Search Results (237)

This study investigates the influence of vacancy engineering and nitrogen doping on the structural, electronic, and optical properties of T-graphene fragments (TFs) using density functional theory (DFT) and time-dependent DFT (TD-DFT). A central vacancy and five pyridinic nitrogen doping configurations are explored to modulate the optoelectronic behavior. All systems are thermodynamically stable, exhibiting tunable HOMO–LUMO gaps, orbital distributions, and charge transfer characteristics. Optical absorption spectra show redshifts and enhanced oscillator strengths in doped variants, notably v-NTF2 and v-NTF4. Nonlinear optical (NLO) analysis reveals significant enhancement in both static and frequency-dependent responses. v-NTF2 displays an exceptionally high first-order hyperpolarizability (⟨β⟩ = 1228.05 au), along with a strong electro-optic Pockels effect (β (−ω; ω, 0)) and second harmonic generation (β (−2ω; ω, ω)). Its third-order response, γ (−2ω; ω, ω, 0), also exceeds 1.2 × 10⁵ au under visible excitation. Conceptual DFT descriptors and energy decomposition analysis further supports the observed trends in reactivity, charge delocalization, and stability. These findings demonstrate that strategic nitrogen doping in vacancy-engineered TFs is a powerful route to tailor electronic excitation, optical absorption, and nonlinear susceptibility. The results offer valuable insight into the rational design of next-generation carbon-based materials for optoelectronic, photonic, and NLO device applications. Full article

In this study, the impact of incorporating energetic substituents such as -NO₂, -NH₂, -NH₃, -N₂ (both with perchlorate anion), and -N₃ into 4,6-dinitrobenzimidazol-2-one on its detonation performance and stability was investigated. The DFT B3LYP/cc-pVTZ method was employed to evaluate key molecular properties: the HOMO–LUMO gap, cohesive energy, chemical hardness, and electronegativity. Based on these parameters, the resulting changes in chemical and thermal stability were assessed. The results achieved highlight the significant role of ionic bonding in enhancing both the stability and density of the compounds. Our results indicate that the benzimidazoles enriched by energetic groups possess energetic properties better than TNT, with some variants surpassing HMX. The analysis of the stability and sensitivity based on oxygen balance investigation suggests that by varying the incorporated substituents, it is possible to design both primary and secondary explosives from a common molecular scaffold. Full article

In the present study, two novel donor–acceptor (D–A) conjugated copolymers, PIDTBDI and PIDTTBDI, were successfully synthesized via Stille coupling polymerization. These alternating copolymers incorporate indacenodithiophene and indacenodithienothiophene as donor units, coupled with benzothiadiazole dicarboxylic imide as the electron-deficient acceptor unit. The influence of extended conjugation on the structural, optical, thermal, and electrochemical properties of the copolymers was systematically investigated and confirmed by density functional theory (DFT). XRD analysis confirmed that both polymers are amorphous. Thermogravimetric analysis revealed that both materials possess excellent thermal stability, with decomposition temperatures exceeding 270 °C. The theoretical and experimental values of the energy gap confirmed the thermal stability of the studied polymers. The molecular weight was determined to be 10,673 Da for PIDTBDI and 7149 Da for PIDTTBDI. Despite the variation in molecular weight, both copolymers exhibited comparable optical and electrochemical bandgaps of approximately 1.57 and 1.69 eV, respectively. Electrochemical measurements showed that PIDTBDI has a HOMO energy level of −5.30 eV and a LUMO level of −3.61 eV, while PIDTTBDI displays HOMO and LUMO levels of −5.28 eV and −3.59 eV, respectively. These results indicate that minor structural differences can considerably affect the electronic characteristics of the polymers, thus altering their overall efficacy in solar cell applications. Full article

In this study, three alternating donor–acceptor (D–A) type [12]cycloparaphenylene ([12]CPP) derivatives ([12]CPP 1a, 2a, and 3a) were designed through precise molecular engineering, and their multidimensional photophysical responses and chiroptical properties were systematically investigated. The effects of the alternating D–A architecture on electronic structure, excited-state dynamics, and optical behavior were elucidated through density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. The results show that the alternating D–A design significantly reduced the HOMO–LUMO energy gap (e.g., 3.11 eV for [12]CPP 2a), enhanced charge transfer characteristics, and induced pronounced red-shifted absorption. The introduction of an imide-based acceptor ([12]CPP 2a) further strengthened the electron push-pull interaction, exhibiting superior performance in two-photon absorption, while the symmetrically multifunctionalized structure ([12]CPP 3a) predominantly exhibited localized excitation with the highest absorption intensity but lacked charge transfer features. Chiral analysis reveals that the alternating D–A architecture modulated the distribution of chiral signals, with [12]CPP 1a displaying a strong Cotton effect in the low-wavelength region. These findings not only provide a theoretical basis for the molecular design of functionalized CPP derivatives, but also lay a solid theoretical foundation for expanding their application potential in optoelectronic devices and chiral functional materials. Full article

Access to clean water is a pressing global concern and membrane technologies play a vital role in addressing this challenge. Thin-film composite membranes prepared via interfacial polymerization (IPol) using meta-phenylenediamine (MPD) and trimesoyl chloride (TMC) exhibit excellent separation performance, but face limitations such as fouling and low hydrophilicity. This study investigated the interaction between MPD and sulfonated zinc phthalocyanine, Zn(SO₂⁻)₄Pc, as a potential strategy for enhancing membrane properties. Using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT), we analyzed the optimized geometries, electronic structures, UV–Vis absorption spectra, FT-IR vibrational spectra, and molecular electrostatic potentials of MPD, Zn(SO₂⁻)₄Pc, and their complexes. The results show that MPD/Zn(SO₂⁻)₄Pc exhibits reduced HOMO-LUMO energy gaps and enhanced charge delocalization, particularly in aqueous environments, indicating improved stability and reactivity. Spectroscopic features confirmed strong interactions via hydrogen bonding and π–π stacking, suggesting that Zn(SO₂⁻)₄Pc can act as a co-monomer or additive during IPol to improve polyamide membrane functionality. A conformational analysis of MPD/Zn(SO₂⁻)₄Pc was conducted using density functional theory (DFT) to evaluate the impact of dihedral rotation on molecular stability. The 120° conformation was identified as the most stable, due to favorable π–π interactions and intramolecular hydrogen bonding. These findings offer computational evidence for the design of high-performance membranes with enhanced antifouling, selectivity, and structural integrity for sustainable water treatment applications. Full article

Background/Objectives: This study aims to present a strategic approach to enhancing the photostability and antioxidative resilience of curcumin and capsaicin by integrating selected natural stabilizers within a nanoemulsion-based delivery system. Methods: Coffee extract (Coffea arabica Linn.), along with its active components and vitamin E-containing natural oils, was assessed in terms of improving the photostabilizing and antioxidative retention abilities of curcumin and capsaicin. An optimized ratio of the active mixture was then loaded into a nanoformulation. Results: The analysis of active contents with validated high-performance liquid chromatography (HPLC), ferric reducing antioxidant power (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assays confirmed the stabilization enhancement after irradiation with UV and white light for 72,000–84,000 lux hours. The optimized combination of coffee extract with turmeric and chili mixtures loaded into the optimized nanoemulsion enhanced the half-lives (T_1/2) of curcumin and capsaicin by 416% and 390%, respectively. The interactions of curcumin and capsaicin with caffeine and chlorogenic acid were elucidated using computational calculations. Interaction energies (E_int), HOMO-LUMO energy gap (HLG) analysis, and global reactivity descriptors revealed hydrogen bonding interactions be-tween capsaicin and chlorogenic acid, as well as between curcumin and caffeine. Conclusions: By leveraging the synergistic antioxidative properties of coffee extract and vitamin E within a nanoemulsion matrix, this study overcomes the intrinsic stability limitations of curcumin and capsaicin, offering a robust platform for future pharmaceutical and nutraceutical applications. Full article

Molybdenum disulfide is more attractive and valuable at the molecular level due to its unique structure and exceptional properties. Here, new-type MoS₂-ring chains are constructed and theoretically investigated for relevant electronic properties influenced by the length of the chain and the bias. Different from traditional wires, our findings demonstrate that the conductance of such a new-type chain presents unusually non-exponential decay with the length of the chain, with a particularly anomalous length of seven rings, which shows stronger equilibrium conductance than a shorter four-ring chain. Multi-peaks of electron transmission and delocalized electronic states contribute such uniqueness. Mo atoms play a vital role in electron transport. Essentially, a narrower “HOMO-LUMO” (the two closest energy levels to the Fermi level of MoS₂-ring chain) gap compensates for the lower device density of states of new-type molybdenum disulfide-ring chains. The usual electronic structure of a seven-ring chain is derived from its slightly arched structure and mainly originates from interference, which is the resonance occurring between the electrodes. Noticeably, the bias could greatly enhance conductance, which could reach 1000 times more than the equilibrium conductance. At a certain bias, the conductance of a seven-ring chain even exceeds the shortest one- or two-ring chain. Furthermore, the threshold voltage (at which the maximum conductance appears) gradually decreases with the length of the chain and eventually remains at 0.7 V. The valuable negative differential resistance (NDR) effect could be found in such a molecular chain, which becomes more obvious as the length rises until the seven-ring chain reaches the peak. Our findings shed light on the relations between electronic properties and the length of a new-type molybdenum disulfide-ring chain, and provide support for such new-type chains in applications of innovative low-power and controllable electronics. Full article

Although lithium-ion batteries are considered an ideal postulant for renewable energy harvesting, storage and applications, these batteries show promising performance; however, at the same time, these harvesting devices suffer from some major limitations, including scarce lithium resources, high cost, toxicity and safety concerns. Potassium ion batteries (PIBs) can be proven a favorable alternative to metal ion batteries because of their widespread potassium reserves, low costs and enhanced protection against sparks. In this study, DFT simulations were employed using the B3LYP/6-311⁺⁺g(d p) method to explore the application of graphene and its doped variants (N,B,P-graphene) as potential anode materials for PIBs. Various key parameters such as adsorption energy, Gibbs free energy, molecular orbital energies, non-covalent interactions, cell voltage, electron density distribution and density of states were computed as a means to evaluate the suitability of materials for PIB applications. Among the four structures, nitrogen- and phosphorus-doped graphene exhibited negative Gibbs free energy values of −0.020056 and −0.021117 hartree, indicating the thermodynamic favorability of charge transfer processes. Doping graphene with nitrogen and phosphorus decreases the HOMO-LUMO gap energy, facilitating efficient ion storage and charge transport. The doping of nitrogen and phosphorus increases the cell voltage from −1.05 V to 0.54 V and 0.57 V, respectively, while boron doping decreases the cell voltage. The cell voltage produced by graphene and its doped variants in potassium ion batteries has the following order: P-graphene (0.57 V) > N-graphene (0.54 V) > graphene (−1.05 V) > B-graphene (−1.54 V). This study illustrates how nitrogen- and phosphorus-doped graphene can be used as a propitious anode electrode for PIBs. Full article

Perylenediimides are an interesting group of compounds that are finding more and more applications. However, the synthetic route of obtaining and modifying them is usually very complicated, costly, and time-consuming. Therefore, the conducted research aimed to develop new, greener, electrochemical methods of obtaining unknown perylenediimides (containing 2-ethylhexyl at the nitrogen atom). For the products obtained in this way, optical and electrochemical studies were conducted and compared with DFT results (i.e., energy gaps and HOMO and LUMO levels). Asa result of optical studies, different emission wavelengths of two isomers originating from the same excitation wavelength were observed. Electrochemical studies also confirmed significant differences in properties between the obtained isomers. Spectroelectrochemical measurements were also performed; they revealed the electrochromic properties of the obtained isomers in the visible and near-infrared range. Considering all the properties (optical and (spectro)electrochemical), the obtained compounds have a high potential for use in optoelectronic devices. Moreover, unprecedented pi-expansion of cis-DBPDI via 1,2-bis(p-bromophenyl)acetylene Diels–Alder cycloaddition into the bay region was also realized successfully. Summing up, electrosynthesis and further pi-expansion via cycloaddition offer a sea of opportunities for obtaining nanographenes. Full article

This study explored the extraction of genistein-7-O-[α-rhamnopyranosyl-(1→6)]-β-glucopyranoside (GTG) from Derris scandens using an aqueous-ethanol solvent system, aiming to optimize yield and antioxidant activity. Hansen solubility parameters (HSP) were employed to determine the optimal solvent composition, with the highest GTG yield (6.83 ± 0.06 mg/g dried weight) obtained from 50% ethanol—correlating well with HSP predictions. Ultrasonic extraction was most effective with solvents having a dielectric constant between 50 and 60. The antioxidant potential of isolated GTG was evaluated using the DPPH assay, which yielded an IC₅₀ of 87.86 ± 1.85 μM, and the FRAP assay, with a value of 34.23 ± 2.75 mg FeSO₄ equivalents. Molecular orbital analysis revealed HOMO and LUMO energy gaps (ΔE = 10.6715 eV) similar to known antioxidants such as gallic acid, ascorbic acid, Trolox, and quercetin. These findings demonstrate that HSP effectively guided solvent selection for ultrasound-assisted extraction of GTG. The antioxidant activity is attributed to GTG’s capacity to donate electrons and stabilize radicals via extended charge delocalization within the aglycone structure, confirming its potential as a natural antioxidant agent. Full article

Background: Hyaluronicacid (HA)-conjugated nanocarriers leverage CD44 receptor overexpression on tumor cells for targeted delivery of platinum chemotherapeutics. Methods: This study compares non-functionalized (DDS1) versus HA-conjugated single-walled carbon nanotubes (DDS2) for encapsulation stability and CD44 binding of Cisplatin, Carboplatin, and Lobaplatin. Density Functional Theory calculations employed PBE-GGA with Tkatchenko–Scheffler dispersion and ZORA relativistic treatment, using a finite (8,8) armchair SWCNT (24.6 Å, H-capped) for DDS1 and an EDC/NHS-coupled HA oligomer for DDS2. We computed binding energies, HOMO–LUMO gaps, Molecular Electrostatic Potentials, and energy decompositions. Molecular docking to CD44 (PDB ID: 4PZ3) used Molegro Virtual Docker, validated by re-docking the native HA fragment (RMSD 1.79 Å). Results: DFT binding energies (eV) for DDS2 versus DDS1 were −7.92/−7.48 (Cisplatin), −8.93/−8.30 (Carboplatin), and −9.72/−9.25 (Lobaplatin), indicating enhanced stabilization by HA functionalization. Energy decomposition showed increases of ∼0.4 eV (vdW) and ∼0.2 eV (electrostatic) in DDS2. MEP maps confirmed additional negative-potential regions on DDS2, complementing drug-positive sites. Molecular docking yielded MolDock scores of −171.26 for DDS2 versus −106.68 for DDS1, reflecting stronger CD44 affinity. Docking scores indicate that HA conjugation notably strengthens the predicted affinity of CNT carriers toward the CD44 receptor ($\Delta$Score ≈ −65 kcal mol⁻¹). Conclusions: These results motivate experimental follow-up to confirm whether DDS2 can translate the in silico affinity gains into improved targeted delivery of platinum chemotherapeutics. Full article

This article discloses the synthesis of four new positional isomeric zwitterionic ligands exhibiting semi-flexible and flexible characteristics—n-pyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-PTCA), and n-methylpyridinium-1,2,3-triazole-4-carboxy-5-Acetate (n-MPTCA; where n = 3, 4)—which were derived from an aqueous solution of the corresponding sodium salts in an acidic medium (HCl). These compounds are successfully synthesized and characterized with FT-IR and multinuclear NMR spectroscopy; likewise, proper single crystals are obtained for each compound. All compounds adopt zwitterionic forms in the solid state, which are stabilized via intermolecular proton transfer processes involving HCl and solvent molecules. A single-crystal X-ray analysis revealed how positional isomerism and molecular flexibility influence the supramolecular topology. Specifically, 3-PTCA and 4-PTCA exhibit isomorphic hydrogen bond networks, while 3-MPTCA and 4-MPTCA display distinct packing motifs, attributed to the presence of a methylene spacer between the pyridinium and triazole rings. The Hirshfeld surface analysis quantitatively confirmed the dominance of O···H/H···O and N···H/H···N interactions in the solid-state architecture. These strong hydrogen-bonding networks are indicative of the potential proton-conductive behavior in the crystalline state, positioning these compounds as promising candidates for applications in proton-conducting materials. The structural insights gained underscore the pivotal role of molecular topology in tailoring crystal packing, with implications for the rational design of zwitterionic ligands in functional materials, including MOFs and coordination polymers. The calculated HOMO-LUMO energy gaps reveal a significant electronic variability among the ligands, influenced primarily by the positional isomerism and structural flexibility introduced by the methylene spacer. Full article

Lysosomes are important acidic subcellular organelles whose dysfunction can lead to some related diseases. The development of new lysosome-imaging-guided AIEgens for the photodynamic therapy of cancer cells is important. In this work, two novel organic compounds with AIE characteristics, namely, TPAB-CF₃ and TPAB-diCF₃, were designed and synthesized by introducing the weakly basic morpholinyl moiety with lysosome-targeting ability into a triphenylamine-based luminogen. The distorted spatial feature of TPA and the D₁-D₂-π-A structure of these AIEgens prevented the aggregation-caused quenching of traditional fluorescent molecules and efficiently promoted the separation of the HOMO and LUMO. The outcomes were AIE features and a narrow single-triplet energy gap. Furthermore, TPAB-CF₃ and TPAB-diCF₃ showed bright yellow fluorescence emission peaks at 577 and 601 nm; large Stokes shifts of 234 and 256 nm, respectively; and excellent lysosome-targeted imaging of HeLa cells (Pearson’s coefficient = 0.90). In addition to the good ¹O₂-generation ability under light irradiation, these AIEgens achieved the high-efficiency bright lysosome imaging-guided photodynamic killing of cancer cells under white-light irradiation. Full article

High internal phase emulsions (HIPEs), in which the dispersed water phase exceeds 70%, play a critical role in enhancing oil recovery through in situ permeability modification. However, their stability remains a major challenge due to frequent phase inversion and coalescence. In this study, the formation and stabilization mechanisms of water-in-oil HIPEs were investigated using a multiscale modeling approach that combines dissipative particle dynamics (DPD), molecular dynamics (MD), and density functional theory (DFT). Fourteen oil types and six polyaromatic emulsifiers with varying side-chain configurations and polar functional groups were modeled. Emulsifier performance was evaluated across 42 DPD-simulated systems with 70% and 80% water content. The results showed that emulsifiers with moderate dipole moments (~6 Debye) and spatially distributed heteroatoms achieved the most stable emulsion structures, forming continuous interfacial films or micelle-bridged networks. In contrast, emulsifiers with weak polarity (<1 Debye) or excessive stacking tendencies failed to prevent phase separation. The HOMO–LUMO energy gap and cohesive energy density (CED) were found to be poor predictors of emulsification performance. Four distinct stabilization mechanisms were identified, including interfacial film co-construction with oils and steric stabilization via side-chain architecture. The findings demonstrate that dipole moment is a reliable molecular descriptor for emulsifier design. This study provides a theoretical foundation for the rational development of high-performance emulsifiers in petroleum-based HIPE systems and highlights the potential of multiscale simulations in guiding formulation strategies. Full article

In this work, the structural and optical properties of calcium monochalcogenide nanoparticles were numerically examined by using Density Functional Theory and Time Dependent Density Functional Theory. The composition of the examined nanoparticles was obtained from an initial cubic-like building block of the form Ca₄Y₄, where Y could be one of the chalcogen elements sulfur, selenium, and tellurium, after its proper numerical examination to check their structural stability. The examined nanoparticles were then created from these initial cubic-like building blocks after their elongation along one, two, and three perpendicular directions. Τhe Absorption Spectrum, the Binding Energy, together with the highest occupied-lowest unoccupied molecular orbital (HOMO-LUMO) gap, were included in the calculations of the studied calcium monochalcogenides. The calculations provided numerical evidence regarding the existence of stable structures for a wide range of morphologies. In addition, the examination of the properties of such nanostructures after placing different kinds of defects was also included in the calculations, thus leading to new groups of nanoparticles with several potential uses in technological applications, such as hydrogen storage, CO₂ capture, and ultraviolet-responsive devices. Full article