization probabilities of carriers and excitons. Besides, FIrpic acts also as an energy transfer ladder to facilitate the energy transfer from host to yellow emitter. Consequently, warm WOLED with enhanced yellow emission achieves the maximum EQE, ηc, and ηp of 33.27%, 75.66 cd A−1 and 88.04 lm W−1, respectively.

Bromo substituted aroylhydrazones: Synthesis, crystal structures, Hirshfeld surface analysis, 3D energy frameworks, DNA/BSA binding, and antimicrobial activity

Two bromo substituted aroylhydrazones such as 2-benzoylpyridine-4-bromobenzhydrazone (HBpB) and di-2-pyridyl ketone-4-bromobenzhydrazone (HDpB) were synthesized. The synthesized compounds have been characterized physicochemically using CHNS analysis, FT-IR, UV-vis absorption, 1H NMR and high resolution-mass spectra and the structures have been confirmed with single crystal X-ray diffraction technique. HBpB got crystallized in the monoclinic P21/c space group and the HDpB in the triclinic P1¯ space group. The supramolecular interactions present in the crystal system were studied with Hirshfeld surface (HS) analysis. The energy frameworks have been built by using different intermolecular interaction energies in order to study the stability of the molecule and determine the dominant energy type. The average interaction energy values for compounds HBpB and HDpB are found to be -280.4 and -327.2 kJ mol−1, respectively. Further, the nature of frontier orbitals and the stability of the compounds in the gas phase were theoretically analyzed, and the electrostatic potential surface diagram were plotted on optimized geometries. The binding potentials of HBpB and HDpB with DNA and BSA protein were investigated using spectroscopic, electrochemical, and in silico molecular docking methods. The results showed that HBpB has a higher binding affinity with both DNA and BSA compared to HDpB. Both HBpB and HDpB interact with DNA through a minor groove mode, while their binding to BSA involves mainly hydrophobic type. The ADMET analysis of compounds yielded favorable results for their potential use in pharmacological applications. When assessing the antibacterial capabilities of the tested samples, both the compounds showed good antimicrobial activities towards Klebsiella pneumonia, Bacillus Subtilis, Pseudomonas aeruginosa and Escherichia Coli.

Exploring the nonlinear optical characteristics of supersalt-decorated graphyne via DFT analysis: unveiling quantum insights into light-matter interaction

In this comprehensive study, we explore into the nonlinear optical (NLO) properties of graphyne (GRY) and its compounds decorated with a super salt (OLi3BeF3), namely GRY@SS1, and GRY@SS2) using the rB3LYP/6−31G(d,p) DFT method. Our findings reveal a substantial enhancement in the electron transfer properties of decorated compounds compared to the pristine GRY surface. This enhancement is evidence by the reduction in the bandgap energies (Eg) from 3.52 eV to 1.68 eV and remarkable boost in maximum absorption ( λmax) from 372.66 to 807.73 nm. Noteably, GRY@SS2 exhibits a significant increase in linear polarizability ( α0 ) (538.18 au), first hyperpolarizability ( β0 ) (3872.76 au), and second hyperpolarizability ( γ0 ) (1.00 × 106) due to reduced excitations energies compared to the GRY ( α0 = 448.61, β0 = 0.14 and γ0 = 5.97 × 105 au). NBO charges show that electrons are transferring from the dopant (supersalt) to the GRY sheet. Furthermore, Non-covalent interactions (NCl), iso-surface, infrared (IR), 1H NMR, and 13C NMR studies have been conducted to provide insights into the nature of interactions, vibrational frequencies, and structural-functional aspects of GRY and GRY@SS1, and GRY@SS2. According to TD-DFT calculations, all compounds demonstrate superior vertical ionization potential, UV–vis absorbance, HOMO–LUMO characteristics, as well as interaction energies. Our results underscore the potential of these compounds as valuable NLO materials, particularly highlighting the promising prospects of GRY@SS2.

Oxidative Addition of (Hetero)aryl (Pseudo)halides at Palladium(0): Origin and Significance of Divergent Mechanisms.

Two limiting mechanisms are possible for oxidative addition of (hetero)aryl (pseudo)halides at Pd(0): a 3-centered concerted and a nucleophilic displacement mechanism. Until now, there has been little understanding about when each mechanism is relevant. Prior investigations to distinguish between these pathways were limited to a few specific combinations of the substrate and ligand. Here, we computationally evaluated over 180 transition structures for oxidative addition in order to determine mechanistic trends based on substrate, ligand(s), and coordination number. Natural abundance 13C kinetic isotope effects provide experimental results consistent with computational predictions. Key findings include that (1) differences in highest occupied molecular orbital (HOMO) symmetries dictate that, although 12e- PdL is strongly biased toward a 3-centered concerted mechanism, 14e- PdL2 often prefers a nucleophilic displacement mechanism; (2) ligand electronics and sterics, including ligand bite angle, influence the preferred mechanism of the reaction at PdL2; (3) phenyl triflate always reacts through a displacement mechanism regardless of the catalyst structure due to the stability of a triflate anion and the inability of oxygen to effectively donate electron density to Pd; and (4) the high reactivity of C-X bonds adjacent to nitrogen in pyridine substrates relates to stereoelectronic stabilization of a nucleophilic displacement transition state. This work has implications for controlling rate and selectivity in catalytic couplings, and we demonstrate application of the mechanistic insight toward chemodivergent cross-couplings of bromochloroheteroarenes.

High-Performance PM6:Y6-Based Ternary Solar Cells with Enhanced Open Circuit Voltage and Balanced Mobilities via Doping a Wide-Band-Gap Amorphous Acceptor.

Great progress has been made in organic solar cells (OSCs) in recent years, especially after the report of the highly efficient small-molecule electron acceptor Y6. However, the relatively low open circuit voltage (VOC) and unbalanced charge mobilities remain two issues that need to be resolved for further improvement in the performance of OSCs. Herein, a wide-band-gap amorphous acceptor IO-4Cl, which possessed a shallower lowest unoccupied molecular orbital (LUMO) energy level than Y6, was introduced into the PM6:Y6 binary system to construct a ternary device. The mechanism study revealed that the introduced IO-4Cl was alloyed with Y6 to prevent the overaggregation of Y6 and offer dual channels for effective hole transportation, resulting in balanced hole and electron mobilities. Taking these advantages, an enhanced VOC of 0.894 V and an improved fill factor of 75.58% were achieved in the optimized PM6:Y6:IO-4Cl-based ternary device, yielding a promising power conversion efficiency (PCE) of 17.49%, which surpassed the 16.72% efficiency of the PM6:Y6 binary device. This work provides an alternative solution to balance the charge mobilities of PM6:Y6-based devices by incorporating an amorphous high-performance LUMO A-D-A small molecule as the third compound.

Investigation on the Influence of Solvents Environment on the Optoelectronic Properties of the Fluorescent Probe 1,3,4-Oxadiazole Analogues: A Combined Theoretical and Experimental Study.

This study investigates the photophysical properties of a nitrobenzene-substituted 1,3,4-oxadiazole derivative (OX-NO) using both theoretical and experimental methods. The impact of the solvent on OX-NO absorption and fluorescence spectra, as well as its fluorescence quantum yield, was initially studied. A noticeable bathochromic shift in the Stokes shift indicated a π→ π* transition within the molecules. Solute-solvent interactions were analysed using Catalan parameters, distinguishing between specific and nonspecific interactions. Excited state dipole moments were derived from Lippert's, Bakshiev's, and Chamma Viallet's equations, showing increased polarity in the excited state compared to the ground state. Ground state dipole moments were determined via solvatochromic shift methods and ab initio techniques. Additionally, detailed analyses of bond length, angles, dihedral angles, Mulliken charge distribution, and HOMO-LUMO energy gap were conducted using the DFT-B3LYP-6-311G basis set in Gaussian-09W. The energy band gap values obtained from theoretical calculations and experimental methods (cyclic voltammetry and UV-Visible spectroscopy) exhibited excellent agreement. Reactive sites such as electrophilic and nucleophilic regions were identified through total electron density, electrostatic maps, molecular electrostatic potential, and 3D plots using DFT computational analysis. Global descriptors were employed to characterize the compounds' chemical reactivity comprehensively. The observed photophysical attributes underscore the potential of these fluorophores in various applications like organic light-emitting diodes, solar cells, and chemosensors. This study contributes crucial insights into the optoelectronic properties of nitrobenzene-substituted 1,3,4-oxadiazole derivatives, paving the way for their future integration in advanced technological domains.

Sulfone-infused covalent organic polymer derived from poly(2-aminothiophenol) and erythrosine B as an excellent tool for C–H activation

The generation of a low HOMO-LUMO energy gap makes organic polymer-based composites an important class of materials with outstanding catalytic efficiency. The present work describes the simple and direct synthesis of an excellent photocatalyst, PC (C26H16NO7S)n via doping of erythrosine-B dye on sulfone infused poly(2-amino thiophenol) assembly (PA, (C6H4NO2S)n). The O 1 s spectrum displays peaks at 531.8 eV and 533.3 eV, representing the O=C and O–C groups of the in-situ generated fluorescein loaded on PA surface. Through absorption study (Tauc’s plot), the optical band gap (Eg) for polymer PA (2.9 eV) and photocatalyst PC (2.1 eV) has been calculated. Further, due to the efficient absorbance in the range of 400–600 nm with a low optical band gap, the applicability of the catalyst, PC has been checked in photocatalytic C–H activation in thiophene, and the generation of C–C bond with p-nitro aryldiazonium salt.

Facile synthesis, corrosion inhibition, adsorption and DFT studies of 2-(4-(methylsulfanyl) phenyl) −4, 5-diphenyl-1H-imidazole for mild steel in acidic environment

A green, solvent-free, cost effective one-pot synthesis method is employed to produce the innovative corrosion-inhibiting compound 2-(4-(methylsulfanyl)phenyl)-4,5-diphenyl-1H-imidazole (MDPI). The molecular structure of MDPI can be identified using CHN analyses, FT-IR, 1H and 13C NMR spectra. Various electrochemical and gravimetric techniques are utilized to evaluate the anti-corrosion properties of MDPI. The results indicate that MDPI effectively inhibits the corrosion of mild steel under all tested conditions. At 306 K, MDPI achieved a maximum corrosion inhibition efficiency of 98.01 % at a concentration of 10 mM. MDPI exhibited strong adsorption and excellent anti-corrosion properties, forming a protective layer on the mild steel surface. The Langmuir adsorption isotherm, with a ΔGoads value of −39.55 kJ/M was found to be more suitable for this study, indicating that the process occurred by physisorption. Tafel curves indicated that MDPI functions as a mixed-type corrosion inhibitor. Surface characteristics were analyzed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and atomic force microscopy (AFM). Quantum chemistry studies revealed a HOMO-LUMO energy gap of 3.926 eV, corroborating the anti-corrosion effectiveness of MDPI in hydrochloric acid solution. MDPI exhibited promising anti-corrosion activity due to its heterocyclic ring containing nitrogen heteroatoms as well as a methylsulfanyl functional group.

Synthesis, DFT, and in silico biological evaluation of chalcone bearing pyrazoline ring against Helicobacter pylori receptors

Peptic ulcer disease (PUD), often caused by Helicobacter pylori infection, is a prevalent gastrointestinal condition characterized by the erosion of the gastric or duodenal mucosal lining. H. pylori adheres to gastric epithelial cells, secreting toxins and disrupting the stomach's defenses. H. pylori relies on various receptors to establish infection, making these molecules attractive therapeutic targets. This study aimed to develop novel anti-ulcer compounds by combining benzothiazole, pyrazoline, and chalcone pharmacophores. A series of chalcone derivatives 4a-c were synthesized via Claisen-Schmidt condensation and characterized using spectroscopic techniques such as FT-IR, NMR and elemental analysis. The DFT calculations, using B3LYP method with 6-311G basis set, revealed the p-tolyl derivative 4b exhibited the highest thermal stability while the p-bromophenyl derivative 4c showed the lowest stability but highest chemical reactivity. The HOMO-LUMO energy gaps as well as the dipole moments decreased in the order: 4b > 4a >4c, reflecting a similar reactivity trend. Molecular docking showed ligands 4a-c bound effectively to the H. pylori urease enzyme, with docking scores from −5.3862 to −5.7367 kcal/mol with superior affinity over lansoprazole. Key interactions involved hydrogen bonds and hydrophobic pi-hydrogen bonds with distances ranging 3.46–4.34 Å with active site residues ASN666, SER714 and ASN810. The combined anti-inflammatory, antimicrobial, and H. pylori anti-adhesion properties make these novel chalcones promising PUD therapeutic candidates.

Photophysical properties and photostability of novel 2-amino-3-benzothiazole thiophene-based azo disperse dyes

The design, synthesis, and use of four new thiophene-based dispersed azo dyes with salicylic and carboxylic acid acceptors are shown in this work. The produced dyes exhibit a wide range of light absorption characteristics, including near UV–visible, and deep red wavelengths. PG9 and PG12, which are thiophene disperse azo dyes with carboxylic acid acceptor, showed red-shifted absorption, but PG10 and PG11, which are azo dyes with salicylic acid, showed blue-shifted absorption. The synthesized dyes exhibited good photostability in solvents. The experimental results are supported by theoretical results from Density Functional Theory (DFT) and Time-Dependent Density Functional Theory (TD-DFT).Furthermore, the dyes exhibit outstanding dyeability with percentage exhaustion characteristics of 90% when applied to acrylic, nylon, and polyester fabrics. Rich shades ranging from deep orange to black are seen in the dyed fabrics. Salicylic acid acceptor-dyed materials have higher K/S values when applied to nylon-dyed fabrics, while acrylic and polyester-dyed fabrics respond better to carboxylic acid acceptor dyes. The fabrics that have been colored display exceptional light, wash, and rubbing fastness. Inlight and wash fastness, polyester-dyed fabrics performed better than acrylic and nylon-dyed fabrics. Studies on UV protection show that fabrics with high UPF ratings canblock damaging UV-A and UV-B radiation efficiently. All synthetic dyes have their antibacterial activity assessed using the AATCC 100 test method, which is associated with the HOMO-LUMO energy gap.

Structural and theoretical exploration of a multi-methoxy chalcone: Synthesis, quantum theory, electrostatics, molecular packing, DFT analysis, and in-silico anti-cancer evaluation

This study explores the pharmacological potential of chalcones through a multidisciplinary approach, including synthesis, quantum theory, molecular electrostatics, and density functional theory (DFT) calculations. The synthesized compound, analyzed via single crystal X-ray diffraction, crystallized in the triclinic system (space group P-1) with C–H⋯O interactions stabilizing its structure. Hirshfeld surface analysis confirms these interactions, with H–H contacts dominating (45.1 %). Molecular electrostatics analysis reveals charge distribution, and a 3.10 eV HOMO-LUMO energy gap indicates bioactivity. Molecular docking identifies the compound (3a) showed a maximum Gscore of HTNF-α (−9.81 kcal/mol); Tubulin (−7.96 kcal/mol); COX2 (−7.88 kcal/mol), EGFR (−6.72 kcal/mol), and VEGFR1(-2.50 kcal/mol). Where compound (3c) showed maximum binding at the putative binding site with dock scores for VEGFR2 (−9.24 kcal/mol). This research not only advances molecular science but also holds promise for diverse applications, including drug design. The significance of this study lies in its comprehensive exploration of the pharmacological potential of chalcones using a multidisciplinary approach. Through the integration of synthesis, quantum theory, molecular electrostatics, and density functional theory (DFT) calculations, we have extensively explored the structural and biochemical characteristics of these compounds. This investigation has revealed valuable insights that have the potential to lead to significant advancements in the fields of molecular science and drug design. Moreover, the molecular docking studies shed light on the compound's interaction with various biological targets. The significant binding affinities observed for these targets underscore the potential therapeutic relevance of the synthesized compound in diverse disease conditions.

Enhancing visible light photocatalytic activity of holmium doped g-C3N4 and DFT theoretical insights

In the search of novel photocatalysts to increase the effect of visible light in photocatalysis, g-C3N4 (CN) has become a shining star. Rare earth metals have been used as dopant material to reinforce the photocatalytic activity of CN due to their unique electron configuration recently. In this present study, the pure and different amounts of Ho-doped g-C3N4 (HoCN) photocatalysts were successfully synthesized using urea as a precursor by the one-pot method. Morphological, structural, optical, and vibrational properties of the synthesized photocatalysts were characterized by SEM, EDX, XRD, TGA, XPS, FTIR, PL, TRPL, Raman, DRS, and BET analyses. In addition, theoretical calculations using density functional theory (DFT) were meticulously carried out to delve the changes in the structural and electronic structure of CN with holmium doping. According to calculations, the chemical potential, electrophilicity, and chemical softness are higher for HoCN, while HOMO–LUMO gap, dipole moment, and the chemical hardness are lower for the pure one. Thus, holmium doping becomes desirable with low chemical hardness which indicates more effectivity and smaller HOMO–LUMO gap designate high chemical reactivity. To determine the photocatalytic efficiency of the pure and doped CN photocatalysts, the degradation of methylene blue (MB) was monitored under visible light. The results indicate that holmium doping has improved the photocatalytic activities of CN samples. Most strikingly, this improvement is noticeable for the 0.2 mmol doped CN sample that showed two times better photocatalytic activity than the pure one.

Defect tailoring in K-doped carbon nitride: Enabling efficient decoupling of light and dark reactions for timely and delayed on-demand solar hydrogen production

Decoupling hydrogen production from diurnal cycles is challenging in solar energy conversion. Recently, defect-modified K-doped carbon nitride has demonstrated the potential to realize this unique property. However, the concomitant undesirable defects during eutectic treatment, such as triazine ring insertion, impose substantial limitations on the decoupling performance. In this study, a one-step eutectic method assisted by CCl4 was developed, which removed the detrimental triazine-based defects while introducing beneficial nitrogen vacancies. The engineered structure efficiently enhances visible light absorption, and spatially separates the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). The localized LUMO on N-K sites serves as an electron reservoir, facilitating carrier separation and inhibiting the recombination. Consequently, one of the highest timely light-driven activities among polymeric photocatalysts was achieved, reaching 2557 times the H2 production rate compared to the un-engineered counterpart. More significantly, the electron reservoir could store active electrons for several weeks, successfully enabling delayed on-demand solar H2 production and decoupling H2 evolution from diurnal cycles. This study effectively achieves both spatial and temporal separation of light absorption, solar storage, and release through defect tailoring, which is expected to advance the development of decoupled catalytic studies.

Synthesis, characterisation, DFT and biological evaluation of 4-(1-ethylbenzimidazol-2-yl)-2-(arylamino)thiazoles

The compounds 4-(1-ethylbenzimidazol-2-yl)-2-(arylamino)thiazoles were expected to have many biological activities and were synthesized from 1,2-diaminobenzene and lactic acid. The synthesized compounds are characterised by FT-IR, 1H NMR and mass spectroscopy. Thiazole moiety present in the compounds was found to possess anticancer, anti-HIV activities. Theoretical information on the optimized geometry, vibrational frequencies and atomic charges in the ground state were determined by means of density functional theory (DFT) using standard B3LYP/6-31G basis set with Gaussian ’09 software. Mulliken population analysis was performed on the atomic charges and the HOMO-LUMO energies were calculated. From the HOMO-LUMO energy gap, we know that the charge transfer occurs within the molecule. Docking studies are also done by using PyRx and are visualized by PyMoL software. By 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method, anti-oxidant activity of the synthesized compounds was evaluated. In vitro cytotoxic activity of the compounds against A549 cell lines was evaluated by MTT assay.

Ring and Linear Structures of CdTe Clusters

We report the results of an ab initio study of the linear and ring structures of cadmium telluride clusters [CdTe]n (CdnTen) n ≤ 10 within the generalized gradient approximation (GGA) and Purdue–Burke–Ernzerhof (PBE) parameterization with Hubbard corrections (GGA+U). We optimized the linear and ring isomers for each size to obtain the lowest-energy structures and to understand their growth behavior. The cases of n < 8 for ring-type structures and n = 6 and 9 for linear-type structures were found to be the most favorable. All observed clusters with a linear structure were found to have a small highest-occupied–lowest-unoccupied molecular orbital (HOMO–LUMO) gap. The CdTe clusters with ring structure showed larger values of the HOMO–LUMO gaps than the band gap value for the bulk crystal. Structural and electronic properties like bond length, the HOMO–LUMO gap, binding energy, and electronegativity were analyzed.

The First-Principles investigation of sensing and removal applications of nitrobenzene using pristine and Sc decorated B9N9 nanoring

Nitrobenzene (NB), an aromatic organic compound widely used in various industries, has several environmental risks. Due to its risks, reliable sensing mechanisms are crucial. In the present work, we investigated the potential of the pristine and Sc decorated B9N9 nanoring as a sensor for detection of the toxic NB molecule using density functional theory (DFT). We have analyzed the structural parameters, adsorption energy (Ead), highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), HOMO-LUMO gap, density of states (DOS) spectra, Mulliken charge transfer, dipole moment, IR spectra, non-covalent interactions (NCI) iso-surfaces, recovery time (τ) and work function (φ) before and after the adsorption of NB onto pristine and Sc decorated B9N9 nanorings. Our analysis revealed that the NB interacted optimally with the pristine B9N9 nanoring, as evidenced by changes in electronic properties and Ead value of −0.58 eV. However, the Sc decorated B9N9 nanoring indicated a strong interaction with NB with Ead of −4.09 eV at a proximal distance of 2.12 Å. Furthermore, our study demonstrated that the pristine B9N9 nanoring could be used as both an “electronic sensor” and “φ-type sensor”. Additionally, to esteem rapid recovery for practical feasibility, we calculated τ for both the pristine and Sc decorated B9N9 nanoring. The short τ of the pristine nanoring indicates its suitability as NB sensor. In contrast, the longer τ of the Sc decorated nanoring suggests its applicability for NB storage or its removal from the surroundings. Overall, our findings underscore the potential of pristine B9N9 nanoring as effective NB sensor and removal. We hope that our study will assist experimentalists to develope a reliable B9N9 nanoring based sensor for the detection of NB molecules.