In this work, the influence of coordination environment on the electrochemical sensing performance of Zn(II) Schiff base complexes toward nitrite detection is investigated. Two complexes, Zn(SB1)I₂ and Zn(SB2)I₂, with different coordination geometries were synthesized and used to modify screen-printed carbon electrodes. Zn(SB1)I₂ exhibited superior sensing performance, with a wide linear range up to 5 mM, a detection limit of 1.82 μM, and good repeatability, relative standard deviation (RSD: 5.26%), whereas Zn(SB2)I₂ showed a weaker response. This difference highlights the critical role of coordination structure in controlling sensor behavior. Computational studies, including density functional theory (DFT), molecular electrostatic potential (MEP), and frontier molecular orbital (FMO) analysis, suggest that nitrite interaction at the Zn center induces electronic redistribution and facilitates charge transfer, more effectively in Zn(SB1)I₂. These findings demonstrate that the coordination environment of the metal center governs sensing performance, providing insight for the rational design of electrochemical sensors.

A novel Schiff base ligand, N¹,N²-bis(2-(((1E,2E)-3-(2-methoxyphenyl)allylidene)amino)ethyl)ethane-1,2-diamine (L), was synthesized from triethylenetetramine and o-methoxycinnamaldehyde, and its six new zinc halide/pseudohalide complexes were prepared and characterized using molar conductance measurements, melting point analysis and spectroscopic techniques. Thermogravimetric and differential thermal analyses (TG/DTG/DTA) coupled with the Coats-Redfern method provided key thermo-kinetic activation parameters (A*, E*, ΔH*, ΔG*, ΔS*) for the synthesized complexes. In vitro, zinc(II) complexes with Cl⁻, N₃⁻, and NO₃⁻ exhibited superior antimicrobial activity against Gram-positive (B. subtilis and S. aureus), Gram-negative (E. coli and P. aeruginosa) bacteria, and fungi (C. albicans and A. oryzae) compared to the free ligand. In DPPH and FRAP assays, zinc complexes, especially ZnL(N₃)₂ and ZnLI₂, exhibited superior antioxidant activity compared to the SB-ligand. In the MTT assay, ZnLI₂ and ZnL(NCS)₂ showed the highest anticancer activity against MCF-7 and PC3 cells, respectively. ZnLBr₂, ZnL(NCS)₂, ZnL(NO₃)₂, and ZnL(N₃)₂ completely cleaved E. coli DNA via a non-oxidative hydrolytic mechanism. Finally, the wound-healing potential of the SB-ligand and its ZnLI2 (zinc iodide complex) was evaluated in a rat model of second-degree burns, demonstrating a wound closure percentage of 100% at day 21, which promises its therapeutic efficacy.

Post-synthetic functionalization of robust metal-organic frameworks (MOFs) with chiral functional groups is a useful approach to endow the structures with chirality and rich functionality for wide areas of applications. Herein, MOF-808 containing 1,3,5-benzene tricarboxylate (BTC3-) as the linker and formate as the modulator was selected for a two-step post-functionalization. Through the post-synthetic exchange (PSE) in the first stage, some formate modulators were replaced with D-histidine to prepare CMOF-808. The incorporation of D-histidine in MOF-808 caused chirality induction in the framework and created a unique platform for chemical modification. Then, via the post-synthetic modification (PSM) in the second step, the amino acid was functionalized with propyl sulfonic acid groups to produce CMOF-808-SO3H. The prepared CMOF-808-SO3H was characterized by powder X-ray diffraction (PXRD), FT-IR, nuclear magnetic resonance (NMR), field emission scanning electron microscopy (FE-SEM), elemental analysis, circular dichroism (CD) spectroscopy, thermogravimetric analysis, N2 adsorption-desorption isotherms, and temperature-programmed desorption of NH3 (NH3-TPD). As a heterogeneous acid catalyst, CMOF-808-SO3H was used for the methanolysis of styrene oxide and the acetalization of benzaldehyde with alcohols. By using methanol for these acid-catalyzed reactions, high conversion (>= 99%) and excellent selectivity were obtained within 5 min at room temperature. The catalyst maintained its activity after recycling and displayed structural stability during the reaction. High catalytic performance of CMOF-808-SO3H could be ascribed to its promoted acidity (743.3 mu mol/g) compared to the original MOF-808 with 245.7 mu mol/g acidic content. In brief, this work contributes to the rapidly expanding field of chiral MOF-based catalysis.

A series of novel zinc(II) complexes derived from a tetradentate N2O2-Schiff base ligand were synthesized using zinc halide and pseudohalide salts with the general formula ZnLX2 (X = Cl-, Br-, I-, N3 -, SCN-). The resulting compounds were thoroughly characterized by a range of spectroscopic and physicochemical techniques. Additionally, nanostructured zinc complexes such as ZnLBr2 and ZnLI2 were synthesized via an ultrasound-assisted approach, with ZnLI2 subsequently utilized as a precursor for the fabrication of ZnO nanoparticles. The nanostructures were confirmed by scanning electron microscopy (SEM), EDX, and x-ray diffraction (XRD) analyses. Thermal decomposition studies of the ligand and its zinc complexes revealed two- to three-step degradation processes, for which key thermokinetic parameters (E*, ΔS*, ΔH*, A, and ΔG*) were determined. From a biological standpoint, the synthesized compounds displayed potent antimicrobial activity against selected Gram-positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Pseudomonas aeruginosa and Escherichia coli) bacterial strains, as well as fungal pathogens (Aspergillus oryzae and Candida albicans). DNA cleavage assays further confirmed the nucleolytic potential of these complexes. Selected compounds demonstrated noteworthy cytotoxic effects against the PC3 human prostate cancer cell line, substantiating their anticancer capabilities. Antioxidant properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl) and FRAP (ferric reducing antioxidant power) assays, exhibiting promising radical-scavenging activity. Notably, the ligand and ZnLI2 complex also exhibited significant efficacy in promoting burn wound healing, highlighting their therapeutic potential in both infectious and regenerative medicine.

Fe 3 O 4 @RHA@TiO 2 nanocatalyst was synthesized using an eco-benign material, rice husk ash derived from natural waste, and applied in the preparation of pyrans.

In this investigation, a novel tetradentate Schiff base ligand, (ligand L) was synthesized using a simple chemical route assisted by triethylenetetramine with 4-dimethylaminocinnamaldehyde in ethanol. The chemical structure of the as-synthesized ligand was characterized using nuclear magnetic resonance (NMR) and UV-visible spectroscopy. This ligand was then employed to modify the working electrode of screen-printed carbon electrode (SPCE) for developing a modified L/SPCE sensor finalized to detection of lead ions (Pb2+). The electrochemical characteristics of the sensor were assessed by Square Wave Anodic Stripping Voltammetry technique (SWASV). To further enhance the sensitivity, gold nanoparticles (AuNps) were deposited on the surface of the working electrode for obtaining an AuNps-L/SPCE sensor. This device shows a linear response to Pb2+ until to 0.6 mu M, a sensitivity of 897 mu A mu M- 1 cm- 2 and a limit of detection (LOD) of 0.38 mu M. This successful strategy offers promising avenues for lead ion detection also in urine.

In this paper, a new tridentate Schiff base ligand (L) with nitrogen donor atoms and its cadmium(II) complexes with the general formula of CdLX2 (X=Cl-, Br-, I-, SCN-, N3 -, NO3 -) have been synthesized and characterized by physical and spectral (FT/IR, UV-Vis, Mass, and 1H, 13C NMR spectroscopies) methods. Also nano-structured cadmium chloride and bromide complexes were synthesized by sonochemical method and then used to prepare nanostructured cadmium oxide confirmed by XRD and SEM techniques. Thermal behavior of the compounds was studied in the temperature range of 25 to 900 °C under N2 atmosphere at a heating rate of 20 °C/ min. Moreover, thermo-kinetic activation parameters of thermal decomposition steps were calculated according to the Coats-Redfern relationship. Antimicrobial activities of the synthesized compounds against two gram-positive and two gram-negative bacteria such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and two fungi of Candida albicans and Aspergillus niger were investigated by well diffusion method. SEM technique was used to monitor the morphological changes of the bacteria treated with the compounds. The 2,2-Diphenyl-1-picrylhydrazyl(DPPH) and the ferric reducing antioxidant power (FRAP) methods were used to evaluate the antioxidant ability of the ligand and its cadmium(II) complexes. In final, the cytotoxicity properties of the ligand and some cadmium(II) complexes against PC3 cancer cells were evaluated by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) bioassay and nitric oxide (NO) level measurement. The morphological changes of prostate cancer (PC3) cells due to treatment with the ligand and its complexes confirmed their anticancer effectiveness.

In this study, two novel bidentate Schiff base ligands, namely the (1 E,1'E,2E,2'E)-N,N'-(butane-1,4-diyl)bis(3-(2-methoxyphenyl)prop-2-en-1-imine) (L1) and the tetradentate Schiff base ligand namely N1,N2-bis(2-(((1E,2E)-3-(4-(dimethylamino)phenyl)allylidene)amino)ethyl)ethane-1,2-diamine (L2), were successfully synthesized through a simple procedure....

Two Schiff base ligands and some related bidentate and tetradentate Zn(II) complexes were investigated for their biological activity profiles as anticancer agents by resazurin method against two leukemia cell lines. The results clearly evidenced the importance of the tetradentate structure and the presence of the metal ion on the cytotoxicity profile of these complexes. Noteworthy, they also showed an interesting selectivity index (SI; up to 15.1 for the complex [ZnL4(NO3)2] assessed on PBMC cells). The electronic behavior, stable geometries, MEP surfaces, and FMO analysis of the compounds were investigated employing density functional theory (DFT) at B3LYP level with LANL2DZ/6-311G(d,p) basic set. A comparison was made with the computational and experimental structural data of L2 and [ZnL2(NO3)2] compounds. Furthermore, ensemble docking studies were undertaken on a quadruplex-duplex (Q-D) DNA model to shed light on the interactions at molecular level of the complexes with the target. In silico ADME profiling was performed using the SwissADME program, which indicated their promising therapeutic applicability.

A new N-3-tridentate Schiff base ligand(L) was synthesized by condensation reaction of 2-methoxycinnamaldehyde and diethylenetriamine. Thereafter some new zinc complexes formulated as [ZnLX2] (X is halide or pseudo-halide) were prepared using this chelating ligand. The suggested structures of these compounds were identified by melting point and molar conductivity measuring, UV-Visible, FT/IR, H-1 and C-13 NMR and MASS spectral analyses. Moreover, the thermal behaviors of the ligand and zinc complexes were investigated under N-2 atmosphere and at a heating rate of 20 degrees C/min. Zinc bromide and chloride complexes were synthesized in nanostructured sizes by sonochemical method and used as precursor to prepare nanostructured ZnO approved by SEM, EDX and XRD analyzes. Furthermore antibacterial, antifungal and antioxidant properties were evaluated by well diffusion, ferric reducing antioxidant power (FRAP) and 2, 2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) methods respectively. Cytotoxicity properties of the ligand and zinc complexes were assessed against prostate cancerous cell lines (PC3) as compared with HUVEC normal cells. The morphology of PC3 cancer cells treated by the ligand and some zinc complexes were also visualized by images. Eventually, burn wound healing activities of the ligand and zinc chloride complex were examined for healing of the second degree burns in the rats in a period of 20 days.

A bidentate Schiff base ligand(L) and two new mono and binuclear cadmium(II) complexes formulated as [CdL2(NO3)](NO3) and [Cd2L2Cl4] were synthesized and their structures were characterized by physical and spectral techniques Moreover, the structures of the cadmium(II) complexes were identified using single crystal X-ray analysis. Hirshfeld surface analysis was used to characterize various interactions in the solid state framework. Thermal behaviors of the compounds were investigated from room temperature to 800 degrees C. Furthermore, the antimicrobial bioassays on the cadmium(II) complexes were performed in vitro against two gram-positive and two gram-negative bacterial strains and also against two fungal strains. Finally, the antioxidant capabilities of the Schiff base ligand and its complexes were investigated by means of two in vitro methods of ABTS and DPPH as compared with Trolox as a standard compound.

A new N 2 O 2 ‐tetradentate Schiff base ligand entitled as N,N′‐((ethane‐1,2‐diybis [oxy])bis (ethan‐2,1‐diyl))bis(3‐(4‐methoxyphenyl)prop‐2‐en‐1‐imine was prepared by direct reaction between 3‐(4‐methoxyphenyl)‐2‐propenal and 1,8‐diamino‐3,6‐dioxaoctane. After characterization of the ligand, some novel cadmium coordination compounds formulated as CdLX 2 (X: Cl − , Br − , I − , N 3 − , SCN − and NO 3 − ) were synthesized and characterized by physical and spectral techniques. Typically crystal structure of cadmium nitrate coordination compound was determined suggesting crystallization in monoclinic system (with space group of I 2/a ) and a coordination geometry of square anti‐prism around the Cd (II) ion. Moreover, CdLBr 2 and CdLI 2 compounds were prepared in nanostructured dimensions by sonochemical method confirmed by SEM, EDX, and XRD techniques. In continuation, thermal behavior investigation of the compounds including thermal stabilities, thermal decomposition steps, and thermo‐kinetic parameters was performed based on Coats‐Redfern equations from room temperature to 900 °C. Furthermore, all the compounds were subjected to bioassay against two Gram‐positive bacteria of Staphylococcus aureus and Bacillus subtilis , two Gram‐negative bacteria of Pseudomonas aeruginosa and Escherichia coli, and two fungal strains of Aspergillus oryzae and Candida albicans . The results showed that all the synthesized compounds act well as antimicrobial agents. DNA cleavage power of the materials was also evaluated using extracted DNA from E. coli bacterium. The cytotoxic activities of some compounds were investigated against the prostate cancer cell lines (PC3) and human umbilical vein endothelial cells (HUVEC) (as normal cells) by MTT assay and nitric oxide level evaluation method as compared with cis ‐platin confirming anti‐cancer effects of them. Finally, the antioxidant properties of the N 2 O 2 ‐ligand and its cadmium coordination compounds were examined by DPPH and FRAP methods suggesting all the compounds have good antioxidant activity as compared with standard samples.

Citrate trisulfonic acid (CTSA), as a novel, heterogeneous and organocatalyst, was applied for an efficient synthesis of 4-iminoquinolines using 2-aminobenzonitrile, active methylenes and orthoesters under solvent-free conditions. CTSA was synthesized via the reaction of trisodium citrate and chlorosulfonic acid in high purity. The catalyst was characterized using FT-IR, NMR and Mass spectra. The present method offers several advantages including high yields, short reaction time, and reusability of the catalyst and simple purification of the products.

In the current study, a new long chain tetra-nitrogen donor Schiff base ligand (SB) entitled as N1,N2-bis(2-(((1E,2E)-3-(4-(dimethylamino)phenyl)allylidene)amino)ethyl)ethane-1,2-diamine and some its molecular cadmium (II) complexes formulated as Cd(SB)X2 (X = halide/pseudohalide) were prepared and characterized by various physicochemical and spectral methods such as melting point, micro-analytical data, thermal analysis (TG/DTG/DTA), molar conductivity and UV-Visible, FT-IR, 1H, and 13C NMR spectroscopies. Also nano structured cadmium chloride and iodide chelate complexes approved by PXRD SEM and EDX techniques were synthesized to use as precursor to prepare nanostructure cadmium oxide. The particle sizes about 2-10 nm were estimated for nanostructured cadmium complexes and oxide. Thermo-gravimetric plots showed the compounds are decomposed via 2-4 steps with weight loss of 69-100% to leave out metallic Cd or cadmium salt as final residue. Thermo-kinetic activation parameters calculated based on TG plots suggested non-spontaneous thermal decomposition with activation Ea*, & UDelta;H* and & UDelta;G* parameters in the ranges of (13.54-160.48 kJ.mol-1), (8.22-155.95 kJ.mol-1) and (1.59 x 102-4.1 x 102 kJ.mol-1) respectively. Moreover, the pharmacological activities of the compounds were investigated against some pathogenic fungi and bacteria. According to screening data, the SB ligand showed lower antimicrobial activities than its complexes toward selected microbes so that the cadmium(II) nitrate, thiocyanate and azide were found the most active against B. subtilis, S. aureus, P. aeruginosa and E. coli respectively. The evaluation of DNA cleavage potency using the agarose gel electrophoresis technique suggested Cd(SB)Cl2 as the most destructive compound. Furthermore, the antioxidant assessment of the compounds as compared with the standard references by DPPH and FRAP methods proposed Cd(SB)Cl2 and Cd(SB) Br2 as the best antioxidant. In final, the cytotoxicity of the synthesized compounds was appraised toward human breast cancer (MCF-7) and prostate cancer (PC3) cell lines employing MTT and nitric oxide level assays. The results suggested Cd(SB)Br2 as more cytotoxic than other complexes against two studied cancer cell lines.

On the basis of the sulfonated polystyrene, a new proton-exchange membrane was prepared in this study. In order to be applied in the direct-methanol fuel cells (DMFCs), the modification of sulfonated polystyrene was conducted by MIL-53(Al)-NH 2 . Membranes were fabricated using sulfonated polystyrene, polyethylene, and different amounts of MIL-53(Al)-NH 2 , then they were briefly illustrated by SPS-PE-MIL-53. The membranes were characterized using the FT-IR, SEM, and TGA. The proton conductance, water uptake, oxidative resistance, ionic conductance, and the permeability of methanol were measured to assess its performance in a DMFC with a cation-exchange membrane. The SPS-PE-MIL-53 (1:1:0.25 w:w:w) membrane showed relatively better performance than the other membranes. The selectivity factor for this membrane was 7.17 × 10 4 S.s.cm -3 . To assess the performance, the fabricated membranes were used in a fuel cell. All membranes fabricated in the fuel cell performed well, but the SPS-PE-MIL-53 (1:1:0.25 w:w:w) membrane performed better than the other membranes. DMFC on the basis of SPS-PE-MIL-53 (1:1:0.25 w:w:w) membrane had a maximum peak power density of 17.04 mAcm -2 with a maximum current density of 115.38 mAcm -2 . In general, the prepared membranes performed well than similar membranes.

The mononuclear chelating complex [Cd(i-mnt)(tren)]n (1) fabricated from binary ligand systems 1,1-dicyano-ethylene-2,2-dithiolate (i-mnt2) and diethylenetriamine (tren) has been synthesized and structurally charac-terized by spectroscopic methods (IR, NMR). The single-crystal X-ray diffraction study reveals that Cd+2 has CdN3S3 coordination kernel having distorted trigonal prism geometry (TP) [twist angle (theta) 37.6(11)0] and the secondary ligand tren influences the ligation pattern of i-mnt2 towards metal center in the formation of 1D polymeric chain where asymmetric units linked by bridging thiolate S2-atom of each i-mnt2. The N - H...N, N - H...S type hydrogen bonds link the 1D polymeric chains in a 3D stacked chain supramolecular arrangement with apparent graph-set-motifs R11(8),C(4), and C(8). The Hirshfeld surface analysis corroborates well with X- ray data and explores all possible intermolecular interactions especially dominant N...H (16.6%) and H...S (7.3%) contacts. The MIC, MBC and in-vitro antibacterial study against Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) human pathogenic bacterial strains shows promising bactericidal activity. In-vitro antifungal study disclosing more activity against Aspergillus niger compared to Candida albicans at 50 mg/mL. DNA cleavage study (E. coli DNA) via Agarose gel electrophoresis shows DNA cleaving property of the title compound similar to that of H2O2 due to the suitable coordination of Cd (II) metal center.

A novel electrochemical sensor for the determination of nitrites based on the modified screen‐printed electrode (SPCE) by Zn‐bidentate Schiff base complexes (ZnLX 2 ) is presented. ZnLX 2 complexes have been synthesized and characterized using several morphological and microstructural techniques such as scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), and fourier transformed‐infrared (FT‐IR) spectroscopy. Cyclic voltammetry (CVs) proved the good electrochemical performances of the ZnLX 2 /SPCE for nitrite ions determination. The influence of pH, scan rate, nitrite concentration, and interfering ions was investigated. After optimization of the operating parameters, the developed ZnLX 2 /SPCE sensor displayed two linear relationships between response current and nitrite concentration in the overall range 2–4838 μM and a lower detection limit estimated to be 0.78 μM based on 3σ/m. Finally, the analytical application of the developed sensor was evaluated to quantify nitrite in a real sample of mineral water. Results obtained demonstrate that the ZnLX 2 /SPCE electrochemical sensor provided an effective tool for the detection of nitrite ions.

Melamine-based porous network was prepared by the strong binding ability of amino functional groups of melamine with Pd(0) surface and pre-polymerization at the oil-water interface that confirmed by X-ray diffraction analysis. Palladium nanoparticles not only stimulate the pre-polymerization, but also stabilize themselves by this porous structure. Fourier-transform infrared spectroscopy, transmission electron microscopy, field-emission scanning electron microscopy, energy dispersive analysis of X-ray and thermal gravimetric analysis were applied for the catalyst characterization. The as-prepared catalyst forms an inclusion complex according to the host-guest chemistry in the presence of nitrophenols or different dyes. An efficient catalytic activity of this catalyst is due to the entrapment of the guest molecule in the cavity of the mesoporous structure and reaction progress on the Pd(0) nanoparticles surfaces which was approved by Brunauer-Emmett-Teller (BET) analysis. Simple preparation, unique structure and high catalytic reaction rate are some of the considerable advantages of this catalyst that can play key roles in the industrial processes.

A novel bidentate Schiff base (L) is here proposed for the detection of Zn ions in water. The structure of the synthesized Schiff base L was characterized by FT-IR, 1H NMR and 13C NMR. Optical characteristics were addressed by UV-Visible spectroscopy and Photoluminescence (PL) measurements. PL demonstrated that L displays a “turn-off” type fluorescence quenching in the presence of Zn2+ ion in aqueous solution, indicating its ability to preferentially coordinate this ion. Based on these findings, an L-M (where M is a suitable membrane) modified screen-printed carbon electrode (SPCE) was developed to evaluate the electrochemical behavior of the Schiff base (L) with the final objective of undertaking the electroanalytical determination of Zn ions in water. Using various electrochemical techniques, the modified L-M/SPCE sensor demonstrates high sensitivity and selectivity to Zn ions over some common interferents ions, such as Ca2+, Mg2+, K+, Ni++ and Cd++. The potentiometric response of the L-M/SPCE sensor to Zn ions was found to be linear over a relatively wide concentration range from 1 μM to 100 mM.

In this study, the synthesis and characterization of a new bidentate ligand and some its zinc halide/pseudohalide complexes and nano-structures are described. The crystal structures of the ligand and its zinc nitrate complex as typical examples were determined by single crystal X-ray diffraction. Hirshfeld surface analysis of these structures provided insight into the various intra and inter-molecular interactions and therefore a description of the supramolecular structure for the ligand and its zinc nitrate complex in solid state. Furthermore, the thermal behavior of the complexes was established by TG/DTG/DTA curves analysis. Moreover an antibacterial bioassay of the zinc complexes was been performed in vitro against two gram-positive (Staphylococcus aureus and Bacillus subtilis) and two gram negative (Escherichia coli and Pseudomonas aeruginosa)] bacterial strains. The antifungal activities of the compounds against two fungal strains of Aspergilus niger and Candida albicans were also investigated. The antioxidant capabilities of the Schiff base ligand and its zinc complexes were determined by the in vitro methods of ABTS and DPPH as compared with the standard Trolox. Finally, ZnO nanoparticles were synthesized by direct calcination of the zinc iodide complex at 550 °C under air atmosphere confirmed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) and energy dispersive X-ray analyses (EDX).