Schiff-base pyrazolone derivatives have garnered significant attention due to their intriguing photochromic and electrochromic properties, which hold promise for applications in molecular switches, sensors, and advanced optical materials. Schiff base, 5-methyl-2-phenyl-4-(phenyl-o-tolylamino-methylene)-2,4-dihydropyrazol-3-one (PMBP-2A1MB), was synthesized and characterized by means of NMR, IR, LC-MS, and UV-Vis absorption spectra. This research paper aims to dive into the synthesis and photochromic and electrochromic properties of Schiff base pyrazolone derivative. The photochromic study was investigated using 365 and 430 nm light and shows good results. The electrochromic study was conducted using a cyclic voltammetry study, which demonstrates quasi-reversibility in nature. Theoretical calculations were performed using geometries optimized at the B3LYP/6-31G(d,p) level of theory. By integrating these aspects, we seek to enhance the understanding of photoisomerization and structure-property relationships.
Among solid state electrolytes, garnet-type Li7La3Zr2O12 (LLZO) has attracted considerable attention due to its high electrochemical stability, safety, and compatibility with lithium metal anodes. However, its lithium-ion conductivity strongly depends on the crystal structure: the tetragonal phase exhibits a significantly lower ionic conductivity than the cubic phase. In this work, first-principles density functional theory (DFT) and ab initio molecular dynamics (AIMD) are employed to systematically investigate the crystallographic structure, lithium-ion migration pathways, and ionic conductivity of both tetragonal and cubic LLZO. Lithium ion trajectories were analysed to determine diffusion coefficients over a wide temperature range. Activation energies are extracted from Arrhenius behaviour, and room-temperature ionic conductivities are extrapolated from high-temperature simulations. The results reveal that cubic LLZO possesses an intrinsically disordered lithium sublattice with abundant vacant sites and shorter migration pathways, which significantly enhance lithium-ion mobility. Consequently, the extrapolated room temperature ionic conductivity of cubic LLZO reaches the order of ~10-3 S/cm, in good agreement with experimental reports, while tetragonal LLZO exhibits much lower conductivity. This study provides atomistic-level insight into lithium diffusion mechanisms in LLZO and offers guidance for designing high-performance garnet-type solid electrolytes through structural disorder and vacancy engineering.
This study investigates the levels of selected heavy metals (Zn, Pb, Cd, and Cr) in the leaves of C. aurea and Z. scabra. Flame atomic absorption spectrophotometry (FAAS) was used for the determination of these metals. Wet digestion of the C. aurea and Z. scabra required 4:1 HNO3/HCl (v/v) for 1:45 h, with a temperature of 210 °C and 3:1 HNO3/HCl (v/v) for 1:30 h, with a temperature of 240 °C, respectively, for complete digestion of 0.5 g of both medicinal plant leaves using the Kjeldahl apparatus. The experimental results revealed that the metals studied found in the plants were determined as follows, in mg/kg: Zn (0.5727, 0.4547); Pb (0.2394, 0.2334) and Cd (0.0365, 0.0468) in C. aurea and Z. scabra, respectively, while Cr was not detected in both plant samples. The recovery percentages for C. aurea and Z. scabra samples ranged from 88.2-95.8% and 90.0-98.9%, with LOD values of 0.0087-0.1476 and 0.0174-0.1176, respectively. The levels of these metals were found to be below the allowable limits of the World Health Organization. The plant C. aurea was found to contain higher concentrations of Zn and Pb compared to Z. scabra, which had a slightly higher Cd level. The hazard quotient and hazard index values of Zn, Pb, and Cd in both medicinal plants were lower than one, which may ensure that these plant spices do not pose substantial health risks to consumers.
This article reports on one of the newly synthesized 5-bromo ortho vanillin (C8H7BrO3) (1) polymorphs, whose X-ray structure was determined by single crystal X-ray diffraction. The polymorph attains a monoclinic system, space group P21/c, V = 824.3(9), and Z = 4. In this work, the cell parameters observed are a = 4.080(2) Å, b = 20.733(12) Å, c = 9.844(7) Å, and β = 98.4(2). Polymorph 1 is compared with the reported compound 2. The article discusses the structural characterization of polymorph 1 using HRMS, FTIR, UV-vis, 1H/13C NMR, and 13C DEPT NMR spectroscopy, and explores NCSI (noncovalent supramolecular interactions) within the crystal network. Furthermore, the Hirshfeld surface and 2D fingerprint plot analyze the presence of significant H···Br (20.8%) and H···O (23.8%) contacts in the crystal assembly. In addition, interaction energies and energy frameworks have been calculated. The study revealed that the constructed frameworks fall into electrostatic (Eele, red cylinders) and dispersion (Edis, green cylinders) categories, along with total interaction energies (Etot, blue cylinders). The polymorph is rationalized using physicochemical, crystallographic, Hirshfeld surface, interaction energy and energy frameworks.
Lake Bogoria geothermal springs are a cultural heritage site in Kenya, offering benefits such as tourism, therapeutic use of hot spring water and recreational activities. However, the hot spring water contains dissolved minerals and potentially harmful organic compounds that can pose risks to humans and the environment, including flamingos. The benzene derivatives present in the water may undergo transformation and bioaccumulation, leading to long-term ecological impacts. This study focuses on the determination of benzene derivatives in Lake Bogoria geothermal springs using gas chromatography - mass spectrometry (GC-MS). Quantitative analysis revealed a total mean concentration of 0.368±0.29 ppm for all identified benzene derivatives. Concentrations were found to be below the recommended limits set by the United States Environmental Protection Agency (US EPA). Among the sampling points, SP4 exhibited the highest total mean concentration (0.120±0.08 ppm). 1,2,4,5-Tetramethylbenzene showed the highest relative abundance (19.97%), while 2-ethyl-1,3-dimethylbenzene had the lowest contribution (1.78%).
In this paper, we report a green and efficient method for the synthesis of N-substituted benzimidazoles under grinding conditions using PEG-400 as reaction solvent at room temperature. 2-Substituted-1H-benzimidazole was prepared from the reaction between various aromatic aldehydes and o-phenylenediamine in mortar and pestle under a grinding process using NH4Cl as catalyst in PEG-400 as green reaction solvent. Additionally, 2-substituted-1H- benzimidazole were treated with 4-halophenacylbromide in the K2CO3 / PEG system, yielding the corresponding 1-(4-fluoro/bromophenacyl)-2-susbtituted-benzo[d]imidazole (N-substituted benzimidazoles). This methodology incorporates inexpensive catalysts, suppressed reaction times, high yields, easy work-up, and the use of green reaction solvents are reported. All of the structures of products were established by spectroscopic and analytical methods. The IR spectra of 2-substituted-1H-benzimidazole (2a-e) showed the disappearance of the stretching frequency band at 1680-1695 cm-1 due to >C=O of aromatic aldehydes and the presence of stretching bands at 1610-1630 cm-1 due to -C=N stretching, which confirms the formation products. Furthermore, 1H NMR spectra of N-substituted benzimidazoles (4a-j) showed the presence of a singlet at δ 6.10-6.25 ppm, indicating the presence of -CH2 in the structure of the phenacyl ring. The mass spectra (EIMS) of the compounds also agree with their molecular formula.
Poly(vinyl alcohol) (PVA) membranes are popular in pervaporation, where interaction between polymers and solvents and the level of cross-linking have a significant effect on swelling, sorption, and transport behavior. The swelling behavior of chemically cross-linked polyvinyl alcohol membranes in various solvents in the presence of two cross-linking agents, including glutaraldehyde and maleic acid, was methodically studied. The equilibrium swelling was used to estimate the Flory-Huggins interaction parameter (χ), which is a measure of the thermodynamic affinity between the polymer network and the penetrant molecules. This parameter is particularly important in pervaporation simulations, where the parameter χ is an expression of the thermodynamic affinity of the solvent and polymer in the membrane phase, which is directly related to the behavior of solvent sorption and can be applied to explain permeation fluxes in solution diffusion-like transport models. The degree of equilibrium swelling was clearly correlated with the percent and the type of cross-linking agent, which allowed correlating χ with the degree of cross-linking density. The results indicate that the swelling ratio and the corresponding values of χ are affected by the type of crosslinker, the degree of cross-linking, and the character of the solvent-polymer system, so different behaviors are found in the acidic and alcoholic solvents. The correlations developed in this work provide reliable information on Flory-Huggin’s interaction parameter for use in pervaporation sorption and contribute to the rational design and optimization of cross-linked PVA membranes for separation applications.
Cancer remains a leading cause of death worldwide and early‑stage detection is essential to improve patient outcomes. Recent advances in nanoscale sensing have opened up new pathways for ultrasensitive, label-free detection of nucleic acid biomarkers. In this work, we compare two sensor platforms for a KRAS G12V RNA biomarker: (i) a classical bioelectrochemical sensor that exploits the redox activity of methylene blue modified DNA probes, and (ii) a recently reported quantum transport-based single-molecule sensor that measures conductance changes of individual DNA: RNA hybrids using scanning ‑ tunneling‑microscopy break‑junctions (STM‑BJ). By comparing both approaches, we evaluate their key performance metrics -limit of detection, specificity, and robustness- in biologically relevant complex media. The electrochemical sensor reaches a femtomolar detection limit, but fails to discriminate a single‑base mismatch under the tested conditions. In contrast, the STM-BJ platform delivers attomolar sensitivity and single-base resolution; however, its operation is hindered in complex media, particularly in protein-rich environments. However, this weakness is also shared with the electrochemical approach. Our comparative analysis highlights the complementary strengths of these platforms, suggesting that integrating both could improve point-of-care cancer screening by combining sensitivity, specificity, and robustness in complex samples.
3-(Benzo[d][1,3]dioxol-5-yl)-2-(pyridin-3-yl)thiazolidin-4-one, a novel derivative of 1,3-thiazolidin-4-one, was synthesized by Schiff base formation followed by cyclocondensation with thioglycolic acid. The structure of the synthesized compound was characterized by spectroscopic techniques, including NMR, GC-MS, and HRMS. The molecular structure was unambiguously established by single-crystal X-ray diffraction. The compound crystallizes in the monoclinic crystal system with space group C2/c (No. 15) and unit-cell parameters a = 14.69 Å, b = 9.615 Å, c = 22.198 Å, and β = 98.49°. The molecular geometry reveals that the sulfur atom of the 1,3-thiazolidin-4-one ring is significantly out of the plane of the remaining ring atoms and adopts a puckered conformation. In the solid state, the supramolecular architecture is stabilized by a combination of interactions, including hydrogen bonding and weak π···π interactions. Furthermore, Hirshfeld surface analysis and two-dimensional fingerprint plots were used to quantify the intermolecular interactions, revealing that H···H (32.4%), O···H/H···O (20.2%) C···H/H···C (18.1%) contacts make the most significant contribution to Hirshfeld surfaces. Energy framework calculations indicated that dispersion energy, arising mainly from π···π interactions, is the dominant contributor to stabilization of the crystal packing.
Andrographis paniculata, popularly known as Kalmegh in the Indian subcontinent, is a multifunctional herb that possesses immense pharmacological properties. It has been used in Ayurvedic and other herbal formulations globally, in particular as a hepatoprotectant, antimalarial, and anti-inflammatory agent. Recent years have witnessed substantial progress in the research initiatives focused on the herb. The present review considers the pharmaceutical dosage forms of the multifarious herb A. paniculata along with discussing recent patents on the plant, venturing into the details of its therapeutic uses, methods of preparation of its extracts and their modification along with a brief discussion of various roles of the plant that constitute its pharmacological properties. The analysis was carried out using various web-based sources such as Scopus, PubMed, ScienceDirect, Google Scholar, Google Patents, and other allied databases. The data of patents on A. paniculata was extracted from the Google Patents database along with the use of the advanced search option to access the exact data on the plant along with the specific dates of publication, grant date, language, and countries. A. paniculata has huge potential as a major pharmaceutical drug on the market as evident from its many pharmacological activities. China dominated this field and had the highest number of patents granted and published. America, Australia, Korea, and Japan also contributed significantly towards new inventions.
In this work, the efficacy of imibenconazole (IB) as a new mild steel corrosion inhibitor in 1 N sulfuric acid is examined. With 95.4-96.6% inhibition at an ideal dose of 500 µM, weight loss measurements show strong inhibitory efficiency. The formation of a protective coating by imibenconazole on the steel surface is demonstrated by scanning electron microscopy (SEM) photographs. Improvements in charge transfer resistance (Rct), a shift in Tafel lines to higher potentials, and a drop-in double-layer capacitance (Cdl) are indicative of improved corrosion resistance as measured by electrochemical methods. The inhibitor’s adsorption aligns with the Langmuir isotherm, and the values of ΔG°ads (25-30 kJ/mol) indicate a combined physisorption and chemisorption mode of adsorption. Reliable long-term corrosion prevention is ensured by its durable protective action up to 120 h. Due to its adaptability, the inhibitor can be applied by coatings, injections, and immersions, making it suitable for a range of situations. While stressing the need for more research to examine the applicability of imibenconazole in various materials and situations, the study offers a strong foundation for the adoption of imibenconazole as an efficient corrosion inhibitor. To guarantee long-term protection and effectiveness, routine maintenance and observation are recommended.
Nrf2 (nuclear factor erythroid 2–related factor 2) is a crucial transcription factor that regulates cellular defense against oxidative and electrophilic stress. Under basal conditions, Nrf2 binds to Keap1 (Kelch-like ECH-associated protein 1), which promotes its ubiquitination and degradation. The primary cellular response to oxidative or electrophilic stress is mediated through a redox-sensitive protein complex in which actin-associated Keap1 interacts with Nrf2. Upon exposure to stress-inducing agents, critical cysteine residues of Keap1 undergo modification, leading to conformational changes that disrupt the Keap1-Nrf2 interaction. As a result, Nrf2 escapes ubiquitination, stabilizes, and accumulates in the cytoplasm before translocating to the nucleus. Metalloproteins are well recognized as essential reservoirs and protective agents for trace metals such as iron, zinc, and copper, which are critical cofactors for numerous antioxidant enzymes. By controlling the expression of genes encoding metalloproteins and metal-binding proteins, Nrf2 contributes to the precise regulation of intracellular metal balance. This coordination is particularly important because, while essential metals are required for antioxidant defense, their dysregulation can promote oxidative damage through redox cycle reactions. Therefore, Nrf2-mediated regulation of metalloproteins represents a crucial interface between redox homeostasis and metal metabolism, reinforcing its central role in cellular protection.
Decolorization of methylene blue by new fungus: Trichaptum biforme and decolorization of three
As herein defined; a ring closing metathesis (RCM) reaction of N-anchored homoallylic dienes followed by enzymatic kinetic resolution and ring closing enyne metathesis (RCEM) with an intramolecular Pauson-Khand reaction of N-tethered homopropargylic enynes are described for the first time. RCM afforded azaspirodeca and -undecadiene with 78 and 82% chemical yields, as well as azaspironona and decadienecarboxylates with 65 and 70% chemical yields, respectively. Furthermore, RCEM protocol resulted in conjugated diene 50% chemical yield. Moreover, intramolecular Pauson-Khand reaction is also applied to enynes, which yielded cyclopenta[c]pyrrole-carboxylate as diastereomeric mixtures; besides cyclopenta[c]pyridin-one and cyclopenta[c]pyridin-carboxylate frameworks as single diastereomers. Above all, secondary amines (azaspirodeca and undecadiene) have been efficiently resolved through an enzyme-catalyzed reaction in a moderate ee up to 77 and 20% ee, with their corresponding esters up to 75 and 55% ee, in the presence of CAL-B (being the most effective biocatalyst) and recombinant from Aspergillus oryzae. Both CAL-B and CAL-A-CLEA afforded reverse enantiomeric separation of them for the first time.
In need of information on the precise structural data of the monomer of azulene, we were long frustrated by our inability to characterize it thus because the known specimens always contained its extremely stable head-to-tail dimer. Recently, a claim was made of having prepared such a monomeric species in the case of (tris(1,2,4,5-tetrafluoro-3,6-diiodobenzene)bis(azulene), whose REFCODE = LADWEW), which the authors used to “demonstrate how a highly robust C-I⋯π motif permits the systematic exchange of original co-crystal components with azobenzene and azulene, resulting in optically interesting dichroic or pleochroic materials.” We demonstrate that the structural data used in the theoretical treatment of the title compound were derived from an improper crystallographic analysis. The hkl values provided in the original report were used to obtain the correct structural solution in P1, (Z’ = 1) as opposed to the original centrosymmetric P-1, (Z’ = 0.5) interpretation. These new data have been deposited with the CCDC #2403565.
Thiosemicarbazones are a class of iminic organosulfur compounds synthesized by condensation reaction between a thiosemicarbazide and an aldehyde or ketone. Such compounds present a wide range of biological activities, either as sole organic compounds or in association with metallic species. The fluorinated pyrazoline cyclic thiosemicarbazones described herein were synthesized from 4,4,4-trifluoro-1-phenyl-1,3-butanedione and three thiosemicarbazides. The reactions resulted in thiosemicarbazones 1, 2, and 3, with 51, 70, and 71% yields, respectively. which were characterized by elemental analysis, FTIR, 1H and 19F{1H} NMR, mass spectrometry and single crystal X-ray diffraction. The spectral data confirm that the thiosemicarbazones are cyclic the both in solid state and solution, as no evidence of ring-chain tautomerism has been observed. Additionally, single-crystal X-ray diffraction studies revealed that the compounds mentioned above crystallized in centrosymmetric space groups, two of them in monoclinic P21/n and the last one in triclinic P . Theoretical free energies of formation were calculated using the DFT methodology, and the results indicate that the ring isomer is significantly more stable than the chain isomer; thus, no ring-chain isomerism is expected to form, in agreement with the experimental data.
In recent decades, the detection of non-steroidal anti-inflammatory drugs (NSAIDs) in various water bodies has raised concerns for their environmental impact, since conventional wastewater treatment plants are inefficient for removing these pharmaceutical contaminants. In this way, many researchers have proposed various techniques, including the use of adsorbent materials. In this work, we conducted a theoretical study of the adsorption of the paracetamol (PCT) molecule on a large cluster (C80H26O24) of graphene oxide (GO) that simulates a sheet. The calculations were based on the DFT formalism using the combination M06-2X/6-31G**. The GO sheet used, with a C/O ratio of 3.5 and an oxygen content of 17%, exhibited a high adsorption capacity and stability. The adsorption energies for the most preferred complexes were 22 kcal/mol with adsorption distances between 1.84 and 2.60 Å, which allowed us to conclude that this is a very favored chemisorption process. The interaction distances and adsorption energies obtained were compared with those from other studies, confirming that the DFT approach used in this work, as well as the GO sheet modeled, were suitable. The percentages of elongation of the bonds in the PCT molecule, calculated from the bond distances before and after the adsorption process, evidenced a weakening of certain bonds in the molecule related to its most likely fragmentations. Therefore, it is concluded that these adsorption processes mediated by GO sheets can help, together with other methods, with PCT degradation.
Polyphenolic flavonoid compounds are commonly found in colorful vegetables and fruits, as well as other foods such as coffee, tea, wine, beer, and chocolate. Recent studies have highlighted their potent antioxidant properties, which contribute significantly to various biological functions and overall health. Chalcones and flavones represent important subclasses of flavonoids. In addition to their natural occurrence, these compounds can also be synthesized in the laboratory using chemical methods. In this study, chalcones and flavones were synthesized through Claisen-Schmidt condensation. To produce flavone derivatives (4a-e) from their corresponding chalcones (3a-e), microwave irradiation (MWI) and conventional heating (CH) methods were employed. The MWI technique proved to be more eco-friendly and cost-effective and offers greater yields and reduced reaction time compared to the conventional method. The structures of the synthesized compounds were confirmed by ultraviolet (UV) spectroscopy, nuclear magnetic resonance (NMR), infrared (IR) spectroscopy, and elemental analysis. Using Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), the antibacterial activities of the synthesized compounds were analysed. All synthesized flavones showed significant antibacterial activity but zero activity against Gram-negative bacteria, Pseudomonas aeruginosa, in different concentrations. Compound 4a showed highest activity 19 mm zone of inhibition against Gram-positive bacteria Staphylococcus aureus with concentration 128 µg/disc.
This study reports on the synthesis and characterization of novel cyclodiboradisiloxane derivatives. A one-pot 2+2 cyclo-condensation reaction of diphenylsilanediol and phenylboronic acid produced an eight-membered 2,2,4,6,6,8-hexaphenyl-1,3,5,7,2,6,4,8-tetraoxadisiladiborocane (Ph6B2Si2O4) (3). The reaction of compound 3 with 3,5-di-(3-pyridyl)-1,2,4-thiadiazole (L) and phenylboronic acid produced an oligomer (4) and a hydrogen-bonded-induced 1D polymer (5), respectively. Products (4 and 5) have been characterized by melting point, FT-IR spectroscopy, nuclear magnetic resonance, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction revealed triclinic crystal systems with centrosymmetric space group for compounds 4 and 5. On the other hand, the hydrogen-bonded induced 1D polymer [Ph6B2Si2O4]·2L·2[PhB(OH)2] is colourless blocky cocrystals which also crystallized in the triclinic crystal system with a centrosymmetric space group of P-1. These two novel products (4 and 5) exhibit various intermolecular and intramolecular π-π non-covalent interactions and hydrogen bonds in their crystal packing. Compound 4 shows intramolecular non-covalent C-H···π (3.427 Å), C-H···N (2.601 and 2.684 Å), C-H···O (2.360 and 2.684 Å), C-H···S (2.601 Å and 2.701 Å) interactions in its crystal packings. In addition, compound 4 also displays some intermolecular short distance non-covalent interactions in its crystal packing such as π centroid···π centroid (3.805 Å) and C-H17A···π centroid (3.112 Å). On the other hand, the crystal packing of compound 5 also shows intra-molecular non-covalent C-H···π 3.440 Å, C-H···N 2.563 Å, C-H···O 2.654 Å, C-H···S 2.876 Å and H···B 2.939 Å interactions. Furthermore, compound 5 also exhibits short noncovalent intermolecular interactions in its crystal packing such as π···π, (3.362 Å, C14-C3 and 3.243, C11-C37), CH···π (2.587 Å, CH37A···πC38 and 2.452 Å, H7A···O42). The individual molecules of compounds 4 and 5 interact intermolecularly via C-H···N, C-H···O, C-H···S and N-B. Therefore, this study demonstrates the potential for the production of novel materials via the combination of cyclodiboradisiloxane (a Lewis acid) and a nitrogen-, oxygen-, and sulphur-containing ligand (a Lewis bases).
This research aimed to examine the effect of contact time on total organic carbon (TOC) removal rates associated with adsorption of pollutants from different olive mill wastewater (OMW) samples onto activated granular activated carbon (GAC). The first sample was a raw OMW that was microfiltered through a 100 µm membrane and the second sample was an OMW’s permeate from a 50 kDa filtration. The TOC removal rate (%) of pollutants from prefiltered OMW increased over time, reaching its peak after 34 h (2040 min). Subsequently, the system reached adsorption equilibrium, corresponding to a removal rate of 60%. Then, it stabilized at this value till the end of adsorption at 48 h (2880 min). TOC removal rates (%) (corresponding to adsorption at different concentrations of GAC) of pollutants permeating 50 kDa also increased over time, reaching their peaks after 2040 minutes. The highest TOC removal rate was around 85%. This study also investigated the kinetics associated with this adsorption. To gain a comprehensive process understanding, pseudo-first-order (PFO) and pseudo-second-order (PSO) were employed as kinetic models. The second-order model best expressed the adsorption process which achieved equilibrium within 34 h.
