The contemporary textile industry is increasingly seeking chromophores that can provide vibrant, long-lasting coloration and minimizing environmental impact. Effective performance relies on chromophores exhibiting pronounced colorimetric intensity, strong fiber-dye affinity, and superior thermal and photochemical stability, all of which are essential for sustainable, high-performance textile applications. A series of structurally customized quinacridone-derived dyes were developed, modeled, and synthesized to provide better chromatic depth, enhanced fastness properties, increased heat resistance, and strong dye-fiber affinity. Density functional theory was used to clarify molecular structures. Fourier transform infrared spectroscopy (FTIR) and liquid chromatography-mass spectrometry (LC-MS) were used for thorough spectroscopic validation. The electronic excitation characteristics of the synthesized derivatives R, QR1, QR2, and QR3 were interrogated through a combined theoretical-experimental framework. Among these systems, QR3 manifested the most pronounced bathochromic displacement, exhibiting λmax values of 560 nm, computed using the CAM-B3LYP functional with the aug-cc-pVTZ basis set and 562 nm as verified experimentally. This derivative further distinguished itself by demonstrating exceptional resilience toward photo-degradation, aqueous laundering and mechanical abrasion, underscoring its superior fastness behaviour. Frontier molecular orbital analysis revealed substantial molecular polarizability and a well-defined intramolecular charge-transfer trajectory extending from donor-enriched HOMO orbitals toward acceptor-centered LUMO domains. The structural integrity of all derivatives, including elemental composition and molar mass, was unequivocally substantiated through liquid chromatography-mass spectrometry and Fourier transform infrared spectroscopy. Dye-fiber interaction studies yielded exhaustion and fixation efficiencies in the 55–65
A local surface plasmon resonance (LSPR)-based biosensor utilizing four-way junction (4WJ) DNA probes and gold nanoparticles (Au NPs) was developed for detection and genotyping of Mycobacterium tuberculosis. The sensor combines Au nanorods functionalized with a 4WJ probe and universal molecular beacon (UMB)-capped Au nanospheres, enabling target-induced nanoparticle assembly only in a presence of specific DNA analyte. These sensors achieved a limit of detection (LOD) of 8.5 nM for rifampicin-resistant M. tuberculosis DNA for fluorescent detection and 50 nM for LSPR detection, demonstrating specificity for single-nucleotide variation (SNV) discrimination in the vapC37 gene. The approach offers a new cost-effective, rapid combination of 2 technologies: conventional SPR microscopy and 4WJ probes, with potential post-amplification applications in point-of-care tuberculosis diagnostics.
The current research work combines thermo-acoustic measurements with density functional theory (DFT) analysis to elucidate the molecular interactions between the non-steroidal anti-inflammatory drug (NSAID) diclofenac sodium (DS) and the commonly used pharmaceutical excipient D-mannitol in an aqueous environment. It is crucial to comprehend drug-excipient interactions to maximize formulation performance. Density (ρ) and sound velocity (u) of above mentioned anti-inflammatory drug with various concentrations of D-mannitol in an aqueous system was measured at a temperature range 293.15–313.15 K and 101.325 kPa pressure. The observed data of density and sound velocity were further used to compute apparent and partial molar volume ( O̸_v,O̸_v^^∘ ), transfer of partial molar volume ( Δ_trO̸_v^^∘ ), apparent and partial molar compressibility ( O̸_k,O̸_k^^∘ ), adiabatic compressibility (β), and hydration number (nH). Pair and triplet interaction coefficients, VAB and VABB, indicate the domination of pairwise interaction. Positive values of Δ_trO̸_v^^∘ for the investigated system indicate the predominant ion-hydrophilic/hydrophilic interactions. The DFT calculations confirm that hydrogen bonding and ion-hydrophilic interactions are being strengthened in an aqueous phase. These findings are consistent with the hydrogen bonding capability of mannitol and its capacity to modulate the local solvent structure, providing a mechanistic foundation for rational excipient selection and formulation optimization.
In this study, the density and dynamic viscosity of pure liquids and their mixtures were measured over the entire benzyl acetate composition for binary systems of benzyl acetate with butyl amine isomers (n-butylamine, sec-butylamine, and tert-butylamine) at 298.15 to 308.15 K temperature under atmospheric pressure. Excess molar volume and deviation in viscosity were computed from measured data and correlated with Redlich–Kister model data. Predict the formation of intermolecular interactions between benzyl acetate and isomeric butyl amine based on excess molar volume and deviation in viscosity results. The obtained excess molar volume had a negative deviation, whereas the deviation in viscosity had a positive deviation across the whole benzyl acetate composition range. The excess molar volume and deviation in viscosity data suggested to the formation of a molecular interaction (H-bonding and packing efficiency) between benzyl acetate and butyl amine isomers. Explain the impact of temperature on molecular interactions. In addition, the Jouyban–Acree (J–A) model was used to analyze measured density and dynamic viscosity data.
In this study, cyclic voltammetry and chronoamperometry techniques were employed to investigate the effect of applied potential on the electrocrystallization kinetics of indium electrodeposition onto platinum and indium tin oxide (ITO) substrates. The deposition was carried out in an acidic medium (pH 4) containing indium trichloride (InCl3) and sodium citrate at room temperature. Potentiostatic current transients were analyzed based on the Scharifker–Hills model. The surface morphology of the indium deposits was examined using scanning electron microscopy (SEM), while atomic force microscopy (AFM) was utilized to assess surface roughness. Results revealed that the nucleation of indium on the platinum substrate follows an instantaneous mechanism with three-dimensional hemispherical growth. The maximum current density (im) increased linearly with the applied potential, whereas the nucleation density (N0) and the time to reach maximum current (tm) showed an exponential dependence on it. At deposition potentials of –1.2 and –1.3 V, the indium grains exhibited spherical morphology with nanoscale dimensions and relatively smoother surfaces.
In this work, three armchair configurations (n, n), where n = 5, 6, or 7 of carbon nanotube were selected to investigate as an absorbent to remove thiourea molecules. Density functional theory utilizes the principles of quantum mechanics to calculate changes in the electronic properties of CNTs before and after the adsorption of thiourea at two different positions on the CNTs. The obtained data from HOMO and LUMO energies of Tx (n, n), where x = I, O, show that the conductivity of complexes is increased due to the reduction of band gap energies. The thermodynamically favorable adsorption of thiourea was confirmed by the negative values of binding energies for all complexes. According to the calculation of total density of state (TDOS) and partial density of state (PDOS), the changes in energy states around Fermi levels show the change in electronic properties after thiourea adsorption. Values of chemical potential and electrophilicity for all complexes show an increase in their stability and electrophilic properties, respectively.
This paper focuses on discussing X-ray diffraction patterns of carbon materials that are promising for use as components of electrodes in electrochemical energy storage devices such as supercapacitors, lithium-ion and post-lithium-ion batteries: graphites, graphenes, carbon nanofibers, nanotubes, and carbon blacks. Based on the X-ray diffraction patterns, the following characteristics of carbons were calculated: interplanar distance, crystallite sizes, the number of aromatic layers and carbon atoms in crystallites, the content of the amorphous phase, and the crystallographic density. In the studied graphites, the content of the amorphous phase varies in the range 0.5–10
Using three independent variants of the density functional theory (DFT) with the B3PW91, M06, and OPBE functionals and the TZVP basis set, the molecular structures of heteroligand (6666) macrotetracyclic chelates of 3d metals of the [M(OFP)(F)2] type (M = Ti, V, Cr, Mn, Fe, Co, Ni, Cu) with a doubly deprotonated form of the tetradentate macrocyclic ligand, octafluoroporphyrazine (OFP2–), and two axially oriented fluoro ligands were calculated. Selected bond lengths and bond and nonbonded angles in the resulting metal complexes are presented. According to data from all the above-mentioned DFT methods, seven of these eight complexes have a planar MN4 chelate core and a planar macrocycle structure. Moreover, all five-membered and six-membered rings in each of these seven metal chelates are identical to each other (both in the sum of their bond angles and in their range). An NBO analysis of the coordination compounds under consideration, was performed, images of their highest occupied (HOMO) and lowest unoccupied (LUMO) molecular orbitals, as well as the values of the effective charges on individual atoms, are presented. The standard enthalpy, entropy, and Gibbs free energy of formation of these compounds were calculated. It was found that the values of the standard enthalpy and standard Gibbs energy for both the H2OFP ligand itself and the metal complexes it forms are negative, which indicates their high thermodynamic stability. There is good agreement, both qualitative and quantitative, between analogous parameters calculated by various DFT methods.
The crystal field and zero field splitting parameters of the Mn2+ infused MgCs2(SO4)2·6H2O (MCS) single crystals are modeled using the superposition model. The evaluated parameters are consistent with those from EPR. The result of EPR experiment that the Mg2+ site is occupied by the Mn2+ ion in MCS is confirmed. Programs for crystal field analysis and crystal field parameters are used to obtain optical spectra of the crystal. A good correspondence is seen with the positions of the experimental bands. As a result, theoretical computation verifies the observations of experiment.
The crystallization of three samples of polyethylene glycols of different molecular weights from melts was studied by polarization microscopy method. An oscillatory mechanism of PEG crystallization was found, manifested in an increase and decrease in the layer-by-layer crystallization rate. The crystallization of polyether is described by the Kolmogorov–Avrami equation.
Corrosion, the oxidative degradation of metals in aggressive environments, poses significant economic and environmental challenges. This study comprehensively evaluates the structural, electronic, and adsorption properties of Aditoprim (ADP) and Brodimoprim (BDP) as green corrosion inhibitors using density functional theory DFT and B3LYP/6–311++G(2d,p) level of theory, topological analyses, and Monte Carlo (MC) simulations in dry and acid environment comprising 100 water molecules, 4 hydronium ions (H3O+), and 4 chloride ions (Cl–1). A 25 Å vacuum layer was applied along the *c*-axis to mitigate periodic interactions on the Fe(110) surface. Fukui function and Mulliken charge analyses identify nucleophilic/electrophilic sites, while MEP maps highlight reactive regions. Results reveal efficient electron charge transfer from inhibitor to metal, with ADP exhibiting superior adsorption energy and electron-donating ability, attributed to its dimethylamino moiety. The lower HOMO–LUMO energy gap of ADP (4.636 eV) compared to BDP (5.138 eV) correlates with higher reactivity and inhibition potential. These computational insights support the design of effective green corrosion inhibitors.
Over a broad frequency and temperature range, the dielectric characteristics of water contained in 2.5 nm mesoporous nanochannels were investigated. Two noticeable relaxation peaks, dependent on frequency and temperature, were seen in the dielectric tests. Following a thermally stimulated mechanism analogous to that of bulk ice, the glassy transitions of water inside nanochannels cause a low-temperature relaxation. Freezing of water inside the MCM-41 nanochannels is responsible for the non-Arrhenius-type behaviour seen during elevated temperature relaxation (230–280 K).
Plasma-activated medium (PAM) is produced by exposing a liquid solution, consisting of hyaluronic acid gel and deionized water, to nitrogen plasma. Plasma exposure through fast pulsed discharge (FPD) generates reactive oxygen species (ROS) and reactive nitrogen species (RNS) in the liquid. The goal of this work is to figure out how many of these reactive species are in PAM. To test the levels of hydrogen peroxide, nitrite, and nitrate right after treatment and after 96 h of storage, a DC high voltage of about 15 kV was used for 5, 10, 15, and 20 min. The discharge promotes the formation of reactive nitrogen species, leading to moderate RONS levels. These species decay rapidly in water, but the gel remains much more stable due to limited diffusion and a stabilized matrix. Results indicate that fast-pulsed nitrogen discharge is effective and that hyaluronic acid gel efficiently retains plasma-generated reactive species over an extended period.
Changes in the composition of aluminum hypophosphite, calcium hypophosphite, and their mixtures with oxidizers after combustion in air under atmospheric pressure have been studied by X-ray photoelectron spectroscopy (XPS). It has been established that the formation of colored condensed combustion products is associated with the formation of the corresponding phosphides. A hypothesis is proposed that the source of phosphide formation is phosphine and its reactive decomposition products generated during the disproportionation reaction of hypophosphites.
This study is dedicated to exploring the electroless Pd–Ag plating process. The conditional formation constants of Pd and Ag ions with respect to the pH of the plating solution were determined. Leveraging the electrode potential equations of metals, the co-deposition conditions were investigated by altering the pH and Na2EDTA concentration. Through this research, specific plating parameters were obtained, and a 78.7Pd-21.3Ag/α-Al2O3 film was successfully fabricated via electroless plating. The composition of the prepared film was analyzed using X-ray diffraction (XRD), providing experimental evidence for the research findings. This research not only deepens the understanding of the electroless Pd–Ag plating mechanism but also offers valuable parameters for the preparation of Pd–Ag alloy membranes with excellent performance.
Magnesium oxalate is an important biomineral and coordination compound with potential relevance in materials science and optoelectronics. In this work, a comprehensive study combining experimental spectroscopic techniques and quantum chemical calculations was performed to elucidate the molecular structure and electronic properties of magnesium oxalate. The optimized geometry obtained at the B3LYP/6-31G(d,p) level confirms the bidentate coordination of oxalate ligands and the mixed ionic–covalent nature of Mg–O bonds. Vibrational assignments from FT-IR and Raman spectra, supported by DFT calculations, revealed characteristic stretching and bending modes of the oxalate framework and Mg–O linkages. Theoretical UV-Vis and NMR spectra further validated the electronic environment and structural symmetry of the complex. Frontier molecular orbital (HOMO–LUMO) analysis highlighted ligand-to-metal charge transfer processes and provided insight into electronic stability and reactivity. Natural bond orbital (NBO) analysis demonstrated strong donor–acceptor interactions, particularly between oxygen lone pairs and antibonding C–O orbitals, accounting for significant charge delocalization within the molecule. The molecular electrostatic potential (ESP) map identified oxygen atoms as preferred electrophilic sites and magnesium as the main electron-accepting center. Global reactivity descriptors, dipole moment, polarizability, and hyperpolarizability values indicate notable nonlinear optical (NLO) behavior, consistent with charge-transfer mechanisms. Overall, this integrated experimental and theoretical approach provides new insights into the bonding, electronic distribution, and optical properties of magnesium oxalate, underlining its potential applications in supramolecular chemistry and optoelectronic devices.
Mitigating CO2 emissions from mobile combustion sources has been recognized as a pressing need, as heavy-duty engines continue to serve remote and mission-critical applications. Capture systems for such sources faced rapidly fluctuating exhaust compositions, temperatures, and flows, under which solvent performance had been poorly characterized. The research gap concerned the limited availability of transient metrics and comparative evidence for hybrid amine–amino acid sorbents under realistic load changes. The objective was to determine how formulation influenced instantaneous capture efficiency, response time, and regeneration energy during stepwise engine operation. A bench-scale packed column was coupled to a diesel generator subjected to programmed load steps; six solvents—30
This study explores the molecular structure, stability, reactivity, and antibacterial activity of sulfamerazine, a sulfonamide derivative, using computational and experimental approaches. Density functional theory (DFT) at the B3LYP/6-311+G(d,p) level was used to optimize geometry, analyze vibrational modes, and evaluate electronic properties. Key interactions such as S–N bond length, N→π* delocalization, and hydrogen bonding were found to influence antibacterial efficacy. Vibrational analysis and scaled quantum mechanical (SQM) methods revealed functional dynamics supporting molecular stability. Docking studies showed strong binding of sulfamerazine to bacterial enzymes, corroborated by in vitro assays against Staphylococcus aureus and Pseudomonas aeruginosa. Electron localization function (ELF) and natural bond orbital (NBO) analyses confirmed significant charge transfer and delocalization. Pharmacokinetic and toxicity evaluations supported its drug-likeness and safety. These results highlight sulfamerazine’s potential as a versatile antibacterial agent and provide insights for designing improved sulfonamide-based therapeutics.
In recent years, machine learning algorithms have become popular for predicting the physicochemical properties of polymers, including the glass transition temperature (Tg). Accurate Tg prediction is critical for developing polymers with desired properties. Traditional Tg prediction was based on semi-empirical methods, such as Askadskii’s method. The goal of this study was to develop a hybrid approach for predicting the Tg of organic homopolymers, combining Askadskii’s method and the QSPR model with machine learning (ML), which uses the advantages of theoretical analysis and the capabilities of ML to improve prediction accuracy. Random Forest, K-Nearest Neighbors, and a multilayer perceptron were used. The molecular structure of the polymers was represented by structural keys (MACCSKeys) and Morgan fingerprints. Optimization of the random forest algorithm hyperparameters enabled an R2 of up to 0.77 to be achieved on the test set. A comparative analysis showed that Morgan fingerprints that consider the spatial arrangement of fragments provide higher prediction accuracy, especially for isomeric homopolymers, where the spatial arrangement of substituents is important. The results demonstrate the potential of using ML for predicting polymer Tg based on glass transition theories and highlight the need for further research into hybrid models.
A new metal–organic coordination polymer (MOCP) La2(nBrTerPDC)3DMSO3 has been synthesized by a solvothermal reaction (in a DMSO/1,4-dioxane solution) between lanthanum(III) nitrate and a brominated terphenyl dicarboxylic acid derivative nBrTerPDC. The structure of this MOCP was solved for the first time by direct methods using X-ray diffraction data. Selected details of the structure solution and parameters of the experiment carried out on the Belok/RSA diffraction beamline at the Kurchatov synchrotron radiation source (λ = 0.7527) are as follows: C36H30Br9LaO9S3, FW 1560.88; space group P 3̅ , a = b = 26.822(4) Å, c = 8.6710(17) Å, α = β = 90°, γ = 120°, V = 5402.3(19) Å3, F(000) = 1476.0, absorption coefficient μ = 4.399 mm–1, crystal dimensions 0.2 × 0.02 × 0.02 mm, reflection index ranges –21 ≤ h ≤ 32, –32 ≤ k ≤ 32, –10 ≤ l ≤ 9; total reflections 17 717, independent reflections 6459, Rint 0.1072, residual electron density 1.31/–0.62 e/Å3. The unit cell contains two structurally unrelated La3+ cations. The relatively high factor R1 = 0.1942 is associated with disorder in the arrangement and degree of occupancy of bromine atoms. This is a consequence of that during the bromination of terphenyl dicarboxylic acid dimethyl ester, bromine attaches to both the central and peripheral aromatic rings of the acid, forming many homologues, presumably mono-, di-, tri-, tetra-, penta-, and hexabromo derivatives, including positional isomers.
