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This study presents a comprehensive investigation of the structural, electronic, optical, and nonlinear optical (NLO) properties of unsymmetrical N,N′-diaryl-N,N′-dialkyl derivatives of urea, thiourea, and selenourea, using density functional theory (DFT) and time-dependent DFT (TD-DFT) methods. The influence of chalcogen substitution (O, S, Se) and para-substituents (–NH₂, –CH₃, –Cl, –NO₂) was systematically analyzed. Conformational studies reveal a consistent thermodynamic preference for the endo isomers, driven by reduced steric repulsion and favorable π–π stacking, with rotational barriers calculated between 15 and 30 kcal mol⁻¹. Electronic structure analysis indicates that urea and thiourea derivatives possess donor–donor–acceptor (DDA) character, while selenoureas adopt donor–acceptor–acceptor (DAA) configurations. HOMO–LUMO energy gaps range from 6.0–8.0 eV, decreasing notably with electron-withdrawing substituents, particularly –NO₂. TD-DFT calculations show dominant π–π* transitions in ureas, while thiourea and selenourea analogs exhibit additional n–π* transitions. First-order hyperpolarizabilities are significantly enhanced by both the chalcogen atom and para-substituents, with NO₂-substituted derivatives exhibiting the strongest NLO responses. Molecular docking against CDK2 kinase and SARS-CoV-2 main protease reveals that thiourea and selenourea derivatives bind more strongly than parent urea structures. SwissADME predictions indicate favorable pharmacokinetics, drug-likeness, and gastrointestinal absorption, especially for halogenated and nitro derivatives, although some nitro compounds flagged potential toxicity. The combined structural and functional analysis highlights how chalcogen identity and para-substitution can be effectively employed to tailor the multifunctional properties of these derivatives for therapeutic, NLO, and optoelectronic applications.

Five new one-dimensional Mn (III) coordination polymers have been synthesized using bidentate N, O-donor Schiff base ligands, representing the first examples of azido-bridged Mn (III) chains derived from such ligands. Single-crystal x-ray diffraction reveals that all complexes adopt μ1,3-azido bridging with distorted octahedral Mn (III) centers exhibiting characteristic Jahn–Teller elongation along the Mn-N_azide axis. The Mn–Mn separations (5.43–5.82 Å) and azide-mediated super-exchange pathways indicate dominant antiferromagnetic interactions. First-principles DFT (GGA+U) calculations show residual spin polarization due to intrachain spin canting arising from axial anisotropy. These findings highlight the structural-electronic correlation governing spin alignment in azido-bridged Mn (III) chains. Magnetic behavior discussed in this work is derived solely from DFT simulation, no bulk magnetic measurements are reported.

As essential trace elements in the organism, Ag⁺ plays crucial roles in living systems. Deficiency or excess of Ag⁺ can induce various diseases. Notably, hypochlorite (ClO⁻), as a critical component of reactive oxygen species, not only participates in fundamental metabolic processes such as thyroid hormone synthesis but also exerts a crucial function in immune regulation and antibacterial defense. In this study, a bifunctional probe (BHZ) based on benzimidazole was designed and constructed. In the presence of Ag⁺, the fluorescence wavelength of the probe experienced a slight redshift, accompanied by a decrease in fluorescence intensity. The mechanism is attributed to the ICT effect induced by the complexation of BHZ with Ag⁺, leading to changes in the fluorescence spectrum. Meanwhile, the probe selectively recognize ClO⁻ via a fluorescence “OFF-ON” response, and the weak blue light of the probe turned into strong green light upon addition of ClO⁻. The mechanism of ClO⁻ recognition involves addition reaction between ClO⁻ and the probe, thereby inducing structural modifications in the probe that consequently modulated its optical properties. The detection limits of probe BHZ toward Ag⁺ and ClO⁻ were 1.57×10⁻⁸ M and 4.28 nM, respectively. Mass spectrometry was utilized to investigate the response mechanisms of the probe toward Ag⁺ and ClO⁻. By combining the smartphone color recognition, the rapid and real-time detection of Ag⁺ by BHZ in real water samples was achieved by using fluorescence ratiometric recognition and test paper. Moreover, the probe BHZ has been effectively deployed for ClO⁻ bioimaging in mice in vivo.

This study focused on the aggregation behavior of toluidine blue (TB) in aqueous and aqueous salt (NaCl and KCl) solutions. The absorption spectra of TB in aqueous and aqueous 0.1, 0.2, and 0.3 M NaCl and KCl solutions were recorded at room temperature over the wavelength range of 520–720 nm. The main maximum (λ_max) for TB in water observed at 631 nm which is attributed to the monomeric form of TB while the inflection point at 590 nm is indicative of dimeric TB molecules. The effect of added salts was thoroughly analyzed in the concentration range where, monomer–dimer equilibria predominate. The dimer dissociation constants for TB in aqueous and aqueous salt solutions were determined by applying appropriate methodology. The monomer and dimer absorption spectra of TB and the absorption spectra of TB dimers separated into contributions from H– and J–dimers were resolved. Oscillator strength, transition dipole moment, interaction energy and twist angle were calculated by applying molecular exciton theory. The results are explained in terms of interactions between TB dye molecules in aqueous and aqueous salt solutions, which influence the molecular arrangement and subsequently affect the extent of aggregation.

The compound (3E)-3-(2,4-dimethoxybenzylidene)-2,3-dihydro-4H-chromen-4-one (DMBDHC) was thoroughly studied using a combination of experimental techniques and computational methods. DMBDHC was thoroughly characterized using nuclear magnetic resonance (NMR), FT-IR, FT-Raman, and thermogravimetric-differential thermal analysis (TG-DTA), confirming its symmetric chromone structure, strong hydrogen bonding, and high thermal stability with a melting point of 135.72°C. DFT calculations optimized geometric parameters and revealed a hyperpolarizability about 20 times that of urea, indicating strong NLO potential. NBO, highest occupied molecular orbital–lowest unoccupied molecular orbital (HOMO–LUMO), molecular electrostatic potential (MEP), and Fukui analyses highlighted significant charge transfer, chemical stability, and reactivity. Electron localization function (ELF), localized orbital locator (LOL), and non-covalent interaction (NCI) analyses supported molecular stability and favorable interactions. DMBDHC meets Lipinski's rule of five with good ADMET properties, low toxicity, and no allergenicity. Protein modelling and molecular dynamics confirmed stable binding and rigidity, suggesting DMBDHC's promise in therapeutic and nonlinear optical applications.

The copper-malonate coordination polymers [K₂Cu(mal)₂(H₂O)₂]_n (1) and [Cu(mal)(DMF)]_n (2) (mal = dianion of malonic acid) were synthesized using a straightforward method at two different pH settings. The compounds were structurally investigated (XRD, FTIR, UV–visible, TGA, SEM/EDS, and XPS) and showed high crystallinity and purity with discrete morphologies and coordination geometries. Cyclic voltammetry demonstrated that the Cu²⁺ centers remained accessible, exhibiting the redox couplings Cu²⁺/Cu⁺ and Cu⁺/Cu⁰. The processes were found to be irreversible, controlled by diffusion and charge transfer, and exhibited a small capacitive current, indicating a low internal resistance. According to diffusion and charge transfer coefficient analyses, the electron mobility was higher in [Cu(mal)(DMF)]_n than in [K₂Cu(mal)₂(H₂O)₂]_n. Overall, these findings show that both compounds have structural stability and efficient electroactivity, making them potential candidates for electrocatalysis and energy storage/conversion.

A new crystalline tertiary aryl amine, 1-(4-Nitrophenyl)-4-benzylpiperidine (NPBP), was synthesized via a nucleophilic substitution reaction between 4-benzylpiperidine and 1-chloro-4-nitrobenzene. The structure was confirmed using infrared (IR) spectroscopy, ¹H, and ¹³C nuclear magnetic resonance (NMR) spectroscopy. Single-crystal x-ray diffraction analysis revealed that NPBP crystallizes in the orthorhombic, chiral, non-centrosymmetric space group P2₁2₁2₁ with unit cell parameters a = 6.0972(10) Å, b = 8.3575(11) Å, c = 30.373(5) Å, and α = β = γ = 90°. Hirshfeld surface and energy framework analyses highlighted significant intermolecular interactions contributing to crystal stability. Density functional theory (DFT) calculations indicated both electron-donating and electron-accepting character, supporting its potential reactivity. Molecular docking studies showed strong binding affinities with EGFR tyrosine kinase, human cyclooxygenase, as well as with DNA and bovine serum albumin (BSA). Binding interactions with calf thymus DNA (CT-DNA) and BSA were further validated by UV–visible spectroscopic titrations. In vitro assays demonstrated moderate anticancer and anti-inflammatory activities, suggesting NPBP as a promising lead compound for future therapeutic development.

Glycerol is an organic waste that is recyclable, biodegradable, and nontoxic, which is left over after making biodiesel fuel. For a wide range of uses, glycerol is currently regarded as a green solvent cum promoter. Glycerol media perform a wide range of catalytic and non-catalytic organic reactions more efficiently than frequently used organic solvents. The remarkable H-bonding characteristics of glycerol, which lead to increased reactivity in numerous chemical reactions, are the reason for its effectiveness as a green media. Furthermore, expanding the solvent's potential as a green media is its highly polar character, recyclability, high boiling point, low vapor pressure, and low cost. This review article covers the six categories for the synthesis of biologically active compounds in which glycerol may be used as a green solvent: coupling reactions, cyclization processes, catalyzed reactions, non-catalyzed reactions, synergistic reactions, and miscellaneous reactions.

This research presents copper- and iron-based binary and ternary systems synthesized using the mechanical alloying (MA) technique under various processing conditions, using a PM400 planetary mill. Structural and microstructural properties were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), while differential thermal analysis (DTA) and Mössbauer spectroscopy were employed to assess phase evolution. The results reveal the formation of nanostructured phases and composite structures, with significant grain refinement (approximately 10–11 nm). Systematic variations observed in lattice parameters provide quantitative evidence of enhanced solid-state solubility. In the Cu–Fe–Co system, iron and cobalt atoms substitute copper lattice sites, enhancing iron solubility, and DTA confirms the formation of a solid solution after prolonged milling, which agrees with XRD results. In Fe–Al and Fe–Al–Sn alloys, aluminum solubility increases significantly under non-equilibrium conditions, producing a disordered bcc solid solution that evolves into the ordered B2 FeAl phase with iron contents above approximately 40 at.%. Mössbauer spectroscopy reveals a magnetic sextet, detected after 8 h of milling. Additionally, a growing paramagnetic FeAl(Sn) fraction is observed with continued milling, confirming solubility enhancement. Furthermore, results indicate that solid-state solubility increases with milling time due to stress-assisted atomic diffusion, eventually reaching saturation after prolonged milling.