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Herein, we disclose an eco-efficient redox-neutral iron-catalyzed decarboxylative radical addition to chiral azomethine imines upon visible light (427 nm) giving cyclic hydrazine derivatives with dr ranging from 82 : 18 to >96 : 4. This earth-abundant metal promoted sequence proceeds efficiently under ligand-free conditions based on a LMCT process and opens a route to new chiral heterocycles. [ABSTRACT FROM AUTHOR]

Self-assembly of M(ClO4)2 (M(II) = Mn(II), Co(II), Ni(II), Cu(II), and Zn(II)) with dicyclopentyldi(pyridine-3-yl)silane (L) as a donor in a mixture of acetonitrile and toluene produces crystals consisting of M6L12 double-stranded macrocycles. The geometry around the M(II) cations is a typical octahedral arrangement, but the metallamacrocycles' outer axial coordination environment is sensitive to the M(II) cations. The conformation of the unique metallamacrocycles is informatively dependent on the nature of the coordination around the M(II) cations via subtle co-ligand competition among perchlorate anions, water, and acetonitrile. Both the coordinated acetonitriles and the solvate molecules of the crystals are removed at 170 °C, thereby transforming the crystals into new crystals that return to their original form in the mixture of toluene and acetonitrile. Catalytic oxidation of 3,5-di-tert-butylcatechol using [Cu6(ClO4)8(CH3CN)4L12]4ClO4·5C7H8 is much faster than those using the transformed product, [Cu(ClO4)2L2], and a simple mixture of Cu(ClO4)2 + L. [ABSTRACT FROM AUTHOR]

Herein, we present a dark-green crystalline tetranuclear Cu(II) Schiff base complex {C1 = [Cu4L4](ClO4)4(DMF)4(H2O)} using a N,N,O donor ligand (HL), namely 2-(((2-hydroxypropyl)imino)methyl)-6-methoxyphenol. Spectro-photometrical investigation on the β-lactamase-like activity of this coordinately saturated system revealed its catalytic inefficiency towards hydrolysis of nitrocefin as a model substrate. This complex has attracted significant interest as a promising photo-catalyst owing to its narrow band gap (2.40 eV) as predicted from DFT calculations and its higher responsivity towards UV light. Therefore, C1 is effectively involved in the photocatalytic reduction of perchlorate to Cl− in the presence of a hole scavenger (H2O–MeOH) under prolonged UV irradiation and itself becomes photo-cleaved to yield a new dark-brown colored chlorobridged dinuclear crystalline complex C2 {[CuL(H2O)2Cl3]H2O}. Furthermore, C2 was deployed as a functional β-lactamase model and was found to show a remarkable catalytic proficiency towards the hydrolysis of nitrocefin in 70 : 30 (V/V) MeOH–H2O medium. This pro-catalyst C2 has been speculated to generate an aqua bridged active catalyst that plays a crucial factor in hydrolysis. This phenomenon was again experimentally established by potentiometric pH titration where C2 displays only one pKa value (7.11) in the basic pH range, indicating the deprotonation of the bridged water molecule. Based on several other kinetic studies, it may be postulated that the hydrolysis of nitrocefin is initiated by the nucleophilic attack of a bridging hydroxide, followed by very fast protonation of the intermediate to furnish the hydrolyzed product. It is noteworthy that the rate of nitrocefin hydrolysis is greatly inhibited in the presence of external chloride concentration. To the best of our knowledge, this is the first report on the photochemical behavior of such a tetranuclear copper(II) Schiff base complex. Our current interest is focused on inventing a potent β-lactamase inhibitory therapeutic as well as elucidating its mechanism through comprehensive chemical analysis. [ABSTRACT FROM AUTHOR]

The New Journal of Chemistry, published by The Royal Society of Chemistry, has released its latest issue containing a variety of articles and papers on chemistry-related topics. The journal aims to connect the world with the chemical sciences and features papers on bioethanol fermentation, hydrogels in energy storage and biomedical technologies, environmentally responsible production, and other subjects. The document is a list of papers published in the journal, covering topics such as metal-organic frameworks, cycloaddition reactions, photochromic films, supercapacitors, computational predictions, catalysis, nanospheres, electrochemical sensors, and quantum dots. These papers offer valuable insights and advancements in the fields of chemistry and materials science. [Extracted from the article]

New and effective D–π–A and D–π–A–π–A systems of chromophores 1–4 based on the ferrocene core have been synthesized using Knoevenagel condensation reactions and the characterization of chromophores 1–4 was done by modern spectroscopic methods. Moreover, 2 and 4 structures were confirmed using the single crystal X-ray diffraction (SC-XRD) technique. Crystal packing revealed that the chromophores are centrosymmetric and show non-covalent interactions. The observed positive solvatochromism reveals that the stabilization of molecules is greater in excited states than in the ground states. The fluorescence spectra of all the chromophores display weak emission in the solution state, and enhanced emission was observed in a THF:H2O mixture, due to the restriction of intramolecular rotation (RIR), and it is known as aggregation-induced emission (AIE). The SHG (second harmonic generation) measurements were done by the Kurtz–Perry powder method with potassium dihydrogen phosphate (KDP) as a reference material. The presence of hydrogen bonding interactions in the molecules blocks the anti-parallel arrangements and shows second order NLO properties in the bulk, in spite of the fact that chromophores 2 and 4 crystallize in the centrosymmetric space group. The first hyperpolarizabilities (β) [β = 56.5 × 10−30 esu (2); β = 81.5 × 10−30 esu (4)] were measured using the hyper Rayleigh scattering (HRS) technique. Chromophore 4 shows enhanced second-order NLO response compared to the other chromophores, due to an extra phenyl group in the molecule creating more planarity and enhancing the conduction of charges, which happens within a molecule (ICT process), between the ferrocene and acceptor groups (–CN and –NO2). The experimental results were corroborated using DFT calculations that comprise functionals like LC-BLYP, CAM-B3LYP and B3LYP and the 6-31+G** level of theory. [ABSTRACT FROM AUTHOR]

Schiff bases are the most widely used class of molecules and their metal complexes are utilized as medicinally important scaffolds due to their versatile biological profile. So herein, we have reported the synthesis of N2O2-type tetradentate Schiff bases {N,N′-(ethylene)bis(salicylideneimine) (1a) and N,N′-(o-phenylene)bis(salicylideneimine) (1b)} and their Ni(II) complexes, dimeric N,N′-(ethylene)bis(salicylideneiminato)nickel(II) (2a) and N,N′-(o-phenylene)bis(salicylideneiminato)nickel(II) (2b), and their characterization using CHN analysis, ESI-MS and XRD techniques. The interaction of ligands 1a–b and complexes 2a–b with the biomolecules {calf thymus DNA (CT-DNA) and bovine serum albumin (BSA)} has been investigated via electronic absorption and fluorescence spectroscopy. The results show that ligands 1a–b and complexes 2a–b can bind to CT-DNA via a minor groove mode. Moreover, the fluorescence quenching mechanism between ligands 1a–b and complexes 2a–b and BSA is a static quenching process. The results showed that the interaction between ligands 1a–b and BSA is driven by hydrogen bond and van der Waals interactions, while the hydrophobic forces stabilized the interaction between complexes 2a–b and BSA. Additionally, the r values of ligands 1a–b and complexes 2a–b (1a = 0.53 nm, 1b = 0.59 nm, 2a = 0.57 nm and 2b = 0.71 nm) calculated using FRET theory suggested that the distance between ligands 1a–b and complexes 2a–b and BSA is quite close. The radical scavenging activity of ligands 1a–b and complexes 2a–b was determined in terms of EC50, using the DPPH method. The cytotoxicities of ligands 1a–b and complexes 2a–b against human breast cancer (MCF-7) and lung cancer (A549 and H1299) cell lines and healthy lung bronchial (BEAS-2B) and breast epithelial (MCF-10A) cell lines were investigated. Molecular docking simulations were carried out to correlate the data with the experimental findings. The binding interaction of ligands 1a–b and complexes 2a–b with the B-DNA and 1M17 was generated and predicted using Autodock 4.2 software. The results indicated that ligands 1a–b and complexes 2a–b bind at the minor groove of DNA through intercalation and at the active side of the EGFR tyrosine kinase. [ABSTRACT FROM AUTHOR]

In this study, a hydrothermal approach was employed to graft chitosan (Chit)/algae (ALG) with salicylaldehyde (SA), resulting in the synthesis of a biocomposite named salicylaldehyde-based chitosan Schiff base/algae (Chit-SA/ALG). The main objective of this biocomposite was to effectively remove methyl violet (MV), an organic dye, from aqueous solutions. The adsorption performance of Chit-SA/ALG toward MV was investigated in detail, considering the effects of three factors: (A) Chit-SA/ALG dose (ranging from 0.02 to 0.1 g/100 mL), (B) pH (ranging from 4 to 10), and (C) time (ranging from 10 to 120 min). The Box–Behnken design (BBD) was utilized for experimental design and analysis. The experimental results exhibited a good fit with both the pseudo-second-order kinetic model and the Freundlich isotherm, suggesting their suitability for describing the MV adsorption process on Chit-SA/ALG. The maximum adsorption capacity of Chit-SA/ALG, as calculated by the Langmuir model, was found to be 115.6 mg/g. The remarkable adsorption of MV onto Chit-SA/ALG can be primarily attributed to the electrostatic forces between Chit-SA/ALG and MV as well as the involvement of various interactions such as n–π, π–π, and H-bond interactions. This research demonstrates that Chit-SA/ALG exhibits promising potential as a highly efficient adsorbent for the removal of organic dyes from water systems. The novelty of this work comes from introducing a new bio-organic based composite adsorbent of chitosan (Chit) biopolymer and algae (ALG) biomass. Moreover, the functionality and chemical stability of Chit–ALG composite was further developed by grafting process with salicylaldehyde (SA) using hydrothermal process. The incorporation of ALG biomass into polymeric matrix of Chit and grafting process with SA makes Chit a unique hybrid adsorbent toward cationic dye (methyl violet dye). [ABSTRACT FROM AUTHOR]

There is increased interest in developing new eco-friendly materials with antibacterial and antioxidant properties for various technological applications. This study prepared a new chitosan phenolic derivative with a hydroxyl group via a click reaction between chitosan (Ch) and vanillylidene acetone to form the corresponding vanillylidene acetonyl chitosan Schiff base (Va.Ch.SB). Detailed structural characterization was carried out using FTIR, UV–Vis, and 1H-NMR spectroscopy. The substitution degree calculated as 8.81%, according to 1H-NMR analysis. The obtained results confirm the formulation of imine Schiff base bond between chitosan amino groups react and vanillylidene acetone. Furthermore, the thermo-gravimetric analysis indicates that the decomposition behaviour of both chitosan and its vanillylidene acetonyl chitosan Schiff base derivative is nearly identical, with a slight enhancement of the SB derivative. The Va.Ch.SB exhibited duple antioxidant activity of the Va.Ch.SB. The comparative analysis reveals that the antimicrobial properties exhibited efficacy against two strains of gram-positive bacteria, namely Staphylococcus aureus and Staphylococcus haemolyticus, as three strains of gram-negative bacteria, namely Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae. These findings suggest that the Va.Ch.SB has the capability to apply in different medical and environmental contexts. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis, crystal structure, and antibacterial activity of a new Ni(II) complex derived from the N, O donor (E)-2,4-dibromo-6-(2-(1-phenylethylimino) ethyl) phenol ligand. Both the ligand and the complex were characterized by employing FT-IR, UV-Visible, and fluorescence spectroscopy as well as single-crystal X-ray diffraction studies. The crystallographic results reveal that the complex crystalizes in the monoclinic unit cell with the space group C2, and the coordination environment around the Ni centre consists of NiN2O2 donor sites exhibiting a highly distorted tetrahedral geometry. The oxidative assay of DPPH (α,α-diphenyl-β-picrylhydrazyl) was used for evaluating the radical scavenging activity or antioxidant properties of the complex in terms of IC50 values (50% inhibition); it was observed that the complex showed reasonable antioxidant activities with ascorbic acid (AA) as the standard. Detailed interaction studies with calf thymus (CT) DNA and bovine serum albumin (BSA) were performed through various spectroscopic and theoretical approaches and indicated that the complex has promising binding capability with both the systems. Comprehensive biological studies were performed and showed that the complex exhibits notable antibacterial activity against Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) by interfering with its cell wall integrity. Microscopic imaging confirmed cellular abnormalities, such as alterations in the cell shape, size, and quantity. Molecular docking analyses also provided insights into the activities of the complex. In contrast, the complex displayed minimal growth inhibition properties against Gram-negative Klebsiella pneumoniae (KP) even at higher complex concentration, indicating that the specific inhibition activity of the complex is only against Gram-positive MRSA. Moreover, based on optical density readings, the results demonstrated that the complex exhibited effective antibacterial activity against MRSA with an MIC value between 34 and 36 μg ml−1, whereas the MIC value of standard cefoxitin is >70 μg ml−1. Thus, our complex demonstrated better antibacterial activity than the conventional antibiotic. [ABSTRACT FROM AUTHOR]

Zinc(II)-complexes with the general formula [Zn(L)2] containing 8-hydroxyquinoline Schiff bases functionalized with 1-(3-aminopropyl)imidazole or 1-(3-aminopropyl)-2-methyl-1H-imidazole on 2-position and their respective ligands (HL1 or HL2) were synthesized and characterized by NMR, UV-Vis, FTIR and CD spectroscopies as well as ESI-MS spectrometry. Single crystals of HL2 and [Zn(L1)2]n were analysed by SC-XRD. [Zn(L1)2]n shows a 1D polymeric chain structure of alternating Zn(II) cations and bridging Schiff base ligands, in contrast to previously reported monomeric structures of analogous complexes. DFT calculations were performed to rationalize the polymeric X-ray structure of Zn(L1)2. Results showed that the ligands can bind as bi- or tridentate to Zn(II) and there is the possibility of a dynamic behavior for the complexes in solution. Both ligands and complexes present limited stability in aqueous media, however, in the presence of bovine serum albumin the complexes are stable. Molecular docking simulations and circular dichroism spectroscopic studies suggest binding to this protein in close proximity to the Trp213 residue. Biological studies on a panel of cancer cells revealed that the Zn(II)-complexes have a lower impact on cell viability than cisplatin, except for triple-negative breast cancer cells in which they were comparable. Notwithstanding, they display much higher selectivity towards cancer cells vs. normal cells, than cisplatin. They induce the generation of ROS and DNA double-strand breaks, primarily through apoptosis as the mode of cell death. Overall, the novel Zn(II)-complexes demonstrate improved induction of apoptosis and higher selectivity, particularly for melanoma cells, compared to previously reported analogues, making them promising candidates for clinical application. [ABSTRACT FROM AUTHOR]

Over the past 20 years, there has been a notable rise in the incidence of invasive bacterial infections. This increase has been mostly linked to the growth of drug‐resistant bacteria. Tetrazoles have been considered as promising antibacterial agents and their effectiveness may be enhanced by hybridization with other antibacterial pharmacophores. In this work, a series of tetrazole hybrids (1‐6) containing oxazepane and pyrazole rings as well as Mannich bases (7,8) were synthesized via the Schiff and Mannich reactions, respectively. The compositions were proven spectroscopically using infrared spectra, proton (1H) and carbon‐13 (13C) nuclear magnetic resonance spectra and elemental analyses. Moreover, the pharmacokinetic properties viz Absorption, Distribution, Metabolism and Excretion (ADME) were predicted in silico using SwissADME server. Compounds 1,2 and 4–6 attaining the best drug‐likeness properties were screened for their antibacterial activities against Staphylococcus epidermidis and Streptococcus mutans at different concentrations in comparison with tetracycline and amikacin, respectively. Afterwards, a molecular docking study was performed to explore the potential binding patterns of the new antibacterial compounds. Collectively, the tetrazole hybrids 4 and 5 have been found to have higher inhibitory potencies compared to tetracycline, serving them as potential antibacterial candidates which can be further optimized in the future. [ABSTRACT FROM AUTHOR]

Two molybdenum complexes, MoHL1 and MoHL2, are prepared from the corresponding tetradentate salen type (ONNO) ligands, HL1 and HL2, obtained from 3, 5‐dichloro salicylaldehyde, and substituted o‐phenylenediamines. The complexes are characterized by 1H NMR, FTIR, HRMS, and UV‐visible spectral techniques. The DFT studies provide insight into their structural parameters. The band gap energy and molecular orbital energies influence the charge transfer interactions within the molecule. Further, the complexes are assessed for their antioxidant efficacy, α–amylase inhibitory potential, binding propensity with deoxyribonucleic acid, and cytotoxicity studies against breast cancer cell line, MCF7. The DPPH assay demonstrates high radical scavenging ability, as evidenced by the IC50 value of 133.85±1.18 μg/mL, higher than ascorbic acid. From the results of α–amylase inhibitory assay, MoHL1 shows good inhibitory action with the IC50 value of 32.72±2.49 μg/mL higher than that of the standard acarbose. The absorption titration method, to track the binding interactions of the metal complexes with DNA, shows a marked hyperchromic effect indicating preferential binding of the complexes to the grooves of DNA helical structure. MoHL2 exerts higher cytotoxicity against cancer cell lines than MoHL1. Thus, the complexes have the potential to be developed as antidiabetic and anticancer agents. [ABSTRACT FROM AUTHOR]

A bis-(violurate)-based ruthenium(III) complex was synthesized in a pure form as nano-crystallites. Mass spectrum, elemental and thermal analysis, as well as molar conductance measurements, assigned the molecular formula [Ru(VA)2ClH2O]. FTIR, UV-vis, magnetic moment and ESR investigations suggested the structural formula as a distorted octahedron. Structural analysis by DFT calculations and processing of the PXRD data by the computer program Expo 2014 confirmed the proposed structure. Electronic and emission spectroscopy in addition to viscosity measurements displayed the greater binding capability of the [Ru(VA)2ClH2O] complex towards the studied biomolecules DNA and HSA as compared to uncomplexed violuric acid (VA). In vitro antiviral investigations against SARS-CoV-2 of violuric acid and the Ru(III) complex revealed greater activity in the case of the latter. Molecular docking studies reported that [Ru(VA)2ClH2O] binds more strongly to the spike protein of the tested virus cells (Vero-E6 cells), DNA, and HSA than the uncomplexed bis-(violurate) ligand system, consistent with the experimental results. [ABSTRACT FROM AUTHOR]

Two new transition metal complexes of a dipyrazinylpyridine (dppy) ligand 3,4-diethoxyphenyl-2,6-di(pyrazine-2-yl)pyridine L, {[CuL2]Cl2 (1) and [ZnL2]Cl2 (2)}, have been synthesized and characterized using NMR (for L and 2), UV-vis spectroscopy, ESR (for 1), HRMS, elemental analysis and DFT study. Upon interaction with bovine serum albumin (BSA), complexes 1 and 2 demonstrated varying binding capabilities, with 1 displaying superior binding (binding constant 4.5 x 104 M-1) towards BSA than 2 (binding constant 1.2 x 104 M-1). Similarly, with calf-thymus DNA (ct-DNA), 1 showed better binding affinity (1.1 x 106 M-1) than 2 (8.5 x 105 M-1) as observed from UV-visible spectroscopy. The mechanism that leads to the quenching of BSA fluorescence by 1 and 2 is attributed to static quenching. The complexes demonstrated an intercalative binding mode with ct-DNA, and molecular docking has been employed to elucidate the biomolecular interactions with the complexes. Circular dichroism spectra have been utilized to confirm the binding and assessment of the interactions with the biomolecules. Furthermore, studies of the anticancer potentials of 1-2 were evaluated using the Dalton's lymphoma (DL) cancer cell line. Following 48 hours of treatment, the IC50 values for 1 and 2 were identified as 24 mM and 28 mM, respectively, indicating their potency in inhibiting cancer cell growth. [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis and characterization of the novel 2‐aminoguanidine‐derived Schiff base rhenium(I) compounds: fac‐[Re(CO)3(Hguabs)Br]Br (1) (Hguabs ⋅ Cl=2‐((benzothiazole)methyleneamino)guanidine chloride) and fac‐[Re(CO)3(guaquin)Br] (2) (guaquin=2‐((quinolin‐2‐yl)methyleneamino)guanidine). [ABSTRACT FROM AUTHOR]

2-Azetidinones (β-lactams) possess broad and potent bioactivity owing to the presence of lactam rings. As evidence has shown, it is one of the most critical biological frameworks. Some new 2- azetidinones have been synthesized from corresponding Schiff bases using different amines and aldehydes. All compounds (Schiff bases and β- lactams) were synthesized for comparison research using conventional and microwave techniques. The microwave approach has been found to reduce reaction time and boost yield drastically. Analysis combining elemental (C, H, and N) and spectroscopic approaches (NMR, IR, and UV) have been applied to ensure the Schiff bases constitution and corresponding β-lactams constitution. The newly synthesized compound's antibacterial action was estimated opposite to one gram-positive and one gram-negative bacteria. One compound (A-03) among synthesized 2-azitidinones was shown significant activity against the gram-positive bacteria. The other synthesized compounds had no substantial activity on either of the microorganisms. [ABSTRACT FROM AUTHOR]

Objective: Schiff bases are significant pharmacophores and show varied biological applications such as antiurease, antidiabetic, antioxidant, antifungal, antibacterial, and anticancer. In this study, new Schiff bases derivatives of benzimidazole containing thiophene ring were synthesized and characterized by IR, 1H NMR, and 13C NMR spectroscopic methods, and elemental analysis data. Methods: Novel Schiff bases were synthesized in high yield and purity. Their anti-urease activities were evaluated by the Weatherburn method against Jack bean urease and compared with thiourea (0.217 ± 0.16 μM) used as a standard. Results and Discussion: All new Schiff bases have antiurease activity with IC50 values ranging from 0.42 ± 0.03 and 0.10 ± 0.25 μM. N′-[(2-hydroxy5-methylphenyl)methylidene]-2-[5,6-dichloro-2-(thiophen-2-ylmethyl)-1H-benzimidazol-1-yl]acetohydrazide (IVf) has the best inhibition activity with 0.10 ± 0.25 μM IC50 value. Also, N′-[furan-2-ylmethylidene]-2-[5,6dichloro-2-(thiophen-2-ylmethyl)-1H-benzimidazol-1-yl]-acetohydrazide (IVl) and N′-[(5-chloro-2-hydroxyphenyl)methylidene]-2-[5,6-dichloro-2-(thiophen-2-ylmethyl)-1H-benzimidazol-1-yl]acetohydrazide (IVg) have antiurease activities better than the standard Thiourea (0.217 ± 0.160 μM). Conclusions: The dichlorobenzimidazoles derivatives of Schiff bases have excellent antiurease inhibition activity. The thiophene ring at 2-positions of benzimidazole and dichloro atoms has a positive effect on inhibition activity of urease. [ABSTRACT FROM AUTHOR]

With the ultimate goal of discovering new anticancer agents, this study involved the design and synthesis of fifteen novel Schiff bases 4a,b, 5, 6a–d, 7a–e, and 8–10 which contain 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole moiety. The synthetic method depended on reaction of 3-(2-oxo-2H-chromen-3-yl)-1-(4-phenylthiazol-2-yl)-1H-pyrazole-4-carboxaldehyde (3) with a series of aromatic and heteroaryl amines under ultrasound irradiation to explore the influence of aromatic and heteroaryl rings on biological activity. The chemical structures of these Schiff bases were fully elucidated using various spectral and elemental analyses. The antiproliferative activities of the Schiff bases were studied by the standard SRB method. Among the new 15 Schiff bases, derivatives 4a,b, 5, and 7b have significant cytotoxic effects against PC3, HepG2, and HCT116 cancer cell lines. These four bioactive Schiff bases significantly increased the late apoptosis of all studied tumor cells. Also, both products 4a and 4b arrested the cell cycle at the G1 phase, while both compounds 5 and 7b arrested the S and G2 phases against PC3 cells. In addition, the products 4a, 4b, 5, and 7b have promising high abilities to arrest the cell cycle at the G2 phase against HepG2 and HCT116 cells. The different substitutions on the aryl ring were the basis for the structure–activity relationship study. The molecular docking study confirmed good binding interactions of these compounds with Cyclin-dependent kinase 8 (CDK-8) receptor, while the absorption, distribution, metabolism, excretion, and toxicity (ADMET) prediction supported that these bioactive products can be promising anticancer agents. [ABSTRACT FROM AUTHOR]

In this study, a layer of isonicotinohydrazide and pyrene-based Schiff base (PyMIs) was formed on the front side of a p-Si semiconductor using the spin coating method, and an Al/PyMIs/p-Si/Al diode was fabricated. The I-V characteristics of the fabricated diode were measured under dark and from 20 to 100 mW/cm2 illumination intensities for both forward and reverse bias. Diode parameters, including saturation current (), ideality factor (n), and barrier height () were investigated for all measurements based on thermionic emission theory. The values n changed from 2.51 to 2.05, and the changed from 0.77 eV to 0.86 eV as light intensity increased from dark to 100 mW/cm2. The series resistance () values of the diode were investigated using the modified Norde's function and Cheung's functions. An analysis of the forward plot of Al/PyMIs/p-Si (MOmS)-type diode specified the carrier transport domination by ohmic conduction in the lower bias regions, by the space-charge-limited current (SCLC) at medium bias regions and the trap-charge limit current (TCLC) transport mechanism at higher bias regions. The fabricated diode exhibited typical photodiode behavior with reverse current values increasing from 9.13 × 10− 6 A to 1.05 × 10− 4 A, respectively. Furthermore, characteristics illuminated from 20 to 100 mW/cm2 were also studied, and they indicated that the Al/PyMIs/p-Si diode could operate in a photovoltaic regime. [ABSTRACT FROM AUTHOR]

The binding between a fluorescent water-soluble Zn(II) complex of {2-[N-(2-hydroxyethylammonioethyl) imino methyl] phenol} and calf thymus DNA (ct-DNA) was investigated using spectroscopic techniques. The complex was prepared and identified by FT-IR, and 1H NMR spectroscopies. The significant changes in the absorption and the circular dichroism spectra of ct-DNA in the presence of the Zn(II) complex implied the interaction between the Zn(II) complex and ct-DNA. Upon addition of ct-DNA, the fluorescence emission intensity of the Zn(II) complex was increased and indicated the interaction between the Zn(II) complex and ct-DNA was occurred. The binding constant values (Kb) resulted from fluorescence spectra clearly showed the Zn(II) complex affinity to ct-DNA. The fluorescence studies also approved the static enhancement mechanism in the Zn(II) complex-DNA complexation process. The thermodynamic profile exhibited the exothermic and spontaneous formation of ct-DNA-Zn(II) complex system via hydrogen bonds and van der Waals forces. The competitive fluorescence investigation by methylene blue (MB), and Hoechst 33258 demonstrated that the Zn(II) complex could replace the DNA-bound Hoechst and bind to the minor groove binding site in ct-DNA. The viscosity changes were negligible, representing the Zn(II) complex binding to DNA via the groove binding mode. Molecular docking simulation affirmed that the Zn(II) complex is located in the minor groove of ct-DNA near the DG12, DA17, DA18, and DG16 nucleobases. [ABSTRACT FROM AUTHOR]

In this study, Schiff bases (SCH-1 and SCH-2) were synthesized from the condensation reaction of 2-aminobenzothiazole with 3-hydroxy-4-methoxybenzaldehyde and 3-hydroxy-4-ethoxybenzaldehyde. Poly(phenoxy-imine)s were synthesized from Schiff bases via oxidative polycondensation by NaOCl (6–14% aqueous solution) as oxidant in alkaline medium and H2O2 (35% aqueous solution) as oxidant in THF medium. The structures characterizations of Schiff bases and poly(phenoxy-imine)s were confirmed by FT-IR, 1H and 13C NMR, CV, UV–Vis and TGA analyses. Limit oxygen index (LOI) and the heat resistance index (THRI) temperature were determined from thermogravimetric measurements of compounds. P-SCH-2-A showed the highest LOI as 45.50 with self-extinguishing according to other polymers (18–30). The optical band gap of P-SCH-2-A was determined to be 1.99 eV. Additionally, the optical band gap energy of compounds were calculated by using the Tauc method. According to the Tauc method, the optical band gap (Eg) value of P-SCH-2-A was calculated to be 2.20 eV. The glass transition temperatures (Tg) and surface properties of poly(phenoxy-imine)s were determined from DSC and SEM analyses, respectively. The weight average molecular weight (Mw) values of P-SCH-1-O, P-SCH-2-O, P-SCH-1-A and P-SCH-2-A were calculated to be 7400, 8400, 3100 and 19,100 g mol−1 from gel permeation chromatography (GPC) measurements. [ABSTRACT FROM AUTHOR]

At the nanoscale level, several biological processes take place, owing to the potential that engineered nanomaterials might interrelate with bio-molecules and cellular procedures. This study aimed to synthesize cadmium oxide nanoparticles via a one-step calcination process of tetradentate Schiff base-Cd(II) complex at different temperature ranges. The as-synthesized compounds were carried out via a viz UV–visible, elemental analysis, 1H NMR, molar conductivity, transmission electron microscopy (TEM), FT-IR spectroscopy, and X-ray diffraction (PXRD). The band gap energy and average particle sizes of the CdO particles are respectively (2.69 eV, 3.54 eV), 26.88 nm for CdO@250, and (3.20 eV, 3.57 eV), 25.67 nm for CdO@300, while CdO@350 exhibited the 3.78 eV and 28.42 nm values. The antioxidant accomplishments of the test samples through the scavenging activity of DPPH radicals showed CdO@300 to possess (IC50 = 5.18 ± 0.56 µg/mL). Similarly, the as-synthesized CdO nanoparticles exhibited higher antibacterial activities against S. aureus and E. coli as compared to the corresponding Cd-HMB and ligand (HMB), while ciprofloxacin acted as a standard antibiotic. Furthermore, HMB and its complex Cd-HMB were docked against the DNA gyrase enzymes of S. aureus (PDB IDs: 5CDQ) and E. coli (PDB IDs: 6F86) as receptors. The binding sites docking results showed that the binding energies of HMB and Cd-HMB to 5CDQ ranged from − 3.44 to − 4.99 kcal/mol and from − 6.45 to − 6.64 kcal/mol, while the binding energies related to the target 6F86 are in the ranges of (− 3.64, − 4.76) kcal/mol and (− 6.08, − 6.09) kcal/mol respectively. Therefore, the significant antioxidant and antibacterial activities of the ligand (HMB), Cd-HMB, and CdO NPs review the broad application prospects of these compounds as therapeutic agents for wide-ranging biomedical applications. [ABSTRACT FROM AUTHOR]

A novel heterogeneous catalyst Fe3O4@SB@Cu that contains a copper(II) Schiff base complex covalently immobilised on Fe3O4 nanoparticles was synthesised. The prepared catalyst is well characterised by FTIR spectroscopy, UV–Visible spectroscopy, FE-SEM, TEM, VSM analysis, EDX, XRD analysis, TGA, CV technique, XPS and PL studies to confirm its structural and morphological features. The high BET surface area (117.34 m2/g) was achieved for particles with size 25–30 nm and saturation magnetisation of 43.4 emu/g. The catalytic potential of the synthesised catalyst Fe3O4@SB@Cu was investigated by employing H2O2 as an oxidant for the oxidation of anthracene to anthraquinone. Various parameters like catalytic loading, temperature and solvents were varied to determine the optimal catalytic conditions, and 96% yield of the product is obtained within 36 min when the reaction was performed in the acetonitrile solvent with 1.8% loading of the catalyst. The catalytic reaction was monitored by UV–Visible spectroscopy. Using an external magnet, the modified nanoparticles were easily retrieved from the reaction mixture and can be utilised for five more reaction cycles without the significant loss of activity or copper leaching. [ABSTRACT FROM AUTHOR]

A facile metalation of Schiff base organic polymer, Te-TETA obtained from terephthalaldehyde and triethylenetetramine, with zinc to produce metalated organic polymer, Te-TETA-Zn has been reported here. Both Te-TETA and Te-TETA-Zn were analyzed by various analytical techniques viz. FT-IR, PXRD, FE-SEM, EDX, XPS, TGA and BET. Further, HR-TEM images of metalated organic polymer, Te-TETA-Zn was also recorded. EDX and XPS analyses clearly revealed the metalation of Zn in the organic polymer. Further, a huge transformation from the spherical morphology of Te-TETA to the flattened structure in Te-TETA-Zn can be seen in the FE-SEM and TEM images endorsing the successful coordination of zinc with the N-coordinating sites. An investigation of the catalytic activity of Te-TETA-Zn in combination with tetrabutylammonium bromide (TBAB, 2 mol%) reveals it to be an efficient heterogeneous catalyst component for the chemical fixation of CO2 to epoxides producing cyclic carbonate products (up to 99% conversion) under reaction conditions [Te-TETA-Zn (20 mg), TBAB (2 mol%), 5 bar CO2 pressure, 60 °C, 4 h]. [ABSTRACT FROM AUTHOR]

Cancer has become the second leading reason for death in the world. Cell biology states that the bulk of anti‐cancer medications focuses on DNA. A study of how complexes of metals interact with DNA is crucial in creation of the effective chemotherapy drugs. The interactions of DNA with Schiff base and their metal complexes are a thrust area for many researchers, and many papers have reported on them. An amino molecule reacts with carbonyl group to form a variety of chemicals called Schiff bases. Many studies have shown that Schiff bases have compounds that affect biological processes. Due to their potential use as novel reagents for biotechnology and medicine, the research of interactions between transition metal complexes and nucleic acids has grown significantly during the past few decades. It was shown that several metal Schiff base complexes may intercalate DNA. Small molecules can attach themselves to DNA through different ways, such as intercalation and groove binding. The main method to measure nuclease activity was gel electrophoresis, and the ligand alone had much lower activity than the complex. To set the stage for this analysis, a brief overview of Schiff bases and their complexes is provided. Further, this review provides an overview of the DNA interactions brought forth by Schiff base metal complexes. It also draws attention to new developments in the study of Schiff bases and their metal complexes and their prospective use as a bioactive core for DNA cleavage and binding. [ABSTRACT FROM AUTHOR]

A tridentate pyrazolone‐furan Schiff's base ligand, [(E)‐4‐(((5‐[2‐fluorophenyl]furan‐2‐yl)methylene)amino)‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one] (PFSB), was produced by condensation between compounds 5‐(2‐fluorophenyl)furan‐2‐carbaldehyde and 4‐amino‐1,5‐dimethyl‐2‐phenyl‐1,2‐dihydro‐3H‐pyrazol‐3‐one. Spectroscopic characterization evidence suggested the tridentate nature (ONO) of pyrazolone‐furan Schiff's base ligand (PFSB) and coordinated to the metal (II/III) moieties through nitrogen and oxygen donor sites giving tetra‐ and/or hexa‐coordinated geometry to complexes. The complexes have been supported by elemental analyses, molar conductance, magnetic moments, spectral analyses, EPR, ligand field parameters, XRD, and thermogravimetric measurements. Theoretical optimization employing the density functional theory (DFT) was accomplished on the molecular structures of the compounds in question, and subsequently, the quantum chemical descriptors were computed. Cr(III), Co(II), Ni(II), and Zn(II) complexes were allocated octahedral coordination, while the Cu(II) complex was allocated square‐planar coordination. The SEM, TEM, XRD, AFM, and EDX of the studied complexes unveiled distinct and strong diffraction peaks, signifying their crystalline nature, and providing evidence of their particle sizes being within the nano‐size. The crystal sizes calculated for all complexes were determined to be ranging from 27.73 to 76.39 nm. However, the Cr(III) complex exhibited a particle size exceeding 100 nm. The interactions between metal complexes and calf thymus DNA, and their potential for mimicking insulin activity, were investigated in a controlled lab setting by measuring their ability to inhibit alpha‐amylase. The anti‐microbial potential of the ligand (PFSB) and complexes (C1‐C5) were tested. The viscosity and UV–Vis absorption determinations were utilized to assess the calf thymus DNA (CT‐DNA) interaction with the nano‐sized metal (II/III) chelates. Our flow cytometry data indicate significant levels of apoptosis and cell cycle arresting in both liver and breast cancer cell lines. [ABSTRACT FROM AUTHOR]

Novel divalent chelates of Co (II), Cu (II), Zn (II) and Ni (II) were prepared and described of the form [M (NTM)(CH3COO)2] where NTM = [1‐(4‐nitrophenyl)‐1H‐1,2,3‐triazol‐4‐yl)methanol ligand. Elemental analyses, infrared red, 1H and 13CNMR, electronic, magnetic susceptibility, conductivity measurements and X‐ray diffraction studies were used to assess our divalent metal complexes. Moreover, the stability and stoichiometry of the novel metal chelates were examined through the job's method in solutions. Correlation of all spectroscopic techniques states that NTM acts as a bi‐dentate NO ligand to afford octahedral complex geometry for all the investigated metal chelates. Thermodynamic and kinetics factors for various thermal degradation phases were calculated. Moreover, B3LYP/LANL2DZ/6‐311 g(d,p) theoretical study has been applied for estimating the MEP and quantum chemical reactivity descriptors of studied molecules. Moreover, the UV–Vis absorption spectra for the investigated molecules are predicted via the time‐dependent DFT (TD‐DFT) calculations. In addition, MOE‐ docking was tested on two different proteins, the receptor of (3HB5) breast cancer mutant oxidoreductase as well as the receptor of Glucosamine‐6‐phosphate synthase in complex with glucosamine‐6‐ phosphate of (2VF5) E.coli and COVID‐19 protease. The results recommended that the (NTMCo), (NTMNi), (NTMCu) and (NTMZn) complexes showed the highest inhibitory activity compared to the other NTM ligands as antimicrobial and breast cancer candidates. Furthermore, in‐vitro anti‐bacterial, anti‐fungal, cytotoxic and anti‐oxidant performances for the selected ligand as well as its chelates were studied. All metal chelates presented superiority, proceeding free organic ligand ineffective management, definitely NTMCu complex. [ABSTRACT FROM AUTHOR]

A new series of transition metal complexes of bidentate Schiff base compound derived from 2‐hydroxy‐1‐(2‐methoxyethylimino)‐naphthalene (HL) were synthesized and characterized using elemental analysis, Fourier transform infrared spectroscopy (FT‐IR), and UV–vis spectroscopies. X‐ray single crystal structures of Zn(II), Mn(III), and Co(III) complexes (1–4) have also been determined, and it was indicated that these Zn(II) and Co(III) complexes (1, 4) are in an octahedral geometry. Whereas, it was found that the Zn complex (2) is in quite a regular tetrahedral environment. Also, the Mn center in complex (3) is ligated by two azomethine nitrogen atoms, two ligand oxygen atoms, and one Cl atom of metal salt forming five coordinated tetragonal pyramid geometry around the Mn atoms. The cyclic voltammetry of the complexes specifies an irreversible redox behavior for all complexes (1–4). Next, DFT/B3LYP theoretical method was used to determine the optimal geometrical configurations and comparison between experimental and theoretical data, as well as for calculations of molecular electrostatic potential, highest‐occupied molecular orbital (HOMO)‐lowest‐unoccupied molecular orbital (LUMO) energy values of selected compounds. The study of non‐covalent interactions was done by Hirshfeld surface analysis using CrystalExplorer program. Furthermore, molecular docking inspection was carried out to study the binding affinity of the tested complexes towards protein B‐cell lymphorna (PDB ID: 4LXD). Using the results obtained from the molecular docking and the summarized interaction of the binding processes, these structures show the validity of effective inhibition against liver cancer. [ABSTRACT FROM AUTHOR]

One significant class of chemotherapeutic medicines with the ability to overcome drug resistance is metal‐based medications. The creation of novel therapeutic medications with distinct modes of action is required due to the rise in drug resistance, treatment failures, and the scarcity of available treatments. The amino acid isoleucine interacts with the arylidene (synthesized from isatin and 2,6‐diamino‐pyridine) forming the HL Schiff base ligand, which then interacts with some transition metal ions to form the metal complexes. Thermal analysis, spectroscopy (1H‐NMR, IR, mass, and ultraviolet–visible), solid reflectance, magnetic moment, molar conductivity, and elemental analyses were employed for examining the synthesized HL and resultant complexes. Mass spectra besides elemental analyses studies verified the formulae of the Schiff base ligand and metal complexes. All the complexes, except for the Fe(III) complex which is non‐electrolyte, exhibited electrolytic behavior as indicated by their molar conductivity values. The obtained complexes exhibited octahedral geometrical shapes, except for the complexes of Co(II), Ni(II), and Zn(II), which displayed tetrahedral geometry. Thermal analysis showed that the complexes consistently release organic ligands and anionic components following the initial loss of water molecules of hydration. The conducted X‐ray diffraction patterns elucidated their lattice dynamics and not only confirmed the purity of the samples, but also demonstrated that the ligand and complexes of Cr(III), Fe(III), Mn(II), Cu(II), Zn(II), and Cd(II) have a crystalline structure in addition to determination of average size of the crystallites. Scanning electron microscope (SEM) was investigated for Schiff base ligand and Co(II) complex. The complexes demonstrated superior efficacy than HL towards fungal and bacteria organisms against Aspergillus fumigatus and Candida albicans, Salmonella Sp., Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The MCF‐7 cancer cell was subjected to investigation by synthesized complexes and IC50 values ranged from 12 to 23.1 μg/ml. Molecular docking studies define and anticipate the inhibitory potential and binding mode of the generated ligand with the 1GS4, 2HQ6, 3DJD, and 5JPE receptors. [ABSTRACT FROM AUTHOR]

Oxovanadium (IV) and diphenyltin (IV) complexes were synthesized on the nanoscale based on the Schiff base (H2L) derived from salicylaldehyde and d‐glucosamine. The complexes were formed with a molar ratio of 1:1 and 1:2 (metal: dligand) relative to oxovanadium (IV) and diphenyltin (IV), respectively. Fourier‐transform infrared spectroscopy, 1H and 13C nuclear magnetic resonance, mass fragmentations, electronic transitions, thermogravimetric analysis, and density functional theory were employed to validate the structure of synthesized compounds. The results demonstrated that the ligand (H2L) was successfully attached to oxovanadium (IV) and diphenyltin (IV) as di‐anionic and mono‐anionic ligands, respectively. The size of the complexes was investigated using the transmission scanning microscope. The work presents a prospective concept for the drug design of the targeted anticancer through the glucose moiety. All compounds revealed remarkable anticancer activities against the colorectal (HCT‐116) cell line, recording IC50 values 4.94, 21.73, and 62.5 μg/ml for VO (II)(L), free H2L, and Sn (ph)2(HL)2, respectively. The IC50 value of VO (II)(L) complex was increased after the quercetin inhibitor. Therefore, the sugar‐conjugated compound can be recognized by the glucose recognition binding site of GLUT and their cell‐killing effect depends highly on the GLUT inhibitor, quercetin. The potential GLUT transportability of the compounds was investigated through a molecular docking study. The anti‐migration activity was investigated for VO (II)(L) complex. The free ligand observed the best antimicrobial results. The antibacterial stimulation was investigated and represented different interaction types with the selected ribosyl transferase enzyme. [ABSTRACT FROM AUTHOR]

A new copper (II) complex containing the mono basic ligand (HL) azo naringenin was synthesized and structurally characterized by analytical, magnetic, and various spectroscopic techniques. An octahedron geometry was proposed for the assigned molecular formula [Cu(L)(CH3COO)(OH2)2]. Processing of powder X‐ray diffraction data for the copper (II) complex in question by the Expo 2014 computer program confirmed the proposed structure inferred from the spectroscopic studies. The DNA binding ability of the free ligand and its copper (II) complex was tested, and the results obtained demonstrated the stronger DNA binding ability of the copper (II) complex over the azo naringenin ligand. The antioxidant potency of copper (II) complex was investigated via the DPPH free radical‐scavenging assay. The present azo naringenin ligand and its copper (II) complex have shown diverse biological potentials including antitumor, antifungal, and antibacterial activities. [ABSTRACT FROM AUTHOR]

The ternary complexes of the zinc(II), [Zn(met)(gly)(Cl)2] (1), and [Zn(met)(hist)(Cl)2] (2) are synthesized and illustrated utilizing spectroscopic and analytical measurements, and the geometry of the complexes has been identified to be octahedral. The Coats Red fern approach was employed to enumerate the thermodynamic and kinetic variables for both the Zn(II) complexes' decomposition. The quantum chemical variables were estimated utilizing the molecular orbital conformations' energy distribution, which was derived from optimal geometric shapes to test the stabilization of both complexes. DNA‐binding investigations by UV–Vis absorption, fluorescence, and viscosity were all exploited to examine the bonding properties between Zn(II) complexes and ct‐DNA, and a groove mode of bonding was established. The interactions between complexes and BSA/HSA were investigated by employing absorption and emission spectroscopic methods. The results demonstrate that complexes have a powerful ability to diminish BSA and HSA luminescence intensity, and overall associating mode is predominantly a static quenching process. The cytotoxic effect of the two Zn(II) complexes was additionally examined in human breast adenocarcinoma (MCF‐7 and MDA‐MB‐231) cell lines by employing the MTT technique. The IC50 values for every cell line were derived. Each of the two complexes was functional in both cell lines. [ABSTRACT FROM AUTHOR]

Binuclear [{Pd (dien)}2(μ‐pz)](ClO4)4 (Pd1) and [{Pd (dien)}2(μ‐pydz)](ClO4)4 (Pd2) complexes, where pz is 1,4‐diazine and pydz is 1,2‐diazine bridging ligands and dien (diethylenetriamine) is a tridentately coordinated triamine ligand, were synthesized and characterized using elemental analysis, NMR (1H and 13C) spectroscopy, and UV–Vis spectrophotometry. Electronic absorption spectrophotometry and fluorescence spectroscopy were used to study the interactions of the prepared Pd1 and Pd2 complexes with deoxyribonucleic acid (CT‐DNA) and bovine serum albumin (BSA). According to the UV–Vis spectrophotometric data, the complexes interact with CT‐DNA and bind to the BSA as a possible carrier to the target site. The antitumor properties of the tested palladium compounds were evaluated on three types of human cancer cells, namely, squamous cell carcinoma cells SCC‐4, cervical carcinoma cells HeLa and colorectal carcinoma cells HCT116, and one type of malignantly unchanged cells, MRC‐5 fibroblasts. The highest cytotoxicity was shown by the Pd1 compound against SCC‐4 cell, with an IC50 value of 5.4 ± 1.2 μM. The results showed that the cytotoxic potential against SCC‐4 cells of our new palladium complexes Pd1 and Pd2 was comparable with the cytotoxic potential of cisplatin and oxaliplatin. However, Pd1 and Pd2 displayed significantly lower cytotoxicity in comparison with cisplatin and oxaliplatin against non‐malignant cells, fibroblasts MRC5, so these results may suggest that local and systemic complications of antitumor therapy could be reduced and/or avoided. Both compounds selectively decreased the viability of SCC‐4 cells by induction of apoptosis. Also, Pd1 and Pd2 induced S‐phase cell cycle arrest in human SCC‐4 cells, so that could be another mechanism to halt the uncontrolled growth and division of cancer cells. Moreover, the precise molecular mechanism of Pd1 and Pd2 complexes‐induced apoptosis was the activation of the intrinsic signaling pathway of apoptosis, which also included activation of caspase‐3. Therefore, our new palladium (II) complexes might have a promising role as the potential future cytostatic agents. [ABSTRACT FROM AUTHOR]

Under ultrasound irradiation in an ethanol solvent, a new coordination complex of Cu(II) was successfully synthesized within a 10-min timeframe through the treatment of an imidazole-based ligand (PDI) with a copper-containing salt. The formation of the complex was verified through elemental (CHN) analysis and FT-IR spectroscopy. Additionally, the supramolecular assembly and packing of atoms in the crystalline units of the copper complex were elucidated using single-crystal X-ray diffraction method. The synthesized compound exhibits an ionic nature, featuring a copper(II) cation inside the coordination sphere and a chloride anion outside of the coordination sphere. The coordination environment around the copper cation is achieved through the bonding of the N-atom of the non-protonated PDI ligands and a chloride ion. To maintain a neutral charge, a second chloride ion serves as a counterion. The bond angles surrounding the Cu(II) ion showed a somewhat deformed square planar geometry of the complex. The non-covalent intermolecular interactions were executed by Hirshfeld surface analysis (HSA), while the theoretical studies were conducted using DFT employing the B3LYP/Def2-TZVP level of theory. The consistency between the theoretical findings and experimental data attested to the reliability of the theoretical conclusions. [ABSTRACT FROM AUTHOR]

A vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand viz. [VIVO(salala)(phen)]1.66H2O (where salala = Schiff base derived from salicylaldehyde and L-alanine, phen = 1,10-phenanthroline) have been synthesized and its structure determined by single crystal X-ray diffraction. The crystal lattice parameters of the complex was determined by single crystal X-ray diffraction with lattice parameters, a = 18.4361 [5] Å, b = 22.4926 [6] Å, c = 12.4035 [6] Å, β = 126.904 [1]°, C2 space group, Z = 2. In the crystal, the V(IV) ions are in distorted octahedral geometry, coordinated to two oxygen atoms and one nitrogen atom of Schiff base ligand and two phenanthroline nitrogen atoms. The π···π stacking interactions as well as C–H···O hydrogen bonds were found to play an important role in the self-assembly of the complex molecules. The non-covalent interactions of the complex were further evaluated by Hirshfeld Surface Analysis. Spectroscopic characterization of the complex by Infrared and UV–visible spectroscopic techniques is also reported. Crystal structure of a vanadium(IV) Schiff base complex derived from salicylaldehyde and L-alanine with phenanthroline as co-ligand have been determined by single crystal X-ray diffraction and non-covalent interactions between the complex molecules studied by Hirshfeld surface analysis. [ABSTRACT FROM AUTHOR]

The document is a contents list for the New Journal of Chemistry, a publication that aims to connect the world with the chemical sciences. It provides information about the articles and papers included in the journal's latest issue. The articles cover a range of topics in chemistry, including the structural basis for Cu(II) metallocycle hexamer formation, photocatalyst-free hydrothiolation of gem-difluoroalkenes with thiols, and the construction of an alkynyl-containing porous polymer for enhanced photocatalytic H2O2 generation. The journal also invests its profits back into the chemistry community. Additionally, the document includes a correction to a previous paper on the effect of electrolyte optimization. [Extracted from the article]

Two new Zn(II) coordination complexes, namely [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2), were synthesized and designed as self-assembled vaccine candidates against the SARS-CoV-2 receptor-binding domain (RBD) protein and Omicron spike protein (where L = (Z)-N-phenyl-N′-((Z)-phenyl(pyridin-2-yl)methylene)carbamohydrazonic acid, and en = ethylenediamine). Both the Zn(II) complexes were fully characterized using single-crystal X-ray crystallography, cyclic voltammetry, FT-IR spectroscopy, FT-Raman spectroscopy, NMR spectroscopy, UV-Vis and fluorescence spectroscopic experimental techniques and density functional theory calculations. Both the complexes were crystallized in the monoclinic crystal system with the P21/n space group. Crystallographic studies indicated a square pyramidal geometry for [Zn(L)(en)]ClO4 (1) and distorted octahedral for [Zn(L)2] (2). DFT calculations were performed to provide information on the structure–activity relationships. Hirshfeld surface (HS) analysis was also performed. The interactions of the Zn(II) complexes [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2) with CT-DNA were followed by UV-Vis studies. Absorption titration studies revealed that these interacted strongly with CT-DNA. The calculated equilibrium binding constant (Kb) values found were to be 4.75 × 104 and 5.82 × 104 L mol−1 for [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2), respectively. The in vitro cytotoxicity and antibacterial potential of [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2) were studied. In order to gain an insight into the potential applications of the Zn(II) complexes as effective antivirus agents, we performed molecular docking of [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2) with the SARS-CoV-2 (PDB ID: 7LM9) receptor-binding domain (RBD) protein and the Omicron spike protein (PDB ID: 7WOP). The Zn(II) complexes demonstrated similar antivirus effects as ivermectin and levosalbutamol. Therefore, we also docked the control ivermectin (IVM) and levosalbutamol (LVM) with both the SARS-CoV-2 RBD protein (PDB ID: 7LM9) and the Omicron spike (S) protein (PDB ID: 7WOP). The synthesized Zn(II) complexes showed good docking results with the SARS-CoV-2 RBD protein and the Omicron spike (S) protein, suggesting they have the potential as drugs for use against SARS-CoV-2 and its Omicron variants. Molecular docking calculations of [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2) with DNA binding protein (PDB ID: 7UV7) showed that these interact with DNA via a groove binding mode. Overall, our molecular docking results showed that the synthesized Zn(II) complexes [Zn(L)(en)]ClO4 (1) and [Zn(L)2] (2) could be adopted as potential inhibitors for the development of new anti-SARS-CoV-2 Omicron drugs. [ABSTRACT FROM AUTHOR]

Light emission from organoboron compounds of Schiff bases is found to depend strongly on their chemical structure. Two of these compounds (OB1 and OB2), which contain a benzene ring between the Schiff base moieties, exhibit weak fluorescence in methanol, with marked viscosity dependence. Fluorescence lifetimes of these compounds are in picosecond timescale, as determined by femtosecond optical gating (FOG). A significant enhancement in fluorescence intensity and lifetime is observed at 77 K, indicating the operation of an activated nonradiative process. Using fluorescence lifetime imaging microscopy (FLIM), OB1 and OB2 are shown to be potential membrane probes. The third (OB3), which is devoid of this benzene ring, exhibits relatively stronger fluorescence with nanosecond lifetimes at room temperature. No viscosity dependence is observed in this case. The emission spectrum at 77 K is markedly more intense and exhibits an additional red shifted structured feature, which persists for a few seconds. Hence, OB3 seems to have greater promise not only as fluorescent probe but also for light harvesting. The marked improvement of the light emission properties of OB3 compared with OB1 and OB2 is likely to serve as a pointer for the design of Schiff base‐derived organoboron luminophores with diverse potential applications. [ABSTRACT FROM AUTHOR]

Two new nickel(II) complexes, namely Ni(L1)2 (1) and Ni(L2)2·CH2Cl2(2) were obtained by reacting nickel(II) acetate tetrahydrate with the benzothiadiazole Schiff base ligands HL1 = 2-[4-(2,1,3-benzothiadiazole)imino]methyl-phenol or HL2 = 2-[(2,1,3-benzothiadiazol-4-ylimino)methyl]-6-methoxyphenol in the presence of Et3N. The tridentate NNO chelate ligands induce a distorted octahedral environment around the nickel(II) ions. Single crystal X-ray diffraction analysis reveals elongated Ni–N bonds with the nitrogen atom of the benzothiadiazole ring in both complexes. Intermolecular hydrogen bonds and π–π stacking interactions create two-dimensional and three-dimensional supramolecular arrays, respectively, for complexes 1 and 2. Magnetic susceptibility and high-field electron paramagnetic resonance measurements show the presence of significant magnetic anisotropy, with an axial distortion parameter D of −8–−10 cm−1. [ABSTRACT FROM AUTHOR]

Reaction of 2‐chloromethyl‐1H‐benzimidazole with known intermediates (i–iii), prepared from diaminoguanidine hydrochloride with salicylaldehyde, 5‐bromosalicylaldehyde or 3,5‐di‐tert‐butylsalicylaldehyde, in the presence of triethylamine (NEt3) led to the formation of benzimidazole appended new ligands, H4L1‐H4L3 (I–III). The homogeneous nitrogen‐bridged symmetrical binuclear complexes, [(MoVIO2)2(L1)(H2O)2] (1), [(MoVIO2)2(L2)(H2O)2] (2) and [(MoVIO2)2(L3)(MeOH)2] (3) have been isolated by reacting these ligands with [MoVIO2(acac)2] in a 1 : 2 molar ratio in refluxing methanol. Using 1 : 1 (ligand to Mo precursor) molar ratio under above reaction conditions resulted in the corresponding mononuclear complexes, [MoVIO2(H2L1)(MeOH)] (4), [MoVIO2(H2L2)(H2O)] (5) and [MoVIO2(H2L3)(MeOH)] (6). The binuclear heterogeneous compounds [(MoVIO2)2(L1)(DMF)2]@PS (PS‐1), [(MoVIO2)2(L2)(DMF)2]@PS (PS‐2) and [(MoVIO2)2(L3)(DMF)2]@PS (PS‐3) have been obtained by immobilization of 1–3 onto chloromethylated polystyrene (PS) beads. All synthesized ligands, homogeneous as well as supported compounds have been characterized by elemental analyses and various spectroscopic methods. Single crystal X‐ray diffraction study of complexes 1 and 3 confirms their nitrogen‐bridged symmetrical binuclear structures while 4 is mononuclear. Heterogeneous compounds (PS‐1‐PS‐3) have further been studied by microwave plasma atomic emission spectroscopy, X‐ray photoelectron spectroscopy, and field emission scanning electron microscopy along with energy dispersive spectroscopy. These compounds (homogeneous and heterogeneous) were explored for catalytic applications to one‐pot multicomponent reactions (MCRs) for efficient synthesis of biologically active 2‐amino‐3‐cyano‐4H‐chromenes/pyrans (21 examples). Optimising various reaction parameters helped in achieving as high as 97 % yields of products. Though, only half equivalent of the binuclear complexes (1‐3) was required compared to mononuclear analogues (4‐6) to achieve comparable yields, heterogeneous catalysts have an added advantage due to their stability and recyclability. Suitable reaction mechanism has also been proposed based on isolated intermediates. [ABSTRACT FROM AUTHOR]

Herein we report a sustainable approach for the alkylation of ketones, 9H‐fluorene, oxindole, and indole using alcohols as the alkylating agent catalyzed by a well‐defined air‐stable zinc catalyst (1 a) of a tridentate redox non‐innocent arylazo ligand, 2‐((4‐chlorophenyl)diazenyl)‐1,10‐phenanthroline (La). 2–3 mol % of 1 a efficiently produces substituted α‐alkylated ketones, 9‐alkylated fluorenes, C3‐alkylated oxindoles, and C3‐alkylated indoles in moderate to good isolated yields. In aerial condition, the formation of bis(indolyl)methane (BIMs) derivatives were observed when indoles were subjected to alkylation by primary alcohols. A few drug molecules containing BIMs were prepared in good isolated yields. The catalyst 1 a exhibited good chemoselectivity during the functionalization of fluorene and indole with oleyl alcohol and β‐citronellol. A few control experiments, including deuterium labeling experiments, performed to unveil the reaction mechanism indicate that the one‐electron reduced azo‐anion radical species [1 a]‐formed in situ, acts as the active catalyst. All the redox events occur at the redox‐active aryl‐azo ligand, which acts as the reservoir of hydrogen and electrons throughout the catalytic cycle, keeping the Zn(II)‐center as a template. [ABSTRACT FROM AUTHOR]

The homogeneously catalyzed Guerbet upgrading of ethanol to butanol can be modulated by the application of partial H2 pressure before the reaction. Ruthenium(II) PNP pincer complexes with methylene‐extended acridine‐based ligands and singly‐chelated ruthenium(II) complexes with PN ligands perform best at very low catalyst loadings and upon the application of catalyst‐specific pre‐reaction partial H2 pressure. The combination of ruthenium(II) PNP pincer complexes and manganese(I) pincer complexes with MACHO‐type PNP ligands allows for even lower ruthenium loadings while retaining low base load and consumption, thus enabling high space‐time yields, catalyst productivity and recyclability. Mechanistically, Mn is proposed to stabilize coordinatively unsaturated Ru species and allow coordination of ethoxide to Ru instead of attacking the electrophilic ligand backbone based on NMR spectroscopy and X‐ray crystallography. [ABSTRACT FROM AUTHOR]

Chromium is known to play an important role in various metabolic pathways; however, its excessive use can result in negative impact on mankind, this necessitates the development of sensors for Cr(III) ion. The current study has incorporated the synthesis of ether derived Schiff base allied silanes 4 a–4 d, which have been characterized using 1H NMR, 13C NMR and mass spectrometry. The spectroscopic technique of UV‐visible has been utilized to study the sensing behaviour of probe 4 a, resulting in a good sensing ability towards Cr(III) ion, yielding a detection limit of 4.2×10−7 M and an association constant value of 2.25×106 M−1. In order to study the stoichiometric binding between probe and metal ion, Job's plot method has been employed which shows 1 : 1 binding ratio. The mechanism of binding has been studied via 1H NMR, UV‐visible, FT‐IR spectroscopy and mass spectrometry. The binding has been further supported by DFT. The real sample analysis has been performed to validate the utility of the synthesized sensor in practical applications. The theoretical tool of molecular docking has been considered to study the protein‐ligand interaction between S. aureus bacterial protein and ligand 4 a, yielding a value of −7.63 kcal/mol for binding energy. [ABSTRACT FROM AUTHOR]

Three new coordination polymers (CPs), {[Cu(NDC)(Fbtx)(H2O)] ⋅ 1.5H2O}n (1), {[Co(NDC)(Fbtx)(H2O)2] ⋅ 0.5Fbtx}n (2), and [Co2(NDC)2(Fbtx)]n (3), were synthesized by employing acid‐base mixed ligands of rigid 1,4‐naphthalenedicarboxylic acid (H2NDC) and flexible bis(1,2,4‐triazole‐1‐ylmethyl)‐2,3,5,6‐tetrafluorobenzene (Fbtx) under both hydrothermal and microwave‐assisted reaction conditions. Single‐crystal structure analysis establishted that both compounds 1 and 2 exhibit two‐dimensional (2D) layered structures, while compound 3 features a three‐dimensional (3D) complicated framework. The geometries of metal ions vary from square pyramidal (in 1 and 3) to distorted octahedral (in 2). Topological strudy showed that compounds 1 and 2 have exposed common 4‐connected 44‐sql net, while compound 3 has made a novel 4,5‐connected net with point symbol of (43 ⋅ 62 ⋅ 7)(43 ⋅ 64 ⋅ 72 ⋅ 8). The catalytic performance of the three complexes for the solvent‐free ring‐opening polymerization of L‐lactide has been investigated. The results indicated that compound 3 with coordinatively unsaturated cobalt(II) sites showed good activity and the molecular weight of the polymer obtained was high. Moreover, the complex 3 catalyst could be recycled up to five times with the retention of both catalytic activity and crystal structure. [ABSTRACT FROM AUTHOR]

Two new copper(II) complexes (1 and 2) with reduced L -histidine Schiff bases were synthesized and characterized using single-crystal X-ray diffraction, powder X-ray diffraction, UV-visible spectroscopy, and thermal analysis. Single-crystal analysis reveals that 5-methyl-containing 1 possesses a simple phenoxo-bridged binuclear unit, while 5-bromine-substituted 2 possesses a metal–organic cage (MOC) structure. The as-prepared complexes as artificial metallohydrolases displayed catalytic activity towards the hydrolysis of both PNPP (p-nitrophenyl picolinate) and PNPA (p-nitrophenyl acetate). These two complexes provided 28-fold (for 1) and 39-fold (for 2) rate enhancements in comparison with spontaneous hydrolysis of PNPA, respectively. With regard to PNPP, its hydrolysis was accelerated by two orders of magnitude in the presence of 1 or 2. Additionally, positive micellar effects of bis(hexadecyldimethylammonium)hexane bromide (16-6-16) and N-octyldocosylammonium bromide (C22H45N(CH3)2C8H17Br, abbr. C22/8) were observed for the PNPA hydrolysis by 1 or 2, resulting in 1.3 to 3.9 times acceleration compared to that in buffered aqueous solution. In micellar solution of N,N-dimethyl-n-lauroylsarcosine sodium (LSS), no obvious rate enhancement was observed for the PNPA hydrolysis by 1 or 2. [ABSTRACT FROM AUTHOR]

[Display omitted] Copper-based nanomaterials show considerable potential in the chemodynamic therapy of cancers. However, their clinical application is restricted by low catalytic activity in tumor microenvironment and copper-induced tumor angiogenesis. Herein, a novel copper-doxorubicin-anlotinib (CDA) nanoconjugate was constructed by the combination of copper-hydrazide coordination, hydrazone linkage and Schiff base bond. The CDA nanoconjugate consists of a copper-3,3′-dithiobis(propionohydrazide)-doxorubicin core and an anlotinib-hyaluronan shell. Benefiting from hyaluronan camouflage and abundant disulfide bonds and Cu2+, the CDA nanoconjugate possessed excellent tumor-targeting and glutathione-depleting abilities and enhanced chemodynamic efficacy. Released doxorubicin significantly improved copper-mediated chemodynamic therapy by upregulating nicotinamide adenine dinucleotide phosphate oxidase 4 expression to increase intracellular H 2 O 2 level. Furthermore, the nanoconjugate produced excessive •OH to induce lipid peroxidation and mitochondrial dysfunction, thus greatly elevating doxorubicin-mediated chemotherapy. Importantly, anlotinib effectively inhibited the angiogenic potential of copper ions. In a word, the CDA nanoconjugate is successfully constructed by combined coordination and pH-responsive linkages, and displays the great potential of copper-drug conjugate for targeted synergistic chemo/chemodynamic/antiangiogenic triple therapy against cancers. [ABSTRACT FROM AUTHOR]