Acta Chimica Slovenica最新文献

A carbothioamide ligand, 4,5-dihydro-5-(4-methoxyphenyl)-3-phenylpyrazole-1-carbothioamide, [C17H17N3OS], has been synthesized from the condensation of 4-methoxychalcone with thiosemicarbazide. The carbothioamide (L) ligand and triphenylphosphine (Ph3P) as co-ligand, was coordinated with Cu(I), Cu(II), and Pd(II) metal ions to synthesis the corresponding complexes: [CuCl2(L)] 1, [CuCl(L)(Ph3P)] 2, [PdCl2(L)] 3, and [PdCl(L)(Ph3P)]Cl 4. The ligand and all complexes were collected in solid form after the reactions and characterized by magnetic susceptibility, elemental analysis, molar conductivity, FT-IR, UV-Vis, and 1H, 13C, 31P-NMR techniques. The molar conductance values in DMSO (5.8-16.3 Ω-1 cm2 mol-1) confirmed all the complexes to be non-electrolytic except for the Pd(II) complex 4 (32.6 Ω-1cm2 mol-1) that behaves as a 1:1 electrolyte. According to spectroscopic evidence, the carbothioamide ligand behaves as an N, S donor and chelating agent. Magnetic susceptibility measurements combined with electronic spectral data suggest that the Cu(II) and Pd(II) complexes have square planar geometry, whereas the Cu(I) complex 2 has a tetrahedral geometry. Elemental analysis and 1H-NMR spectroscopy confirmed the mononuclear structure of all complexes. DFT calculations showed that the synthesized complexes 1, 3, and 4 exhibit higher thermodynamic stability than the free ligand (L), with ΔE values of 1.4695, 2.1116 eV, 1.9076 eV, and 1.2980 eV, respectively. In contrast, complex 2 has ΔE = 0.5385 eV, indicating lower thermodynamic stability. Among the complexes, complex 2 (S = 3.7140 eV) exhibited the highest softness, and all complexes were observed to be softer than the triphenylphosphine ligand. According to the results, electron transitions are easier in certain complexes than in their ligands, which suggests that the prepared complexes could be used in the photocell in future studies.

In the context of pharmacological intervention for pain, Transient Receptor Potential Vanilloid, member 1 (TRPV1), as a non-selective cation channel belonging to the transient receptor potential (TRP) family of ion channels, has emerged as a promising target. However, the availability of selective TRPV1 antagonists and their associated pharmacological properties remains limited. This research paper explores various QSAR modeling techniques applied to a range of piperazinyl-aryl compounds acting as TRPV1 antagonists. The descriptors utilized in the creation of conformation-independent QSAR models included local molecular graph invariants and the SMILES notation, along with the incorporation of the Monte Carlo optimization method as a model development technique. Several statistical methods were employed to evaluate the quality, robustness, and predictive capacity of the developed models, yielding positive results. For the best developed QSAR model following statistical parameters were obtained for training set R2 = 0.7155, CCC = 0.8134, IIC = 0.7430, Q2 = 0.6970, RMSE = 0.645, MAE = 0.489 and F = 157; and for test set R2 = 0.9271, CCC = 0.9469, IIC = 0.9635, Q2 = 0.9241, RMSE = 0.367, MAE = 0.329 and F = 328. Additionally, molecular fragments derived from SMILES notation descriptors, which explain observed changes in the evaluated activity, were identified, leading to the design of four new antagonists. The final validation of the QSAR model and the designed antagonists was conducted through molecular docking, which demonstrated strong correlation with the QSAR modeling results.

Bleaching is a crucial step in oil refining that removes unwanted pigments and oxidative products, which degrade oil quality. This study evaluated the effects of temperature (75-115 °C), adsorbent concentration (1-3 wt%), and time (20-40 minutes) on sunflower oil bleaching using a Box-Behnken factorial design in Minitab 21. Responses were divided into two groups: (I) peroxide value and spectroradiometric-based chroma and hue-angle, and (II) peroxide value and spectrophotometric-based bleaching efficiency. Under optimal conditions (approximately 78 °C, 2.95 wt% adsorbent, and 20 minutes), peroxide value decreased from 1.8 meq/kg to 0.398 meq/kg, chroma reduced from 45.89 to 9.61, hue-angle increased from 92.69 to 105.55, and bleaching efficiency reached 71.86%. Composite desirability was higher in the first group (0.97 vs 0.89), primarily due to the more objective nature of spectroradiometric parameters (hue-angle and chroma). Keywords: Oil bleaching, Optimisation, Response Surface Method, Sunflower oil.

In this study, the self-assembly of gold and silver-based nanoclusters modified by L-cysteine (Cys@Au-Ag/AgCl) was prepared using a simple and straightforward hydrothermal method. Cys@Au-Ag/AgCl exhibited efficient catalytic activity for the rapid reduction of 4-nitrophenol (4-NP) to the less toxic 4-aminophenol (4-AP) in the presence of NaBH4 as a reducing agent, completing the reaction within a few minutes with a rate constant of 6.1 × 10-3 s-1. The catalytic performance of Cys@Au-Ag/AgCl was optimized by studying the effect of various parameters on the catalytic reduction. In addition, Cys@Au-Ag/AgCl nanocomposite was used for catalytic reduction of K3[Fe(CN)6] in the presence of NaBH4, and the reaction rate constant was found to be 1.73 × 10-2 s-1. The antibacterial activity of Cys@Au-Ag/AgCl nanocomposite was also evaluated against common drug-resistant Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) and Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The results demonstrated that the multifunctional Cys@Au-Ag/AgCl nanocomposite exhibited good antibacterial activity against these clinical drug-resistant bacteria.

Two new cobalt(III) complexes, [CoL2]NO3 (1) and [CoL2]2[CoCl4] (2), where L is 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, have been prepared and characterized by physico-chemical methods and single crystal X-ray analysis. X-ray analysis indicated that the Co atoms in both complexes are in octahedral coordination except for that in [CoCl4] unit which in a tetrahedral coordination. Crystal structures of complexes are stabilized by hydrogen bonds and π···π interactions. Catalytic property of both cobalt complexes was studied on the epoxidation of cyclooctene with tert-butylhydroperoxide (TBHP) as oxidant. Both complexes show good catalytic activity and high epoxides selectivity.

Cobalt and nickel doped catalysts were synthesized by using chitosan and alginate and used in the reduction of Remazol Yellow 4GL (RY) and Remazol Black B (RB) dyes. XRD pattern of catalysts exhibited that amorphous and semi-crystalline form for CoNi-chitosan and Co-alginate, respectively. SEM images showed catalyst's surface was rough and had grainy and rod-like structures. The surface functional groups were determined by FTIR analysis method and it was seen clearly presence of alginate and chitosan. The Co-alginate catalysts exhibited higher dye degradation (74 % for RY) and also lower reaction time (6 min for RB). The reduction reaction was in good agreement with the pseudo-first-order kinetic model and reaction rate constant was determined as 0.140 min-1 and 0.174 min-1 for RY and RB, respectively. The RY reduction percent over both catalysts was higher than RB. Co-alginate showed reduction efficiency was about 70% even after 4 runs for RY. The dye reduction capacity and catalytic activity of the catalysts were promise for organic pollutant dyes catalytic reduction applications.

This research aims to prepare different types of asphalt materials with good rheological specifications compared to unmodified asphalt materials. Three types of polymeric materials used to enhance characteristics of Doura asphalt, namely PS, PFR, PP, to study effect of these polymers on rheological specifications of resulting asphalt systems and compare them with each other and with international, local specifications. To determine its suitability for use in a specific field and not another. Waste polymeric materials used instead of virgin materials for purpose of reducing environmental pollution, reducing costs of modification. The treatment was carried out using two methods: physical treatment based on mixing thermally broken down polymeric materials with asphalt. Chemical treatment depends on carrying out a catalytic chemical reaction using 2%anhydrous ferric chloride and 1%S. From the two methods, asphalt samples were obtained that could be used in field of producing of mastic which is used as a water proofing material, based on measurements that were made (softening point, penetration, ductility, PI, %asphaltene).

This study investigates lysine's conformational behavior and thermal properties at the PBE0-GD3/Def2-TZVP level for geometry optimizations and CCSD(T)/Def2-TZVP level of theory for the calculation of thermal population. Lysine forms pseudocyclic conformations stabilized by hydrogen bonds between amino and carboxyl groups. We identified 36 conformers, split evenly between L- and D-lysine, with small energy differences between structures. When the pseudocyclic conformation is disrupted, the energy is highly affected. Lysine's geometries are remarkably sensitive to temperature. These findings highlight lysine's temperature sensitivity and its potential for diverse applications. Its structural plasticity across 0-1800 K suggests roles in material science, such as temperature-responsive semiconductor thin films, coatings, sensors, catalysis through tunable active sites, and biomedicine for drug delivery or protein stabilization. The insights provided by this study emphasize lysine's versatility as a biomolecule and its implications for technological innovation across multiple fields.

The free radical scavenging activity of benzofuran Schiff base and thiazolidinone derivatives has been investigated using the density functional theory (DFT) calculations. Three primary mechanisms were developed: sequential proton loss electron transfer (SPLET), single electron transfer followed by proton transfer (SET-PT), and hydrogen atom transfer (HAT). Several thermodynamic descriptors were computed in both gas and solvent phases at the B3LYP/6-311G and 6-311G (d, p) level of theory. Our findings suggest that compounds 3a, 3c, 3f, 4d, and 4e may scavenge free radicals through one of these three pathways. The results indicate that SPLET is favored in polar environments, while HAT is the thermodynamically preferred mechanism in the gas phase and non-polar solutions. Electron-withdrawing groups (EWG) attached to the π conjugated system at the N position of the benzofuran derivatives decrease bond dissociation enthalpies (BDE), while electron-donating groups (EDGs) are helpful to decrease the ionization potentials (IPs). The results of the multilinear regression statistical analyses indicate a good correlation between the IC50 and ionization potential, in addition to the proton dissociation enthalpy, proton affinity, and the electron transfer enthalpy descriptors.