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The ultrafast proton transfer and the following dynamics for aromatic Schiff bases N,N′-bis(salicylidene)ethylenediamine (salen) and N,N′-bis(salicylidene)-1,4-butylenediamine (salbn) were investigated with experimental and theoretical methods. A dual emission property with a large Stokes shift in salen and salbn indicates that excited state intramolecular proton transfer occurs with photoexcitation. An efficient single proton transfer was confirmed within 200 fs for both molecules. Subsequently, a fast twisted motion of the keto moiety carries cis-keto to a relaxed stable geometry in the S1 state. Following the twisted motion, the phenol ring at keto moiety further rotates to a conical intersection with the ground state and a cis–trans isomerization occurs. The isomerization rate is high, which dominates the competition with the radiative transition, resulting in weak emission intensity. It is confirmed that the length of alkyl chain affects the direction of phenol ring twisting and rotation during the whole subsequent relaxation of excited cis-keto tautomer. Compared with polar solvent acetonitrile, the barrier of isomerization is higher and the hydrogen bond on keto moiety is stronger in nonpolar solvent toluene. It makes fluorescence radiation channels competing with isomerism more likely to occur, contributing to the observed difference of enol/keto emission ratios of salen and salbn in toluene and acetonitrile. [ABSTRACT FROM AUTHOR]

To develop a green nanomaterial for specialty applications, spherical nanocellulose (SNC) was functionalized to a semicarbazone-Schiff base via a polymer analogous reaction. Firstly, SNC was synthesized from cellulose extracted from huge forest biomass, pine needles (PNs). The glucopyranose ring of SNC was oxidatively cleaved at C2-C3 to form SNC-dialdehyde (SNC-DA) by periodate oxidation. Both the aldehydic groups generated were reacted with semicarbazide to form a semicarbazone-Schiff base, referred to as functional spherical nanocellulose (FSNC). All the materials synthesized were characterized by FTIR, FESEM, EDS, TEM, and XRD studies. The FSNC was evaluated as an adsorbent for [Hg.sup.2+] ions. The adsorption adhered to pseudo-second order kinetics and Langmuir adsorption isotherm having a maximum adsorption capacity/Lungmuir adsorption capacity of 172.412 mg/g at 60 min. The selectivity of FSNC for [Hg.sup.2+] ions was confirmed from its appreciable removal (82%) from solution in tap water and 70% with other metal ions. FSNC exhibited bifunctional nature as it possesses antimicrobial activity against bacteria, that is, Gram (+) (Bacillus aereus) and Gram (--) (Escherichia coll and Salmonella typhi), and a fungus Byssochlamys fiilva. FSNC showed good recyclability up to eight sorption-desorption cycles. Thus, we have valorized biomass into an eco-friendly and low-cost bifunctional material as an adsorbent for [Hg.sup.2+] ions cum antimicrobial agent. Highlights * Spherical nanocellulose (SNC) prepared via acidic hydrolysis from pine needles * SNC functionalized to semicarbazone-based bifunctional Schiff base * The Schiff base is a rapid and efficient [Hg.sup.2+] ions adsorbent * The Schiff base has good antimicrobial activities against Gram (-) bacteria * Biowaste-based adsorbent has the potential to sustain the bio-circular economy KEYWORDS antimicrobial, pine needles, Schiff base, semicarbazone, spherical nanocellulose, 1 | INTRODUCTION The sustainability development goals have a deep link with the failing water quality and low availability of drinkable water across the world. (1) Among different pollutants, dyes [...]

The article focuses on recent advancements in chemistry, highlighting the development of new materials and chemical processes. Topics include the synthesis of insensitive energetic materials with enhanced detonation performance, the use of vanadium(V) complexes for syndiospecific ring-opening metathesis polymerization (ROMP) of cyclic olefins, and the exploration of metal-support interactions to enhance catalytic activity for hydrogen production.

The equimolar reaction between 1,9-bis(N,N-dimethylaminomethyl)-5,5′-diphenyldipyrromethane, H2L1 or 1,9-bis(3,5-dimethylpyrazolylmethyl)-5,5′-diethyldipyrromethane, H2L2 and [NiCl2(DME)] in the presence of KH yielded the neutral mononuclear nickel(II) complexes [Ni(L1)-κ4N,N,N,N], 1 and [Ni(L2)-κ4N,N,N,N], 2, respectively. Their X-ray structures revealed the formation of triple chelation by the ligand in both structures with quite different nickel(II)-surrounded square planar geometries owing to the steric difference between –NMe2 and 3,5-dimethylpyrazolyl groups. While the –NMe2 group substituted ligand L1 afforded nickel complex 1 with a plane of symmetry, 3,5-dimethylpyrazole substituted L2 rendered helical chirality in the structure of complex 2. Both the enantiomers (Δ and Λ) of complex 2 were observed in the crystal lattice. Their solution state behaviors were consistent with the solid-state structures as monitored by 1H NMR spectroscopy. Both the enantiomers of complex 2 were present in a dynamic equilibrium in solution and studied by variable temperature 1H NMR spectroscopy. Similar to the chiral complex, the corresponding ligand H2L2 also exhibited chirality as shown by its crystal structure and the two ligand enantiomers participated in a very fast dynamic interconversion, which became slower upon metalation. [ABSTRACT FROM AUTHOR]

Two mononuclear complexes, [Cu(L1)2] (complex 1) and [Cu(HL2)2](NO3)2 (complex 2) where HL1 is 1-((cyclohexylmethylimino)methyl)-naphthalen-2-ol and HL2 is 4-bromo-2-((2-morpholinoethylimino)methyl)phenol, have been synthesized under mild conditions and characterized by different standard analytical methods. Single crystal X-ray diffraction analysis shows that the copper atoms in both copper(II) complexes are in a square planar geometry. These complexes have been used as catalysts in the oxidation of benzyl alcohol and benzyl alcohol with various substituents in the presence of NaOCl as the terminal oxidant. The results show that complex 1 acts as a better catalyst than the other with the highest yield of 91% in the case of 4-methoxy benzyl alcohol oxidation. The copper complex transfers the oxygen of sodium hypochlorite to the alcohol to produce the aldehyde. The use of NaOCl as an oxidant in alcohol oxidation is rare although it is cheap and nonexplosive. [ABSTRACT FROM AUTHOR]

In this paper, we present the synthesis of four new complexes: the dimeric precursor [Ir(dmppz)2(μ-Cl)]2 (1) (Hdmppz -- 3,5-dimethyl-1-phenyl-1H-pyrazole) and heteroleptic bis-cyclometalated complexes: [Ir(dmppz)2(Py2CO)]PF6•½CH2Cl2 (2), [Ir(dmppz)2(H2biim)]PF6•H2O (3), and [Ir(dmppz)2(PyBIm)]PF6 (4), with auxiliary N,N-donor ligands: 2-di(pyridyl)ketone (Py2CO), 2,2'-biimidazole (H2biim) and 2-(2'-pyridyl)benzimidazole (PyBIm). In the obtained complexes, SC-X-ray analysis revealed that Ir(III) has an octahedral coordination sphere with chromophores of the type {IrN2C2Cl2} (1) or {IrN4C2} (2-4). The complexes obtained, which have been fully characterised by physicochemical methods (CHN, TG, FTIR, UV-Vis, PL and ¹H, 13C, 15N NMR), were used to continue our studies on the factors influencing the cytotoxic properties of potential chemotherapeutic agents (in vitro). To this end, the following studies are presented: (i) comparative analysis of the effects on the biological properties of N,N-donor ligands and C,N-donor ligands in the studied complexes, (ii) studies of the interactions of the compounds with the selected molecular target: DNA and BSA (UV-Vis, CD and PL methods), (iii) and the reactivity towards redox molecules: GSH, NADH (UV-Vis and/or ESI-MS methods), (iv) cytotoxic activity (IC50) of potential chemotherapeutics against MCF-7, K-562 and CCRF-CEM cell lines. [ABSTRACT FROM AUTHOR]

ABSTRACT Nano‐sized bivalent metal complexes, specifically [M(L)2] with L = 2‐((E)‐((4,5‐dimethyl‐2‐(((E)‐4‐methylbenzylidene)amino)phenyl)‐imino)methyl)benzenethiol] (C23H22N2S) and M = Cu (II) (C1), Co (II) (C2), Ni (II) (C3), and Zn (II) (C4), underwent synthesis and subsequent characterization. Elemental analyses, infrared, NMR, mass, electronic, magnetic susceptibility, conductivity assessments, and X‐ray diffraction studies were used to assess our bivalent metal complexes. DFT studies were used to study the tautomeric equilibrium of the tridentate thio‐Schiff base ligand (HL), via the DFT\B3LYP method in connection with a 6–311G* correlation consistent basis set. Two tautomers, which are thione and thiol forms, were studied to estimate the predominant one. The metal formed four coordinated with the tridentate N2S donor thio‐Schiff base to form octahedral geometry complexes. 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. 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 antimicrobial potential of thio‐Schiff base ligand (HL) plus complexes (C1–C4) 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) 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]

Metal–organic frameworks (MOFs) constitute an assorted class of multi-dimensional materials that offer the potential to serve as luminescent sensors for the sensitive and selective detection of antibiotics in wastewater. Herein, a new Zn(II)-based MOF with the formula [Zn(PMA)0.5(bbp)·H2O·DMA] (1) (bbp = 3,5-bis(benzoimidazo-1-ly)pyridine; PMA = pyromellitic acid) was synthesized by a solvothermal method and characterized. Crystallographic analysis reveals that MOF 1 possesses a 4,4-connected net with the Schläfli symbol {32·4·52·6}2{32·42·52}. The fabricated MOF exhibited luminescent property and was employed as a luminescent sensor to sensitively and selectively detect tetracycline (TCY) antibiotic amongst thiamphenicol (THI), 2-methyl-4-chlorophenoxyacetic acid (MCPA), tetracycline (TCY), sulfamethoxazole (SMT), thiabendazole (TBZ), tinidazole (TDZ), sulfadiazine (SDZ), chloramphenicol (CAP), metamitron (MMT), and dinotefuran (DTF). Further, restoration of the emissive response of TCY@1 was achieved by adding salicylic acid with a concomitant bathochromic shift in the emissive response. The possible sensing mechanism and restoration of emissive response were assessed with the aid of theoretical calculations. [ABSTRACT FROM AUTHOR]

O-Vanillin derived Schiff base 1-[(E)-(2-hydroxy-3-methoxybenzylidene) amino]-4-methylthiosemicarbazone (VCOH) has been synthesized for colorimetric and fluorescence chemosensors towards PO43− ions. A fluorescence 'turn-on' sensing mechanism of VCOH towards PO43− ions has been explained due to emission from the VCO− ion formed upon transfer of the phenolic proton of VCOH to a PO43− ion. The 1 : 1 stoichiometry between the VCOH probe and PO43− ion is confirmed by Job's plot based on UV-vis titration. The limit of detection (LOD) of VCOH towards PO43− ions is found to be 0.49 nM. The PO43− ion sensing property of probe VCOH has been applied to prepare portable paper strips and for the analysis of real water samples. Fluorescence 'turn-on' and 'turn-off' responses of VCOH towards PO43−and H+ respectively have been used to construct a molecular logic gate. Fluorescence based sensing studies in which the concentration of analytes is adjusted over a broad range can be both laborious and expensive. In order to address these challenges, we have utilized various soft computing methods, including artificial neural networks (ANN), fuzzy logic (FL), and adaptive neuro-fuzzy inference systems (ANFIS), to appropriately model the 'turn-on' and 'turn-off' behaviors of the VCOH probe upon addition of PO43− and H+ respectively as well as to predict the experimental sensing data. [ABSTRACT FROM AUTHOR]

Square planar complexes of Ni(II) and Pd(II) of a new redox-active pentadentate azo-appended 2-aminophenol ligand (H4L = N,N′-bis(2-hydroxy-3,5-di-tert-butylphenyl)-2,2′-diamino-ortho-azobenzene) in three accessible redox levels [amidophenolate(2−), semiquinonate(1−) π radical, and quinone(0)] were synthesized. The coordinated HL(3−) ligand provides four donor sites [two N(iminophenolates), an N′(azo), and an O(phenolate)], while the phenolic OH group remains free in the three complexes. Cyclic voltammetry on complex [Ni(L)] 1 and its corresponding Pd(II) analogue [Pd(L)] 2 in CH2Cl2 displayed three redox responses (two oxidative at E1/2 = 0.06 V and Epa (anodic peak potential) = 0.80 V and one reductive at −0.77 V for 1 and at E1/2 = 0.08 V and Epa = 0.85 V and at −0.74 V for 2vs. Fc+/Fc). The chemical oxidation of 1 with AgSbF6 afforded [Ni(L)]SbF6·2CH2Cl2 (3·2CH2Cl2). Complex [Pd(L*)] 4, which is coordinated by a phenoxazinyl derivative of L(4−), was obtained via intraligand cyclization in the parent complex 2 under basic oxidizing conditions. The molecular structures of 1, 2, 3·2CH2Cl2 and 4 were elucidated through X-ray crystallography at 100 K. Characterization using 1H NMR, X-band EPR, and UV–VIS–NIR spectroscopy established that the complexes have [NiII{(LISQ)˙2−}] 1, [PdII{(LISQ)˙2−}] 2, [NiII{(LIBQ)−}]SbF6/1+SbF6−(3), and [PdII{(L*AP)˙2−}] 4 electronic states. Complexes 1, 2, and 4 possess paramagnetic St (total spin) = 1/2 ground-state, whereas 3 is diamagnetic (St = 0). Density functional theory (DFT) electronic structural calculations at the B3LYP level rationalized the observed experimental results. Time-dependent (TD)-DFT calculations allowed us to identify the nature of the observed absorption spectra. [ABSTRACT FROM AUTHOR]

We present herein magneto-structural studies of three heterometallic Zn2Dy complexes: [Zn2Dy(L)2Cl2(H2O)](ClO4)·4H2O (1), [Zn2Dy(L)2Br2(H2O)](ClO4)·4H2O (2) and [Zn2Dy(L)2(OAc)I(H2O)]I3·4H2O (3), utilizing a new Schiff base ligand, N,N'-bis(3-methoxy-5-methylsalicylidene)-1,2-diaminocyclohexane (H2L). Complexes 1 and 2 exhibit remarkable magnetic relaxation behaviour with relatively high energy barriers in zero field (Ueff: 244 K for 1 and 211 K for 2) and notable hysteresis temperatures, despite the low local geometric symmetry around the central DyIII ions. The SMM performance of these complexes is further enhanced under an applied magnetic field, with Ueff increasing to 309 K for 1 and 269 K for 2, positioning them as elite members within the Zn–Dy SMM family. These findings emphasize the substantial influence of remote modulation on ZnII beyond the first coordination sphere of DyIII ions on their dynamic magnetic relaxation properties. Ab initio studies demonstrate that the relative orientation of the phenoxo-oxygen donor atoms around the DyIII ion is critical for determining the magnetic anisotropy and relaxation dynamics in these systems. Additionally, experimental and theoretical investigations reveal that the coordination of the bridging acetate towards the hard plane, combined with significant distortion from the ideal ZnO2Dy diamond core arrangement caused by the acetate ion, results in low magnetic anisotropy in complex 3, thereby leading to field-induced SMM behaviour. Overall, this study unveils the effects of co-ligands on the SMM performance in a series of linear trinuclear Zn–Dy–Zn complexes, which exhibit low local geometric symmetry around the DyIII centres. [ABSTRACT FROM AUTHOR]

The present review deeply delves the major methods for the synthesis of organotellurium compounds along with their biological significance. Elaboration of various precursors (ligands) including Schiff bases, naphthoquinones, amino acids, β-hydroxy alkylated compounds, β-phenyltelluro alcohols, β-aryltelluro amines, β-aryl-chalcogenium azides, chalcogenobiotin, benzenesulfonamide, carbonic anhydrase, and Sulpha compounds has been briefly described. Furthermore, the article investigates their possible biological uses, specifically as antioxidant and anticancer agents while comparing their effectiveness with their respective ligands and with the standard medications in terms IC50 values. All types of details are haunted to make the information a priceless resource for researchers who wish to probe deeper into and examine the diverse roles that organotellurium complexes play in biological settings. [ABSTRACT FROM AUTHOR]

ABSTRACT Amid growing environmental concerns and the need for a sustainable future, green synthetic methodologies are gaining popularity for their simplicity and nontoxicity. In pursuit of the eco‐friendly synthesis of nanomaterials, the study reports an innovative synthesis of Ag‐CuO nanocomposites via the coprecipitation method utilizing Citrus limetta fruit juice extract as the bioreductant and stabilizing agent. The morphological and structural characteristics of the fabricated nanocomposites were evaluated by ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Raman and Brunauer–Emmett–Teller (BET) analyses. The nanocomposites were crystalline with particle sizes ranging from 15 to 24 nm and exhibited spherical and rod‐like shapes. The band gap value and specific surface area of the nanocomposites were found to be 1.5 eV and 25.50 m2/g, respectively. The photoluminescence (PL) analysis and electrochemical studies revealed significant charge separation and effective charge migration behaviour of the nanocomposites, respectively. The nanocomposites effectively catalysed the synthesis of Schiff bases from aryl aldehydes and aromatic amines at room temperature and without solvents. The reactions proceeded in a brief time with excellent product yields, and the nanocatalyst retained its activity for five consecutive cycles. The nanocomposites also efficiently catalysed the photodegradation of Congo red dye under visible light. A significant degradation of 94.33% was attained in 55 min, and the nanocatalyst maintained its efficacy over four consecutive reaction cycles. Moreover, the nanocomposites exhibited notable anticancer properties against the MCF‐7 (human breast) cell line, demonstrating a remarkable cytotoxicity rate of 87.79%. The findings highlight the efficacy of the biosynthesized nanocomposites in catalysis, environmental remediation and biological applications. [ABSTRACT FROM AUTHOR]

The present study focuses on the synthesis and structural characterization of a novel dinuclear CuII complex, [trichloridocopper(II)]-μ-chlorido-{bis[2-hydroxy-N′-(propan-2-ylidene)benzohydrazide]copper(II)} monohydrate, [Cu2Cl4(C10H12N2O2)2]·H2O or [Cu(H2L)2(μ-Cl)CuCl3]·H2O [H2L = 2-hydroxy-N′-(propan-2-ylidene)benzohydrazide]. The complex crystallizes in the monoclinic space group P21/n with one molecule of water, which forms interactions with the ligands. The first copper ion is penta-coordinated to two benzohydrazine-derived ligands via two nitrogen and two oxygen atoms, and one bridging chloride, which is also coordinated by the second copper ion alongside three terminal chlorines in a distorted tetrahedral geometry. The arrangement around the first copper ion exhibits a distorted geometry intermediate between trigonal bipyramidal and square pyramidal. In the crystal, chains are formed via intermolecular interactions along the a-axis direction, with subsequent layers constructed through hydrogen-bonding interactions parallel to the ac plane, and through slipped π–π stacking interactions parallel to the ab plane, resulting in a three-dimensional network. The intermolecular interactions in the crystal structure were quantified and analysed using Hirshfeld surface analysis. Residual electron density from disordered methanol molecules in the void space could not be reasonably modelled, thus a solvent mask was applied. [ABSTRACT FROM AUTHOR]

Organic compounds display several electronic and structural features which enable their application in various fields, ranging from biological to non-biological. These compounds contain heteroatoms like sulfur, nitrogen and oxygen, which provide coordination sites to act as ligands in the field of coordination chemistry and are used as chemosensors to detect various metal ions. This review article covers different organic compounds including thiourea, Schiff base, pyridine, thiophene, coumarin, triazolyl pyrenes, imidazole, fluorescein, thiazole, tricarbocyanine, rhodanine, porphyrin, hydrazone, benzidine and other functional groups based chemosensors, that contain heteroatoms like sulfur, nitrogen and, oxygen for fluorimetric and colorimetric detection of Ag+ in different environmental, agricultural, and biological samples. Further, the sensing mechanism and performances of these chemosensors have been discussed, which could help the readers for the future design of highly efficient, selective, and sensitive chemosensors for the detection and determination of Ag+ ions. [ABSTRACT FROM AUTHOR]

The new methacrylic azomethine-containing monomers with side chain quinoline moiety were synthesized by reaction of their corresponding alcohols with methacryloyl chloride. The polymers based on new monomers were synthesized by free radical polymerization. Polymers were characterized by 1HNMR spectroscopy, and the results of their photochemical and optical activities are presented. [ABSTRACT FROM AUTHOR]

Herein, a newly synthesized intermediate, piperazine-based Schiff base (PBSB) gas sensor was fabricated by the Schiff base condensation of amino functionalized methylpiperazine with aromatic aldehyde containing nitro substituent. This organic sensor material was structurally identified with spectroscopic techniques such as FTIR, HRMS, 1H- and 13C-NMR. The designed sensor candidate was explored for its optical response to chlorinated volatile organic compounds, namely trichloroethylene, dichloromethane and chloroform in the light of structure–property relationship investigation by using surface plasmon resonance (SPR) technique. The results showed that Schiff bases could be candidates for chlorinated vapour sensing materials with their good response and reversibility. Concordantly, compound PBSB exhibited good response against chlorinated solvent vapours aided by the electron-withdrawing group on benzene ring that promoted better intermolecular interactions and opened up a new strategy to create a novel set of responsive materials for gas sensing applications. In addition, the adsorption kinetics of SPR data obtained from PBSB spun film on exposure to these chlorinated vapours at different concentrations was also evaluated using the Elovich Model. The values of the initial adsorption rate, a and Elovich constant, b were analysed depending on the concentration values and the highest values were obtained for dichloromethane between 372.92 and 4377.53 ppm/mm2. [ABSTRACT FROM AUTHOR]

Developing environmentally benevolent and sustainable approaches is a vital objective of research in any field. By upholding these parameters and strategizing the methodology, herein we report the development of a new heterogeneous nanocatalyst based on Schiff base functionalized Pd(II) complex onto titania-coated magnetic nanoparticles [Pd@SB/Fe3O4–TiO2]. The developed catalytic system is well characterized with various techniques such as FE-SEM, TEM, XPS, XRD, TGA, BET, FTIR, VSM, CHN, EDX, and ICP-AES analysis. The catalytic activity of [Pd@SB/Fe3O4–TiO2] for the Suzuki coupling reaction to synthesize biaryls and for the hydrogenation reaction of aromatic nitro compounds to synthesize aromatic amines under sustainable reaction conditions was tested which revealed excellent results. Pd@SB/Fe3O4–TiO2 showed remarkably higher activity than the homogeneous PdCl2 and Pd(OAc)2, which might be due to the presence of electronic synergism between support and Pd. Schiff base functionalization provides excellent support to the palladium as leaching of the metal was not observed. The magnetic core of the catalyst ascertains its easy recoverability, thereby maintaining the sustainability of the reaction. The magnetic catalyst was easily separable with the help of an external magnet and showed very good recyclability for up to six cycles with no appreciable loss in catalytic efficiency. Furthermore, the reported catalyst remains unchanged even after six consecutive runs as established by the FTIR, XPS, and XRD analysis of the recovered catalyst. [ABSTRACT FROM AUTHOR]

Reactions of a chromone‐based hydrazone (SalHFC; HL) with Ni(II), Co(II), and Cd(II) ions yielded new solid chelates with the general formula [M(L)X].nZ, M = Ni(II), Co(II) and Cd(II), X = NO3− or OAc−, n = 0.5–2, Z = H2O or EtOH for complexes 1, 3, 4, 6, 7, 8 and [M2(L)(OAc)3X].0.5EtOH.nH2O, M = Ni(II) and Co(II), X = H2O or EtOH, n = 1 or zero for complexes 2 and 5. The synthesized chelates have been successfully characterized by means of different analytical and spectroscopic tools. SalHFC performs as a monoanionic tridentate in all chelates except chelate 2 and 5 (monoanionic tetradentate). Molar conductivity measurements demonstrated a non‐electrolytic manner of all chelates. Nickel(II) and cobalt(II)‐SalHFC chelates displayed tetrahedral geometries whereas cadmium(II) chelates (7 and 8) were octahedral. TG was employed to inspect the thermal degradation patterns of SalHFC‐complexes, and the Coats‐Redfern equations were employed to estimate the kinetic parameters of the thermal degradation steps. Density functional theory (DFT) level implementation in the Gaussian 09 program at B3LYP/6‐311G(d,p) level was efficaciously used to predict the molecular structural properties of SalHFC and its chelates and the theoretical data and experimental findings were then integrated. SalHFC and its chelates displayed anticancer action against the HepG2 cell line and the results were verified by molecular docking studies. [ABSTRACT FROM AUTHOR]

Levofloxacin and 4‐aminoantipyrine undergo a condensation process to synthesize a novel Schiff base ligand (L). Metal complexes containing Co(II), Cu(II), Cd(II), Mn(II), Zn(II), Cr(III), Ni(II), and Fe(III) metal ions are prepared using this Schiff base ligand. The new ligand and its complexes are characterized by elemental analyses, Fourier transform infrared, mass spectrometry, ultraviolet–visible, magnetic moment, 1H‐NMR, molar conductivity, and powder X‐ray diffraction, and further thermogravimetric analysis (TG, DTA) verifies their thermal stability. The metal to ligand ratio is 1:1, according to the analytical results. Spectroscopic methods reveal that metal complexes are expected to have an octahedral geometry and demonstrate a neutral tridentate ligand behavior. It also becomes apparent from the molar conductivity values that all metal complexes are electrolytic in nature except zinc(II) and cadmium(II) complexes which are non‐electrolytes. Moreover, the bioactivity of the compounds are investigated. The antibacterial activity is investigated in relation to various Gram‐positive and Gram‐negative bacteria. The results give good indication for higher activity of the prepared compounds than the standard antibiotic drug. Also, the antioxidant activity of the newly prepared ligand and its complexes has been investigated via 2,2‐diphenyl‐1‐picrylhydrazyle (DPPH) free radical scavenging assay. The findings show that Schiff base complexes exhibit good antioxidant activity. Finally, theoretical density functional theory using density functional theory/B3LYP method and molecular docking studies with two receptors of 3T88 and 3Q8U are calculated for the investigated compounds. [ABSTRACT FROM AUTHOR]

In the present work, 2‐hydroxy‐1‐naphthaldhyde and 2‐hydrazino‐N‐phenyl‐2‐thioxo‐acetamide are combined to create a new Schiff base. The novel ligand and its six new binuclear complexes with Ni(II), Cu(II), Ag(I), Zn(II), Cd(II), and La(III) are characterized via spectroscopic and analytical techniques, such as ultraviolet‐visible (UV–vis), infrared (IR), 1H NMR, 13C NMR, mass spectra, powder X‐ray diffraction (XRD), and thermogravimetric (TG) analysis. The spectral analysis indicated that the novel Schiff base may coordinate with the two metal ions. Additionally, the results indicated a square planar geometry for NiL, CuL, and AgL complexes and an octahedral geometry for ZnL, CdL, and LaL complexes. In contrast to the Schiff base ligand, different complex crystallinities were displayed in the powder XRD patterns. Significant thermodynamic parameter values were computed using the Coats–Redfern method which revealed high thermal stabilities of the complexes in the TG analysis. In vitro antibacterial, DNA‐binding, and anti‐inflammatory techniques were used for the biological evaluation. Moreover, to visualize the anti‐inflammatory action of complexes employing the cyclooxygenase enzyme receptor (PDB ID: 6COX), in silico docking was used. The serial dilution method evaluated the new compounds' in vitro antibacterial efficacy against three bacterial and one fungal strain. The results showed that the novel complexes showed remarkable efficiency against the bacterial growth of gram (+ve) Staphylococcus aureus compared to the parent ligand and the control. On the other hand, the ZnL, CdL, and AgL complexes showed excellent bactericidal activity. The inhibition of protein denaturation followed the following sequence: Ibuprofen > ZnL ˃ NiL ˃ AgL ˃ CuL > CdL > LaL > H2L. UV–visible and gel electrophoresis methods were used to examine the metal complexes and their ligand's affinity for binding DNA. An intercalative binding mechanism was suggested by the findings. [ABSTRACT FROM AUTHOR]

Four novel lanthanide La (III), Ce (III), Nd (III), and Dy (III) complexes with (Z)‐4‐(benzo[d]thiazol‐2‐ylamino)‐3‐((benzo[d]thiazol‐2‐ylimino)methyl)‐2H‐chromen‐2‐one (L) were prepared and characterized. The novel compounds' structural compositions were elucidated by the application of analytical and spectroscopic methodologies. From physical and chemical measurements, the general formula for the [LnLCl3]2H2O complexes (C1‐C4) was proposed, which was proven by theoretical measurements. Using cisplatin, gentamicin, ampicillin, and ascorbic acid as standards, the compound's anticancer, antibacterial, and antioxidant qualities were assessed, and activities followed the order: Ce (III)L(C2) > Nd (III)L(C3) > Dy (III)L(C4) > La (III)L(C1) > L where the Ce (III) complexes exhibited the highest activity followed by Nd (III) complexes. Molecular docking studies were performed using the MOA2022 software to identify putative binding mechanisms for the methionine adenosyl‐transferases in liver cancer (PDB ID: 5A19) and the most active site of the Bacillus subtilis receptor (PDB ID: 5e6k), where the strength of the interaction increases with the negative binding energy L ˂ [LaLCl3] ˂ [DyLCl3] ˂ [NdLCl3] ˂ [CeLCl3]. [ABSTRACT FROM AUTHOR]

Equimolar reactions of Zn2+ and Cd2+acetates with the carbothiohydrazide, [2‐HO‐C6H4‐C(H) = N‐N(H)‐C(=S)‐N(C2H4)2O] chelating agent (H2L) have produced the binuclear [M(L)]2 metal chelates. The isolated compounds have been evaluated by elemental analyses, XRD, molar conductivities, 1H and 13C‐NMR, FTIR, FAB‐MS, UV–Vis, and thermal analyses. The crystal structure of the chelating agent has been resolved and indicates the presence of the chelating agent exclusively in its E conformer regarding the C(H) = N bond. Elemental analyses and molar conductance data indicated that the investigated metal chelates are nonelectrolytes and were formed with 2 M:2 L stoichiometry. FT‐IR along 1H‐NMR spectral data gave evidence for a di‐anionic chelating agent that bonded with central metal ions via azomethine N, deprotonated phenolic O, and thiolate S atoms. The anti‐corrosion performance of the chelating agent and its metal chelates have been evaluated for protecting carbon steel (CS) in 15% HCl aqueous solution using electrochemical examination (EIS and PDP), surface examination (SEM and XPS) and theoretical approach (DFT calculations and MC simulation). The results revealed that [Zn(L)]2 complexes remarkably performed with an inhibition efficiency of about 94.7%, which was better than those for [Cd(L)]2 complex (93.0%) and H2L (88.2%), respectively. The EIS results revealed the gradual rise of charge transfer resistance (Rct) with concentration, while the PDP proved the mixed‐type inhibition performance with cathodic advantage consistent with the Langmuir adsorption model. It was verified that the Zn (II) complex could adsorb on the metallic surface, forming a protective layer responsible for mitigating the corrosion reaction and ions diffusion. This study provided novel inhibitors with structures designed and developed for inhibiting the corrosion process with marked performance. The results derived from various methodologies contribute to a substantiated interpretation of the mechanism of inhibition. [ABSTRACT FROM AUTHOR]

In this study, we introduce a novel porous metal–organic framework named Co2(bbda)2(DMF)2·5H2O, or MOF‐UoR‐1, synthesized via hydrothermal techniques employing a unique Schiff base ligand. The framework underwent comprehensive characterization, confirming its microporous nature through gas‐sorption measurements. MOF‐UoR‐1 demonstrated remarkable efficacy as a catalyst for the one‐step synthesis of pyrimidine analogs. Structural validation of the synthesized pyrimidines was accomplished via 1H‐nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) analyses. Through systematic experimentation, the optimal catalyst dosage (40 mg) was determined, showcasing its effectiveness across various aldehydes, 1,3‐carbonyl compounds, and urea substrates. Noteworthy is the broad applicability of this environmentally friendly protocol, which offers advantages such as high yields (96%), rapid reaction times (90 min), straightforward product isolation, and product purity without necessitating column chromatography. Furthermore, the catalytic integrity of the framework remained intact, enabling its reuse without compromising performance. This research presents a promising approach for the synthesis of pyrimidine derivatives, with significant implications for sustainable and efficient chemical synthesis methodologies. [ABSTRACT FROM AUTHOR]

Purpose: The paper aims to the preparation of novel disperse dye based on azo salicylaldehyde derivatives TF-A [2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde] and full evaluation of their use as disperse dye TF-ASC [bis 2-hydroxy-5-((3-(trifluoromethyl)phenyl)diazenyl)benzaldehyde Schiff base with 4,4'-methylenedianiline] for dyeing polyester fabric at various conditions. Design/methodology/approach: The dispersed dye was synthesized via Schiff base condensation in the presence of ceric ammonium nitrate cerium ammonium nitrate 10 mmole% as an eco-friendly catalyst at room temperature. The chemical structure of the prepared dye was characterized via elemental analysis, Fourier-transform infrared spectroscopy, 1H- and 13 C-NMR spectroscopic analysis tools. This study thoroughly examined the dyeing of disperse dye TF-ASC on polyester at various conditions. The characteristics of dyed polyester fabric were measured by colour measurements, as well as light, washing, crock fastness and finally, colour strength. The discrete fourier transform (DFT) theoretical studies, including EHOMO, ELUMO and optimized geometrical structure, were assumed and discussed in detail. Findings: The results showed that the synthesized organic dye TF-ASC was highly functional and appropriate for this kind of dyeing method. The dyeing fabrics obtained from disperse dye TF-ASC, properties possess high colour strength as well as good overall fastness properties. These dyes had a high affinity for polyester fabric, with just a tiny change in dye affinity when the pH was changed, even under alkaline circumstances. The dye levelness and shade depth of the colour results were good, and there were a variety of hues from light brownish yellow to deep brownish yellow. The results obtained from DFT computational studies such as EHOMO, ELUMO, optimized structure, diploe moment µ and electrophilicity index deduced that prepared organic dye TF-ASC is more applicable as a dispersed dye. Originality/value: This research is significant because it provides a new dye for dyeing polyethylene terephthalate fibres with exceptional brightness and levelness; the method of preparation is a useful pathway due to its being known as a green chemistry method. [ABSTRACT FROM AUTHOR]

Salamo‐type ligand H2L was designed and synthesized and reacted with Cu (II) and Zn (II) acetate, respectively, to obtain two binuclear Cu (II) and Zn (II) complexes: [Cu2(L)2]·2CH3OH (1) and [Zn2(L)2] (2) having the same coordination number but distinct geometries. Complex 1 is a Cu (II) complex containing two crystalline ethanol molecules, where two Cu (II) atoms are surrounded by two utterly deprotonated (L)2− parts, forming slightly twisted tetragonal pyramidal configurations of pentacoordinate. In complex 2, two utterly deprotonated (L)2− parts surround two Zn (II) atoms, forming pentadentate twisted triangular bipyramidal configurations. The complexes were elucidated via IR analyses and ultraviolet spectroscopy. Using DFT theoretical calculation, MEPs, IRI, and Hirshfeld surface analysis to investigate further the molecular interactions and reaction sites. Ultimately, the fluorescence characteristics of H2L and its complexes 1 and 2 were discussed. [ABSTRACT FROM AUTHOR]

In situ mesenchymal stem cells (MSCs) regenerative therapy holds promising potential for treating osteoarthritis. However, MSCs engraftment and intra-articular inflammation limit the therapeutic efficacy of this approach. This study introduces porous microspheres (PMs) composed of aldehyde-modified poly(lactic-co-glycolic acid), that encapsulate platelet derived growth factor-AB and kartogenin. Metformin (Met) is also incorporated onto the microsphere through a Schiff base reaction to create PMs@Met. In vitro, in vivo and ex experiments revealed that PMs@Met can be injected into the joint cavity, effectively recruiting endogenous MSCs in situ. This approach creates a favorable environment for MSCs proliferation. It also controls the intra-articular inflammatory environment by modulating the polarization of synovial macrophages, ultimately promoting cartilage repair. In summary, our study presents an innovative tissue engineering strategy for the treatment of osteoarthritis-induced articular cartilage injuries. Cell therapy using autologous mesenchymal stem cells (MSCs) has potential to slow the progression of osteoarthritis (OA). Nonetheless, there are some disadvantages to adopting in situ MSCs therapy, including difficulties with MSC engraftment into cartilage-deficient regions, the effect of intra-articular inflammation on MSC therapeutic efficacy, and attaining selective chondrogenic MSC differentiation. We created injectable PLGA microspheres (PMs) that were loaded with PDGF-AB and KGN. Metformin was bonded to the surface of microspheres using a Schiff base reaction. The microspheres can recruit intra-articular MSCs and encourage their development into chondrocytes. The microspheres actively modulate the inflammatory joint environment by altering synovial macrophage polarization, thereby supporting MSCs in effective cartilage treatment. To summarize, microspheres hold great potential in the treatment of OA. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel and cost-effective 2,4-dinitrophenyl hydrazine derived from Schiff base 1-benzylidine-2-(2,4-dinitrophenyl) hydrazine (L) was designed and characterized using various spectroscopic techniques. The interaction between L and bovine serum albumin (BSA) has been carried out using UV–Vis and fluorescence spectroscopy, DSC, SEM, and molecular docking methods. The phosphate buffer (pH = 7. 4) solution of BSA showed fluorescence emission maxima at 342 nm. Upon addition of L to the BSA solution, it quenched the fluorescence emission at 342 nm. The quenching of the fluorescence emission is due to the formation of a complex between L and BSA. The binding constant was calculated from the fluorescence titrations and found to be 6. 7 4 5 × 1 0 6 M − 1 . Further, molecular docking analysis was carried out to establish the binding between L and BSA. [ABSTRACT FROM AUTHOR]

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In this study, new chitosan Schiff base functionalized malic acid (CS-SB/MA) and its Fe2O3 (CS-SB/MA/Fe) composite were prepared through a simple route and characterized by different techniques including FT-IR, XRD, TGA, DSC, FESEM, and BET. The characterization results indicated that the desired compounds, CS-SB/MA and CS-SB/MA/Fe, were successfully prepared. In addition, the adsorption of Eosin Y (EY) from aqueous solution using the as-prepared compound, CS-SB/MA/Fe, was studied. The influence of important parameters such as pH solution and contact time were also studied and reported. EY adsorption by the as-prepared CS-SB/MA/Fe2O3 composite was found to be optimal at a pH solution of 5, a contact time of 90 min, and an adsorbent dosage of 0.02 g. The maximum removal percentage and adsorption capacity were calculated to be 93.56% and 65.52 mg/g, respectively. The EY adsorption followed by the pseudo-second-order (PSO) kinetic model as a chemisorption process including different interactions between anionic groups of EY and the functional groups of CS-SB/MA/Fe. Therefore, the prepared chitosan-base adsorbent, CS-SB/MA/Fe, has great potential application for the removal of organic dyes from wastewater. [ABSTRACT FROM AUTHOR]

Integrating multi‐step reactions through tandem catalysis offers potential for efficient chemical engineering processes, but designing an efficient tandem catalyst is challenging. Herein, we report tailoring the d‐band centers of Ni through alloying with a second metal (M = Fe/Co/Cu/Ga), which enables it to be multifunctional site for tandem reductive amination. A linear correlation of d‐band center with yield of primary amine product was observed. Density functional theory and experiments revealed the upshifted d‐band center strengthened the adsorption of Schiff base intermediate in advantageous di(C&N) mode, also narrowed the adsorption energy gap between NH3 and H2. Furthermore, the multifunctional nanoparticles provide a confined space with short diffusion pathway for NH3* and H* to timely react with Schiff base. As a result, the NiFe/AlOx with a d‐band center nearest to the Fermi level exhibited the highest primary amine yield of 96.2% with five consecutive reusability under extremely low H2 pressure, which is superior to other reported precious‐metal‐based catalysts. [ABSTRACT FROM AUTHOR]

Conventional thermosetting polymers, mostly derived from nonrenewable petroleum resources, are not reprocessable and recyclable due to their highly cross-linked three-dimensional networks and face the disadvantage of high flammability. To solve these issues, in this study, we synthesized a novel Schiff base covalent adaptable thermoset from a furan-derived tri-aldehyde monomer (TMFP) and a furan-derived di-amine monomer (DFDA). The as-prepared TMFP-DFDA-Vitrimer exhibited superior anti-flammability with a high limiting oxygen index (LOI) of 35.0% and a UL-94 V-0 rating, which was attributed to the excellent charring ability. Additionally, TMFPDFDA-Vitrimer could also be conveniently recycled by chemical decomposition under a mixed hydrochloric acid/tetrahydrofuran (HCl/THF) solution. After recycling for 5 times, the thermal, mechanical, and flame retardant properties of the recycled TMFP-DFDA-Vitrimer retained almost unchanged compared to the original one. This work provides a prime instance to develop advanced thermosetting polymers from abundant furan-based compounds. [ABSTRACT FROM AUTHOR]

Copyright of Baghdad Science Journal is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: To investigate the recovery of molybdate from water and hydrodesulfurization catalysts, a novel synthesized phosphonate Schiff base, 4,4′‐(((2,2‐dimethylpropane‐1,3‐diyl) bis(azaneylylidene)) bis(methaneylylidene)) bis(2‐methoxyphenol) (HMI) and 4‐(((3‐((4‐(((S)‐hydroxyhydrophosphoryl)oxy)‐3‐methoxybenzylidene) amino)‐2,2‐dimethylpropyl)imino)methyl)‐2‐methoxyphenyl hydrogen phosphonate (HIMP), was utilized. This study aimed to assess the structural and property aspects of this synthesized compound using diverse characterizations, including FTIR, Thermogravimetric Analysis (TGA), mass spectrometry (GC–MS), fluorescence transfer spectra, scanning electron microscopy (SEM), and 1H‐NMR, 13C‐NMR, and 31P‐NMR. RESULTS: The study systematically examined several factors controlling molybdate recovery, including temperature, adsorbent dosage, pH, interaction time, and molybdate concentration using the batch technique. Optimal sorption effectiveness was achieved at pH 2, with an interaction time of 40 min, a 0.06 g adsorbent dose, at ambient temperature. The newly devised adsorbent exhibited an impressive adsorption capacity (Qe) of 372.54 mg of Mo per gram, with empirical data fitting the Langmuir and D‐R adsorption models. The kinetics of molybdate uptake followed second‐order kinetics. Thermodynamic aspects, including ΔG°, ΔS°, and ΔH°, were also investigated, providing appreciated perceptions into the energetic dynamics of the sorption process. Additionally, molybdate adsorption in the occurrence of other ions was explored, highlighting the selectivity of the modified phosphonate Schiff base for molybdate removal. CONCLUSION: The study underscores the potential of the modified phosphonate Schiff base as a crucial adsorbent for molybdate elimination from both solutions and spent hydrodesulfurization catalysts. The findings offer important insights into the adsorption kinetics, thermodynamics, and selectivity of the adsorbent, enhancing our understanding of molybdate recovery processes and their broader applications. © 2024 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

ABSTRACT N‐Methylbenzylamine and ethylenediamine were utilized as primary and auxiliary ligands, respectively, alongside metal salts to synthesize ternary metal complexes: [FeCl3(Nmba)(en)], [CoCl2(Nmba)(en)(H2O)] and [CuCl2(Nmba)(en)(H2O)]. These complexes were thoroughly characterized using spectral and analytical techniques, revealing an octahedral geometry for all. Coats–Redfern calculations indicated their non‐spontaneous nature yet highlighted their thermal stability. DNA binding studies unveiled a groove binding mode for the complexes, with intrinsic binding constants (Kb) and Stern–Volmer quenching constant (Ksq) supporting their strong binding capabilities. Nuclease activity against pBR322 was assessed through gel electrophoresis. Additionally, docking studies using AutoDock 4.2 software provided insights into their binding affinities. In terms of biological activities, the Cu complex demonstrated superior cytotoxicity and antibacterial and antifungal properties compared to the other ternary metal complexes. This suggests its potential for further exploration in biomedical applications. [ABSTRACT FROM AUTHOR]

ABSTRACT 2‐Aminophenol‐based Schiff bases and their metal complexes have drawn a lot of interest because of their wide range of biological activity and their uses in several fields. These Schiff bases are synthesized through the condensation of 2‐aminophenol and various carbonyl compounds, and metal complexes formed easily by coordinating Schiff bases with transition metal ions possess a wide range of intriguing properties that have rendered them promising candidates in biomedical research. These compounds have a diverse array of captivating biological properties including antibacterial, antifungal, anticancer, and antioxidant actions. Their versatile nature and potential for tailored modifications hold the promise for innovative biomedical applications. Compared to standard antibiotics and other studied compounds, C2, C8–C11, and C116 complexes, along with L16 and L17 ligands, exhibit the highest antibacterial activity, while C3 and C115 complexes demonstrate the highest antifungal activity. The metal chelate formation of the ligands enhanced the antimicrobial activity by increasing their lipophilic nature. C66, C76, and C112 complexes and L39 ligand showed higher anticancer activity than standard anticancer drugs. The metal complexes have higher anticancer activity than the ligand due to improved permeability and cellular uptake. The anticancer activity of the complexes is related to the substituents of the Schiff base ligands. In compounds containing an electron‐withdrawing group (e.g., Cl or Br or NO2), the activity is obviously better than others. Ligands L1–L3 and L5, L6, and L32 demonstrated the most potent antioxidant activity, surpassing both metal complexes and standard conventional antioxidants. The ligands showed greater antioxidant activity than the metal complexes due to their capability of donating free protons to scavenge free radicals. More study is needed to fully explore the potential of 2‐aminophenol‐based Schiff bases and their transition metal complexes for the development of new drugs. This review summarizes different synthetic methods, biological activities, and the structure–activity relationship. This study aims to conduct further research on 2‐aminophenol‐based Schiff bases and their metal complexes. [ABSTRACT FROM AUTHOR]

The sous‐vide technique is increasingly used to improve the quality of poultry meat; the study aimed to compare the quality of traditional and sous‐vide marinated (SVM) duck drumsticks by analyzing the sensory‐related, nutritional, storage‐related, and in vitro digestive‐related quality of duck meat. The results showed that the sensory quality scores of color, odor, and appearance, L* and a* values of duck drumsticks in SVM group were significantly increased compared with the traditional marinated (TM) group (t‐test, p < 0.05, the same below), and the b* values on the outside and inside of duck drumsticks were decreased by 22.47% and 38.04%, respectively. Compared with TM group, hardness, springiness, chewiness, adhesion, cohesion, and resilience of duck drumsticks in SVM group decreased by 43.32%, 29.52%, 65.08%, 62.35%, 20.23%, and 30.33%, respectively. The moisture content and total fat content of duck drumsticks in SVM group were significantly higher than those in TM group (p < 0.05), and the protein loss, total volatile basic nitrogen, and thiobarbituric acid reactive substances values were decreased by 61.4%, 25.86%, and 20.45%, respectively. The results of in vitro digestion experiments showed that the content of free sulfhydryl groups of duck drumsticks in SVM group was significantly increased (p < 0.05), and the contents of Schiff base and carbonyl groups were significantly decreased compared with the TM group (p < 0.05). In conclusion, the SVM technology could significantly improve the sensory‐related qualities, reduce the loss of nutrients, and improve the storage‐related qualities of duck drumsticks. This study provided theoretical reference for the high‐value application of SVM technology in duck meat. [ABSTRACT FROM AUTHOR]

In this paper, three different Zn(II) complexes with (E)-2-(2-(1-(6-bromopyridin-2-yl)ethylidene)hydrazinyl)-N,N,N-trimethyl-2-oxoethan-1-aminium chloride (HLCl) have been synthesized and characterized by single crystal X-ray diffraction, elemental analysis, IR and NMR spectroscopy. All complexes are mononuclear, with the ligand (L) coordinated in a deprotonated formally neutral zwitterionic form via NNO donor set atoms. Complex 1 forms an octahedral geometry with the composition [ZnL2](BF4)2, while complexes 2 [ZnL(NCO)2] and 3 [ZnL(N3)2] form penta-coordinated geometry. Density functional theory (DFT) calculations were performed to enhance our understanding of the structures of the synthesized complexes and the cytotoxic activity of the complexes was tested against five human cancer cell lines (HeLa, A549, MDA-MB-231, K562, LS 174T) and normal human fibroblasts MRC-5. Additionally, antibacterial and antifungal activity of these complexes was tested against a panel of Gram-negative and Gram-positive bacteria, two fungal strains, and a yeast strain. It is noteworthy that all three complexes show selective antifungal activity comparable to that of amphotericin B. Molecular docking analysis predicted that geranylgeranyl pyrophosphate synthase, an enzyme essential for sterol biosynthesis, is the most likely target for inhibition by the tested complexes. [ABSTRACT FROM AUTHOR]

Background: The discovery of new lead compounds with desired properties and biological activity is an excellent challenge in pesticide chemistry. Chloroacetamide are an important class of synthetic herbicides. Results: To explore the herbicidal activity of chloroacetamides, several new chloroacetamide derivatives have been designed, and synthesized. The compounds have been described by forming Schiff bases followed by chloroacetylation of imines. The herbicidal activity as a chlorophyll inhibition was evaluated against two broadleaf weeds (Chenopodium album and Anagallis arvensis) and two grass weeds (Lolium temulentum and Echinochloa crus-galli) in comparison with acetochlor as a standard herbicide. 1H-NMR, 13C-NMR and mass spectroscopic analyses confirmed the chemical structures of the synthesized compounds. Several compounds have demonstrated highly potent herbicidal activity compared to the standard herbicide acetochlor. Some of them have been described as the most effective against weeds tested, such as compounds 5b and 18b. Molecular docking to the active sites of Very Long Chain Fatty Acid Synthase (VLCFAS) has indicated that most compounds are low-energy binding agents and show high affinity for the active pocket. Conclusion: Novel herbicides may be discovered by combining chloroacetamide derivatives with these existing lead structures. [ABSTRACT FROM AUTHOR]

ABSTRACT The current investigation involved the synthesis and detailed characterization of novel mixed‐ligand complexes of Mn(II) (MnDPPNPH) and Cu(II) (CuDPPNPH). These complexes incorporate 2,6‐di(1H‐pyrazol‐1‐yl)pyridine (DPP) and a Schiff base derived from 2‐hydroxy naphthaldehyde (NPH). The synthesized complexes revealed a stoichiometric ratio of 1:1:1 (metal:DPP:NPH), indicative of an octahedral coordination geometry around the Mn(II) and Cu(II) centers, as represented by the chemical formula [M (DPP)(NPH)(Cl)]. To elucidate their structural and electronic properties, theoretical calculations were performed. These calculations facilitated the optimization of the geometrical structures and provided insights into the molecular orbital characteristics of the complexes. The MnDPPNPH and CuDPPNPH complexes demonstrated potential phenoxazinone synthase mimicking activity by catalyzing aerial coupling of o‐aminophenol (OAPh) to form phenoxazine‐2‐one (phenox). The mimicking activity of these complexes was quantitatively assessed using Michaelis–Menten enzymatic kinetics. Various enzyme kinetics plots were employed to determine several kinetic parameters, including the specificity constant and turnover number (kcat), which are crucial for understanding the efficiency of the catalytic cycles. Remarkably, the synthesized MnDPPNPH and CuDPPNPH complexes exhibited significantly higher turnover numbers (kcat) compared to previously reported complexes. This finding suggests that these new complexes possess superior catalytic activity, highlighting their potential as effective catalysts for reactions mimicking the function of phenoxazinone synthase. [ABSTRACT FROM AUTHOR]

ABSTRACT In the present work, new heterobimetallic complexes with the general formula [Zn(C16H32N8)M2(R)4Cl2], where M = Sn (IV) and Si (IV) and R = ‐CH3 and ‐C6H5, were synthesized by reacting the methanolic solution of the monometallic complex [Zn(C16H36N8)Cl2] with group 14 organometallic dichloride [(CH3)2SnCl2/(C6H5)2SnCl2/(CH3)2SiCl2/(C6H5)2SiCl2]. The structures of the synthesized complexes were determined using several spectrometric techniques, including FT‐IR, 1H NMR, 13C NMR, 119Sn NMR, 29Si NMR, ESI‐MS, PXRD, and molar conductivity measurements. Density functional theory (DFT) calculations were carried out to investigate the quantum chemical characteristics of the newly synthesized Zn (II) complexes. The antimicrobial potential of the monometallic and heterobimetallic complexes was evaluated against two Gram‐positive bacteria (Bacillus subtilis and Bacillus cereus), two Gram‐negative bacteria (Xanthomonas campestris and Pseudomonas aeruginosa), and two fungal strains (Aspergillus flavus and Fusarium oxysporum) by the agar well diffusion method, with heterobimetallic complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] as the most potent complex against microbes. The complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] exhibited significant potential in inhibiting inflammation, demonstrating an IC50 value of 9.75 μg/mL, which closely rivals that of the standard drug sodium diclofenac (IC50 = 4.59 μg/mL). Furthermore, all the synthesized compounds were assessed for their anticancer potential against three cancer cell lines (HCT‐116, MCF‐7, and HeLa) by the MTT assay. The results indicated that the complex [Zn(C16H32N8)Sn2(C6H5)4Cl2] exhibited the most pronounced cytotoxic effects, with values of 4.25 ± 0.15 μM, 4.90 ± 0.18 μM, and 5.20 ± 0.24 μM observed for HCT‐116, MCF‐7, and HeLa cancer cell lines, respectively. [ABSTRACT FROM AUTHOR]

ABSTRACT Novel compounds with pharmacological activity were synthesized from Pd(II), Fe(III), Cr(III), Ni(II), and Cu(II) ions with 1‐cyclopropyl‐6‐fluoro‐4‐(2‐hydroxy‐phenylimino)‐7‐piperazin‐1‐yl‐1,4‐dihydro‐quinoline‐3‐carboxylic acid (CFAP). The ligand's NH and OH groups allowed it to interact with the metals as a neutral tridentate. The investigated novel compounds were described using 1H and 13C NMR spectra, FT‐IR spectrums, TGA and UV–Vis (conductance of molecules), and CHN‐analysis. Additionally, the pH profile of the CFAP complexes indicated great stability, and the complexes' stability constant was discovered in the solution. To extract important properties for CFAP and its complexes, computational research was used, CFAPCu, CFAPCr, CFAPNi, and CFAPFe have octahedral geometry, while CFAPPd has square planar geometry. To investigate the molecular geometry, density functional theory calculations (DFT) were carried out. The molar ratio and continuous fluctuation data confirmed that the (M:L) ratio was (1:1). In vitro tests were conducted to evaluate Schiff base's antimicrobial action ligand and its metal chelates against fungal and bacterial infections. The findings showed that the antimicrobial efficacy is as follows: When CFAPPd is compared to fluconazol and ofloxacin as reference medications, it is the highly inhibitor complex. The novel CFAP ligand and its complexes were investigated for In vitro carcinogenic potential against Hep‐G2, MCF‐7, and HCT‐116 cell lines. As compared to the medication vinblastine, the results once again demonstrated that CFAPPd is the most active agent. Moreover, the complexes demnstrated strong reactivity in capturing free radicals when their antioxidant activity was investigated. Viscosity, spectral investigations, and gel electrophoreses were used to identify the interaction between metal chelates and DNA. Every examined compound is shown to be an enthusiastic DNA binder by viscosity and spectrophotometric titration investigations. The heightened hydrophobic and electrostatic interactions between aromatic rings could be the cause of this. Ultimately, these compounds could be regarded as promising bioactive substances. [ABSTRACT FROM AUTHOR]

Comprehensive Summary Salicylaldehyde Schiff base is a kind of important photochromism system, whose photochromism process is widely acknowledged to be co‐determined by the electronic structure and molecular conformation. Normally, salicylaldehyde Schiff base derivatives with α‐type structures tend to exhibit photochromism while those with β‐type structures tend to be photostable. However, more and more counterexamples are found, and the root cause of photochromism property of salicylaldehyde Schiff base is still unclear. In this work, a series of chiral salicylaldehyde Schiff bases and their racemates were prepared. The formers are photochromic while the latters are photostable. Influenced by Wallach's rule, the homochiral counterparts have looser packing modes than that of the racemic counterparts. Mechanism study revealed that the pressure should be the root cause of photochromism property. Close molecule packing can restrict the photochromism property effectively after being pressed, which also explains why the photochromism of salicylaldehyde Schiff base is usually observed in solid state. This work not only reports the unique photo‐responsive difference between the chiral salicylaldehyde Schiff bases and their racemates, more importantly, provides a new perspective to understand the influence of molecule pressure on their photophysical properties. [ABSTRACT FROM AUTHOR]

Eugenol, the major constituent of clove oil, has been explored as an essential natural ingredient for ages owing to its versatile pharmacological properties. However, to date, the coordination chemistry of eugenol derivatives has not been much explored. In the present work, an eugenol-based Schiff base ligand (HL) was synthesized and structurally confirmed through ESI-MS, NMR, and FT-IR spectroscopy studies. Consequently, the N,O-donor chelating ligand HL was coordinated with Cd2+, in the presence of bridging pseudohalides (thiocyanate, SCN−, and dicyanamide, N(CN)2−) to synthesize two luminescent coordination polymers (CPs 1 and 2): [Cd2(L)2(X)2]n (where HL = 4-allyl-2-(((2-(benzylamino)ethyl) imino)methyl)-6-methoxyphenol and Xs are bridging pseudohalides, i.e., SCN− and N(CN)2−) on a Cd-eugenol scaffold. The CPs depicted structural diversity, bulk-phase purity, thermal stability, and the presence of interlayer supramolecular C–H⋯π interactions together with C–H⋯S (for CP 1) and C–H⋯N (for CP 2) interactions. The CPs further exemplified themselves as selective and sensitive 'turn-off' probes towards trinitrophenol (TNP) (quenching efficiency: 82.02% and 83.86% for 1 and 2) among a pool of hazardous nitroaromatic compounds (NACs). Accordingly, 1 and 2 exhibited an ultralow limit of detection (LOD) of 0.29 and 0.15 μM, with high quenching constants (KSV) of 5.91 × 104 and 17.60 × 104 M−1, respectively. In addition, TNP sensing events were evidenced to be recyclable and exhibited fast response (∼31 s, 1, and ∼40 s, 2), which increased its real-world viability. Vapor phase TNP sensing was also accomplished upon drop-casted CP films. Experimental investigations and theoretical DFT study confirmed the cooperative occurrence of RET-IFE-PET-collisional quenching and non-covalent π⋯π stacking as key factors involved in the TNP sensing performance. The competency of 1 and 2 in the detection of TNP from several complex environmental matrices (CEMs), viz. matchstick powder, river and sewage water, and soil specimens, was also established with good recovery (∼66–86% and ∼68–93% for 1 and 2, respectively) and high KSV values (3.90–11.39 × 104 and 6.17–18.79 × 104 M−1 for 1 and 2, respectively). [ABSTRACT FROM AUTHOR]

New graphene Schiff base iron nanocomplexes (S-792-Fe, S-550-Fe, and S-590-Fe) were designed and fabricated based on investigations of reactions mechanisms of AP pyrolysis, structural analysis of new materials and simulation results of quantum mechanics to deal with the long-standing contradiction between safety and performance for composite propellent combustion catalyst. By taking traditional catalyst Catocene as the benchmark, the S-550-Fe nanocomplexes exhibited competitive catalytic performances, much better anti-migration properties and significantly reduced impact and electrostatic sensitivities. After adding S-550-Fe, the burning rate of propellant enhanced from 13.87 to 19.77 mm s−1 at 15 MPa, and the impact and electrostatic sensitivities are improved to 50.2 cm and 172.12 mJ, respectively. The excellent catalytic performance of S-550-Fe is closely related to its molecular structure, which is manifested by an increase in charge density and a decrease in NH 3 oxidation energy barriers. The promotion effects of S-550-Fe on desorption and oxidation of NH 3 from the surface of AP is conducive to the rapid and complete pyrolysis of AP, which is reflected in the improvement of combustion rate and temperature gradient. The theory-driven design mode of this work may provide new pathways to tune combustion behaviors of composite propellants from the view of molecular-level insights. Effects and mechanisms of S-550-Fe on combustion and safety of AP-HTPB propellant were disclosed. [Display omitted] • Graphen Schiff base Fe nanocomplexes were first investigated in AP-HTPB propellant. • S-550-Fe is conducive to the combustion and safety performance of AP-HTPB propellant. • The structure-activity relationship of S-550-Fe at the molecular level was explored. • The influence of catalysts on NH 3 oxidation process was revealed. [ABSTRACT FROM AUTHOR]

A modified carbon paste sensor based on N,N′-(((ethane-1,2-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))bis(pyridine-2-amine; BPA Schiff base as Cr(III) selective carrier was fabricated and studied in this work. The proposed sensor homogenization and mechanism of action was studied by infra-red (IR) and scanning electron microscope (SEM) with energy dispersive X-ray (EDX) tools. The sensor covered 1.0 × 10−7–1.0 × 10–1 mol L−1 linear range and a detection limit of 7.22 × 10–8 mol L−1 for Cr(III) with 20.17 ± 0.13 mV decade−1 Nernstian slope. 5 s was the response time of the prepared sensor and it was reproducible and stable for 3 months. The working pH range was 3.3–6.0 and it also works well to determine Cr(III) ion in presence of water miscible solvents up to 12.5% content of the methanol and 17.5% of ethanol. The electrode's selectivity was studied using separate and mixed solution methods for selectivity coefficients determination and the sensor showed good selectivity relative to a variety of metal ions (selectivity coefficients = 1.01 × 10−5–8.57 × 10−3). In addition, the practical analysis value of the sensor was demonstrated by measurement of Cr(III) quantitatively in mineral water, supplement and also as an indicator electrode in Cr(III) against EDTA potentiometric titration with good reproducibility (RSDs of 0.91–2.15%). [ABSTRACT FROM AUTHOR]

The occurrence of peritendinous adhesion, which hampers the quality and function of the healed tendon, is strongly linked to oxidative stress, inflammatory, and infection that occur after surgery. Tendon damage and repair provide a considerable obstacle for regenerative medicine owing to the absence of patches that possess comprehensive functionality, including self‐healing capacity, anti‐inflammatory and anti‐bacterial properties, as well as tissue repair guidance. A dual dynamic crosslinked network is created by coordination bonds between catechol groups in protocatechuic aldehyde (PA) and Fe3+, as well as a dynamic Schiff base reaction between amino groups in hyaluronic acid‐adipic acid dihydrazide (HA‐ADH) and aldehyde groups in PA. The HA‐ADH@PA/Fe hydrogel exhibits self‐healing ability, tissue adhesion, anti‐bacterial activity, regulation of macrophage polarization via the NF‐κB signaling, oxidative stress elimination, and anti‐inflammation. In addition, a dual‐layer Janus patch is created, taking inspiration from the anatomy and disease progression of tendon adhesion. The inner layer of the patch, which is in direct contact with the operated tendon, is a multifunctional HA‐ADH@PA/Fe hydrogel, encircled further by a poly(ɛ‐caprolactone) (PCL) electrospinning membrane outer layer facing the surrounding tissue. The PCL@HA‐ADH@PA/Fe hydrogel patch reduced tendon adhesion and supported tissue regeneration by stimulating macrophages polarization into an anti‐inflammatory phenotype and resolving both local and systemic inflammation. This research showcased the PCL@HA‐ADH@PA/Fe hydrogel patch as an alternative therapeutic method for preventing the development of adhesions around tendons. [ABSTRACT FROM AUTHOR]

Metal-based drugs are finding new medical applications, particularly in antibacterial therapies. Compounds such as Prontosil and ciprofloxacin, as well as its derivatives such as beta-lactam drugs, aminoglycosides, vancomycin, fosfomycin, as well as tetracyclines, play critical roles in the prevention of bacterial and fungal infections. The increasing prevalence of microbial resistance is prompting the use of metal complexes to tackle fungal and bacterial strains. Mercury-based complexes, which are known for their unusual characteristics and reactivity, have received a lot of interest in the field of medicine recently. Additionally, Schiff base complexes are widely used as antifungal, antibacterial, and anticancer drugs, as well as in dye manufacturing. This article discusses current advances in the use of mercury compounds for combating fungus and bacteria, offering information on their efficacy and future applications. [ABSTRACT FROM AUTHOR]

Gastric ulcers accompanied by acute or chronic bleeding represent a significant risk of fatality. However, the development of effective strategies for achieving rapid hemostasis and wound healing in gastric ulcer bleeding represents a formidable challenge. To address this challenge, thrombin‐derived C‐terminal peptide (TCP‐25) is employed as a targeted agent, and it is incorporated into two novel injectable and biocompatible carboxymethyl chitosan (CMCs) hydrogels via Schiff's base reaction. The TCP‐25 peptide hydrogels display optimal adaptability within the distinctive gastrointestinal microenvironment, demonstrating a balance of acid resistance and degradation, along with controlled release and bioactivity, and good bio‐adhesive properties. Both in vitro and in vivo reveal that the hydrogel achieves rapid hemostasis. In an ethanol‐induced gastric ulcer model in rats, it demonstrates that the hydrogel effectively inhibits gastric ulcer bleeding by 92% within 24‐h, exhibiting efficacy that surpasses that of omeprazole medicine, a commonly used clinical treatment. This enhanced performance is attributed to the synergistic effects of the CMCs hydrogel and TCP‐25 peptide in effectively achieving hemostasis, inhibiting bacterial growth, and promoting gastric wound healing in acute or chronic bleeding gastric ulcers. Consequently, the present work offers promising clinical applications for rapid hemostasis and wound healing in gastric ulcers. [ABSTRACT FROM AUTHOR]

Twenty-two eco-friendly, novel Schiff bases were synthesized from 2,4,5-trichloro aniline and characterized by using FT-IR, 1H NMR, and 13C NMR techniques. Fungicidal activity against pathogenic fungi Sclerotium rolfsii and Rhizoctonia bataticola and insecticidal activity against the stored grain insect pest Callosobruchus maculatus of the test compounds were evaluated under control condition. All of the investigated compounds, according to the study, exhibited moderate to good antifungal and insecticidal activities. The best antifungal activity against both pathogenic fungi was demonstrated by C15 and C16 whose ED50 values were recorded 11.4 and 10.4 μg/mL against R. bataticola and 10.6 and 11.9 μg/mL against S. rolfsii, respectively. They were further screened in for disease suppression against both pathogenic fungi under pot condition through different methods of applications in green gram (Vigna radiata L.) crop. The compounds C10 and C18 had the highest insecticidal activity, with LD50 values of 0.024 and 0.042 percentages, respectively. Stepwise regression analysis using root mean square error (RMSE) and correlation coefficient (R) method used to validate the quantitative structure activity relationship (QSAR) of synthesized compounds in addition to their fungicidal and insecticidal actions. To the best of our knowledge, this investigation on the 22 new Schiff bases as possible agrochemicals is the first one that has been fully reported. [ABSTRACT FROM AUTHOR]