Spectroscopic studies, density functional theory calculations, non-linear optical properties, biological activity of 1-hydroxy-4-((4-(N-(pyrimidin-2-yl)sulfamoyl)phenyl)diazenyl)-2-naphthoic acid and its chelates with Nickel (II), Copper (II), Zinc (II) and Palladium (II) metal ions

Efficient Extraction of Olefin from Liquid-Phase Olefin/Alkane Mixtures Using Novel Bimetallic Ionic Liquids

The separation of olefins and alkanes is beneficial for resource utilization of oil products, and liquid-liquid extraction is an important method of liquid-phase olefin/alkane separation. This study investigated the feasibility of bimetallic ionic liquids for the extraction of olefin from liquid-phase olefin/alkane mixtures using 1-hexene/n-hexane as a model hydrocarbon mixture. The bimetallic ionic liquids were first synthesized from different metal chlorides (ZnCl2, SnCl2, AlCl3, FeCl3) and CuCl with triethylamine hydrochloride. This newly prepared Fe-Cu bimetallic ionic liquid [Et3NH]Cl-0.47FeCl3-0.8CuCl had a good extraction performance, and the extraction selectivity could reach up to 8.41, which was about 4 times that of the organic solvent such as N-formylmorpholine and γ-butyrolactone used in the industry. The liquid-liquid equilibrium (LLE) of 1-hexene/n-hexane and Fe-Cu bimetallic ionic liquid system was investigated under different extraction temperatures, extraction times, and mass ratios of extractant to feed. Through 5 recycling experiments, the extraction selectivity decreased by less than 2%, and the characteristic peaks of the recovered bimetallic ionic liquids were unchanged by IR analysis, which proved that the bimetallic ionic liquid had excellent reversibility. Furthermore, the mechanism of 1-hexene extraction was investigated by quantum chemistry calculation and Raman spectroscopy, and there was π-complexation between Cu+ and 1-hexene. Then, the charge density of Cu+ in bimetallic ionic liquids was larger than that of cuprous-based ionic liquids. The results revealed that the addition of FeCl3 could activate Cu+ and weaken the Cu-Cl bond, enhancing the ability of the bimetallic ionic liquid to extract 1-hexene. Therefore, [Et3NH]Cl-0.47FeCl3-0.8CuCl was a good potential extractant during the efficient extraction of 1-hexene.

Exploring key electronic and non-linear optical amplitute with bilateral intramolecular charge transfer into thieno[3,2-b]thiophene-based compounds: a DFT approach

Organic molecules are considered important NLO materials in the modern age because of their potential optoelectronic features. Therefore, a series of organic molecules (DBTD1-DBTD7) with a D-π-A architecture was designed from the reference compound (DBTR) by structurally tailoring it with effective donors and making significant modifications to the π-spacers. All derivatives and references were initially optimized at the M06 functional with a 6-311G(d,p) basis set. Furthermore, the optimized structures (DBTR and DBTD1-DBTD7) were used to determine the density of states (DOS), frontier molecular orbitals (FMOs), natural bond orbital (NBO), UV-Visible, transition density matrix (TDM) analyses, and the most significant NLO properties. Among the compounds, DBTD4 had the smallest band gap (2.882 eV) which was further supported by DOS analysis. The global reactivity parameters were also related to the HOMO-LUMO band gap, where the compound with the lowest band gap showed a lower hardness value and higher softness value. NBO analysis was used to explain the molecular stability and hyperconjugation. DBTD4 and DBTD5 demonstrated comparable low bandgaps with the highest comparable NLO parameter values. However, we also observed efficient NLO characteristics for DBTD6 and DBTD7. The highest μ tot value is observed in DBTD6 as 10.362 D, whereas the highest α tot (1.48 × 10-22 and 1.47 × 10-22 esu) is observed in DBTD6 and DBTD7. Further, β tot (6.68 × 10-28 and 6.23 × 10-28 esu) in DBTD4 and DBTD5 and γ tot (6.20 × 10-33 and 6.59 × 10-33 esu) values are observed in DBTD5 and DBTD6. To acquire favorable NLO responses in molecules, structural modelling utilizing efficient donor units played significant role. Thus, current research insights encourage researches to develop efficient NLO materials for optoelectronic applications.

Unveiling Anti-Malarial, Antimicrobial, Antioxidant Efficiency and Molecular Docking Study of Synthesized Transition Metal Complexes Derived From Heterocyclic Schiff Base Ligands

Malaria, a persistent and ancient adversary, continues to impact vast regions worldwide, afflicting millions and severely affecting human health and well-being. Recently, despite significant progress in combating this parasitic disease, malaria remains a major global health concern, especially in areas with limited resources and vulnerable populations. Consequently, identifying and developing effective agents to combat malaria and its associated dysfunctions is essential therefore the two new Schiff base ligands incorporated Co(II), Ni(II), Cu(II) and Zn(II) ions were synthesized and thoroughly characterized. The synthesized compounds were assessed for in vitro anti-malarial and antimicrobial efficacy, compounds (9, 10) demonstrated highest potential with IC50=1.08±0.09 to 1.18±0.04 μM against P. falciparum and MIC=0.0058 μmol/mL against C. albicans and E. coli, respectively. The complexes (5, 6) were effectively reduce mitigate oxidative stress with lowest IC50 value of 2.69±0.12 to 2.87±0.09 μM. Moreover, the biological findings were reinforced by a molecular docking investigation involving the potential compounds (2, 7-10) against dihydroorotate dehydrogenase and sterol 14-alpha demethylase proteins which exposed complex's excellent biological response than their parent ligands. ADMET profiling was used to confirm the compounds' oral drug-like features. This research offers promising prospects for future multi-functional drug innovations targeting malaria, pathogenic infections, and oxidative stress.

Nonlinear optical properties of azo sulfonamide derivatives

CONTEXT

The present work deals with the linear and nonlinear optical properties such as the dipole moment, polarizability, total hyperpolarizability, electric field-induced second harmonic generation, and hyper-Rayleigh scattering first hyperpolarizability of four heterocyclic azo compounds containing the sulfonamide group considered promise in nonlinear optic. The obtained polarizability and hyperpolarizability were supported by the frontier molecular orbital analysis. The properties have been effectively estimated and thoroughly examined to shed light on the nonlinear optical activity based on the density functional theory. The observed results show a high total first hyperpolarizability β tot up to 2503 a.u. and a low energy gap E g less than 1.41 eV. An inverse relationship has been obtained between the β tot and E g . The calculated E g values confirm that charge occurs within the azo sulfonamides. The new study provides a promising avenue for the development of these azo sulfonamides as novel NLO materials.

METHODS

The molecular modeling and the theoretical studies were performed with Gaussian software packages. The B3LYP/6-311 + G** level was used for optimization. All the linear and nonlinear optical properties reported here are obtained using the DFT. The optimized structures and their frontier molecular orbitals were plotted using the GaussView 5.1 program.

A smartphone-based visual ratiometric fluoroprobe for rapid and sensitive detection hypochlorous acid based on dual-emission metal organic frameworks

Herein, we designed/developed a mixed fluorescence system with europium metal-organic framework (EDB) and zinc metal-organic framework (ZBNB). At the 270-nm excitation wavelength, the EDB-ZBNB dually emitted at 425 and 615 nm and displayed blue solution under 365-nm UV lamp. When HOCl was fortified, the 425-nm blue emission dropped progressively, while the 615-nm red emission was relatively stable. Upon addition of ClO-, the shortened fluorescence lifetime demonstrated that the quenched 425-nm fluorescence of ZBNB was owing to the occurrence of dynamic quenching effect. Besides, amino groups are protonated in water to form -NH3+, which interact with ClO- to form hydrogen bonds, reduce the distance between -NH3+ and ClO-, produce energy transfer and result in fluorescence quenching. The ratiometric fluoroprobe provided a significant color change from blue to red, making HOCl detection visual and rapid. This fluorescent probe overcome the disadvantage of conventional redox-based fluorescent probes that can be interfered by MnO4- and other oxidants with stronger oxidizing capacity than free ClO-. Furthermore, a smartphone-based portable sensing platform was developed based on EDB-ZBNB. By using a "Thingidentify" software on smartphone, the sensing platform was used to detect HOCl in waters with a low detection limit of 28.0 nM and the fortified recoveries of 98.87-103.60%. Thus, this study provides a novel and promising platform for the detection of free ClO- in monitoring water quality.

Synthesis, crystal structure, spectroscopic characterization, DFT calculations, Hirshfeld surface analysis, molecular docking, and molecular dynamics simulation investigations of novel pyrazolopyranopyrimidine derivatives

A series of new pyrazolopyranopyrimidine derivatives (3-9) were synthesized from 5-amino-2,4-dihydro-3-methyl-4-phenylpyrano-[2,3-c]pyrazole-5-carbonitrile (2) by multicomponent reactions (MCR) involving malononitrile, benzaldehyde, and pyrazolone under refluxing ethanol in the presence of piperidine. Compound (2) was then converted to 2-acetylpyrazolopyranopyrimidine (3) through a reaction with acetic anhydride. The deprotection of 3 using ammonium hydroxide in ethanol, leads to 4. Subsequent chlorination of 4 by phosphorus oxychloride affords 5 which was alkylated using methyl iodide and ethyl bromoacetate in DMF, leading to regioisomers 6-9. The products were characterized by spectroscopic techniques (1H and 13C NMR) and confirmed by single crystal X-ray diffraction (XRD) studies for 2, 5, 6, and 9. Moreover, the geometrical parameters, molecular orbital calculations, and spectral data of 2, 5, 6, and 9 were compared by DFT at the B3LYP/6-311G(d,p) level of theory. There is good agreement between the calculated results and the experimental data. The intermolecular contacts for 2, 5, 6, and 9 were studied by Hirshfeld surface analysis. In addition, the molecular docky study was conducted to investigate the binding patterns of 2, 5, 6, and 9 within the binding site of cyclin-dependent kinase 2 (CDK2) and penicillin-binding protein 1 A. After the docking process, molecular dynamics (MD) simulations for 100 ns were performed on CDK2 and PBP 1 A proteins in the complex with 5.Communicated by Ramaswamy H. Sarma.

Study of novel bidentate heterocyclic amine-based metal complexes and their biological activities: cytotoxicity and antimicrobial activity evaluation

Metallic antitumor drugs with heterocyclic ligands, such as novel AMI (amino methyl imidazole) complexes [Pd(AMI)Cl₂](1), [Cu(AMI)L¹](2), and [Cu(AMI)L²·2H₂O](3) where L¹ = oxalate and L² = malonate, were synthesized and characterized. Assessments included elemental analyses, mass spectrometry, Fourier transform-infrared spectroscopy, ultraviolet-visible spectroscopy, and thermal analysis. The cytotoxicity of AMI complexes compared to cisplatin was assessed using MTT (3-[4,5-dimethylthiazol-2-yl] 2,5diphenyl tetrazolium bromide) assay with breast (MCF-7) and cervical (HeLa) cancer cell lines. After treating these cells with the AMI complexes' IC₅₀ values for 48 h, malondialdehyde levels and catalase activity were used to assess oxidative stress, antioxidant activity was evaluated with DPPH radical scavenging method, comet assays assessed DNA damage, and DNA fragmentation was evaluated using the gel electrophoresis. In vitro, antimicrobial activity was assessed using a disc diffusion method. The anticancer activity results showed that IC₅₀ (half-maximal inhibitory concentration) values of complex one, two, and three against MCF-7 and HeLa cancer cells are 0.156 ± 0.0006, 0.125 ± 0.001, 0.277 ± 0.002 μM respectively for MCF-7 cells and 0.222 ± 0.0005, 0.126 ± 0.0009, 0.152 ± 0.001 μM respectively for HeLa cells. Complex two demonstrated strong anticancer activity against MCF-7 and Hela cells. The study of oxidative stress parameters revealed that Malondialdehyde levels increased in cancer cell lines treated with complexes compared to untreated cells. Catalase activity decreased in cells treated with palladium chelate. The DPPH radical scavenging assay results identified that complex one was a more potent antioxidant in MCF-7 and Hela cells than other complexes with SC₅₀ values of 227.5 ± 0.28 and 361 ± 1.2 μL/mL, respectively. The comet assay results showed that complex two caused significant DNA damage in MCF-7 and HeLa cancer cells treated. Antimicrobial assays identified complex three as the most effective. Copper complexes give better antifungal activity against A. flavus than the palladium complex. We conclude that complex two is the most active in both cell types and might be assessed as a clinically useful drug for breast cancer treatment. The significance of the current study is the synthesis of antitumor drugs containing heterocyclic ligands, such as novel AMI complexes, and the study of their biological activities.

Molecular Design and Mechanism Analysis of Phthalic Acid Ester Substitutes: Improved Biodegradability in Processes of Sewage Treatment and Soil Remediation

Phthalic acid esters (PAEs) have the characteristics of environmental persistence. Therefore, improving the biodegradability of PAEs is the key to reducing the extent of ecological harm realized. Firstly, the scoring function values of PAEs docking with various degrading enzymes in sewage treatment were calculated. Based on this, a 3D-quantitative structure-activity relationship (3D-QSAR) model for PAE biodegradability was built, and 38 PAE substitutes were created. By predicting the endocrine-disrupting toxicity and functions of PAE substitutes, two types of PAE substitutes that are easily degraded by microorganisms, have low toxicity, and remain functional were successfully screened. Meanwhile, the differences in the mechanism of molecular degradation difference before and after PAE modification were analyzed based on the distribution characteristics of amino acid residues in the molecular docking complex. Finally, the photodegradability and microbial degradability of the PAE substitutes in the soil environment was evaluated. From the 3D-QSAR model design perspective, the modification mechanism of PAE substitutes suitable for sewage treatment and soil environment degradation was analyzed. We aim to improve the biodegradability of PAEs at the source and provide theoretical support for alleviating the environmental hazards of using PAEs.

Theoretical investigations in the reactions of group 15 analogues of the monocationic five-membered N-heterocyclic carbenes: interplay of electrophilicity, basicity, and aromaticity governing the reactivity

The nature of the group 15 analogs of the five-membered N-heterocyclic carbenes (G15-Rea; G15 = N, P, As, Sb, and Bi) was investigated by using various methodologies.

Carboxyl-Rich Carbon Dots as Highly Selective and Sensitive Fluorescent Sensor for Detection of Fe3+ in Water and Lactoferrin

As lactoferrin (LF) plays an essential role in physiological processes, the detection of LF has attracted increasing attention in the field of disease diagnosis. However, most current methods require expensive equipment, laborious pretreatment, and long processing time. In this work, carboxyl-rich carbon dots (COOH-CDs) were facilely prepared through a one-step, low-cost hydrothermal process with tartaric acid as the precursor. The COOH-CDs had abundant carboxyl on the surface and showed strong blue emission. Moreover, COOH-CDs were used as a fluorescent sensor toward Fe3+ and showed high selectivity for Fe3+ with the limit of detection (LoD) of 3.18 nM. Density functional theory (DFT) calculations were performed to reveal the mechanism of excellent performance for Fe3+ detection. Meanwhile, COOH-CDs showed no obvious effect on lactobacillus plantarum growth, which means that COOH-CDs have good biocompatibility. Due to the nontoxicity and excellent detection performance for Fe3+, COOH-CDs were employed as a fluorescent sensor toward LF and showed satisfying performance with an LoD of 0.776 µg/mL, which was better than those of the other methods.

Tuning the electronic and nonlinear optical properties of black phosphorus quantum dots by introducing electron-donating/withdrawing molecules (TTF/TCNQ)

Black phosphorous quantum dots can exhibit excellent nonlinear optical properties after adsorbing organic molecules (TTF and TCNQ).